kiln/kiln-egui/src/editor.rs

use eframe::egui;
use egui::{Sense, vec2};

use crate::font::BitmapFont;
use crate::font_dialog::{FontDialogState, show as show_font_dialog};
use crate::render::{PALETTE_PANEL_W, paint_glyph};
use kiln_core::game::{ALL_ARCHETYPES, Archetype, Board, Glyph};

/// Which tab is active in the editor side panel.
#[derive(Copy, Clone, PartialEq, Eq)]
pub(crate) enum EditorTab {
    /// Archetype + glyph palette for painting cells.
    Palette,
    /// Object placement and script assignment.
    Objects,
    /// Board-level properties (font, board script).
    Board,
    /// Named script library for this board.
    Scripts,
    /// World-level properties (placeholder).
    World,
}

/// Transient editor state. Only meaningful when the app is in Edit mode.
pub(crate) struct EditorState {
    /// The archetype that will be stamped when the user clicks a cell.
    pub(crate) selected: Archetype,
    /// The glyph (tile index + colors) to stamp. Independent of the archetype's default.
    pub(crate) glyph: Glyph,
    /// Whether the glyph picker dialog is currently open (Palette tab).
    pub(crate) glyph_picker_open: bool,
    /// Whether the font picker dialog is currently open.
    pub(crate) font_dialog_open: bool,
    /// In-progress state for the font dialog while it is open.
    pub(crate) font_dialog_state: FontDialogState,
    /// Which side-panel tab is currently shown.
    pub(crate) tab: EditorTab,
    /// Index into `board.objects` of the currently selected object, or `None`.
    pub(crate) selected_object: Option<usize>,
    /// Whether the glyph picker is open for editing the selected object's glyph.
    pub(crate) object_glyph_picker_open: bool,
    /// Local copy of the selected object's glyph for the picker to edit.
    ///
    /// Kept separate from `board.objects` to avoid a borrow conflict while the
    /// glyph picker holds `&mut Glyph` and the board is also borrowed. Written
    /// back to `board.objects[i].glyph` each frame while an object is selected.
    pub(crate) object_editing_glyph: Glyph,
    /// When `true`, the next board click in the Objects tab places a new object.
    /// Set by the "Add Object" button; cleared after placement or on tab switch.
    pub(crate) placing_object: bool,
}

impl EditorState {
    /// Creates editor state with `Wall` selected and all dialogs closed.
    pub(crate) fn new() -> Self {
        Self {
            selected: Archetype::Wall,
            glyph: Archetype::Wall.default_glyph(),
            glyph_picker_open: false,
            font_dialog_open: false,
            font_dialog_state: FontDialogState::from_spec(None),
            tab: EditorTab::Palette,
            selected_object: None,
            object_glyph_picker_open: false,
            object_editing_glyph: Glyph::player(), // overwritten on first selection
            placing_object: false,
        }
    }
}

/// Renders the editor side panel (must be called before `CentralPanel`).
///
/// Shows tab bar (Palette / Objects / Board / Scripts / World) and the content
/// for the active tab. `board` is the current board, used by the Objects and
/// Scripts tabs and to read/write the board font. `active_font` is the resolved
/// font currently in use for rendering.
pub(crate) fn show_editor_panel(
    ctx: &egui::Context,
    editor: &mut EditorState,
    board: &mut Board,
    active_font: &BitmapFont,
) {
    let tw = active_font.tile_w as f32;
    let th = active_font.tile_h as f32;

    egui::SidePanel::right("palette_panel")
        .resizable(true)
        .default_width(PALETTE_PANEL_W)
        .show(ctx, |ui| {
            // Tab bar — wraps automatically if the panel is narrow.
            ui.horizontal_wrapped(|ui| {
                ui.selectable_value(&mut editor.tab, EditorTab::Palette, "Palette");
                ui.selectable_value(&mut editor.tab, EditorTab::Objects, "Objects");
                ui.selectable_value(&mut editor.tab, EditorTab::Board, "Board");
                ui.selectable_value(&mut editor.tab, EditorTab::Scripts, "Scripts");
                ui.selectable_value(&mut editor.tab, EditorTab::World, "World");
            });
            ui.separator();

            match editor.tab {
                EditorTab::Palette => {
                    ui.label("Element");

                    // Scrollable archetype list; shows at most 5 rows before scrolling.
                    let row_h = th + ui.spacing().item_spacing.y;
                    egui::ScrollArea::vertical()
                        .max_height(row_h * 5.0)
                        .id_salt("arch_list")
                        .show(ui, |ui| {
                            for &archetype in ALL_ARCHETYPES {
                                let is_selected = editor.selected == archetype;
                                let glyph = archetype.default_glyph();
                                ui.horizontal(|ui| {
                                    let (r, cell_resp) =
                                        ui.allocate_exact_size(vec2(tw, th), Sense::click());
                                    paint_glyph(ui.painter(), r, &glyph, active_font);
                                    let label_resp =
                                        ui.selectable_label(is_selected, archetype.name());
                                    if cell_resp.clicked() || label_resp.clicked() {
                                        editor.selected = archetype;
                                        editor.glyph = archetype.default_glyph();
                                    }
                                });
                            }
                        });

                    ui.separator();

                    ui.label("Glyph");
                    // Paint a preview cell showing the current glyph, sized like a board cell.
                    let (cell_rect, glyph_btn) =
                        ui.allocate_exact_size(vec2(tw, th), Sense::click());
                    paint_glyph(ui.painter(), cell_rect, &editor.glyph, active_font);
                    if glyph_btn.clicked() {
                        editor.glyph_picker_open = true;
                    }
                }

                EditorTab::Objects => {
                    // "Add Object" toggles placement mode; next board click places a new object.
                    let add_label = if editor.placing_object {
                        "Cancel Add"
                    } else {
                        "Add Object"
                    };
                    if ui.button(add_label).clicked() {
                        editor.placing_object = !editor.placing_object;
                        editor.selected_object = None;
                    }
                    if editor.placing_object {
                        ui.label("Click on the board to place.");
                    }

                    ui.separator();

                    match editor.selected_object {
                        None => {
                            if !editor.placing_object {
                                ui.label("Click an object on the board to select it.");
                            }
                        }
                        Some(i) => {
                            // Collect sorted script names before taking a mutable borrow on objects.
                            let mut script_names: Vec<String> =
                                board.scripts.keys().cloned().collect();
                            script_names.sort();

                            ui.label("Glyph");
                            // Preview button — same pattern as Palette tab.
                            let (cell_rect, glyph_btn) =
                                ui.allocate_exact_size(vec2(tw, th), Sense::click());
                            paint_glyph(
                                ui.painter(),
                                cell_rect,
                                &editor.object_editing_glyph,
                                active_font,
                            );
                            if glyph_btn.clicked() {
                                editor.object_glyph_picker_open = true;
                            }

                            let obj = &mut board.objects[i];

                            ui.checkbox(&mut obj.passable, "Passable");
                            ui.checkbox(&mut obj.opaque, "Opaque");

                            let current =
                                obj.script_name.as_deref().unwrap_or("(none)").to_string();

                            ui.label("Script");
                            egui::ComboBox::from_id_salt("obj_script")
                                .selected_text(&current)
                                .show_ui(ui, |ui| {
                                    // "(none)" clears the script assignment.
                                    if ui
                                        .selectable_label(obj.script_name.is_none(), "(none)")
                                        .clicked()
                                    {
                                        obj.script_name = None;
                                    }
                                    for name in &script_names {
                                        let is_sel =
                                            obj.script_name.as_deref() == Some(name.as_str());
                                        if ui.selectable_label(is_sel, name.as_str()).clicked() {
                                            obj.script_name = Some(name.clone());
                                        }
                                    }
                                    // Placeholder for future "create and edit a new script" flow.
                                    let _ = ui.selectable_label(false, "(create new...)");
                                });

                            if ui.button("Edit Script").clicked() {
                                // TODO: open script editor
                            }
                        }
                    }
                }

                EditorTab::Board => {
                    let font_label = match &board.font {
                        Some(s) => s.path.clone(),
                        None => "(default)".to_owned(),
                    };
                    ui.label(format!("Font: {font_label}"));
                    if ui.button("Font…").clicked() {
                        editor.font_dialog_state =
                            FontDialogState::from_spec(board.font.as_ref());
                        editor.font_dialog_open = true;
                    }
                }

                EditorTab::Scripts => {
                    if board.scripts.is_empty() {
                        ui.label("No scripts defined.");
                    } else {
                        let mut names: Vec<&String> = board.scripts.keys().collect();
                        names.sort();
                        egui::ScrollArea::vertical()
                            .id_salt("scripts_list")
                            .show(ui, |ui| {
                                for name in names {
                                    ui.horizontal(|ui| {
                                        ui.label(name);
                                        if ui.button("Edit").clicked() {
                                            // TODO: open script editor
                                        }
                                    });
                                }
                            });
                    }
                }

                EditorTab::World => {}
            }
        });

    // Font dialog floats outside the side panel; show it here so it renders on top.
    if editor.font_dialog_open {
        show_font_dialog(
            ctx,
            &mut editor.font_dialog_open,
            &mut editor.font_dialog_state,
            &mut board.font,
        );
    }
}