BREP_app 0.4.0

//! Display-settings panel — the schema-driven settings form. Drawn as a
//! FLOATING window (movable + resizable [`egui::Window`], toggled from the
//! toolbar gear ⚙ button), mirroring the Properties window: a `pub open` flag the
//! toolbar binds + a ctx-level `show(&mut self, ctx, state, store)` the shell
//! calls after the panels. The panel OWNS only its transient UI state (which
//! nodes are open); `EngineState` stays the single brain, borrowed in.
//!
//! # Model colours are NOT set here
//!
//! A body's or face's colour is a durable `color` METADATA attribute, set in the
//! Info window and saved with the document. This panel carries only the display
//! switch over it — `Faces ▸ Override model colors`, an ordinary schema `Bool`
//! that makes the viewport ignore those colours without touching them. The old
//! `Per-Solid Colors` tab wrote a transient override that no document ever
//! stored and any feature edit threw away; it is gone.
//!
//! # One TAB per section, each drawn as a tree
//!
//! The window opens on a tab strip ([`Tab`], the Info window's `selectable_value`
//! strip) — `Display` / `Assemblies` — and draws exactly ONE section below it. Each section is still the SAME connector-line `[+]/[-]` tree
//! the feature history and Scene panels use (the shared [`tree`] node helper), so
//! the whole app reads as one system:
//!   * `Display` → `[-] Display settings` (root) → one collapsible BRANCH per
//!     schema group (`Scene`, `Faces`, `Edges`, …) → one LEAF per field, whose
//!     node label is the field label and whose right-aligned content is the field
//!     input ([`form::field_input`], EXACTLY like the feature tree's
//!     `schema_field`).
//!   * `Assemblies` → `[-] Assemblies` (root) → the BOM column configuration.
//! Group open-state is tracked on the panel (default open). Every ROOT defaults
//! OPEN too: the roots that used to default collapsed did so only because they
//! shared one scroll — a tab whose entire content is one `[+]` row is not
//! worth the click.
//!
//! Only the ACTIVE tab's widget rects are published to `__brepSettingsHit`, since
//! `hits` is rebuilt each frame from what was actually drawn.

use crate::automation::hit_keys::HitKeyDoc;
use crate::form;
use crate::panels::bom_columns;
use crate::panels::tree::{self, TreeRow};
use crate::store::{ModelStore, SETTINGS_KEY};
use brep_render::engine_state::EngineState;
use brep_render::style::{settings_form_fields, FormField, RenderSettings};
use eframe::egui;
use serde_json::Value;
use std::collections::{HashMap, HashSet};

/// The amber a BOM-column parse problem is listed in — the status map's
/// warning amber, the same one the structure tree's outdated badge uses. A
/// problem is a note about ONE line, not a failure, so it is not error red.
const PROBLEM_AMBER: egui::Color32 = egui::Color32::from_rgb(0xff, 0x9f, 0x0a);

/// The tabs of the Settings window — one per section. Each draws its own tree;
/// nothing is shared between them but the window.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum Tab {
    /// The schema-driven render settings.
    Display,
    /// Assembly-wide configuration (today: the BOM's columns).
    Assemblies,
}

/// The display-settings panel's own transient UI state. It holds NO model state:
/// the settings buffer is re-seeded from the live engine each frame (see
/// [`SettingsPanel::settings_section`]).
pub struct SettingsPanel {
    /// Whether the floating window is shown. Toggled by the toolbar gear button
    /// and by the window's own close (`×`) button; public so the toolbar can bind
    /// it.
    pub open: bool,
    /// Per-frame egui widget screen rects (keyed `tab:<name>` / `field:<key>` /
    /// `group:<name>` / …), published to JS for the headed verifier. Rebuilt every
    /// frame, so it holds only the ACTIVE tab's widgets.
    hits: HashMap<String, egui::Rect>,
    /// Which tab is shown. Defaults to `Display`, the tab the window has always
    /// opened on.
    tab: Tab,
    /// The `Display settings` root is collapsed (false = open — it defaults open).
    display_collapsed: bool,
    /// Setting GROUPS explicitly COLLAPSED, by group name (absent = open — groups
    /// default open, matching the retired per-group CollapsingHeaders).
    closed_groups: HashSet<String>,
    /// The `Assemblies` root is collapsed (false = open — see above).
    assemblies_collapsed: bool,
    /// The BOM-columns textarea's live edit buffer. Held here, not re-seeded
    /// per frame like the settings JSON, because a multi-line editor cannot be
    /// re-seeded mid-edit without fighting the caret. It tracks the engine
    /// while UNFOCUSED and commits on focus-loss (the expressions editor's
    /// rule); `None` = not yet seeded.
    bom_columns_buf: Option<String>,
}

impl SettingsPanel {
    /// A fresh panel. The settings buffer is re-seeded from the engine every frame
    /// (not stored), so construction needs no engine handle.
    pub fn new() -> Self {
        Self {
            open: false,
            hits: HashMap::new(),
            tab: Tab::Display,
            display_collapsed: false,
            closed_groups: HashSet::new(),
            assemblies_collapsed: false,
            bom_columns_buf: None,
        }
    }

    /// Draw the floating window (if open) at ctx level — after the panels, like
    /// the file dialog, so it floats over the shell. The `open` flag is shared with
    /// the toolbar gear button (which toggles it) and the window's own `×` (which
    /// closes it). `EngineState` is the single brain, borrowed in.
    pub fn show(&mut self, ctx: &egui::Context, state: &mut EngineState, store: &dyn ModelStore) {
        if self.open {
            // `egui::Window::open` needs its own `&mut bool`; borrow a copy so the
            // draw closure can still take `&mut self`, then fold the close back in.
            let mut open = true;
            egui::Window::new("Settings")
                .open(&mut open)
                .movable(true)
                .resizable(true)
                // A bounded default size + a fill ScrollArea (in `body`, under the
                // tab strip) makes the window FREELY resizable LARGER than its
                // content: without a filling child egui hugs the window to content
                // and won't grow.
                .default_size([320.0, 400.0])
                // Rest on the right so it floats clear of the left panel; the user
                // can drag it anywhere.
                .default_pos([720.0, 56.0])
                .show(ctx, |ui| self.body(ui, state, store));
            self.open = open;

            // Publish this frame's widget rects for the headed verifier (parity
            // with the history + scene panels).
            if crate::automation::registry::enabled() {
                crate::automation::registry::publish("__brepSettingsHit", "settings window widget rects (field:*, group:*)", &self.hits_json());
            }
        }
    }

    /// The window body: the tab strip, then the ONE section that tab selects —
    /// each still built on the shared [`tree`] node helper, so every tab reads as
    /// the same tree the history + scene panels draw.
    ///
    /// The strip sits ABOVE the ScrollArea (rather than inside the one `show` used
    /// to wrap the whole body in), so the tabs stay put while a long settings tree
    /// scrolls under them.
    fn body(&mut self, ui: &mut egui::Ui, state: &mut EngineState, store: &dyn ModelStore) {
        self.hits.clear();

        // The tab drawn this frame is the one that was active BEFORE the strip.
        // `selectable_value` switches `self.tab` mid-frame, and a section that
        // vanishes the same frame it loses the click never gets its focus-loss —
        // which is how the Assemblies editor COMMITS. Deferring by one frame lets
        // the editor blur normally (invisible at 60fps, and the difference between
        // "my BOM columns saved" and "my typing disappeared").
        let tab = self.tab;
        ui.horizontal(|ui| {
            let display = ui.selectable_value(&mut self.tab, Tab::Display, "Display");
            let assemblies = ui.selectable_value(&mut self.tab, Tab::Assemblies, "Assemblies");
            self.hits.insert("tab:display".into(), display.rect);
            self.hits.insert("tab:assemblies".into(), assemblies.rect);
        });
        // ...and because of that defer, the switch needs ONE more frame to show
        // its new section. The shell only requests a repaint while work is
        // pending (`app.rs`: a run / queries / mesh imports), so on native a
        // click with no further input would leave the strip highlighting a tab
        // whose content has not been drawn yet. Ask for that frame here.
        if self.tab != tab {
            ui.ctx().request_repaint();
        }
        ui.separator();

        egui::ScrollArea::vertical()
            .auto_shrink([false, false])
            .show(ui, |ui| {
                // Tight, tree-like row spacing so connector verticals read
                // continuously — the same the history + scene trees set (this panel
                // must match them). Set INSIDE the scroll so the tab strip above
                // keeps ordinary widget spacing.
                ui.spacing_mut().item_spacing.y = 2.0;
                match tab {
                    Tab::Display => self.settings_section(ui, state, store),
                    Tab::Assemblies => self.assemblies_section(ui, state, store),
                }
            });
    }

    /// The `Assemblies` TAB: the BOM's COLUMN CONFIGURATION as one multiline
    /// textarea, one column per line, a leading `*` for shown.
    ///
    /// A hand-written root rather than a schema field: the schema's `FieldKind`s
    /// are all
    /// single-widget and render into a tree row's RIGHT-ALIGNED content slot,
    /// which is exactly the wrong place for a full-width multi-line editor.
    /// Adding a `TextArea` variant would also force both exhaustive
    /// `FieldKind` matches open for one consumer.
    ///
    /// Commits on focus-LOSS — which includes LEAVING THE TAB, since [`body`]
    /// draws the pre-click tab for one more frame so this editor is still on
    /// screen to blur ([`SettingsPanel::body`]) — not per keystroke: this text is
    /// persisted to the store on commit, and on native that is a rewrite of
    /// `~/.config/brep-app/settings.json` — per character is a file write per
    /// character. Parse problems are listed under the editor, naming the line,
    /// and the text is never rewritten by the panel: a typo costs one column,
    /// not the configuration.
    fn assemblies_section(
        &mut self,
        ui: &mut egui::Ui,
        state: &mut EngineState,
        store: &dyn ModelStore,
    ) {
        let open = !self.assemblies_collapsed;
        let root_resp = tree::node(
            ui,
            TreeRow {
                guides: &[],
                is_last: true,
                expandable: true,
                expanded: open,
                root: true,
                glyph: None,
                label: "Assemblies",
                selected: false,
                draggable: false,
                tint: None,
            },
            |_| {},
        );
        self.hits.insert("box:__assemblies".into(), root_resp.box_rect);
        if root_resp.toggled || root_resp.label.clicked() {
            self.assemblies_collapsed = !self.assemblies_collapsed;
        }
        if !open {
            // Drop the buffer while closed so the next open re-seeds from the
            // engine (a BOM header drag rewrites this text behind the panel).
            self.bom_columns_buf = None;
            return;
        }

        // Empty stored text means "the shipped default", so the editor shows
        // the default rather than a blank box the user has to guess at.
        let stored = bom_columns::effective_text(&state.settings.bom_columns);
        let buffer = self.bom_columns_buf.get_or_insert_with(|| stored.clone());

        ui.label(egui::RichText::new("BOM columns").strong());
        ui.label(
            egui::RichText::new(
                "One per line, in order. A leading * shows it. \
                 part.<Field> is stored on the part, occurrence.<Field> on one placement. \
                 A line that is just - freezes the columns above it; the rest scroll.",
            )
            .weak(),
        );
        let editor = ui.add(
            egui::TextEdit::multiline(buffer)
                .id_salt("bom-columns-editor")
                .desired_rows(8)
                .desired_width(f32::INFINITY)
                .code_editor(),
        );
        self.hits.insert("field:bomColumns".into(), editor.rect);

        if editor.lost_focus() {
            // Commit: store the text VERBATIM (never the parse's idea of it).
            let mut settings_json: serde_json::Value =
                serde_json::from_str(&state.settings_json()).unwrap_or(serde_json::Value::Null);
            if let Some(object) = settings_json.as_object_mut() {
                object.insert(
                    "bomColumns".into(),
                    serde_json::Value::String(buffer.clone()),
                );
                let json = settings_json.to_string();
                let _ = state.apply_settings_json(&json);
                let _ = store.write(SETTINGS_KEY, &json);
            }
        } else if !editor.has_focus() && *buffer != stored {
            // Unfocused and out of step with the engine — the BOM's own header
            // drag rewrote the configuration. Track it rather than showing a
            // stale copy the next commit would write back.
            *buffer = stored;
        }

        // Parse problems, by line. Listed rather than thrown: the text stands
        // exactly as typed and every other line still works.
        let parsed = bom_columns::parse(buffer);
        if parsed.problems.is_empty() {
            ui.label(
                egui::RichText::new(format!(
                    "{} columns, {} shown",
                    parsed.columns.len(),
                    parsed.columns.iter().filter(|column| column.shown).count()
                ))
                .weak(),
            );
        } else {
            for problem in &parsed.problems {
                ui.label(egui::RichText::new(problem).color(PROBLEM_AMBER));
            }
        }
        let reset = ui.button("Reset BOM columns");
        self.hits.insert("bom-columns:reset".into(), reset.rect);
        if reset.clicked() {
            self.bom_columns_buf = None;
            let mut settings_json: serde_json::Value =
                serde_json::from_str(&state.settings_json()).unwrap_or(serde_json::Value::Null);
            if let Some(object) = settings_json.as_object_mut() {
                // Back to EMPTY, which means "the shipped default" — so a later
                // change to that default still reaches this user.
                object.insert("bomColumns".into(), serde_json::Value::String(String::new()));
                let json = settings_json.to_string();
                let _ = state.apply_settings_json(&json);
                let _ = store.write(SETTINGS_KEY, &json);
            }
        }
        ui.add_space(4.0);
    }

    /// The schema-driven display-settings TREE: a `Display settings` root, one
    /// collapsible branch per schema group, one leaf per field. Any edit applies to
    /// `EngineState` (bumps `settings_generation` + `dirty`, so the GPU refreshes)
    /// and persists through the storage seam.
    fn settings_section(
        &mut self,
        ui: &mut egui::Ui,
        state: &mut EngineState,
        store: &dyn ModelStore,
    ) {
        // Re-seed a per-frame LOCAL buffer from the LIVE engine settings BEFORE
        // rendering. The apply below writes the WHOLE buffer, so a buffer kept
        // across frames would clobber every setting changed elsewhere (the toolbar
        // wireframe / projection toggles) back to a stale snapshot — the "changing
        // Render Quality resets my wireframe" bug. A fresh local each frame makes
        // external changes authoritative and keeps untouched fields a no-op
        // round-trip (`apply_json`/`to_json` are a documented identity).
        let mut settings_json: Value =
            serde_json::from_str(&state.settings_json()).unwrap_or(Value::Null);
        let fields = settings_form_fields();

        // Group the schema's contiguous same-group runs, preserving order (the
        // schema lists each group's fields together).
        let mut groups: Vec<(String, Vec<&FormField>)> = Vec::new();
        for f in &fields {
            if let Some(g) = groups.iter_mut().find(|(n, _)| *n == f.group) {
                g.1.push(f);
            } else {
                groups.push((f.group.clone(), vec![f]));
            }
        }

        // --- ROOT: `[-] Display settings` (defaults open) ---------------------
        let root_open = !self.display_collapsed;
        let root_resp = tree::node(
            ui,
            TreeRow {
                guides: &[],
                is_last: true,
                expandable: true,
                expanded: root_open,
                root: true,
                glyph: None,
                label: "Display settings",
                selected: false,
                draggable: false,
                tint: None,
            },
            |_| {},
        );
        if root_resp.toggled || root_resp.label.clicked() {
            self.display_collapsed = !self.display_collapsed;
        }

        let mut changed = false;
        if root_open {
            let n = groups.len();
            for (gi, (gname, gfields)) in groups.iter().enumerate() {
                let is_last = gi + 1 == n;
                let open = !self.closed_groups.contains(gname);
                let resp = tree::node(ui, TreeRow::branch(&[], is_last, open, gname), |_| {});
                self.hits.insert(format!("group:{gname}"), resp.box_rect);
                if resp.toggled || resp.label.clicked() {
                    if open {
                        self.closed_groups.insert(gname.clone());
                    } else {
                        self.closed_groups.remove(gname);
                    }
                }
                if !open {
                    continue;
                }
                let base = tree::child_guides(&[], is_last);
                let m = gfields.len();
                for (fi, &f) in gfields.iter().enumerate() {
                    changed |= self.settings_leaf(ui, f, &mut settings_json, &base, fi + 1 == m);
                }
            }
        }

        // Commit the whole buffer ONCE on any edit (same apply + persist path as
        // before), so the engine re-runs / the GPU refreshes exactly as it did.
        if changed {
            let json = settings_json.to_string();
            let _ = state.apply_settings_json(&json);
            let _ = store.write(SETTINGS_KEY, &json);
        }

        // Reset to defaults — only while the display root is OPEN, matching the
        // retired CollapsingHeader that hid it when the section was collapsed. It
        // resets the DISPLAY settings only, which is why it belongs to this tab.
        if root_open {
            ui.add_space(2.0);
            if ui.button("Reset to defaults").clicked() {
                // Full reset: rebase to defaults, then apply the serialized defaults
                // (so every key returns, not just the overridden ones) + persist.
                state.settings = RenderSettings::default();
                let json = state.settings.to_json();
                let _ = state.apply_settings_json(&json);
                let _ = store.write(SETTINGS_KEY, &json);
            }
        }
    }

    /// Render one settings field as a tree LEAF: the field label is the node label;
    /// its input widget ([`form::field_input`]) fills the row's RIGHT-aligned
    /// content, exactly like the feature tree's `schema_field`. Settings keys are
    /// unique across the schema, so no id-stack scoping is needed. Returns whether
    /// the field changed (the caller commits the whole buffer once).
    fn settings_leaf(
        &mut self,
        ui: &mut egui::Ui,
        field: &FormField,
        current: &mut Value,
        guides: &[bool],
        is_last: bool,
    ) -> bool {
        let mut changed = false;
        let mut rect = egui::Rect::NOTHING;
        tree::node(ui, TreeRow::leaf(guides, is_last, &field.label), |ui| {
            // The tree row's content area is RIGHT-aligned (`right_to_left`), so the
            // input sits at the panel edge with the label on the left — the feature
            // tree's exact placement, and the layout `field_input` reads to keep its
            // inputs COMPACT here. Settings have no reference / button fields, so
            // `field_input`'s click sink is `None`.
            let (ch, r) = form::field_input(ui, field, current, None, &mut form::FieldActions::default());
            changed = ch;
            rect = r;
        });
        self.hits.insert(format!("field:{}", field.key()), rect);
        changed
    }

    /// The published widget hit-rects (egui points) for the headed verifier.
    pub fn hits_json(&self) -> String {
        crate::automation::hit_rects::hits_json(&self.hits)
    }
}

// BREP private tests: fbeefa5a776131c6

/// The hit keys this panel publishes (see `automation::hit_keys`).
pub static HIT_KEYS: &[HitKeyDoc] = &[
    HitKeyDoc { panel: "settings", prefix: "field:", meaning: "a settings field by key", command: None },
    HitKeyDoc { panel: "settings", prefix: "group:", meaning: "a settings group header", command: None },
    HitKeyDoc { panel: "settings", prefix: "tab:", meaning: "a settings tab (tab:display, tab:assemblies)", command: None },
    HitKeyDoc { panel: "settings", prefix: "box:", meaning: "expand/collapse a section", command: None },
    HitKeyDoc { panel: "settings", prefix: "bom-columns:reset", meaning: "reset the BOM columns", command: None },
];