/**
 * KHAELOR
 * File: src/tui/commands.ts
 * Description: The single command registry — one source powers keys, slash commands, and the universal palette (TUI_DESIGN §4.2).
 *
 * Author: Simon-Pierre Boucher
 * Contact: contact@spboucher.ai
 */

import type { PaletteItem } from "./composer/palette.js";

export interface CommandDef {
  /** Stable id, e.g. `diff.show`. */
  id: string;
  /** Palette title, e.g. `View diff`. */
  title: string;
  /** Slash form, e.g. `/diff`. */
  slash?: string;
  /** Bound key, shown in the universal palette, e.g. `d`. */
  key?: string;
  /** Short description for the slash palette. */
  description?: string;
  run(): void;
}

/**
 * All bindings are declared here with name/title/key, so every palette lists
 * them and a future rebinding config gets them for free — users never need
 * to memorize commands.
 */
export class CommandRegistry {
  private readonly commands = new Map<string, CommandDef>();

  register(def: CommandDef): void {
    this.commands.set(def.id, def);
  }

  find(id: string): CommandDef | null {
    return this.commands.get(id) ?? null;
  }

  bySlash(slash: string): CommandDef | null {
    for (const def of this.commands.values()) {
      if (def.slash === slash) return def;
    }
    return null;
  }

  list(): CommandDef[] {
    return [...this.commands.values()];
  }

  /** Slash-palette items: `/name  description`. */
  slashItems(): PaletteItem[] {
    return this.list()
      .filter((d) => d.slash !== undefined)
      .map((d) => {
        const item: PaletteItem = { id: d.id, label: d.slash as string };
        if (d.description !== undefined) item.detail = d.description;
        return item;
      });
  }

  /** Universal-palette items: `Title  /slash  key`. */
  paletteItems(): PaletteItem[] {
    return this.list().map((d) => {
      const item: PaletteItem = { id: d.id, label: d.title };
      if (d.slash !== undefined) item.detail = d.slash;
      if (d.key !== undefined) item.keyHint = d.key;
      return item;
    });
  }
}