kiln/src/editor.rs

use eframe::egui;
use egui::{Align2, FontId, Sense, vec2};

use crate::game::{Archetype, Board, Glyph, ALL_ARCHETYPES};
use crate::render::{CELL_H, CELL_W, PALETTE_PANEL_W};

/// 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,
    /// Board-level properties (placeholder).
    Board,
    /// 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 (character + colors) to stamp. Independent of the archetype's default.
    pub(crate) glyph: Glyph,
    /// Whether the glyph picker dialog is currently open.
    pub(crate) glyph_picker_open: bool,
    /// Which side-panel tab is currently shown.
    pub(crate) tab: EditorTab,
}

impl EditorState {
    /// Creates editor state with `Wall` selected and the picker closed.
    pub(crate) fn new() -> Self {
        Self {
            selected: Archetype::Wall,
            glyph: Archetype::Wall.default_glyph(),
            glyph_picker_open: false,
            tab: EditorTab::Palette,
        }
    }
}

/// Renders the editor side panel (must be called before `CentralPanel`).
///
/// Shows tab bar (Palette / Board / World) and, on the Palette tab, the
/// scrollable archetype list and current-glyph preview button.
pub(crate) fn show_editor_panel(ctx: &egui::Context, editor: &mut EditorState, _board: &Board) {
    egui::SidePanel::right("palette_panel")
        .resizable(true)
        .default_width(PALETTE_PANEL_W)
        .show(ctx, |ui| {
            // Tab bar
            ui.horizontal(|ui| {
                ui.selectable_value(&mut editor.tab, EditorTab::Palette, "Palette");
                ui.selectable_value(&mut editor.tab, EditorTab::Board,   "Board");
                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 = CELL_H + 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(CELL_W, CELL_H), Sense::click());
                                    {
                                        let p = ui.painter();
                                        p.rect_filled(r, 0.0, glyph.bg);
                                        p.text(r.center(), Align2::CENTER_CENTER,
                                            glyph.ch, FontId::monospace(CELL_H), glyph.fg);
                                    }
                                    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(CELL_W, CELL_H), Sense::click());
                    {
                        let p = ui.painter();
                        p.rect_filled(cell_rect, 0.0, editor.glyph.bg);
                        p.text(
                            cell_rect.center(),
                            Align2::CENTER_CENTER,
                            editor.glyph.ch,
                            FontId::monospace(CELL_H),
                            editor.glyph.fg,
                        );
                    }
                    if glyph_btn.clicked() {
                        editor.glyph_picker_open = true;
                    }
                }
                EditorTab::Board => {}
                EditorTab::World => {}
            }
        });
}