fraiseql-cli 2.19.1

//! Query and mutation operation definitions for TOML schema.

use serde::{Deserialize, Serialize};

use super::types::ArgumentDefinition;

/// What the compiler does about the order a paginated read's pages are cut in
/// (#1303).
///
/// An offset page is a slice of a *sequence*, and a read with no `ORDER BY` is not
/// a sequence — two pages of the same relation can overlap and skip rows, under a
/// `200`. The deployment-wide answer is here; a query overrides it with its own
/// `pagination_order`.
///
/// # Why all three are compile-time
///
/// #1303 framed the strict posture as a request-time `400`, because it framed the
/// ordering as a request property. It is not one: since the order is recorded per
/// query in the compiled schema, every posture resolves into what the compiler
/// writes there, and a second switch at runtime would be a second place the answer
/// lives — free to disagree with the artifact that is supposed to *be* the answer.
/// Refusing at compile time is also strictly earlier than refusing at request time.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Default, Deserialize, Serialize)]
#[serde(rename_all = "snake_case", deny_unknown_fields)]
pub enum PaginationPosture {
    /// Every paginating query gets the entity identity, and an author may declare
    /// `pagination_order = "none"` to keep a self-ordering view's own `ORDER BY`.
    ///
    /// The default, and the founder decision of 2026-09-08: the boilerplate of a
    /// must-declare rule is a permanent tax on every paginated query written from
    /// now on, while the identity default's cost is bounded, measured (1.7–7.7×
    /// on unordered paginated reads) and recoverable by one declaration in the
    /// minority of cases where it is wrong.
    #[default]
    Identity,
    /// As [`Identity`](Self::Identity), and `pagination_order = "none"` is refused.
    ///
    /// #1303's option 1, kept as a posture rather than a default: in this
    /// deployment every paginated read has a total order and there are no
    /// exceptions, including the self-ordering-view one. The refusal is a compile
    /// error naming the query, not a `400` a client discovers.
    Refuse,
    /// Derive nothing: a query is ordered only where its author declared a column.
    ///
    /// The pre-#1303 behaviour, kept because this release changes what an
    /// unordered paginated read returns and an operator may need the old answer
    /// while their clients catch up. It restores the defect with it — which is why
    /// the compile warns for every query it leaves unordered.
    Allow,
}

/// Global defaults for list-query auto-params.
///
/// Applied when a per-query `auto_params` does not specify a given flag.
/// Relay queries and single-item queries are never affected.
///
/// ```toml
/// [query_defaults]
/// where            = true
/// order_by         = true
/// limit            = false  # e.g. Relay-first project
/// offset           = false
/// pagination_order = "identity"
/// ```
#[derive(Debug, Clone, Deserialize, Serialize)]
#[serde(default, deny_unknown_fields)]
pub struct QueryDefaults {
    /// Enable automatic `where` filter parameter (default: true)
    #[serde(rename = "where", default = "default_true")]
    pub where_clause:     bool,
    /// Enable automatic `order_by` parameter (default: true)
    #[serde(default = "default_true")]
    pub order_by:         bool,
    /// Enable automatic `limit` parameter (default: true)
    #[serde(default = "default_true")]
    pub limit:            bool,
    /// Enable automatic `offset` parameter (default: true)
    #[serde(default = "default_true")]
    pub offset:           bool,
    /// What the compiler does about the order paginated reads are cut in (#1303).
    ///
    /// ```toml
    /// [query_defaults]
    /// pagination_order = "identity"  # default | "refuse" | "allow"
    /// ```
    #[serde(default)]
    pub pagination_order: PaginationPosture,
}

impl Default for QueryDefaults {
    fn default() -> Self {
        Self {
            where_clause:     true,
            order_by:         true,
            limit:            true,
            offset:           true,
            pagination_order: PaginationPosture::Identity,
        }
    }
}

fn default_true() -> bool {
    true
}

/// Schema metadata
#[derive(Debug, Clone, Deserialize, Serialize)]
#[serde(default, deny_unknown_fields)]
pub struct SchemaMetadata {
    /// Schema name
    pub name:            String,
    /// Schema version
    pub version:         String,
    /// Optional schema description
    pub description:     Option<String>,
    /// Target database. Only `postgresql` is accepted: MySQL, SQLite and SQL Server
    /// were removed in v2.15.0 (#374), and [`Self::validate_database_target`] refuses
    /// them rather than compiling PostgreSQL SQL under a target the engine cannot serve.
    pub database_target: String,
}

impl SchemaMetadata {
    /// Refuse a `database_target` other than `postgresql` (see
    /// `config::validate_database_target`, shared with `[project] database_target`).
    ///
    /// # Errors
    ///
    /// Returns an error naming the removed backends and `docs/database-compatibility.md`
    /// when the target is anything but `postgresql` (compared case-insensitively).
    pub fn validate_database_target(&self) -> anyhow::Result<()> {
        crate::config::validate_database_target("[schema]", &self.database_target)
    }
}

impl Default for SchemaMetadata {
    fn default() -> Self {
        Self {
            name:            "myapp".to_string(),
            version:         "1.0.0".to_string(),
            description:     None,
            database_target: "postgresql".to_string(),
        }
    }
}

/// Query definition in TOML
#[derive(Debug, Clone, Deserialize, Serialize)]
#[serde(default, deny_unknown_fields)]
pub struct QueryDefinition {
    /// Return type name
    pub return_type:  String,
    /// Whether query returns an array
    #[serde(default)]
    pub return_array: bool,
    /// SQL source for the query
    pub sql_source:   String,
    /// Query description
    pub description:  Option<String>,
    /// Query arguments
    pub args:         Vec<ArgumentDefinition>,
}

impl Default for QueryDefinition {
    fn default() -> Self {
        Self {
            return_type:  "String".to_string(),
            return_array: false,
            sql_source:   "v_entity".to_string(),
            description:  None,
            args:         vec![],
        }
    }
}

/// Mutation definition in TOML
#[derive(Debug, Clone, Deserialize, Serialize)]
#[serde(default, deny_unknown_fields)]
pub struct MutationDefinition {
    /// Return type name
    pub return_type:         String,
    /// SQL function or procedure source.
    ///
    /// When absent, the compiler resolves the function name from the `[crud]`
    /// naming config using the `operation` and the entity name derived from
    /// `return_type`. A compile error is emitted if both are missing.
    #[serde(skip_serializing_if = "Option::is_none")]
    pub sql_source:          Option<String>,
    /// Operation type (CREATE, UPDATE, DELETE)
    pub operation:           String,
    /// How the GraphQL `input` argument is passed to the SQL function:
    /// `"flatten"` (positional columns, the default) or `"jsonb"` (the whole
    /// input as one `jsonb` arg).
    ///
    /// Orthogonal to `operation`: set `"jsonb"` so a backend using the
    /// single-`jsonb`-wrapper convention can register the real DML verb and
    /// still receive the whole input as one argument — letting the Change Spine
    /// record the true `modification_type`. Defaults to `"flatten"`.
    #[serde(default = "default_input_style")]
    pub input_style:         String,
    /// Whether a successful, state-changing run of this mutation also records the
    /// changed entity's pre-image (before-state) into the Change-Spine
    /// `object_data_before` column, sourced from an optional `entity_before` on the
    /// mutation's `app.mutation_response`.
    ///
    /// Set `true` to opt an audit-sensitive mutation into an inline Debezium-style
    /// `{before, after}` on the single change event. Defaults to `false`,
    /// byte-identical to a schema authored before this field existed.
    #[serde(default)]
    pub changelog_pre_image: bool,
    /// Whether this mutation exposes the typed graphql-cascade `cascade` field
    /// on its success payload.
    ///
    /// Set `true` to expose a typed, selection-gated `cascade` (mutation
    /// responses carrying all affected entities per the graphql-cascade spec),
    /// projected to camelCase and field-authorized per entity. Defaults to
    /// `false`, byte-identical to a schema authored before this field existed.
    #[serde(default)]
    pub cascade:             bool,
    /// Mutation description
    pub description:         Option<String>,
    /// Mutation arguments
    pub args:                Vec<ArgumentDefinition>,
}

impl Default for MutationDefinition {
    fn default() -> Self {
        Self {
            return_type:         "String".to_string(),
            sql_source:          None,
            operation:           "CREATE".to_string(),
            input_style:         default_input_style(),
            changelog_pre_image: false,
            cascade:             false,
            description:         None,
            args:                vec![],
        }
    }
}

/// Serde default for [`MutationDefinition::input_style`]: positional flatten.
fn default_input_style() -> String {
    "flatten".to_string()
}