ferro_json_ui/

component.rs

//! Component catalog for JSON-UI.
//!
//! Defines the available UI components with typed props. Each component
//! uses serde's tagged enum representation so JSON includes `"type": "Card"`.

use schemars::JsonSchema;
use serde::de::{self, Deserializer};
use serde::ser::{SerializeMap, Serializer};
use serde::{Deserialize, Serialize};

use crate::action::Action;
use crate::visibility::Visibility;

/// Shared size enum for components (Button, Badge, Avatar, Input).
#[derive(Debug, Clone, Default, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
#[serde(rename_all = "snake_case")]
pub enum Size {
    Xs,
    Sm,
    #[default]
    Default,
    Lg,
}

/// Icon placement relative to button label.
#[derive(Debug, Clone, Default, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
#[serde(rename_all = "snake_case")]
pub enum IconPosition {
    #[default]
    Left,
    Right,
}

/// Sort direction for table columns.
#[derive(Debug, Clone, Default, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
#[serde(rename_all = "snake_case")]
pub enum SortDirection {
    #[default]
    Asc,
    Desc,
}

/// Separator orientation.
#[derive(Debug, Clone, Default, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
#[serde(rename_all = "snake_case")]
pub enum Orientation {
    #[default]
    Horizontal,
    Vertical,
}

/// Button visual variants (aligned to shadcn/ui).
#[derive(Debug, Clone, Default, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
#[serde(rename_all = "snake_case")]
pub enum ButtonVariant {
    #[default]
    Default,
    Secondary,
    Destructive,
    Outline,
    Ghost,
    Link,
}

/// Input field types.
#[derive(Debug, Clone, Default, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
#[serde(rename_all = "snake_case")]
pub enum InputType {
    #[default]
    Text,
    Email,
    Password,
    Number,
    Textarea,
    Hidden,
    Date,
    Time,
    Url,
    Tel,
    Search,
}

/// Alert visual variants.
#[derive(Debug, Clone, Default, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
#[serde(rename_all = "snake_case")]
pub enum AlertVariant {
    #[default]
    Info,
    Success,
    Warning,
    Error,
}

/// Badge visual variants (aligned to shadcn/ui).
#[derive(Debug, Clone, Default, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
#[serde(rename_all = "snake_case")]
pub enum BadgeVariant {
    #[default]
    Default,
    Secondary,
    Destructive,
    Outline,
}

/// Text element types for semantic HTML rendering.
#[derive(Debug, Clone, Default, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
#[serde(rename_all = "snake_case")]
pub enum TextElement {
    #[default]
    P,
    H1,
    H2,
    H3,
    Span,
    Div,
    Section,
}

/// Column display format for tables.
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
#[serde(rename_all = "snake_case")]
pub enum ColumnFormat {
    Date,
    DateTime,
    Currency,
    Boolean,
}

/// Table column definition.
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize, JsonSchema)]
pub struct Column {
    pub key: String,
    pub label: String,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub format: Option<ColumnFormat>,
}

/// Select option (value + label pair).
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
pub struct SelectOption {
    pub value: String,
    pub label: String,
}

/// Props for Card component.
// JsonSchema skipped: contains Vec<ComponentNode> — Component has custom Serialize/Deserialize
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
pub struct CardProps {
    pub title: String,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub description: Option<String>,
    #[serde(default, skip_serializing_if = "Vec::is_empty")]
    pub children: Vec<ComponentNode>,
    #[serde(default, skip_serializing_if = "Vec::is_empty")]
    pub footer: Vec<ComponentNode>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub max_width: Option<FormMaxWidth>,
}

/// Props for Table component.
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize, JsonSchema)]
pub struct TableProps {
    pub columns: Vec<Column>,
    pub data_path: String,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub row_actions: Option<Vec<Action>>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub empty_message: Option<String>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub sortable: Option<bool>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub sort_column: Option<String>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub sort_direction: Option<SortDirection>,
}

/// Maximum width constraint for form containers.
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, JsonSchema, Default)]
#[serde(rename_all = "snake_case")]
pub enum FormMaxWidth {
    #[default]
    Default,
    Narrow,
    Wide,
}

/// Props for Form component.
// JsonSchema skipped: contains Vec<ComponentNode> — Component has custom Serialize/Deserialize
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
pub struct FormProps {
    pub action: Action,
    pub fields: Vec<ComponentNode>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub method: Option<crate::action::HttpMethod>,
    /// Form guard type. When set, the runtime JS disables the submit button
    /// until the guard condition is met. Value: `"number-gt-0"` — at least
    /// one number input must have value > 0.
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub guard: Option<String>,
    /// Optional max-width constraint for the form container.
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub max_width: Option<FormMaxWidth>,
}

/// Which display mode the component uses.
///
/// Set from a URL query parameter — typically `?mode=edit` — by
/// [`EditMode::from_query`]. Defaults to [`EditMode::View`].
#[derive(Debug, Clone, Copy, PartialEq, Eq, Default, Serialize, Deserialize, JsonSchema)]
#[serde(rename_all = "snake_case")]
pub enum EditMode {
    /// Read-only display with a "Modifica" action.
    #[default]
    View,
    /// Inline-edit form with "Salva" / "Annulla" actions.
    Edit,
}

impl EditMode {
    /// Parse a URL query-parameter value into an `EditMode`.
    ///
    /// Returns [`EditMode::Edit`] when `raw` equals `"edit"` (ASCII
    /// case-insensitive); [`EditMode::View`] otherwise, including when
    /// `raw` is `None` or any other string.
    ///
    /// Handlers typically call this with `req.query("mode").as_deref()`.
    pub fn from_query(raw: Option<&str>) -> Self {
        match raw {
            Some(s) if s.eq_ignore_ascii_case("edit") => EditMode::Edit,
            _ => EditMode::View,
        }
    }
}

/// A single field row within a [`DetailFormProps`].
///
/// Rendered as `<div><dt>{label}</dt><dd>…</dd></div>` in both modes.
/// In View mode, `<dd>` shows the escaped `value` as plain text.
/// In Edit mode, `<dd>` renders the `input` [`ComponentNode`] via the
/// normal component dispatch — making any form-field component (Input,
/// Select, Textarea, Switch, Checkbox, plugin) usable inside.
///
/// **Authoring rule (Option A).** When `input` is an `Input` / `Select` /
/// `Textarea` / `Checkbox` / `Switch` component, the caller MUST set its
/// `label` prop to an empty string. The `<dt>` already provides the
/// visible label; a non-empty input label produces duplicate UI text.
/// DetailForm does not mutate caller-supplied props.
// JsonSchema skipped: contains ComponentNode — Component has custom Serialize/Deserialize
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
pub struct DetailField {
    /// Description term shown in both modes as the field label.
    pub label: String,
    /// Display string shown in View mode (plain text, html_escape'd at render).
    pub value: String,
    /// Component rendered in Edit mode in place of `value`.
    pub input: ComponentNode,
}

impl DetailField {
    /// Convenience constructor mirroring [`ComponentNode::input`] ergonomics.
    pub fn new(label: impl Into<String>, value: impl Into<String>, input: ComponentNode) -> Self {
        Self {
            label: label.into(),
            value: value.into(),
            input,
        }
    }
}

/// Props for [`crate::Component::DetailForm`].
///
/// Renders a description-list-style block in two modes — View and Edit —
/// driven by the `mode` field. The outer scaffold (`<dl>` + rows) is
/// byte-for-byte identical across modes per the structural coherence
/// contract (147-UI-SPEC §5); only the inner `<dd>` content and the
/// action bar differ. Edit mode additionally wraps the scaffold in a
/// `<form>` with method spoofing for PUT/PATCH/DELETE.
///
/// Mode is URL-driven (server-side only) — no JavaScript. Callers
/// typically derive `mode` via [`EditMode::from_query`] on
/// `req.query("mode").as_deref()`.
// JsonSchema skipped: contains Vec<DetailField> which contains ComponentNode
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
pub struct DetailFormProps {
    /// Which mode to render. Defaults to [`EditMode::View`].
    #[serde(default)]
    pub mode: EditMode,
    /// Form submit target (used only in Edit mode; resolver populates `action.url`).
    pub action: crate::action::Action,
    /// The rows.
    pub fields: Vec<DetailField>,
    /// Href for the "Modifica" button (View mode only). Emitted verbatim after html_escape.
    pub edit_url: String,
    /// Href for the "Annulla" button (Edit mode only). Emitted verbatim after html_escape.
    pub cancel_url: String,
    /// Override for the default "Modifica" label.
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub edit_label: Option<String>,
    /// Override for the default "Salva" label.
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub save_label: Option<String>,
    /// Override for the default "Annulla" label.
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub cancel_label: Option<String>,
    /// Override for the form tag's HTTP method (mirrors [`FormProps::method`]).
    /// Unset means use `action.method`.
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub method: Option<crate::action::HttpMethod>,
}

/// HTML button type attribute.
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, JsonSchema, Default)]
#[serde(rename_all = "snake_case")]
pub enum ButtonType {
    #[default]
    Button,
    Submit,
}

/// Props for Button component.
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize, JsonSchema)]
pub struct ButtonProps {
    pub label: String,
    #[serde(default)]
    pub variant: ButtonVariant,
    #[serde(default)]
    pub size: Size,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub disabled: Option<bool>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub icon: Option<String>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub icon_position: Option<IconPosition>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub button_type: Option<ButtonType>,
}

/// Props for Input component.
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize, JsonSchema)]
pub struct InputProps {
    /// Form field name for data binding.
    pub field: String,
    pub label: String,
    #[serde(default)]
    pub input_type: InputType,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub placeholder: Option<String>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub required: Option<bool>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub disabled: Option<bool>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub error: Option<String>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub description: Option<String>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub default_value: Option<String>,
    /// Data path for pre-filling from handler data (e.g., "/data/user/name").
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub data_path: Option<String>,
    /// HTML step attribute for number inputs (e.g., "any", "0.01").
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub step: Option<String>,
    /// HTML datalist id for autocomplete suggestions.
    /// When set, renders `list="..."` on the input and a companion `<datalist>`
    /// whose options come from a view data key matching this id.
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub list: Option<String>,
}

/// Props for Select component.
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize, JsonSchema)]
pub struct SelectProps {
    /// Form field name for data binding.
    pub field: String,
    pub label: String,
    pub options: Vec<SelectOption>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub placeholder: Option<String>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub required: Option<bool>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub disabled: Option<bool>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub error: Option<String>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub description: Option<String>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub default_value: Option<String>,
    /// Data path for pre-filling from handler data (e.g., "/data/user/name").
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub data_path: Option<String>,
}

/// Props for Alert component.
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize, JsonSchema)]
pub struct AlertProps {
    pub message: String,
    #[serde(default)]
    pub variant: AlertVariant,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub title: Option<String>,
}

/// Props for Badge component.
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
pub struct BadgeProps {
    pub label: String,
    #[serde(default)]
    pub variant: BadgeVariant,
}

/// Props for Modal component.
// JsonSchema skipped: contains Vec<ComponentNode> — Component has custom Serialize/Deserialize
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
pub struct ModalProps {
    pub id: String,
    pub title: String,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub description: Option<String>,
    #[serde(default, skip_serializing_if = "Vec::is_empty")]
    pub children: Vec<ComponentNode>,
    #[serde(default, skip_serializing_if = "Vec::is_empty")]
    pub footer: Vec<ComponentNode>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub trigger_label: Option<String>,
}

/// Props for Text component.
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
pub struct TextProps {
    pub content: String,
    #[serde(default)]
    pub element: TextElement,
}

/// Props for Checkbox component.
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize, JsonSchema)]
pub struct CheckboxProps {
    /// Form field name for data binding.
    pub field: String,
    /// HTML value attribute. When set, the checkbox submits this value instead of "1".
    /// Required for multi-value checkbox groups (same name, different values).
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub value: Option<String>,
    pub label: String,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub description: Option<String>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub checked: Option<bool>,
    /// Data path for pre-filling from handler data (e.g., "/data/user/name").
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub data_path: Option<String>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub required: Option<bool>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub disabled: Option<bool>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub error: Option<String>,
}

/// Props for Switch component.
// JsonSchema skipped: contains Option<Action> — Action has custom Serialize/Deserialize
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
pub struct SwitchProps {
    /// Form field name for data binding.
    pub field: String,
    pub label: String,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub description: Option<String>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub checked: Option<bool>,
    /// Data path for pre-filling from handler data (e.g., "/data/user/name").
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub data_path: Option<String>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub required: Option<bool>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub disabled: Option<bool>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub error: Option<String>,
    /// Auto-submit action. When set, the switch renders inside a minimal
    /// form and submits on change.
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub action: Option<Action>,
    /// Compact mode: label hugs the toggle (gap-3) instead of justify-between.
    /// Use when the switch is inside a narrow grid column.
    #[serde(default, skip_serializing_if = "std::ops::Not::not")]
    pub compact: bool,
}

/// Props for `KeyValueEditor` component.
///
/// Renders a dynamic list of key/value rows backed by a hidden `<input>`
/// that holds the current pairs serialized as a JSON object. The runtime
/// module `key_value_editor` wires add/remove/input events and keeps the
/// hidden field in sync on every mutation.
///
/// When `data_path` resolves to a JSON object, each entry seeds one row.
/// `suggested_keys` drives a `<datalist>` (when `allow_custom_keys`) or a
/// `<select>` (when `!allow_custom_keys`).
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize, JsonSchema)]
pub struct KeyValueEditorProps {
    /// Name of the hidden input that receives the serialized JSON.
    pub field: String,
    /// Optional visible label above the editor block.
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub label: Option<String>,
    /// Keys offered as suggestions (via `<datalist>` or `<select>`).
    #[serde(default)]
    pub suggested_keys: Vec<String>,
    /// If true (default), the key input accepts any text with suggestions;
    /// if false, the key input is a `<select>` restricted to `suggested_keys`.
    #[serde(default = "default_true")]
    pub allow_custom_keys: bool,
    /// JSON pointer path whose resolved object seeds the initial rows.
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub data_path: Option<String>,
    /// Validation error message rendered below the editor.
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub error: Option<String>,
}

/// Props for Separator component.
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
pub struct SeparatorProps {
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub orientation: Option<Orientation>,
}

/// A single item in a description list.
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
pub struct DescriptionItem {
    pub label: String,
    pub value: String,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub format: Option<ColumnFormat>,
}

/// Props for DescriptionList component.
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
pub struct DescriptionListProps {
    pub items: Vec<DescriptionItem>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub columns: Option<u8>,
}

/// A single tab within a Tabs component.
// JsonSchema skipped: contains Vec<ComponentNode> — Component has custom Serialize/Deserialize
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
pub struct Tab {
    pub value: String,
    pub label: String,
    #[serde(default, skip_serializing_if = "Vec::is_empty")]
    pub children: Vec<ComponentNode>,
}

/// Props for Tabs component.
// JsonSchema skipped: contains Vec<Tab> which contains Vec<ComponentNode>
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
pub struct TabsProps {
    pub default_tab: String,
    pub tabs: Vec<Tab>,
}

/// A single item in a breadcrumb trail.
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
pub struct BreadcrumbItem {
    pub label: String,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub url: Option<String>,
}

/// Props for Breadcrumb component.
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
pub struct BreadcrumbProps {
    pub items: Vec<BreadcrumbItem>,
}

/// Props for Pagination component.
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
pub struct PaginationProps {
    pub current_page: u32,
    pub per_page: u32,
    pub total: u32,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub base_url: Option<String>,
}

/// Props for Progress component.
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
pub struct ProgressProps {
    /// Percentage value (0-100).
    pub value: u8,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub max: Option<u8>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub label: Option<String>,
}

/// Props for Image component.
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
pub struct ImageProps {
    pub src: String,
    pub alt: String,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub aspect_ratio: Option<String>,
    /// Optional label shown in a skeleton placeholder that sits behind the
    /// image. When the image fails to load (or is still being generated),
    /// the `<img>` is hidden via `onerror` and the placeholder remains
    /// visible, keeping the container at its aspect-ratio size.
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub placeholder_label: Option<String>,
}

/// Props for Avatar component.
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
pub struct AvatarProps {
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub src: Option<String>,
    pub alt: String,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub fallback: Option<String>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub size: Option<Size>,
}

/// Props for Skeleton loading placeholder.
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
pub struct SkeletonProps {
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub width: Option<String>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub height: Option<String>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub rounded: Option<bool>,
}

/// Toast visual variants.
#[derive(Debug, Clone, Default, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
#[serde(rename_all = "snake_case")]
pub enum ToastVariant {
    #[default]
    Info,
    Success,
    Warning,
    Error,
}

/// A single item in a checklist.
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
pub struct ChecklistItem {
    pub label: String,
    #[serde(default)]
    pub checked: bool,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub href: Option<String>,
}

/// A single item in a notification dropdown.
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
pub struct NotificationItem {
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub icon: Option<String>,
    pub text: String,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub timestamp: Option<String>,
    #[serde(default)]
    pub read: bool,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub action_url: Option<String>,
}

/// A single navigation item in the sidebar.
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
pub struct SidebarNavItem {
    pub label: String,
    pub href: String,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub icon: Option<String>,
    #[serde(default)]
    pub active: bool,
}

/// A collapsible group in the sidebar.
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
pub struct SidebarGroup {
    pub label: String,
    #[serde(default)]
    pub collapsed: bool,
    pub items: Vec<SidebarNavItem>,
}

/// Props for StatCard component (live-updatable metric card).
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
pub struct StatCardProps {
    pub label: String,
    pub value: String,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub icon: Option<String>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub subtitle: Option<String>,
    /// SSE target key for live updates; maps to `data-sse-target` on the value element.
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub sse_target: Option<String>,
}

/// Props for Checklist component.
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
pub struct ChecklistProps {
    pub title: String,
    pub items: Vec<ChecklistItem>,
    #[serde(default = "default_true")]
    pub dismissible: bool,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub dismiss_label: Option<String>,
    /// Server-side state persistence key for this checklist.
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub data_key: Option<String>,
}

fn default_true() -> bool {
    true
}

/// Props for Toast component (declarative notification intent).
///
/// The JS runtime reads data attributes from the rendered element to
/// display the toast. Timeouts and dismissal are handled client-side.
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
pub struct ToastProps {
    pub message: String,
    #[serde(default)]
    pub variant: ToastVariant,
    /// Seconds before auto-dismiss. Default 5.
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub timeout: Option<u32>,
    #[serde(default = "default_true")]
    pub dismissible: bool,
}

/// Props for NotificationDropdown component.
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
pub struct NotificationDropdownProps {
    pub notifications: Vec<NotificationItem>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub empty_text: Option<String>,
}

/// Props for Sidebar component.
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
pub struct SidebarProps {
    #[serde(default, skip_serializing_if = "Vec::is_empty")]
    pub fixed_top: Vec<SidebarNavItem>,
    #[serde(default, skip_serializing_if = "Vec::is_empty")]
    pub groups: Vec<SidebarGroup>,
    #[serde(default, skip_serializing_if = "Vec::is_empty")]
    pub fixed_bottom: Vec<SidebarNavItem>,
}

/// Props for Header component.
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
pub struct HeaderProps {
    pub business_name: String,
    /// Unread notification count for badge display.
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub notification_count: Option<u32>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub user_name: Option<String>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub user_avatar: Option<String>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub logout_url: Option<String>,
}

/// Gap size for Grid layout.
#[derive(Debug, Clone, Default, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
#[serde(rename_all = "snake_case")]
pub enum GapSize {
    None,
    Sm,
    #[default]
    Md,
    Lg,
    Xl,
}

/// Props for Grid component — multi-column layout.
// JsonSchema skipped: contains Vec<ComponentNode> — Component has custom Serialize/Deserialize
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
pub struct GridProps {
    /// Number of columns (1-12) at base (mobile) viewport.
    #[serde(default = "default_grid_columns")]
    pub columns: u8,
    /// Number of columns at md breakpoint (768px+). When set, creates a responsive grid.
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub md_columns: Option<u8>,
    /// Number of columns at lg breakpoint (1024px+). Optional; falls back to md.
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub lg_columns: Option<u8>,
    /// Gap between grid items.
    #[serde(default)]
    pub gap: GapSize,
    /// Enables horizontal scroll mode. Children get `min-w-[280px]` and the grid
    /// uses `grid-flow-col` auto-cols layout for Trello-like horizontal scrolling.
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub scrollable: Option<bool>,
    #[serde(default, skip_serializing_if = "Vec::is_empty")]
    pub children: Vec<ComponentNode>,
}

fn default_grid_columns() -> u8 {
    2
}

/// Props for Collapsible section — expandable `<details>`/`<summary>`.
// JsonSchema skipped: contains Vec<ComponentNode> — Component has custom Serialize/Deserialize
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
pub struct CollapsibleProps {
    pub title: String,
    #[serde(default)]
    pub expanded: bool,
    #[serde(default, skip_serializing_if = "Vec::is_empty")]
    pub children: Vec<ComponentNode>,
}

/// Props for EmptyState component — standardized empty view.
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize, JsonSchema)]
pub struct EmptyStateProps {
    pub title: String,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub description: Option<String>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub action: Option<Action>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub action_label: Option<String>,
}

/// Layout variant for form sections.
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, JsonSchema, Default)]
#[serde(rename_all = "snake_case")]
pub enum FormSectionLayout {
    #[default]
    Stacked,
    TwoColumn,
}

/// Props for FormSection component — visual grouping within forms.
// JsonSchema skipped: contains Vec<ComponentNode> — Component has custom Serialize/Deserialize
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
pub struct FormSectionProps {
    pub title: String,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub description: Option<String>,
    #[serde(default, skip_serializing_if = "Vec::is_empty")]
    pub children: Vec<ComponentNode>,
    /// Optional layout variant. Defaults to stacked (single column).
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub layout: Option<FormSectionLayout>,
}

/// Props for PageHeader component -- page title with optional breadcrumb and action buttons.
// JsonSchema skipped: contains Vec<ComponentNode>
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
pub struct PageHeaderProps {
    pub title: String,
    #[serde(default, skip_serializing_if = "Vec::is_empty")]
    pub breadcrumb: Vec<BreadcrumbItem>,
    #[serde(default, skip_serializing_if = "Vec::is_empty")]
    pub actions: Vec<ComponentNode>,
}

/// Props for ButtonGroup component -- horizontal button row with consistent gap.
// JsonSchema skipped: contains Vec<ComponentNode>
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
pub struct ButtonGroupProps {
    #[serde(default, skip_serializing_if = "Vec::is_empty")]
    pub buttons: Vec<ComponentNode>,
}

/// A single action item in a dropdown menu.
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
pub struct DropdownMenuAction {
    pub label: String,
    pub action: Action,
    #[serde(default)]
    pub destructive: bool,
}

/// Props for DropdownMenu component — trigger button with absolutely-positioned action panel.
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
pub struct DropdownMenuProps {
    pub menu_id: String,
    pub trigger_label: String,
    pub items: Vec<DropdownMenuAction>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub trigger_variant: Option<ButtonVariant>,
}

/// Props for the DataTable component — Stripe-style alternating rows with DropdownMenu per row,
/// mobile card fallback, and empty state.
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
pub struct DataTableProps {
    pub columns: Vec<Column>,
    pub data_path: String,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub row_actions: Option<Vec<DropdownMenuAction>>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub empty_message: Option<String>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub row_key: Option<String>,
    /// URL pattern for row click navigation. Use `{row_key}` as placeholder.
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub row_href: Option<String>,
}

/// Props for a single column in a KanbanBoard.
// JsonSchema skipped: contains Vec<ComponentNode>
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
pub struct KanbanColumnProps {
    pub id: String,
    pub title: String,
    pub count: u32,
    #[serde(default, skip_serializing_if = "Vec::is_empty")]
    pub children: Vec<ComponentNode>,
}

/// Props for KanbanBoard component — horizontal scrollable columns on desktop, tab-based on mobile.
// JsonSchema skipped: contains Vec<ComponentNode> (via KanbanColumnProps)
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
pub struct KanbanBoardProps {
    pub columns: Vec<KanbanColumnProps>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub mobile_default_column: Option<String>,
}

/// Props for a calendar day cell.
///
/// Renders a single day in a month grid with today highlight,
/// out-of-month muting, and event count indicator.
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize, JsonSchema)]
pub struct CalendarCellProps {
    pub day: u8,
    #[serde(default)]
    pub is_today: bool,
    #[serde(default)]
    pub is_current_month: bool,
    #[serde(default)]
    pub event_count: u32,
    /// Optional per-event Tailwind color classes (e.g. "bg-blue-500").
    /// When non-empty, colored dots are rendered instead of plain primary dots.
    #[serde(default, skip_serializing_if = "Vec::is_empty")]
    pub dot_colors: Vec<String>,
}

/// Visual variant for action cards.
#[derive(Debug, Clone, Default, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
#[serde(rename_all = "snake_case")]
pub enum ActionCardVariant {
    #[default]
    Default,
    Setup,
    Danger,
}

/// Props for a horizontal action card with variant-colored left border.
///
/// Renders icon + title + description + chevron in a clickable row.
/// When `href` is set, the card wraps in an `<a>` element with `aria-label`.
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize, JsonSchema)]
pub struct ActionCardProps {
    pub title: String,
    pub description: String,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub icon: Option<String>,
    #[serde(default)]
    pub variant: ActionCardVariant,
    /// Optional navigation URL. When set, the card renders as an `<a>` element.
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub href: Option<String>,
}

/// Props for a touch-friendly product tile with quantity controls.
///
/// Renders product name, price, and +/- buttons that drive a hidden input
/// via JS. Used for POS-style product selection during order creation.
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize, JsonSchema)]
pub struct ProductTileProps {
    pub product_id: String,
    pub name: String,
    pub price: String,
    pub field: String,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub default_quantity: Option<u32>,
}

/// Props for a plugin component.
///
/// The `plugin_type` field holds the original `"type"` value from JSON,
/// and `props` holds the remaining fields. Used for custom interactive
/// components registered via the plugin system.
// JsonSchema skipped: custom Serialize/Deserialize impl
#[derive(Debug, Clone, PartialEq)]
pub struct PluginProps {
    /// The plugin component type name (e.g., "Map").
    pub plugin_type: String,
    /// Raw props passed to the plugin's render function.
    pub props: serde_json::Value,
}

impl Serialize for PluginProps {
    fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
        // Flatten plugin_type back as "type" and merge in the props object.
        let obj = self.props.as_object();
        let extra_len = obj.map_or(0, |m| m.len());
        let mut map = serializer.serialize_map(Some(1 + extra_len))?;
        map.serialize_entry("type", &self.plugin_type)?;
        if let Some(obj) = obj {
            for (k, v) in obj {
                if k != "type" {
                    map.serialize_entry(k, v)?;
                }
            }
        }
        map.end()
    }
}

impl<'de> Deserialize<'de> for PluginProps {
    fn deserialize<D: Deserializer<'de>>(deserializer: D) -> Result<Self, D::Error> {
        let mut value = serde_json::Value::deserialize(deserializer)?;
        let plugin_type = value
            .get("type")
            .and_then(|v| v.as_str())
            .map(|s| s.to_string())
            .ok_or_else(|| de::Error::missing_field("type"))?;
        // Remove "type" from the props to avoid redundancy.
        if let Some(obj) = value.as_object_mut() {
            obj.remove("type");
        }
        Ok(PluginProps {
            plugin_type,
            props: value,
        })
    }
}

/// Component catalog enum. Built-in types are deserialized by name,
/// unknown types fall through to the `Plugin` variant.
///
/// Serializes built-in variants with `"type": "Card"` etc. The Plugin
/// variant serializes with the plugin's own type name.
// JsonSchema skipped: custom Serialize/Deserialize impl
#[derive(Debug, Clone, PartialEq)]
pub enum Component {
    Card(CardProps),
    Table(TableProps),
    Form(FormProps),
    Button(ButtonProps),
    Input(InputProps),
    Select(SelectProps),
    Alert(AlertProps),
    Badge(BadgeProps),
    Modal(ModalProps),
    Text(TextProps),
    Checkbox(CheckboxProps),
    Switch(SwitchProps),
    Separator(SeparatorProps),
    DescriptionList(DescriptionListProps),
    Tabs(TabsProps),
    Breadcrumb(BreadcrumbProps),
    Pagination(PaginationProps),
    Progress(ProgressProps),
    Avatar(AvatarProps),
    Skeleton(SkeletonProps),
    StatCard(StatCardProps),
    Checklist(ChecklistProps),
    Toast(ToastProps),
    NotificationDropdown(NotificationDropdownProps),
    Sidebar(SidebarProps),
    Header(HeaderProps),
    Grid(GridProps),
    Collapsible(CollapsibleProps),
    EmptyState(EmptyStateProps),
    FormSection(FormSectionProps),
    PageHeader(PageHeaderProps),
    ButtonGroup(ButtonGroupProps),
    DropdownMenu(DropdownMenuProps),
    KanbanBoard(KanbanBoardProps),
    CalendarCell(CalendarCellProps),
    ActionCard(ActionCardProps),
    ProductTile(ProductTileProps),
    DataTable(DataTableProps),
    Image(ImageProps),
    KeyValueEditor(KeyValueEditorProps),
    DetailForm(DetailFormProps),
    Plugin(PluginProps),
}

// ── Custom Serialize for Component ───────────────────────────────────────

/// Helper: serialize a built-in variant by serializing its props, then
/// injecting `"type": "<name>"` into the resulting JSON object.
fn serialize_tagged<S: Serializer, T: Serialize>(
    serializer: S,
    type_name: &str,
    props: &T,
) -> Result<S::Ok, S::Error> {
    let mut value = serde_json::to_value(props).map_err(serde::ser::Error::custom)?;
    if let Some(obj) = value.as_object_mut() {
        obj.insert(
            "type".to_string(),
            serde_json::Value::String(type_name.to_string()),
        );
    }
    value.serialize(serializer)
}

impl Serialize for Component {
    fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
        match self {
            Component::Card(p) => serialize_tagged(serializer, "Card", p),
            Component::Table(p) => serialize_tagged(serializer, "Table", p),
            Component::Form(p) => serialize_tagged(serializer, "Form", p),
            Component::Button(p) => serialize_tagged(serializer, "Button", p),
            Component::Input(p) => serialize_tagged(serializer, "Input", p),
            Component::Select(p) => serialize_tagged(serializer, "Select", p),
            Component::Alert(p) => serialize_tagged(serializer, "Alert", p),
            Component::Badge(p) => serialize_tagged(serializer, "Badge", p),
            Component::Modal(p) => serialize_tagged(serializer, "Modal", p),
            Component::Text(p) => serialize_tagged(serializer, "Text", p),
            Component::Checkbox(p) => serialize_tagged(serializer, "Checkbox", p),
            Component::Switch(p) => serialize_tagged(serializer, "Switch", p),
            Component::Separator(p) => serialize_tagged(serializer, "Separator", p),
            Component::DescriptionList(p) => serialize_tagged(serializer, "DescriptionList", p),
            Component::Tabs(p) => serialize_tagged(serializer, "Tabs", p),
            Component::Breadcrumb(p) => serialize_tagged(serializer, "Breadcrumb", p),
            Component::Pagination(p) => serialize_tagged(serializer, "Pagination", p),
            Component::Progress(p) => serialize_tagged(serializer, "Progress", p),
            Component::Avatar(p) => serialize_tagged(serializer, "Avatar", p),
            Component::Skeleton(p) => serialize_tagged(serializer, "Skeleton", p),
            Component::StatCard(p) => serialize_tagged(serializer, "StatCard", p),
            Component::Checklist(p) => serialize_tagged(serializer, "Checklist", p),
            Component::Toast(p) => serialize_tagged(serializer, "Toast", p),
            Component::NotificationDropdown(p) => {
                serialize_tagged(serializer, "NotificationDropdown", p)
            }
            Component::Sidebar(p) => serialize_tagged(serializer, "Sidebar", p),
            Component::Header(p) => serialize_tagged(serializer, "Header", p),
            Component::Grid(p) => serialize_tagged(serializer, "Grid", p),
            Component::Collapsible(p) => serialize_tagged(serializer, "Collapsible", p),
            Component::EmptyState(p) => serialize_tagged(serializer, "EmptyState", p),
            Component::FormSection(p) => serialize_tagged(serializer, "FormSection", p),
            Component::PageHeader(p) => serialize_tagged(serializer, "PageHeader", p),
            Component::ButtonGroup(p) => serialize_tagged(serializer, "ButtonGroup", p),
            Component::DropdownMenu(p) => serialize_tagged(serializer, "DropdownMenu", p),
            Component::KanbanBoard(p) => serialize_tagged(serializer, "KanbanBoard", p),
            Component::CalendarCell(p) => serialize_tagged(serializer, "CalendarCell", p),
            Component::ActionCard(p) => serialize_tagged(serializer, "ActionCard", p),
            Component::ProductTile(p) => serialize_tagged(serializer, "ProductTile", p),
            Component::DataTable(p) => serialize_tagged(serializer, "DataTable", p),
            Component::Image(p) => serialize_tagged(serializer, "Image", p),
            Component::KeyValueEditor(p) => serialize_tagged(serializer, "KeyValueEditor", p),
            Component::DetailForm(p) => serialize_tagged(serializer, "DetailForm", p),
            Component::Plugin(p) => p.serialize(serializer),
        }
    }
}

// ── Custom Deserialize for Component ─────────────────────────────────────

impl<'de> Deserialize<'de> for Component {
    fn deserialize<D: Deserializer<'de>>(deserializer: D) -> Result<Self, D::Error> {
        let value = serde_json::Value::deserialize(deserializer)?;
        let type_str = value
            .get("type")
            .and_then(|v| v.as_str())
            .ok_or_else(|| de::Error::missing_field("type"))?;

        match type_str {
            "Card" => serde_json::from_value::<CardProps>(value)
                .map(Component::Card)
                .map_err(de::Error::custom),
            "Table" => serde_json::from_value::<TableProps>(value)
                .map(Component::Table)
                .map_err(de::Error::custom),
            "Form" => serde_json::from_value::<FormProps>(value)
                .map(Component::Form)
                .map_err(de::Error::custom),
            "Button" => serde_json::from_value::<ButtonProps>(value)
                .map(Component::Button)
                .map_err(de::Error::custom),
            "Input" => serde_json::from_value::<InputProps>(value)
                .map(Component::Input)
                .map_err(de::Error::custom),
            "Select" => serde_json::from_value::<SelectProps>(value)
                .map(Component::Select)
                .map_err(de::Error::custom),
            "Alert" => serde_json::from_value::<AlertProps>(value)
                .map(Component::Alert)
                .map_err(de::Error::custom),
            "Badge" => serde_json::from_value::<BadgeProps>(value)
                .map(Component::Badge)
                .map_err(de::Error::custom),
            "Modal" => serde_json::from_value::<ModalProps>(value)
                .map(Component::Modal)
                .map_err(de::Error::custom),
            "Text" => serde_json::from_value::<TextProps>(value)
                .map(Component::Text)
                .map_err(de::Error::custom),
            "Checkbox" => serde_json::from_value::<CheckboxProps>(value)
                .map(Component::Checkbox)
                .map_err(de::Error::custom),
            "Switch" => serde_json::from_value::<SwitchProps>(value)
                .map(Component::Switch)
                .map_err(de::Error::custom),
            "Separator" => serde_json::from_value::<SeparatorProps>(value)
                .map(Component::Separator)
                .map_err(de::Error::custom),
            "DescriptionList" => serde_json::from_value::<DescriptionListProps>(value)
                .map(Component::DescriptionList)
                .map_err(de::Error::custom),
            "Tabs" => serde_json::from_value::<TabsProps>(value)
                .map(Component::Tabs)
                .map_err(de::Error::custom),
            "Breadcrumb" => serde_json::from_value::<BreadcrumbProps>(value)
                .map(Component::Breadcrumb)
                .map_err(de::Error::custom),
            "Pagination" => serde_json::from_value::<PaginationProps>(value)
                .map(Component::Pagination)
                .map_err(de::Error::custom),
            "Progress" => serde_json::from_value::<ProgressProps>(value)
                .map(Component::Progress)
                .map_err(de::Error::custom),
            "Avatar" => serde_json::from_value::<AvatarProps>(value)
                .map(Component::Avatar)
                .map_err(de::Error::custom),
            "Skeleton" => serde_json::from_value::<SkeletonProps>(value)
                .map(Component::Skeleton)
                .map_err(de::Error::custom),
            "StatCard" => serde_json::from_value::<StatCardProps>(value)
                .map(Component::StatCard)
                .map_err(de::Error::custom),
            "Checklist" => serde_json::from_value::<ChecklistProps>(value)
                .map(Component::Checklist)
                .map_err(de::Error::custom),
            "Toast" => serde_json::from_value::<ToastProps>(value)
                .map(Component::Toast)
                .map_err(de::Error::custom),
            "NotificationDropdown" => serde_json::from_value::<NotificationDropdownProps>(value)
                .map(Component::NotificationDropdown)
                .map_err(de::Error::custom),
            "Sidebar" => serde_json::from_value::<SidebarProps>(value)
                .map(Component::Sidebar)
                .map_err(de::Error::custom),
            "Header" => serde_json::from_value::<HeaderProps>(value)
                .map(Component::Header)
                .map_err(de::Error::custom),
            "Grid" => serde_json::from_value::<GridProps>(value)
                .map(Component::Grid)
                .map_err(de::Error::custom),
            "Collapsible" => serde_json::from_value::<CollapsibleProps>(value)
                .map(Component::Collapsible)
                .map_err(de::Error::custom),
            "EmptyState" => serde_json::from_value::<EmptyStateProps>(value)
                .map(Component::EmptyState)
                .map_err(de::Error::custom),
            "FormSection" => serde_json::from_value::<FormSectionProps>(value)
                .map(Component::FormSection)
                .map_err(de::Error::custom),
            "PageHeader" => serde_json::from_value::<PageHeaderProps>(value)
                .map(Component::PageHeader)
                .map_err(de::Error::custom),
            "ButtonGroup" => serde_json::from_value::<ButtonGroupProps>(value)
                .map(Component::ButtonGroup)
                .map_err(de::Error::custom),
            "DropdownMenu" => serde_json::from_value::<DropdownMenuProps>(value)
                .map(Component::DropdownMenu)
                .map_err(de::Error::custom),
            "KanbanBoard" => serde_json::from_value::<KanbanBoardProps>(value)
                .map(Component::KanbanBoard)
                .map_err(de::Error::custom),
            "CalendarCell" => serde_json::from_value::<CalendarCellProps>(value)
                .map(Component::CalendarCell)
                .map_err(de::Error::custom),
            "ActionCard" => serde_json::from_value::<ActionCardProps>(value)
                .map(Component::ActionCard)
                .map_err(de::Error::custom),
            "ProductTile" => serde_json::from_value::<ProductTileProps>(value)
                .map(Component::ProductTile)
                .map_err(de::Error::custom),
            "DataTable" => serde_json::from_value::<DataTableProps>(value)
                .map(Component::DataTable)
                .map_err(de::Error::custom),
            "Image" => serde_json::from_value::<ImageProps>(value)
                .map(Component::Image)
                .map_err(de::Error::custom),
            "KeyValueEditor" => serde_json::from_value::<KeyValueEditorProps>(value)
                .map(Component::KeyValueEditor)
                .map_err(de::Error::custom),
            "DetailForm" => serde_json::from_value::<DetailFormProps>(value)
                .map(Component::DetailForm)
                .map_err(de::Error::custom),
            _ => {
                // Unknown type: treat as a plugin component.
                let plugin_type = type_str.to_string();
                let mut props = value;
                if let Some(obj) = props.as_object_mut() {
                    obj.remove("type");
                }
                Ok(Component::Plugin(PluginProps { plugin_type, props }))
            }
        }
    }
}

/// A component node wrapping a component with shared fields.
///
/// Every component in a view tree is wrapped in a `ComponentNode` that
/// provides a unique key, optional action binding, and optional visibility
/// rules. The component itself is flattened into the node's JSON.
// JsonSchema skipped: contains Component via flatten — Component has custom Serialize/Deserialize
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
pub struct ComponentNode {
    pub key: String,
    #[serde(flatten)]
    pub component: Component,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub action: Option<Action>,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub visibility: Option<Visibility>,
}

impl ComponentNode {
    /// Create a Card component node.
    pub fn card(key: impl Into<String>, props: CardProps) -> Self {
        Self {
            key: key.into(),
            component: Component::Card(props),
            action: None,
            visibility: None,
        }
    }

    /// Create a Table component node.
    pub fn table(key: impl Into<String>, props: TableProps) -> Self {
        Self {
            key: key.into(),
            component: Component::Table(props),
            action: None,
            visibility: None,
        }
    }

    /// Create a Form component node.
    pub fn form(key: impl Into<String>, props: FormProps) -> Self {
        Self {
            key: key.into(),
            component: Component::Form(props),
            action: None,
            visibility: None,
        }
    }

    /// Create a DetailForm component node.
    ///
    /// Renders the same outer scaffold in both [`EditMode::View`] and
    /// [`EditMode::Edit`] modes per the structural coherence contract
    /// (147-UI-SPEC §5). In Edit mode the scaffold is additionally
    /// wrapped in a `<form>` with method-spoofing for PUT/PATCH/DELETE.
    ///
    /// **Authoring rule (Option A, 147-UI-SPEC §9).** When a
    /// [`DetailField::input`] is an `Input` / `Select` / `Textarea` /
    /// `Checkbox` / `Switch` component, the caller MUST set the input's
    /// `label` prop to an empty string. The `<dt>` already provides the
    /// visible label; DetailForm does not mutate caller-supplied props.
    /// When Option A is applied, the renderer also emits `aria-label`
    /// derived from the field's `label` so screen readers retain context.
    pub fn detail_form(key: impl Into<String>, props: DetailFormProps) -> Self {
        Self {
            key: key.into(),
            component: Component::DetailForm(props),
            action: None,
            visibility: None,
        }
    }

    /// Create a Button component node.
    pub fn button(key: impl Into<String>, props: ButtonProps) -> Self {
        Self {
            key: key.into(),
            component: Component::Button(props),
            action: None,
            visibility: None,
        }
    }

    /// Create an Input component node.
    pub fn input(key: impl Into<String>, props: InputProps) -> Self {
        Self {
            key: key.into(),
            component: Component::Input(props),
            action: None,
            visibility: None,
        }
    }

    /// Create a Select component node.
    pub fn select(key: impl Into<String>, props: SelectProps) -> Self {
        Self {
            key: key.into(),
            component: Component::Select(props),
            action: None,
            visibility: None,
        }
    }

    /// Create an Alert component node.
    pub fn alert(key: impl Into<String>, props: AlertProps) -> Self {
        Self {
            key: key.into(),
            component: Component::Alert(props),
            action: None,
            visibility: None,
        }
    }

    /// Create a Badge component node.
    pub fn badge(key: impl Into<String>, props: BadgeProps) -> Self {
        Self {
            key: key.into(),
            component: Component::Badge(props),
            action: None,
            visibility: None,
        }
    }

    /// Create a Modal component node.
    pub fn modal(key: impl Into<String>, props: ModalProps) -> Self {
        Self {
            key: key.into(),
            component: Component::Modal(props),
            action: None,
            visibility: None,
        }
    }

    /// Create a Text component node.
    pub fn text(key: impl Into<String>, props: TextProps) -> Self {
        Self {
            key: key.into(),
            component: Component::Text(props),
            action: None,
            visibility: None,
        }
    }

    /// Create a Checkbox component node.
    pub fn checkbox(key: impl Into<String>, props: CheckboxProps) -> Self {
        Self {
            key: key.into(),
            component: Component::Checkbox(props),
            action: None,
            visibility: None,
        }
    }

    /// Create a Switch component node.
    pub fn switch(key: impl Into<String>, props: SwitchProps) -> Self {
        Self {
            key: key.into(),
            component: Component::Switch(props),
            action: None,
            visibility: None,
        }
    }

    /// Create a Separator component node.
    pub fn separator(key: impl Into<String>, props: SeparatorProps) -> Self {
        Self {
            key: key.into(),
            component: Component::Separator(props),
            action: None,
            visibility: None,
        }
    }

    /// Create a DescriptionList component node.
    pub fn description_list(key: impl Into<String>, props: DescriptionListProps) -> Self {
        Self {
            key: key.into(),
            component: Component::DescriptionList(props),
            action: None,
            visibility: None,
        }
    }

    /// Create a Tabs component node.
    pub fn tabs(key: impl Into<String>, props: TabsProps) -> Self {
        Self {
            key: key.into(),
            component: Component::Tabs(props),
            action: None,
            visibility: None,
        }
    }

    /// Create a Breadcrumb component node.
    pub fn breadcrumb(key: impl Into<String>, props: BreadcrumbProps) -> Self {
        Self {
            key: key.into(),
            component: Component::Breadcrumb(props),
            action: None,
            visibility: None,
        }
    }

    /// Create a Pagination component node.
    pub fn pagination(key: impl Into<String>, props: PaginationProps) -> Self {
        Self {
            key: key.into(),
            component: Component::Pagination(props),
            action: None,
            visibility: None,
        }
    }

    /// Create a Progress component node.
    pub fn progress(key: impl Into<String>, props: ProgressProps) -> Self {
        Self {
            key: key.into(),
            component: Component::Progress(props),
            action: None,
            visibility: None,
        }
    }

    /// Create an Avatar component node.
    pub fn avatar(key: impl Into<String>, props: AvatarProps) -> Self {
        Self {
            key: key.into(),
            component: Component::Avatar(props),
            action: None,
            visibility: None,
        }
    }

    /// Create a Skeleton component node.
    pub fn skeleton(key: impl Into<String>, props: SkeletonProps) -> Self {
        Self {
            key: key.into(),
            component: Component::Skeleton(props),
            action: None,
            visibility: None,
        }
    }

    /// Create a StatCard component node.
    pub fn stat_card(key: impl Into<String>, props: StatCardProps) -> Self {
        Self {
            key: key.into(),
            component: Component::StatCard(props),
            action: None,
            visibility: None,
        }
    }

    /// Create a Checklist component node.
    pub fn checklist(key: impl Into<String>, props: ChecklistProps) -> Self {
        Self {
            key: key.into(),
            component: Component::Checklist(props),
            action: None,
            visibility: None,
        }
    }

    /// Create a Toast component node.
    pub fn toast(key: impl Into<String>, props: ToastProps) -> Self {
        Self {
            key: key.into(),
            component: Component::Toast(props),
            action: None,
            visibility: None,
        }
    }

    /// Create a NotificationDropdown component node.
    pub fn notification_dropdown(key: impl Into<String>, props: NotificationDropdownProps) -> Self {
        Self {
            key: key.into(),
            component: Component::NotificationDropdown(props),
            action: None,
            visibility: None,
        }
    }

    /// Create a Sidebar component node.
    pub fn sidebar(key: impl Into<String>, props: SidebarProps) -> Self {
        Self {
            key: key.into(),
            component: Component::Sidebar(props),
            action: None,
            visibility: None,
        }
    }

    /// Create a Header component node.
    pub fn header(key: impl Into<String>, props: HeaderProps) -> Self {
        Self {
            key: key.into(),
            component: Component::Header(props),
            action: None,
            visibility: None,
        }
    }

    /// Create a Grid component node.
    pub fn grid(key: impl Into<String>, props: GridProps) -> Self {
        Self {
            key: key.into(),
            component: Component::Grid(props),
            action: None,
            visibility: None,
        }
    }

    /// Create a Collapsible component node.
    pub fn collapsible(key: impl Into<String>, props: CollapsibleProps) -> Self {
        Self {
            key: key.into(),
            component: Component::Collapsible(props),
            action: None,
            visibility: None,
        }
    }

    /// Create an EmptyState component node.
    pub fn empty_state(key: impl Into<String>, props: EmptyStateProps) -> Self {
        Self {
            key: key.into(),
            component: Component::EmptyState(props),
            action: None,
            visibility: None,
        }
    }

    /// Create a FormSection component node.
    pub fn form_section(key: impl Into<String>, props: FormSectionProps) -> Self {
        Self {
            key: key.into(),
            component: Component::FormSection(props),
            action: None,
            visibility: None,
        }
    }

    /// Create a DropdownMenu component node.
    pub fn dropdown_menu(key: impl Into<String>, props: DropdownMenuProps) -> Self {
        Self {
            key: key.into(),
            component: Component::DropdownMenu(props),
            action: None,
            visibility: None,
        }
    }

    /// Create a KanbanBoard component node.
    pub fn kanban_board(key: impl Into<String>, props: KanbanBoardProps) -> Self {
        Self {
            key: key.into(),
            component: Component::KanbanBoard(props),
            action: None,
            visibility: None,
        }
    }

    /// Create a CalendarCell component node.
    pub fn calendar_cell(key: impl Into<String>, props: CalendarCellProps) -> Self {
        Self {
            key: key.into(),
            component: Component::CalendarCell(props),
            action: None,
            visibility: None,
        }
    }

    /// Create an ActionCard component node.
    pub fn action_card(key: impl Into<String>, props: ActionCardProps) -> Self {
        Self {
            key: key.into(),
            component: Component::ActionCard(props),
            action: None,
            visibility: None,
        }
    }

    /// Create a ProductTile component node.
    pub fn product_tile(key: impl Into<String>, props: ProductTileProps) -> Self {
        Self {
            key: key.into(),
            component: Component::ProductTile(props),
            action: None,
            visibility: None,
        }
    }

    /// Create a DataTable component node.
    pub fn data_table(key: impl Into<String>, props: DataTableProps) -> Self {
        Self {
            key: key.into(),
            component: Component::DataTable(props),
            action: None,
            visibility: None,
        }
    }

    /// Create an Image component node.
    pub fn image(key: impl Into<String>, props: ImageProps) -> Self {
        Self {
            key: key.into(),
            component: Component::Image(props),
            action: None,
            visibility: None,
        }
    }

    /// Create a Plugin component node.
    ///
    /// Use `plugin_component` to avoid ambiguity with any `plugin` module.
    pub fn plugin_component(key: impl Into<String>, props: PluginProps) -> Self {
        Self {
            key: key.into(),
            component: Component::Plugin(props),
            action: None,
            visibility: None,
        }
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::action::HttpMethod;
    use crate::visibility::{VisibilityCondition, VisibilityOperator};

    #[test]
    fn card_component_tagged_serialization() {
        let card = Component::Card(CardProps {
            title: "Test Card".to_string(),
            description: Some("A description".to_string()),
            children: vec![],
            footer: vec![],
            max_width: None,
        });
        let json = serde_json::to_value(&card).unwrap();
        assert_eq!(json["type"], "Card");
        assert_eq!(json["title"], "Test Card");
        assert_eq!(json["description"], "A description");
    }

    #[test]
    fn button_variant_defaults_to_default() {
        let json = r#"{"type": "Button", "label": "Click me"}"#;
        let component: Component = serde_json::from_str(json).unwrap();
        match component {
            Component::Button(props) => {
                assert_eq!(props.variant, ButtonVariant::Default);
                assert_eq!(props.label, "Click me");
            }
            _ => panic!("expected Button"),
        }
    }

    #[test]
    fn input_type_defaults_to_text() {
        let json = r#"{"type": "Input", "field": "email", "label": "Email"}"#;
        let component: Component = serde_json::from_str(json).unwrap();
        match component {
            Component::Input(props) => {
                assert_eq!(props.input_type, InputType::Text);
                assert_eq!(props.field, "email");
            }
            _ => panic!("expected Input"),
        }
    }

    #[test]
    fn alert_variant_defaults_to_info() {
        let json = r#"{"type": "Alert", "message": "Hello"}"#;
        let component: Component = serde_json::from_str(json).unwrap();
        match component {
            Component::Alert(props) => assert_eq!(props.variant, AlertVariant::Info),
            _ => panic!("expected Alert"),
        }
    }

    #[test]
    fn badge_variant_defaults_to_default() {
        let json = r#"{"type": "Badge", "label": "New"}"#;
        let component: Component = serde_json::from_str(json).unwrap();
        match component {
            Component::Badge(props) => assert_eq!(props.variant, BadgeVariant::Default),
            _ => panic!("expected Badge"),
        }
    }

    #[test]
    fn text_element_defaults_to_p() {
        let json = r#"{"type": "Text", "content": "Hello world"}"#;
        let component: Component = serde_json::from_str(json).unwrap();
        match component {
            Component::Text(props) => {
                assert_eq!(props.element, TextElement::P);
                assert_eq!(props.content, "Hello world");
            }
            _ => panic!("expected Text"),
        }
    }

    #[test]
    fn table_component_round_trips() {
        let table = Component::Table(TableProps {
            columns: vec![
                Column {
                    key: "name".to_string(),
                    label: "Name".to_string(),
                    format: None,
                },
                Column {
                    key: "created_at".to_string(),
                    label: "Created".to_string(),
                    format: Some(ColumnFormat::Date),
                },
            ],
            data_path: "/data/users".to_string(),
            row_actions: None,
            empty_message: Some("No users found".to_string()),
            sortable: None,
            sort_column: None,
            sort_direction: None,
        });
        let json = serde_json::to_string(&table).unwrap();
        let parsed: Component = serde_json::from_str(&json).unwrap();
        assert_eq!(parsed, table);
    }

    #[test]
    fn select_component_round_trips() {
        let select = Component::Select(SelectProps {
            field: "role".to_string(),
            label: "Role".to_string(),
            options: vec![
                SelectOption {
                    value: "admin".to_string(),
                    label: "Administrator".to_string(),
                },
                SelectOption {
                    value: "user".to_string(),
                    label: "User".to_string(),
                },
            ],
            placeholder: Some("Select a role".to_string()),
            required: Some(true),
            disabled: None,
            error: None,
            description: None,
            default_value: None,
            data_path: None,
        });
        let json = serde_json::to_string(&select).unwrap();
        let parsed: Component = serde_json::from_str(&json).unwrap();
        assert_eq!(parsed, select);
    }

    #[test]
    fn modal_component_round_trips() {
        let modal = Component::Modal(ModalProps {
            id: "modal-confirm".to_string(),
            title: "Confirm".to_string(),
            description: None,
            children: vec![ComponentNode {
                key: "msg".to_string(),
                component: Component::Text(TextProps {
                    content: "Are you sure?".to_string(),
                    element: TextElement::P,
                }),
                action: None,
                visibility: None,
            }],
            footer: vec![],
            trigger_label: Some("Open".to_string()),
        });
        let json = serde_json::to_string(&modal).unwrap();
        let parsed: Component = serde_json::from_str(&json).unwrap();
        assert_eq!(parsed, modal);
    }

    #[test]
    fn form_component_round_trips() {
        let form = Component::Form(FormProps {
            action: Action {
                handler: "users.store".to_string(),
                url: None,
                method: HttpMethod::Post,
                confirm: None,
                on_success: None,
                on_error: None,
                target: None,
            },
            fields: vec![ComponentNode {
                key: "email-input".to_string(),
                component: Component::Input(InputProps {
                    field: "email".to_string(),
                    label: "Email".to_string(),
                    input_type: InputType::Email,
                    placeholder: Some("user@example.com".to_string()),
                    required: Some(true),
                    disabled: None,
                    error: None,
                    description: None,
                    default_value: None,
                    data_path: None,
                    step: None,
                    list: None,
                }),
                action: None,
                visibility: None,
            }],
            method: None,
            guard: None,
            max_width: None,
        });
        let json = serde_json::to_string(&form).unwrap();
        let parsed: Component = serde_json::from_str(&json).unwrap();
        assert_eq!(parsed, form);
    }

    #[test]
    fn component_node_with_action_and_visibility() {
        let node = ComponentNode {
            key: "create-btn".to_string(),
            component: Component::Button(ButtonProps {
                label: "Create User".to_string(),
                variant: ButtonVariant::Default,
                size: Size::Default,
                disabled: None,
                icon: None,
                icon_position: None,
                button_type: None,
            }),
            action: Some(Action {
                handler: "users.create".to_string(),
                url: None,
                method: HttpMethod::Post,
                confirm: None,
                on_success: None,
                on_error: None,
                target: None,
            }),
            visibility: Some(Visibility::Condition(VisibilityCondition {
                path: "/auth/user/role".to_string(),
                operator: VisibilityOperator::Eq,
                value: Some(serde_json::Value::String("admin".to_string())),
            })),
        };
        let json = serde_json::to_string(&node).unwrap();
        let parsed: ComponentNode = serde_json::from_str(&json).unwrap();
        assert_eq!(parsed, node);

        // Verify flattened structure includes type
        let value = serde_json::to_value(&node).unwrap();
        assert_eq!(value["type"], "Button");
        assert_eq!(value["key"], "create-btn");
        assert!(value.get("action").is_some());
        assert!(value.get("visibility").is_some());
    }

    #[test]
    fn all_component_variants_serialize() {
        let components: Vec<Component> = vec![
            Component::Card(CardProps {
                title: "t".to_string(),
                description: None,
                children: vec![],
                footer: vec![],
                max_width: None,
            }),
            Component::Table(TableProps {
                columns: vec![],
                data_path: "/d".to_string(),
                row_actions: None,
                empty_message: None,
                sortable: None,
                sort_column: None,
                sort_direction: None,
            }),
            Component::Form(FormProps {
                action: Action {
                    handler: "h.m".to_string(),
                    url: None,
                    method: HttpMethod::Post,
                    confirm: None,
                    on_success: None,
                    on_error: None,
                    target: None,
                },
                fields: vec![],
                method: None,
                guard: None,
                max_width: None,
            }),
            Component::Button(ButtonProps {
                label: "b".to_string(),
                variant: ButtonVariant::Default,
                size: Size::Default,
                disabled: None,
                icon: None,
                icon_position: None,
                button_type: None,
            }),
            Component::Input(InputProps {
                field: "f".to_string(),
                label: "l".to_string(),
                input_type: InputType::Text,
                placeholder: None,
                required: None,
                disabled: None,
                error: None,
                description: None,
                default_value: None,
                data_path: None,
                step: None,
                list: None,
            }),
            Component::Select(SelectProps {
                field: "f".to_string(),
                label: "l".to_string(),
                options: vec![],
                placeholder: None,
                required: None,
                disabled: None,
                error: None,
                description: None,
                default_value: None,
                data_path: None,
            }),
            Component::Alert(AlertProps {
                message: "m".to_string(),
                variant: AlertVariant::Info,
                title: None,
            }),
            Component::Badge(BadgeProps {
                label: "b".to_string(),
                variant: BadgeVariant::Default,
            }),
            Component::Modal(ModalProps {
                id: "modal-t".to_string(),
                title: "t".to_string(),
                description: None,
                children: vec![],
                footer: vec![],
                trigger_label: None,
            }),
            Component::Text(TextProps {
                content: "c".to_string(),
                element: TextElement::P,
            }),
            Component::Checkbox(CheckboxProps {
                field: "f".to_string(),
                value: None,
                label: "l".to_string(),
                description: None,
                checked: None,
                data_path: None,
                required: None,
                disabled: None,
                error: None,
            }),
            Component::Switch(SwitchProps {
                field: "f".to_string(),
                label: "l".to_string(),
                description: None,
                checked: None,
                data_path: None,
                required: None,
                disabled: None,
                error: None,
                action: None,
                compact: false,
            }),
            Component::Separator(SeparatorProps { orientation: None }),
            Component::DescriptionList(DescriptionListProps {
                items: vec![DescriptionItem {
                    label: "k".to_string(),
                    value: "v".to_string(),
                    format: None,
                }],
                columns: None,
            }),
            Component::Tabs(TabsProps {
                default_tab: "t1".to_string(),
                tabs: vec![Tab {
                    value: "t1".to_string(),
                    label: "Tab 1".to_string(),
                    children: vec![],
                }],
            }),
            Component::Breadcrumb(BreadcrumbProps {
                items: vec![BreadcrumbItem {
                    label: "Home".to_string(),
                    url: Some("/".to_string()),
                }],
            }),
            Component::Pagination(PaginationProps {
                current_page: 1,
                per_page: 10,
                total: 100,
                base_url: None,
            }),
            Component::Progress(ProgressProps {
                value: 50,
                max: None,
                label: None,
            }),
            Component::Avatar(AvatarProps {
                src: None,
                alt: "User".to_string(),
                fallback: Some("U".to_string()),
                size: None,
            }),
            Component::Skeleton(SkeletonProps {
                width: None,
                height: None,
                rounded: None,
            }),
            Component::StatCard(StatCardProps {
                label: "Revenue".to_string(),
                value: "$1,234".to_string(),
                icon: None,
                subtitle: None,
                sse_target: None,
            }),
            Component::Checklist(ChecklistProps {
                title: "Tasks".to_string(),
                items: vec![],
                dismissible: true,
                dismiss_label: None,
                data_key: None,
            }),
            Component::Toast(ToastProps {
                message: "Saved!".to_string(),
                variant: ToastVariant::Success,
                timeout: None,
                dismissible: true,
            }),
            Component::NotificationDropdown(NotificationDropdownProps {
                notifications: vec![],
                empty_text: None,
            }),
            Component::Sidebar(SidebarProps {
                fixed_top: vec![],
                groups: vec![],
                fixed_bottom: vec![],
            }),
            Component::Header(HeaderProps {
                business_name: "Acme".to_string(),
                notification_count: None,
                user_name: None,
                user_avatar: None,
                logout_url: None,
            }),
            Component::Image(ImageProps {
                src: "/img/screenshot.png".to_string(),
                alt: "Page screenshot".to_string(),
                aspect_ratio: None,
                placeholder_label: None,
            }),
        ];
        assert_eq!(components.len(), 27, "should have 27 component variants");
        let expected_types = [
            "Card",
            "Table",
            "Form",
            "Button",
            "Input",
            "Select",
            "Alert",
            "Badge",
            "Modal",
            "Text",
            "Checkbox",
            "Switch",
            "Separator",
            "DescriptionList",
            "Tabs",
            "Breadcrumb",
            "Pagination",
            "Progress",
            "Avatar",
            "Skeleton",
            "StatCard",
            "Checklist",
            "Toast",
            "NotificationDropdown",
            "Sidebar",
            "Header",
            "Image",
        ];
        for (component, expected_type) in components.iter().zip(expected_types.iter()) {
            let json = serde_json::to_value(component).unwrap();
            assert_eq!(
                json["type"], *expected_type,
                "component should serialize with type={expected_type}"
            );
            let roundtripped: Component = serde_json::from_value(json).unwrap();
            assert_eq!(&roundtripped, component);
        }
    }

    #[test]
    fn size_enum_serialization() {
        let cases = [
            (Size::Xs, "xs"),
            (Size::Sm, "sm"),
            (Size::Default, "default"),
            (Size::Lg, "lg"),
        ];
        for (size, expected) in &cases {
            let json = serde_json::to_value(size).unwrap();
            assert_eq!(json, *expected);
            let parsed: Size = serde_json::from_value(json).unwrap();
            assert_eq!(&parsed, size);
        }
    }

    #[test]
    fn icon_position_serialization() {
        let cases = [(IconPosition::Left, "left"), (IconPosition::Right, "right")];
        for (pos, expected) in &cases {
            let json = serde_json::to_value(pos).unwrap();
            assert_eq!(json, *expected);
            let parsed: IconPosition = serde_json::from_value(json).unwrap();
            assert_eq!(&parsed, pos);
        }
    }

    #[test]
    fn sort_direction_serialization() {
        let cases = [(SortDirection::Asc, "asc"), (SortDirection::Desc, "desc")];
        for (dir, expected) in &cases {
            let json = serde_json::to_value(dir).unwrap();
            assert_eq!(json, *expected);
            let parsed: SortDirection = serde_json::from_value(json).unwrap();
            assert_eq!(&parsed, dir);
        }
    }

    #[test]
    fn button_with_size_and_icon() {
        let button = Component::Button(ButtonProps {
            label: "Save".to_string(),
            variant: ButtonVariant::Default,
            size: Size::Lg,
            disabled: None,
            icon: Some("save".to_string()),
            icon_position: Some(IconPosition::Left),
            button_type: None,
        });
        let json = serde_json::to_value(&button).unwrap();
        assert_eq!(json["size"], "lg");
        assert_eq!(json["icon"], "save");
        assert_eq!(json["icon_position"], "left");
        let parsed: Component = serde_json::from_value(json).unwrap();
        assert_eq!(parsed, button);
    }

    #[test]
    fn card_with_footer() {
        let card = Component::Card(CardProps {
            title: "Actions".to_string(),
            description: None,
            children: vec![],
            max_width: None,
            footer: vec![ComponentNode {
                key: "cancel".to_string(),
                component: Component::Button(ButtonProps {
                    label: "Cancel".to_string(),
                    variant: ButtonVariant::Outline,
                    size: Size::Default,
                    disabled: None,
                    icon: None,
                    icon_position: None,
                    button_type: None,
                }),
                action: None,
                visibility: None,
            }],
        });
        let json = serde_json::to_value(&card).unwrap();
        assert!(json["footer"].is_array());
        assert_eq!(json["footer"][0]["label"], "Cancel");
        let parsed: Component = serde_json::from_value(json).unwrap();
        assert_eq!(parsed, card);
    }

    #[test]
    fn input_with_error_and_description() {
        let input = Component::Input(InputProps {
            field: "email".to_string(),
            label: "Email".to_string(),
            input_type: InputType::Email,
            placeholder: None,
            required: Some(true),
            disabled: Some(false),
            error: Some("Invalid email".to_string()),
            description: Some("Your work email".to_string()),
            default_value: Some("user@example.com".to_string()),
            data_path: None,
            step: None,
            list: None,
        });
        let json = serde_json::to_value(&input).unwrap();
        assert_eq!(json["error"], "Invalid email");
        assert_eq!(json["description"], "Your work email");
        assert_eq!(json["default_value"], "user@example.com");
        assert_eq!(json["disabled"], false);
        let parsed: Component = serde_json::from_value(json).unwrap();
        assert_eq!(parsed, input);
    }

    #[test]
    fn select_with_default_value() {
        let select = Component::Select(SelectProps {
            field: "role".to_string(),
            label: "Role".to_string(),
            options: vec![SelectOption {
                value: "admin".to_string(),
                label: "Admin".to_string(),
            }],
            placeholder: None,
            required: None,
            disabled: Some(true),
            error: Some("Required field".to_string()),
            description: Some("User role".to_string()),
            default_value: Some("admin".to_string()),
            data_path: None,
        });
        let json = serde_json::to_value(&select).unwrap();
        assert_eq!(json["default_value"], "admin");
        assert_eq!(json["error"], "Required field");
        assert_eq!(json["description"], "User role");
        assert_eq!(json["disabled"], true);
        let parsed: Component = serde_json::from_value(json).unwrap();
        assert_eq!(parsed, select);
    }

    #[test]
    fn alert_with_title() {
        let alert = Component::Alert(AlertProps {
            message: "Something happened".to_string(),
            variant: AlertVariant::Warning,
            title: Some("Warning".to_string()),
        });
        let json = serde_json::to_value(&alert).unwrap();
        assert_eq!(json["title"], "Warning");
        assert_eq!(json["message"], "Something happened");
        let parsed: Component = serde_json::from_value(json).unwrap();
        assert_eq!(parsed, alert);
    }

    #[test]
    fn modal_with_footer_and_description() {
        let modal = Component::Modal(ModalProps {
            id: "modal-delete-item".to_string(),
            title: "Delete Item".to_string(),
            description: Some("This action cannot be undone.".to_string()),
            children: vec![],
            footer: vec![ComponentNode {
                key: "confirm".to_string(),
                component: Component::Button(ButtonProps {
                    label: "Delete".to_string(),
                    variant: ButtonVariant::Destructive,
                    size: Size::Default,
                    disabled: None,
                    icon: None,
                    icon_position: None,
                    button_type: None,
                }),
                action: None,
                visibility: None,
            }],
            trigger_label: Some("Delete".to_string()),
        });
        let json = serde_json::to_value(&modal).unwrap();
        assert_eq!(json["description"], "This action cannot be undone.");
        assert!(json["footer"].is_array());
        assert_eq!(json["footer"][0]["label"], "Delete");
        let parsed: Component = serde_json::from_value(json).unwrap();
        assert_eq!(parsed, modal);
    }

    #[test]
    fn table_with_sort_props() {
        let table = Component::Table(TableProps {
            columns: vec![Column {
                key: "name".to_string(),
                label: "Name".to_string(),
                format: None,
            }],
            data_path: "/data/users".to_string(),
            row_actions: None,
            empty_message: None,
            sortable: Some(true),
            sort_column: Some("name".to_string()),
            sort_direction: Some(SortDirection::Desc),
        });
        let json = serde_json::to_value(&table).unwrap();
        assert_eq!(json["sortable"], true);
        assert_eq!(json["sort_column"], "name");
        assert_eq!(json["sort_direction"], "desc");
        let parsed: Component = serde_json::from_value(json).unwrap();
        assert_eq!(parsed, table);
    }

    #[test]
    fn aligned_button_variants_serialize() {
        let cases = [
            (ButtonVariant::Default, "default"),
            (ButtonVariant::Secondary, "secondary"),
            (ButtonVariant::Destructive, "destructive"),
            (ButtonVariant::Outline, "outline"),
            (ButtonVariant::Ghost, "ghost"),
            (ButtonVariant::Link, "link"),
        ];
        for (variant, expected) in &cases {
            let json = serde_json::to_value(variant).unwrap();
            assert_eq!(
                json, *expected,
                "ButtonVariant::{variant:?} should serialize as {expected}"
            );
            let parsed: ButtonVariant = serde_json::from_value(json).unwrap();
            assert_eq!(&parsed, variant);
        }
    }

    #[test]
    fn aligned_badge_variants_serialize() {
        let cases = [
            (BadgeVariant::Default, "default"),
            (BadgeVariant::Secondary, "secondary"),
            (BadgeVariant::Destructive, "destructive"),
            (BadgeVariant::Outline, "outline"),
        ];
        for (variant, expected) in &cases {
            let json = serde_json::to_value(variant).unwrap();
            assert_eq!(
                json, *expected,
                "BadgeVariant::{variant:?} should serialize as {expected}"
            );
            let parsed: BadgeVariant = serde_json::from_value(json).unwrap();
            assert_eq!(&parsed, variant);
        }
    }

    #[test]
    fn checkbox_round_trips() {
        let checkbox = Component::Checkbox(CheckboxProps {
            field: "terms".to_string(),
            value: None,
            label: "Accept Terms".to_string(),
            description: Some("You must accept the terms".to_string()),
            checked: Some(true),
            data_path: None,
            required: Some(true),
            disabled: Some(false),
            error: None,
        });
        let json = serde_json::to_value(&checkbox).unwrap();
        assert_eq!(json["type"], "Checkbox");
        assert_eq!(json["field"], "terms");
        assert_eq!(json["checked"], true);
        assert_eq!(json["description"], "You must accept the terms");
        let parsed: Component = serde_json::from_value(json).unwrap();
        assert_eq!(parsed, checkbox);
    }

    #[test]
    fn switch_round_trips() {
        let switch = Component::Switch(SwitchProps {
            field: "notifications".to_string(),
            label: "Enable Notifications".to_string(),
            description: Some("Receive email notifications".to_string()),
            checked: Some(false),
            data_path: None,
            required: None,
            disabled: Some(false),
            error: None,
            action: None,
            compact: false,
        });
        let json = serde_json::to_value(&switch).unwrap();
        assert_eq!(json["type"], "Switch");
        assert_eq!(json["field"], "notifications");
        assert_eq!(json["checked"], false);
        let parsed: Component = serde_json::from_value(json).unwrap();
        assert_eq!(parsed, switch);
    }

    #[test]
    fn separator_defaults_to_horizontal() {
        let json = r#"{"type": "Separator"}"#;
        let component: Component = serde_json::from_str(json).unwrap();
        match component {
            Component::Separator(props) => {
                assert_eq!(props.orientation, None);
                // When orientation is None, frontend defaults to horizontal.
                // Explicit horizontal also round-trips correctly:
                let explicit = Component::Separator(SeparatorProps {
                    orientation: Some(Orientation::Horizontal),
                });
                let v = serde_json::to_value(&explicit).unwrap();
                assert_eq!(v["orientation"], "horizontal");
                let parsed: Component = serde_json::from_value(v).unwrap();
                assert_eq!(parsed, explicit);
            }
            _ => panic!("expected Separator"),
        }
    }

    #[test]
    fn description_list_with_format() {
        let dl = Component::DescriptionList(DescriptionListProps {
            items: vec![
                DescriptionItem {
                    label: "Created".to_string(),
                    value: "2026-01-15".to_string(),
                    format: Some(ColumnFormat::Date),
                },
                DescriptionItem {
                    label: "Name".to_string(),
                    value: "Alice".to_string(),
                    format: None,
                },
            ],
            columns: Some(2),
        });
        let json = serde_json::to_value(&dl).unwrap();
        assert_eq!(json["type"], "DescriptionList");
        assert_eq!(json["columns"], 2);
        assert_eq!(json["items"][0]["format"], "date");
        assert!(json["items"][1].get("format").is_none());
        let parsed: Component = serde_json::from_value(json).unwrap();
        assert_eq!(parsed, dl);
    }

    #[test]
    fn checkbox_with_error() {
        let checkbox = Component::Checkbox(CheckboxProps {
            field: "agree".to_string(),
            value: None,
            label: "I agree".to_string(),
            description: None,
            checked: None,
            data_path: None,
            required: Some(true),
            disabled: None,
            error: Some("You must agree".to_string()),
        });
        let json = serde_json::to_value(&checkbox).unwrap();
        assert_eq!(json["error"], "You must agree");
        assert!(json.get("description").is_none());
        assert!(json.get("checked").is_none());
        let parsed: Component = serde_json::from_value(json).unwrap();
        assert_eq!(parsed, checkbox);
    }

    #[test]
    fn tabs_round_trips() {
        let tabs = Component::Tabs(TabsProps {
            default_tab: "general".to_string(),
            tabs: vec![
                Tab {
                    value: "general".to_string(),
                    label: "General".to_string(),
                    children: vec![ComponentNode {
                        key: "name-input".to_string(),
                        component: Component::Input(InputProps {
                            field: "name".to_string(),
                            label: "Name".to_string(),
                            input_type: InputType::Text,
                            placeholder: None,
                            required: None,
                            disabled: None,
                            error: None,
                            description: None,
                            default_value: None,
                            data_path: None,
                            step: None,
                            list: None,
                        }),
                        action: None,
                        visibility: None,
                    }],
                },
                Tab {
                    value: "security".to_string(),
                    label: "Security".to_string(),
                    children: vec![ComponentNode {
                        key: "password-input".to_string(),
                        component: Component::Input(InputProps {
                            field: "password".to_string(),
                            label: "Password".to_string(),
                            input_type: InputType::Password,
                            placeholder: None,
                            required: None,
                            disabled: None,
                            error: None,
                            description: None,
                            default_value: None,
                            data_path: None,
                            step: None,
                            list: None,
                        }),
                        action: None,
                        visibility: None,
                    }],
                },
            ],
        });
        let json = serde_json::to_string(&tabs).unwrap();
        let parsed: Component = serde_json::from_str(&json).unwrap();
        assert_eq!(parsed, tabs);
    }

    #[test]
    fn breadcrumb_round_trips() {
        let breadcrumb = Component::Breadcrumb(BreadcrumbProps {
            items: vec![
                BreadcrumbItem {
                    label: "Home".to_string(),
                    url: Some("/".to_string()),
                },
                BreadcrumbItem {
                    label: "Users".to_string(),
                    url: Some("/users".to_string()),
                },
                BreadcrumbItem {
                    label: "Edit User".to_string(),
                    url: None,
                },
            ],
        });
        let json = serde_json::to_string(&breadcrumb).unwrap();
        let parsed: Component = serde_json::from_str(&json).unwrap();
        assert_eq!(parsed, breadcrumb);

        // Verify last item has no URL serialized
        let value = serde_json::to_value(&breadcrumb).unwrap();
        assert!(value["items"][2].get("url").is_none());
    }

    #[test]
    fn pagination_round_trips() {
        let pagination = Component::Pagination(PaginationProps {
            current_page: 3,
            per_page: 25,
            total: 150,
            base_url: None,
        });
        let json = serde_json::to_string(&pagination).unwrap();
        let parsed: Component = serde_json::from_str(&json).unwrap();
        assert_eq!(parsed, pagination);
    }

    #[test]
    fn progress_round_trips() {
        let progress = Component::Progress(ProgressProps {
            value: 75,
            max: Some(100),
            label: Some("Uploading...".to_string()),
        });
        let json = serde_json::to_string(&progress).unwrap();
        let parsed: Component = serde_json::from_str(&json).unwrap();
        assert_eq!(parsed, progress);

        let value = serde_json::to_value(&progress).unwrap();
        assert_eq!(value["value"], 75);
        assert_eq!(value["max"], 100);
        assert_eq!(value["label"], "Uploading...");
    }

    #[test]
    fn avatar_with_fallback() {
        let avatar = Component::Avatar(AvatarProps {
            src: None,
            alt: "John Doe".to_string(),
            fallback: Some("JD".to_string()),
            size: Some(Size::Lg),
        });
        let json = serde_json::to_string(&avatar).unwrap();
        let parsed: Component = serde_json::from_str(&json).unwrap();
        assert_eq!(parsed, avatar);

        let value = serde_json::to_value(&avatar).unwrap();
        assert!(value.get("src").is_none());
        assert_eq!(value["fallback"], "JD");
        assert_eq!(value["size"], "lg");
    }

    #[test]
    fn skeleton_round_trips() {
        let skeleton = Component::Skeleton(SkeletonProps {
            width: Some("100%".to_string()),
            height: Some("40px".to_string()),
            rounded: Some(true),
        });
        let json = serde_json::to_string(&skeleton).unwrap();
        let parsed: Component = serde_json::from_str(&json).unwrap();
        assert_eq!(parsed, skeleton);

        let value = serde_json::to_value(&skeleton).unwrap();
        assert_eq!(value["width"], "100%");
        assert_eq!(value["height"], "40px");
        assert_eq!(value["rounded"], true);
    }

    #[test]
    fn tabs_deserializes_from_json() {
        let json = r#"{
            "type": "Tabs",
            "default_tab": "general",
            "tabs": [
                {
                    "value": "general",
                    "label": "General",
                    "children": [
                        {
                            "key": "name-input",
                            "type": "Input",
                            "field": "name",
                            "label": "Name"
                        }
                    ]
                },
                {
                    "value": "security",
                    "label": "Security"
                }
            ]
        }"#;
        let component: Component = serde_json::from_str(json).unwrap();
        match component {
            Component::Tabs(props) => {
                assert_eq!(props.default_tab, "general");
                assert_eq!(props.tabs.len(), 2);
                assert_eq!(props.tabs[0].value, "general");
                assert_eq!(props.tabs[0].children.len(), 1);
                assert_eq!(props.tabs[1].value, "security");
                assert!(props.tabs[1].children.is_empty());
            }
            _ => panic!("expected Tabs"),
        }
    }

    #[test]
    fn input_data_path_round_trips() {
        let input = Component::Input(InputProps {
            field: "name".to_string(),
            label: "Name".to_string(),
            input_type: InputType::Text,
            placeholder: None,
            required: None,
            disabled: None,
            error: None,
            description: None,
            default_value: None,
            data_path: Some("/data/user/name".to_string()),
            step: None,
            list: None,
        });
        let json = serde_json::to_value(&input).unwrap();
        assert_eq!(json["data_path"], "/data/user/name");
        let parsed: Component = serde_json::from_value(json).unwrap();
        assert_eq!(parsed, input);
    }

    #[test]
    fn select_data_path_round_trips() {
        let select = Component::Select(SelectProps {
            field: "role".to_string(),
            label: "Role".to_string(),
            options: vec![SelectOption {
                value: "admin".to_string(),
                label: "Admin".to_string(),
            }],
            placeholder: None,
            required: None,
            disabled: None,
            error: None,
            description: None,
            default_value: None,
            data_path: Some("/data/user/role".to_string()),
        });
        let json = serde_json::to_value(&select).unwrap();
        assert_eq!(json["data_path"], "/data/user/role");
        let parsed: Component = serde_json::from_value(json).unwrap();
        assert_eq!(parsed, select);
    }

    #[test]
    fn checkbox_data_path_round_trips() {
        let checkbox = Component::Checkbox(CheckboxProps {
            field: "terms".to_string(),
            value: None,
            label: "Accept Terms".to_string(),
            description: None,
            checked: None,
            data_path: Some("/data/user/accepted_terms".to_string()),
            required: None,
            disabled: None,
            error: None,
        });
        let json = serde_json::to_value(&checkbox).unwrap();
        assert_eq!(json["data_path"], "/data/user/accepted_terms");
        let parsed: Component = serde_json::from_value(json).unwrap();
        assert_eq!(parsed, checkbox);
    }

    #[test]
    fn switch_data_path_round_trips() {
        let switch = Component::Switch(SwitchProps {
            field: "notifications".to_string(),
            label: "Enable Notifications".to_string(),
            description: None,
            checked: None,
            data_path: Some("/data/user/notifications_enabled".to_string()),
            required: None,
            disabled: None,
            error: None,
            action: None,
            compact: false,
        });
        let json = serde_json::to_value(&switch).unwrap();
        assert_eq!(json["data_path"], "/data/user/notifications_enabled");
        let parsed: Component = serde_json::from_value(json).unwrap();
        assert_eq!(parsed, switch);
    }

    // ─── Plugin variant tests ────────────────────────────────────────

    #[test]
    fn unknown_type_deserializes_as_plugin() {
        let json = r#"{"type": "Map", "center": [40.7, -74.0], "zoom": 12}"#;
        let component: Component = serde_json::from_str(json).unwrap();
        match component {
            Component::Plugin(props) => {
                assert_eq!(props.plugin_type, "Map");
                assert_eq!(props.props["center"][0], 40.7);
                assert_eq!(props.props["center"][1], -74.0);
                assert_eq!(props.props["zoom"], 12);
                // "type" should be removed from props
                assert!(props.props.get("type").is_none());
            }
            _ => panic!("expected Plugin"),
        }
    }

    #[test]
    fn plugin_round_trips() {
        let plugin = Component::Plugin(PluginProps {
            plugin_type: "Chart".to_string(),
            props: serde_json::json!({"data": [1, 2, 3], "style": "bar"}),
        });
        let json = serde_json::to_value(&plugin).unwrap();
        assert_eq!(json["type"], "Chart");
        assert_eq!(json["data"], serde_json::json!([1, 2, 3]));
        assert_eq!(json["style"], "bar");

        let parsed: Component = serde_json::from_value(json).unwrap();
        assert_eq!(parsed, plugin);
    }

    #[test]
    fn plugin_serializes_with_type_field() {
        let plugin = Component::Plugin(PluginProps {
            plugin_type: "Map".to_string(),
            props: serde_json::json!({"lat": 51.5, "lng": -0.1}),
        });
        let json = serde_json::to_value(&plugin).unwrap();
        assert_eq!(json["type"], "Map");
        assert_eq!(json["lat"], 51.5);
        assert_eq!(json["lng"], -0.1);
    }

    #[test]
    fn plugin_with_empty_props() {
        let json = r#"{"type": "CustomWidget"}"#;
        let component: Component = serde_json::from_str(json).unwrap();
        match component {
            Component::Plugin(props) => {
                assert_eq!(props.plugin_type, "CustomWidget");
                assert!(props.props.as_object().unwrap().is_empty());
            }
            _ => panic!("expected Plugin"),
        }
    }

    #[test]
    fn plugin_in_component_node() {
        let node = ComponentNode {
            key: "map-1".to_string(),
            component: Component::Plugin(PluginProps {
                plugin_type: "Map".to_string(),
                props: serde_json::json!({"center": [0.0, 0.0]}),
            }),
            action: None,
            visibility: None,
        };
        let json = serde_json::to_string(&node).unwrap();
        let parsed: ComponentNode = serde_json::from_str(&json).unwrap();
        assert_eq!(parsed, node);

        let value = serde_json::to_value(&node).unwrap();
        assert_eq!(value["type"], "Map");
        assert_eq!(value["key"], "map-1");
    }

    #[test]
    fn known_types_not_treated_as_plugin() {
        // All known type names must still deserialize to their specific variants.
        let known_types = [
            "Card",
            "Table",
            "Form",
            "Button",
            "Input",
            "Select",
            "Alert",
            "Badge",
            "Modal",
            "Text",
            "Checkbox",
            "Switch",
            "Separator",
            "DescriptionList",
            "Tabs",
            "Breadcrumb",
            "Pagination",
            "Progress",
            "Avatar",
            "Skeleton",
        ];
        for type_name in &known_types {
            // Construct minimal valid JSON for each type (using the
            // all_component_variants_serialize test data format).
            let json_str = match *type_name {
                "Card" => r#"{"type":"Card","title":"t"}"#,
                "Table" => r#"{"type":"Table","columns":[],"data_path":"/d"}"#,
                "Form" => r#"{"type":"Form","action":{"handler":"h","method":"POST"},"fields":[]}"#,
                "Button" => r#"{"type":"Button","label":"b"}"#,
                "Input" => r#"{"type":"Input","field":"f","label":"l"}"#,
                "Select" => r#"{"type":"Select","field":"f","label":"l","options":[]}"#,
                "Alert" => r#"{"type":"Alert","message":"m"}"#,
                "Badge" => r#"{"type":"Badge","label":"b"}"#,
                "Modal" => r#"{"type":"Modal","id":"modal-t","title":"t"}"#,
                "Text" => r#"{"type":"Text","content":"c"}"#,
                "Checkbox" => r#"{"type":"Checkbox","field":"f","label":"l"}"#,
                "Switch" => r#"{"type":"Switch","field":"f","label":"l"}"#,
                "Separator" => r#"{"type":"Separator"}"#,
                "DescriptionList" => r#"{"type":"DescriptionList","items":[]}"#,
                "Tabs" => r#"{"type":"Tabs","default_tab":"t","tabs":[]}"#,
                "Breadcrumb" => r#"{"type":"Breadcrumb","items":[]}"#,
                "Pagination" => r#"{"type":"Pagination","current_page":1,"per_page":10,"total":0}"#,
                "Progress" => r#"{"type":"Progress","value":0}"#,
                "Avatar" => r#"{"type":"Avatar","alt":"a"}"#,
                "Skeleton" => r#"{"type":"Skeleton"}"#,
                _ => unreachable!(),
            };
            let component: Component = serde_json::from_str(json_str).unwrap();
            assert!(
                !matches!(component, Component::Plugin(_)),
                "type {type_name} should not deserialize as Plugin"
            );
        }
    }

    // ── Serde round-trip tests for 6 new components ──────────────────────

    #[test]
    fn test_stat_card_serde_round_trip() {
        let component = Component::StatCard(StatCardProps {
            label: "Orders".into(),
            value: "42".into(),
            icon: Some("package".into()),
            subtitle: Some("today".into()),
            sse_target: Some("orders_today".into()),
        });
        let json = serde_json::to_string(&component).unwrap();
        assert!(json.contains("\"type\":\"StatCard\""));
        assert!(json.contains("\"sse_target\":\"orders_today\""));
        let deserialized: Component = serde_json::from_str(&json).unwrap();
        assert_eq!(component, deserialized);
    }

    #[test]
    fn test_checklist_serde_round_trip() {
        let component = Component::Checklist(ChecklistProps {
            title: "Getting Started".into(),
            items: vec![
                ChecklistItem {
                    label: "Install dependencies".into(),
                    checked: true,
                    href: None,
                },
                ChecklistItem {
                    label: "Read the docs".into(),
                    checked: false,
                    href: Some("/docs".into()),
                },
            ],
            dismissible: true,
            dismiss_label: Some("Dismiss".into()),
            data_key: Some("onboarding".into()),
        });
        let json = serde_json::to_string(&component).unwrap();
        assert!(json.contains("\"type\":\"Checklist\""));
        assert!(json.contains("\"data_key\":\"onboarding\""));
        let deserialized: Component = serde_json::from_str(&json).unwrap();
        assert_eq!(component, deserialized);
    }

    #[test]
    fn test_toast_serde_round_trip() {
        let component = Component::Toast(ToastProps {
            message: "Operation completed".into(),
            variant: ToastVariant::Success,
            timeout: Some(10),
            dismissible: true,
        });
        let json = serde_json::to_string(&component).unwrap();
        assert!(json.contains("\"type\":\"Toast\""));
        assert!(json.contains("\"timeout\":10"));
        let deserialized: Component = serde_json::from_str(&json).unwrap();
        assert_eq!(component, deserialized);
    }

    #[test]
    fn test_notification_dropdown_serde_round_trip() {
        let component = Component::NotificationDropdown(NotificationDropdownProps {
            notifications: vec![
                NotificationItem {
                    icon: Some("bell".into()),
                    text: "New message".into(),
                    timestamp: Some("2m ago".into()),
                    read: false,
                    action_url: Some("/messages/1".into()),
                },
                NotificationItem {
                    icon: None,
                    text: "Old notification".into(),
                    timestamp: None,
                    read: true,
                    action_url: None,
                },
            ],
            empty_text: Some("No notifications".into()),
        });
        let json = serde_json::to_string(&component).unwrap();
        assert!(json.contains("\"type\":\"NotificationDropdown\""));
        assert!(json.contains("\"empty_text\":\"No notifications\""));
        let deserialized: Component = serde_json::from_str(&json).unwrap();
        assert_eq!(component, deserialized);
    }

    #[test]
    fn test_sidebar_serde_round_trip() {
        let component = Component::Sidebar(SidebarProps {
            fixed_top: vec![SidebarNavItem {
                label: "Dashboard".into(),
                href: "/dashboard".into(),
                icon: Some("home".into()),
                active: true,
            }],
            groups: vec![SidebarGroup {
                label: "Management".into(),
                collapsed: false,
                items: vec![SidebarNavItem {
                    label: "Users".into(),
                    href: "/users".into(),
                    icon: None,
                    active: false,
                }],
            }],
            fixed_bottom: vec![SidebarNavItem {
                label: "Settings".into(),
                href: "/settings".into(),
                icon: Some("gear".into()),
                active: false,
            }],
        });
        let json = serde_json::to_string(&component).unwrap();
        assert!(json.contains("\"type\":\"Sidebar\""));
        assert!(json.contains("\"fixed_top\""));
        let deserialized: Component = serde_json::from_str(&json).unwrap();
        assert_eq!(component, deserialized);
    }

    #[test]
    fn test_header_serde_round_trip() {
        let component = Component::Header(HeaderProps {
            business_name: "Acme Corp".into(),
            notification_count: Some(5),
            user_name: Some("Jane Doe".into()),
            user_avatar: Some("/avatar.jpg".into()),
            logout_url: Some("/logout".into()),
        });
        let json = serde_json::to_string(&component).unwrap();
        assert!(json.contains("\"type\":\"Header\""));
        assert!(json.contains("\"business_name\":\"Acme Corp\""));
        assert!(json.contains("\"notification_count\":5"));
        let deserialized: Component = serde_json::from_str(&json).unwrap();
        assert_eq!(component, deserialized);
    }

    // ── Convenience constructor tests ─────────────────────────────────────

    #[test]
    fn test_stat_card_constructor() {
        let props = StatCardProps {
            label: "Revenue".into(),
            value: "$1,000".into(),
            icon: None,
            subtitle: None,
            sse_target: None,
        };
        let node = ComponentNode::stat_card("revenue-card", props.clone());
        assert_eq!(node.key, "revenue-card");
        assert!(node.action.is_none());
        assert!(node.visibility.is_none());
        assert_eq!(node.component, Component::StatCard(props));
    }

    #[test]
    fn test_checklist_constructor() {
        let props = ChecklistProps {
            title: "Tasks".into(),
            items: vec![],
            dismissible: true,
            dismiss_label: None,
            data_key: None,
        };
        let node = ComponentNode::checklist("task-list", props.clone());
        assert_eq!(node.key, "task-list");
        assert!(node.action.is_none());
        assert!(node.visibility.is_none());
        assert_eq!(node.component, Component::Checklist(props));
    }

    #[test]
    fn test_toast_constructor() {
        let props = ToastProps {
            message: "Done!".into(),
            variant: ToastVariant::Success,
            timeout: None,
            dismissible: true,
        };
        let node = ComponentNode::toast("success-toast", props.clone());
        assert_eq!(node.key, "success-toast");
        assert!(node.action.is_none());
        assert!(node.visibility.is_none());
        assert_eq!(node.component, Component::Toast(props));
    }

    #[test]
    fn test_notification_dropdown_constructor() {
        let props = NotificationDropdownProps {
            notifications: vec![],
            empty_text: Some("All caught up!".into()),
        };
        let node = ComponentNode::notification_dropdown("notifs", props.clone());
        assert_eq!(node.key, "notifs");
        assert!(node.action.is_none());
        assert!(node.visibility.is_none());
        assert_eq!(node.component, Component::NotificationDropdown(props));
    }

    #[test]
    fn test_sidebar_constructor() {
        let props = SidebarProps {
            fixed_top: vec![],
            groups: vec![],
            fixed_bottom: vec![],
        };
        let node = ComponentNode::sidebar("main-nav", props.clone());
        assert_eq!(node.key, "main-nav");
        assert!(node.action.is_none());
        assert!(node.visibility.is_none());
        assert_eq!(node.component, Component::Sidebar(props));
    }

    #[test]
    fn test_header_constructor() {
        let props = HeaderProps {
            business_name: "MyApp".into(),
            notification_count: None,
            user_name: None,
            user_avatar: None,
            logout_url: None,
        };
        let node = ComponentNode::header("page-header", props.clone());
        assert_eq!(node.key, "page-header");
        assert!(node.action.is_none());
        assert!(node.visibility.is_none());
        assert_eq!(node.component, Component::Header(props));
    }

    // ── Sub-type serde tests ─────────────────────────────────────────────

    #[test]
    fn test_checklist_item_round_trip() {
        let checked_item = ChecklistItem {
            label: "Completed task".into(),
            checked: true,
            href: Some("/task/1".into()),
        };
        let json = serde_json::to_string(&checked_item).unwrap();
        let parsed: ChecklistItem = serde_json::from_str(&json).unwrap();
        assert_eq!(parsed, checked_item);

        let unchecked_item = ChecklistItem {
            label: "Pending task".into(),
            checked: false,
            href: None,
        };
        let json = serde_json::to_string(&unchecked_item).unwrap();
        let parsed: ChecklistItem = serde_json::from_str(&json).unwrap();
        assert_eq!(parsed, unchecked_item);
        // href is None — should be omitted
        assert!(!json.contains("href"));
    }

    #[test]
    fn test_sidebar_group_round_trip() {
        let expanded = SidebarGroup {
            label: "Main".into(),
            collapsed: false,
            items: vec![
                SidebarNavItem {
                    label: "Home".into(),
                    href: "/".into(),
                    icon: Some("home".into()),
                    active: true,
                },
                SidebarNavItem {
                    label: "About".into(),
                    href: "/about".into(),
                    icon: None,
                    active: false,
                },
            ],
        };
        let json = serde_json::to_string(&expanded).unwrap();
        let parsed: SidebarGroup = serde_json::from_str(&json).unwrap();
        assert_eq!(parsed, expanded);
        assert_eq!(parsed.items.len(), 2);

        let collapsed = SidebarGroup {
            label: "Advanced".into(),
            collapsed: true,
            items: vec![],
        };
        let json = serde_json::to_string(&collapsed).unwrap();
        let parsed: SidebarGroup = serde_json::from_str(&json).unwrap();
        assert_eq!(parsed, collapsed);
        assert!(parsed.collapsed);
    }

    #[test]
    fn test_notification_item_round_trip() {
        let unread = NotificationItem {
            icon: Some("mail".into()),
            text: "You have a new message".into(),
            timestamp: Some("5m ago".into()),
            read: false,
            action_url: Some("/messages/42".into()),
        };
        let json = serde_json::to_string(&unread).unwrap();
        let parsed: NotificationItem = serde_json::from_str(&json).unwrap();
        assert_eq!(parsed, unread);
        assert!(!parsed.read);

        let read_notif = NotificationItem {
            icon: None,
            text: "Welcome to the platform".into(),
            timestamp: None,
            read: true,
            action_url: None,
        };
        let json = serde_json::to_string(&read_notif).unwrap();
        let parsed: NotificationItem = serde_json::from_str(&json).unwrap();
        assert_eq!(parsed, read_notif);
        assert!(parsed.read);
        // Optional fields with None should be omitted
        assert!(!json.contains("\"icon\""));
        assert!(!json.contains("\"action_url\""));
    }

    // ── Edge case tests ──────────────────────────────────────────────────

    #[test]
    fn test_stat_card_all_optionals_none() {
        let component = Component::StatCard(StatCardProps {
            label: "Count".into(),
            value: "0".into(),
            icon: None,
            subtitle: None,
            sse_target: None,
        });
        let json = serde_json::to_string(&component).unwrap();
        assert!(json.contains("\"type\":\"StatCard\""));
        assert!(!json.contains("\"icon\""));
        assert!(!json.contains("\"subtitle\""));
        assert!(!json.contains("\"sse_target\""));
        let deserialized: Component = serde_json::from_str(&json).unwrap();
        assert_eq!(component, deserialized);
    }

    #[test]
    fn test_checklist_empty_items() {
        let component = Component::Checklist(ChecklistProps {
            title: "Empty List".into(),
            items: vec![],
            dismissible: true,
            dismiss_label: None,
            data_key: None,
        });
        let json = serde_json::to_string(&component).unwrap();
        assert!(json.contains("\"type\":\"Checklist\""));
        let deserialized: Component = serde_json::from_str(&json).unwrap();
        assert_eq!(component, deserialized);
        match &deserialized {
            Component::Checklist(props) => assert!(props.items.is_empty()),
            _ => panic!("expected Checklist"),
        }
    }

    #[test]
    fn test_sidebar_empty_groups_and_fixed() {
        let component = Component::Sidebar(SidebarProps {
            fixed_top: vec![],
            groups: vec![],
            fixed_bottom: vec![],
        });
        let json = serde_json::to_string(&component).unwrap();
        assert!(json.contains("\"type\":\"Sidebar\""));
        // Empty vecs should be omitted (skip_serializing_if = "Vec::is_empty")
        assert!(!json.contains("\"fixed_top\""));
        assert!(!json.contains("\"groups\""));
        assert!(!json.contains("\"fixed_bottom\""));
        let deserialized: Component = serde_json::from_str(&json).unwrap();
        assert_eq!(component, deserialized);
    }

    #[test]
    fn test_notification_dropdown_empty_uses_empty_text() {
        let component = Component::NotificationDropdown(NotificationDropdownProps {
            notifications: vec![],
            empty_text: Some("Nothing here!".into()),
        });
        let json = serde_json::to_string(&component).unwrap();
        assert!(json.contains("\"type\":\"NotificationDropdown\""));
        assert!(json.contains("\"empty_text\":\"Nothing here!\""));
        let deserialized: Component = serde_json::from_str(&json).unwrap();
        assert_eq!(component, deserialized);
    }

    // ── Optional field skip_serializing tests ────────────────────────────

    #[test]
    fn test_stat_card_omits_sse_target_when_none() {
        let component = Component::StatCard(StatCardProps {
            label: "Revenue".into(),
            value: "$500".into(),
            icon: None,
            subtitle: None,
            sse_target: None,
        });
        let json = serde_json::to_string(&component).unwrap();
        assert!(
            !json.contains("sse_target"),
            "sse_target must be omitted when None"
        );
    }

    // ── Grid tests ────────────────────────────────────────────────────

    #[test]
    fn grid_round_trips() {
        let grid = Component::Grid(GridProps {
            columns: 3,
            md_columns: None,
            lg_columns: None,
            gap: GapSize::Lg,
            scrollable: None,
            children: vec![ComponentNode::text(
                "t",
                TextProps {
                    content: "cell".into(),
                    element: TextElement::P,
                },
            )],
        });
        let json = serde_json::to_value(&grid).unwrap();
        assert_eq!(json["type"], "Grid");
        assert_eq!(json["columns"], 3);
        assert_eq!(json["gap"], "lg");
        let parsed: Component = serde_json::from_value(json).unwrap();
        assert_eq!(parsed, grid);
    }

    #[test]
    fn grid_defaults() {
        let json = serde_json::json!({"type": "Grid"});
        let parsed: Component = serde_json::from_value(json).unwrap();
        match parsed {
            Component::Grid(props) => {
                assert_eq!(props.columns, 2);
                assert_eq!(props.gap, GapSize::Md);
                assert!(props.children.is_empty());
            }
            _ => panic!("expected Grid"),
        }
    }

    // ── Collapsible tests ────────────────────────────────────────────

    #[test]
    fn collapsible_round_trips() {
        let c = Component::Collapsible(CollapsibleProps {
            title: "Details".into(),
            expanded: true,
            children: vec![],
        });
        let json = serde_json::to_value(&c).unwrap();
        assert_eq!(json["type"], "Collapsible");
        assert_eq!(json["title"], "Details");
        assert_eq!(json["expanded"], true);
        let parsed: Component = serde_json::from_value(json).unwrap();
        assert_eq!(parsed, c);
    }

    // ── EmptyState tests ─────────────────────────────────────────────

    #[test]
    fn empty_state_round_trips() {
        let es = Component::EmptyState(EmptyStateProps {
            title: "No items".into(),
            description: Some("Create one".into()),
            action: Some(Action::get("items.create")),
            action_label: Some("New item".into()),
        });
        let json = serde_json::to_value(&es).unwrap();
        assert_eq!(json["type"], "EmptyState");
        assert_eq!(json["title"], "No items");
        let parsed: Component = serde_json::from_value(json).unwrap();
        assert_eq!(parsed, es);
    }

    #[test]
    fn empty_state_minimal() {
        let json = serde_json::json!({"type": "EmptyState", "title": "Nothing"});
        let parsed: Component = serde_json::from_value(json).unwrap();
        match parsed {
            Component::EmptyState(props) => {
                assert_eq!(props.title, "Nothing");
                assert!(props.description.is_none());
                assert!(props.action.is_none());
                assert!(props.action_label.is_none());
            }
            _ => panic!("expected EmptyState"),
        }
    }

    // ── FormSection tests ────────────────────────────────────────────

    #[test]
    fn form_section_round_trips() {
        let fs = Component::FormSection(FormSectionProps {
            title: "Contact".into(),
            description: Some("Your details".into()),
            children: vec![],
            layout: None,
        });
        let json = serde_json::to_value(&fs).unwrap();
        assert_eq!(json["type"], "FormSection");
        assert_eq!(json["title"], "Contact");
        let parsed: Component = serde_json::from_value(json).unwrap();
        assert_eq!(parsed, fs);
    }

    // ── Switch action tests ──────────────────────────────────────────

    #[test]
    fn switch_with_action_round_trips() {
        let sw = Component::Switch(SwitchProps {
            field: "active".into(),
            label: "Active".into(),
            description: None,
            checked: Some(true),
            data_path: None,
            required: None,
            disabled: None,
            error: None,
            action: Some(Action::new("settings.toggle")),
            compact: false,
        });
        let json = serde_json::to_value(&sw).unwrap();
        assert!(json["action"].is_object());
        assert_eq!(json["action"]["handler"], "settings.toggle");
        let parsed: Component = serde_json::from_value(json).unwrap();
        assert_eq!(parsed, sw);
    }

    #[test]
    fn switch_without_action_omits_field() {
        let sw = Component::Switch(SwitchProps {
            field: "f".into(),
            label: "l".into(),
            description: None,
            checked: None,
            data_path: None,
            required: None,
            disabled: None,
            error: None,
            action: None,
            compact: false,
        });
        let json = serde_json::to_string(&sw).unwrap();
        assert!(!json.contains("\"action\""));
    }

    #[test]
    fn test_toast_omits_timeout_when_none() {
        let component = Component::Toast(ToastProps {
            message: "Hello".into(),
            variant: ToastVariant::Info,
            timeout: None,
            dismissible: false,
        });
        let json = serde_json::to_string(&component).unwrap();
        assert!(
            !json.contains("\"timeout\""),
            "timeout must be omitted when None"
        );
    }

    #[test]
    fn page_header_round_trip_title_only() {
        let component = Component::PageHeader(PageHeaderProps {
            title: "Test Title".to_string(),
            breadcrumb: vec![],
            actions: vec![],
        });
        let json = serde_json::to_value(&component).unwrap();
        assert_eq!(json["type"], "PageHeader");
        assert_eq!(json["title"], "Test Title");
        // Empty vecs are omitted.
        assert!(json.get("breadcrumb").is_none());
        assert!(json.get("actions").is_none());
        let parsed: Component = serde_json::from_value(json).unwrap();
        assert_eq!(parsed, component);
    }

    #[test]
    fn page_header_round_trip_with_breadcrumb_and_actions() {
        let component = Component::PageHeader(PageHeaderProps {
            title: "Users".to_string(),
            breadcrumb: vec![
                BreadcrumbItem {
                    label: "Home".to_string(),
                    url: Some("/".to_string()),
                },
                BreadcrumbItem {
                    label: "Users".to_string(),
                    url: None,
                },
            ],
            actions: vec![ComponentNode {
                key: "add-btn".to_string(),
                component: Component::Button(ButtonProps {
                    label: "Add User".to_string(),
                    variant: ButtonVariant::Default,
                    size: Size::Default,
                    disabled: None,
                    icon: None,
                    icon_position: None,
                    button_type: None,
                }),
                action: None,
                visibility: None,
            }],
        });
        let json = serde_json::to_string(&component).unwrap();
        let parsed: Component = serde_json::from_str(&json).unwrap();
        assert_eq!(parsed, component);
        // Verify type field present.
        let value = serde_json::to_value(&component).unwrap();
        assert_eq!(value["type"], "PageHeader");
        assert_eq!(value["title"], "Users");
        assert!(value["breadcrumb"].is_array());
        assert!(value["actions"].is_array());
    }

    #[test]
    fn page_header_deserialize_from_json() {
        let json = r#"{"type":"PageHeader","title":"Test"}"#;
        let component: Component = serde_json::from_str(json).unwrap();
        match component {
            Component::PageHeader(props) => {
                assert_eq!(props.title, "Test");
                assert!(props.breadcrumb.is_empty());
                assert!(props.actions.is_empty());
            }
            _ => panic!("expected PageHeader"),
        }
    }

    #[test]
    fn button_group_round_trip_empty() {
        let component = Component::ButtonGroup(ButtonGroupProps { buttons: vec![] });
        let json = serde_json::to_value(&component).unwrap();
        assert_eq!(json["type"], "ButtonGroup");
        // Empty vec omitted.
        assert!(json.get("buttons").is_none());
        let parsed: Component = serde_json::from_value(json).unwrap();
        assert_eq!(parsed, component);
    }

    #[test]
    fn button_group_round_trip_with_buttons() {
        let component = Component::ButtonGroup(ButtonGroupProps {
            buttons: vec![
                ComponentNode {
                    key: "save".to_string(),
                    component: Component::Button(ButtonProps {
                        label: "Save".to_string(),
                        variant: ButtonVariant::Default,
                        size: Size::Default,
                        disabled: None,
                        icon: None,
                        icon_position: None,
                        button_type: None,
                    }),
                    action: None,
                    visibility: None,
                },
                ComponentNode {
                    key: "cancel".to_string(),
                    component: Component::Button(ButtonProps {
                        label: "Cancel".to_string(),
                        variant: ButtonVariant::Outline,
                        size: Size::Default,
                        disabled: None,
                        icon: None,
                        icon_position: None,
                        button_type: None,
                    }),
                    action: None,
                    visibility: None,
                },
            ],
        });
        let json = serde_json::to_string(&component).unwrap();
        let parsed: Component = serde_json::from_str(&json).unwrap();
        assert_eq!(parsed, component);
        let value = serde_json::to_value(&component).unwrap();
        assert_eq!(value["type"], "ButtonGroup");
        assert!(value["buttons"].is_array());
        assert_eq!(value["buttons"].as_array().unwrap().len(), 2);
    }

    #[test]
    fn button_group_deserialize_from_json() {
        let json = r#"{"type":"ButtonGroup","buttons":[]}"#;
        let component: Component = serde_json::from_str(json).unwrap();
        match component {
            Component::ButtonGroup(props) => {
                assert!(props.buttons.is_empty());
            }
            _ => panic!("expected ButtonGroup"),
        }
    }

    #[test]
    fn image_round_trips() {
        let json = r#"{"type": "Image", "src": "/img/s.png", "alt": "Screenshot"}"#;
        let component: Component = serde_json::from_str(json).unwrap();
        match component {
            Component::Image(props) => {
                assert_eq!(props.src, "/img/s.png");
                assert_eq!(props.alt, "Screenshot");
                assert!(props.aspect_ratio.is_none());
            }
            _ => panic!("expected Image"),
        }
    }

    #[test]
    fn all_known_types_round_trip() {
        let known_types: &[(&str, &str)] = &[
            ("Alert", r#"{"type":"Alert","message":"m"}"#),
            ("Avatar", r#"{"type":"Avatar","alt":"a"}"#),
            ("Badge", r#"{"type":"Badge","label":"b"}"#),
            ("Breadcrumb", r#"{"type":"Breadcrumb","items":[]}"#),
            ("Button", r#"{"type":"Button","label":"b"}"#),
            ("CalendarCell", r#"{"type":"CalendarCell","day":1}"#),
            ("Checkbox", r#"{"type":"Checkbox","field":"f","label":"l"}"#),
            ("Image", r#"{"type":"Image","src":"/img/s.png","alt":"a"}"#),
            ("Input", r#"{"type":"Input","field":"f","label":"l"}"#),
            (
                "Pagination",
                r#"{"type":"Pagination","current_page":1,"per_page":10,"total":0}"#,
            ),
            ("Progress", r#"{"type":"Progress","value":50}"#),
            (
                "Select",
                r#"{"type":"Select","field":"f","label":"l","options":[]}"#,
            ),
            ("Separator", r#"{"type":"Separator"}"#),
            ("Skeleton", r#"{"type":"Skeleton"}"#),
            ("Text", r#"{"type":"Text","content":"c"}"#),
        ];
        for (type_name, json_str) in known_types {
            let component: Component = serde_json::from_str(json_str)
                .unwrap_or_else(|e| panic!("failed to parse {type_name}: {e}"));
            let serialized = serde_json::to_value(&component).unwrap();
            assert_eq!(
                serialized["type"], *type_name,
                "type mismatch for {type_name}"
            );
            let reparsed: Component = serde_json::from_value(serialized)
                .unwrap_or_else(|e| panic!("failed to reparse {type_name}: {e}"));
            assert_eq!(
                serde_json::to_value(&reparsed).unwrap()["type"],
                *type_name,
                "round-trip type mismatch for {type_name}"
            );
        }
    }
}

#[cfg(test)]
mod key_value_editor_tests {
    use super::*;
    use serde_json::json;

    #[test]
    fn key_value_editor_serde_roundtrip() {
        let original = Component::KeyValueEditor(KeyValueEditorProps {
            field: "metadata".to_string(),
            label: Some("Metadata".to_string()),
            suggested_keys: vec!["env".to_string(), "region".to_string()],
            allow_custom_keys: false,
            data_path: Some("/meta".to_string()),
            error: Some("required".to_string()),
        });

        let serialized =
            serde_json::to_value(&original).expect("serialize KeyValueEditor component");

        // Tagged serialization must inject "type": "KeyValueEditor".
        assert_eq!(
            serialized.get("type").and_then(|v| v.as_str()),
            Some("KeyValueEditor"),
            "serialized form must have type=KeyValueEditor: {serialized}"
        );
        assert_eq!(
            serialized.get("field").and_then(|v| v.as_str()),
            Some("metadata")
        );
        assert_eq!(
            serialized
                .get("allow_custom_keys")
                .and_then(|v| v.as_bool()),
            Some(false)
        );

        // Round-trip: deserialize back into Component, assert structural equality.
        let deserialized: Component =
            serde_json::from_value(serialized).expect("deserialize KeyValueEditor component");
        match deserialized {
            Component::KeyValueEditor(ref p) => {
                assert_eq!(p.field, "metadata");
                assert_eq!(p.label.as_deref(), Some("Metadata"));
                assert_eq!(
                    p.suggested_keys,
                    vec!["env".to_string(), "region".to_string()]
                );
                assert!(!p.allow_custom_keys);
                assert_eq!(p.data_path.as_deref(), Some("/meta"));
                assert_eq!(p.error.as_deref(), Some("required"));
            }
            other => panic!("expected KeyValueEditor, got {other:?}"),
        }
        assert_eq!(original, deserialized, "PartialEq round-trip failed");
    }

    #[test]
    fn key_value_editor_allow_custom_keys_defaults_to_true() {
        // Serde default: when allow_custom_keys is absent from JSON input, it must be true.
        let json_input = json!({
            "type": "KeyValueEditor",
            "field": "meta",
        });
        let parsed: Component =
            serde_json::from_value(json_input).expect("deserialize minimal KeyValueEditor");
        match parsed {
            Component::KeyValueEditor(p) => {
                assert!(
                    p.allow_custom_keys,
                    "allow_custom_keys default must be true"
                );
                assert!(
                    p.suggested_keys.is_empty(),
                    "suggested_keys default must be empty"
                );
                assert!(p.label.is_none());
                assert!(p.data_path.is_none());
                assert!(p.error.is_none());
            }
            other => panic!("expected KeyValueEditor, got {other:?}"),
        }
    }
}

#[cfg(test)]
mod detail_form_tests {
    use super::*;
    use crate::action::{Action, HttpMethod};
    use serde_json::json;

    // ── EditMode (D-01, D-02) ─────────────────────────────────────────────

    #[test]
    fn edit_mode_default_is_view() {
        assert_eq!(EditMode::default(), EditMode::View);
    }

    #[test]
    fn edit_mode_from_query_exact_edit() {
        assert_eq!(EditMode::from_query(Some("edit")), EditMode::Edit);
    }

    #[test]
    fn edit_mode_from_query_case_insensitive_upper() {
        assert_eq!(EditMode::from_query(Some("EDIT")), EditMode::Edit);
    }

    #[test]
    fn edit_mode_from_query_case_insensitive_mixed() {
        assert_eq!(EditMode::from_query(Some("eDiT")), EditMode::Edit);
    }

    #[test]
    fn edit_mode_from_query_title_case() {
        assert_eq!(EditMode::from_query(Some("Edit")), EditMode::Edit);
    }

    #[test]
    fn edit_mode_from_query_none_is_view() {
        assert_eq!(EditMode::from_query(None), EditMode::View);
    }

    #[test]
    fn edit_mode_from_query_empty_is_view() {
        assert_eq!(EditMode::from_query(Some("")), EditMode::View);
    }

    #[test]
    fn edit_mode_from_query_view_literal_is_view() {
        assert_eq!(EditMode::from_query(Some("view")), EditMode::View);
    }

    #[test]
    fn edit_mode_from_query_unknown_is_view() {
        assert_eq!(EditMode::from_query(Some("anything-else")), EditMode::View);
    }

    #[test]
    fn edit_mode_serializes_as_snake_case() {
        assert_eq!(
            serde_json::to_value(EditMode::Edit).expect("serialize Edit"),
            json!("edit")
        );
        assert_eq!(
            serde_json::to_value(EditMode::View).expect("serialize View"),
            json!("view")
        );
        let parsed_edit: EditMode =
            serde_json::from_value(json!("edit")).expect("deserialize 'edit'");
        assert_eq!(parsed_edit, EditMode::Edit);
        let parsed_view: EditMode =
            serde_json::from_value(json!("view")).expect("deserialize 'view'");
        assert_eq!(parsed_view, EditMode::View);
    }

    // ── DetailFormProps serde (D-03, D-04, D-17, D-19) ────────────────────

    fn sample_detail_form_props() -> DetailFormProps {
        DetailFormProps {
            mode: EditMode::Edit,
            action: Action {
                handler: "users.update".to_string(),
                url: Some("/users/1".to_string()),
                method: HttpMethod::Put,
                confirm: None,
                on_success: None,
                on_error: None,
                target: None,
            },
            fields: vec![
                DetailField {
                    label: "Name".to_string(),
                    value: "Ada".to_string(),
                    input: ComponentNode::input(
                        "name",
                        InputProps {
                            field: "name".to_string(),
                            label: "".to_string(),
                            input_type: InputType::Text,
                            placeholder: None,
                            required: None,
                            disabled: None,
                            error: None,
                            description: None,
                            default_value: None,
                            data_path: None,
                            step: None,
                            list: None,
                        },
                    ),
                },
                DetailField {
                    label: "Email".to_string(),
                    value: "ada@example.com".to_string(),
                    input: ComponentNode::input(
                        "email",
                        InputProps {
                            field: "email".to_string(),
                            label: "".to_string(),
                            input_type: InputType::Email,
                            placeholder: None,
                            required: None,
                            disabled: None,
                            error: None,
                            description: None,
                            default_value: None,
                            data_path: None,
                            step: None,
                            list: None,
                        },
                    ),
                },
            ],
            edit_url: "/users/1?mode=edit".to_string(),
            cancel_url: "/users/1".to_string(),
            edit_label: Some("Modifica".to_string()),
            save_label: Some("Salva".to_string()),
            cancel_label: Some("Annulla".to_string()),
            method: Some(HttpMethod::Put),
        }
    }

    #[test]
    fn detail_form_props_serde_roundtrip() {
        let original = Component::DetailForm(sample_detail_form_props());
        let serialized = serde_json::to_value(&original).expect("serialize DetailForm component");
        assert_eq!(
            serialized.get("type").and_then(|v| v.as_str()),
            Some("DetailForm"),
            "serialized form must have type=DetailForm: {serialized}"
        );
        let deserialized: Component =
            serde_json::from_value(serialized).expect("deserialize DetailForm component");
        assert_eq!(original, deserialized, "PartialEq round-trip failed");
    }

    #[test]
    fn detail_form_props_omits_optional_nones() {
        let props = DetailFormProps {
            mode: EditMode::View,
            action: Action {
                handler: "x".to_string(),
                url: None,
                method: HttpMethod::Post,
                confirm: None,
                on_success: None,
                on_error: None,
                target: None,
            },
            fields: Vec::new(),
            edit_url: "/x?mode=edit".to_string(),
            cancel_url: "/x".to_string(),
            edit_label: None,
            save_label: None,
            cancel_label: None,
            method: None,
        };
        let v = serde_json::to_value(&props).expect("serialize");
        assert!(
            v.get("edit_label").is_none(),
            "edit_label=None must be skipped, got: {v}"
        );
        assert!(
            v.get("save_label").is_none(),
            "save_label=None must be skipped"
        );
        assert!(
            v.get("cancel_label").is_none(),
            "cancel_label=None must be skipped"
        );
        assert!(v.get("method").is_none(), "method=None must be skipped");
    }

    #[test]
    fn detail_form_props_defaults_mode_to_view() {
        let v = json!({
            "action": {"handler": "x", "method": "POST"},
            "fields": [],
            "edit_url": "/x?mode=edit",
            "cancel_url": "/x"
        });
        let props: DetailFormProps =
            serde_json::from_value(v).expect("deserialize DetailFormProps without mode");
        assert_eq!(
            props.mode,
            EditMode::View,
            "missing 'mode' must default to View"
        );
    }

    // ── ComponentNode::detail_form factory (D-18) ─────────────────────────

    #[test]
    fn component_node_detail_form_factory_shape() {
        let node = ComponentNode::detail_form("details", sample_detail_form_props());
        assert_eq!(node.key, "details");
        assert!(node.action.is_none());
        assert!(node.visibility.is_none());
        assert!(
            matches!(node.component, Component::DetailForm(_)),
            "expected Component::DetailForm variant"
        );
    }
}