import {
  DEFAULT_EDITOR_KEYBINDINGS,
  type EditorAction,
  type EditorKeybindingsConfig,
  EditorKeybindingsManager,
  type KeyId,
  matchesKey,
  setEditorKeybindings,
} from "@mariozechner/companion-tui";
import { existsSync, readFileSync } from "fs";
import { join } from "path";
import { getAgentDir } from "../config.js";

/**
 * Application-level actions (coding agent specific).
 */
export type AppAction =
  | "interrupt"
  | "clear"
  | "exit"
  | "suspend"
  | "cycleThinkingLevel"
  | "cycleModelForward"
  | "cycleModelBackward"
  | "selectModel"
  | "expandTools"
  | "toggleThinking"
  | "toggleSessionNamedFilter"
  | "externalEditor"
  | "followUp"
  | "dequeue"
  | "pasteImage"
  | "newSession"
  | "tree"
  | "fork"
  | "resume";

/**
 * All configurable actions.
 */
export type KeyAction = AppAction | EditorAction;

/**
 * Full keybindings configuration (app + editor actions).
 */
export type KeybindingsConfig = {
  [K in KeyAction]?: KeyId | KeyId[];
};

/**
 * Default application keybindings.
 */
export const DEFAULT_APP_KEYBINDINGS: Record<AppAction, KeyId | KeyId[]> = {
  interrupt: "escape",
  clear: "ctrl+c",
  exit: "ctrl+d",
  suspend: "ctrl+z",
  cycleThinkingLevel: "shift+tab",
  cycleModelForward: "ctrl+p",
  cycleModelBackward: "shift+ctrl+p",
  selectModel: "ctrl+l",
  expandTools: "ctrl+o",
  toggleThinking: "ctrl+t",
  toggleSessionNamedFilter: "ctrl+n",
  externalEditor: "ctrl+g",
  followUp: "alt+enter",
  dequeue: "alt+up",
  pasteImage: process.platform === "win32" ? "alt+v" : "ctrl+v",
  newSession: [],
  tree: [],
  fork: [],
  resume: [],
};

/**
 * All default keybindings (app + editor).
 */
export const DEFAULT_KEYBINDINGS: Required<KeybindingsConfig> = {
  ...DEFAULT_EDITOR_KEYBINDINGS,
  ...DEFAULT_APP_KEYBINDINGS,
};

// App actions list for type checking
const APP_ACTIONS: AppAction[] = [
  "interrupt",
  "clear",
  "exit",
  "suspend",
  "cycleThinkingLevel",
  "cycleModelForward",
  "cycleModelBackward",
  "selectModel",
  "expandTools",
  "toggleThinking",
  "toggleSessionNamedFilter",
  "externalEditor",
  "followUp",
  "dequeue",
  "pasteImage",
  "newSession",
  "tree",
  "fork",
  "resume",
];

function isAppAction(action: string): action is AppAction {
  return APP_ACTIONS.includes(action as AppAction);
}

/**
 * Manages all keybindings (app + editor).
 */
export class KeybindingsManager {
  private config: KeybindingsConfig;
  private appActionToKeys: Map<AppAction, KeyId[]>;

  private constructor(config: KeybindingsConfig) {
    this.config = config;
    this.appActionToKeys = new Map();
    this.buildMaps();
  }

  /**
   * Create from config file and set up editor keybindings.
   */
  static create(agentDir: string = getAgentDir()): KeybindingsManager {
    const configPath = join(agentDir, "keybindings.json");
    const config = KeybindingsManager.loadFromFile(configPath);
    const manager = new KeybindingsManager(config);

    // Set up editor keybindings globally
    // Include both editor actions and expandTools (shared between app and editor)
    const editorConfig: EditorKeybindingsConfig = {};
    for (const [action, keys] of Object.entries(config)) {
      if (!isAppAction(action) || action === "expandTools") {
        editorConfig[action as EditorAction] = keys;
      }
    }
    setEditorKeybindings(new EditorKeybindingsManager(editorConfig));

    return manager;
  }

  /**
   * Create in-memory.
   */
  static inMemory(config: KeybindingsConfig = {}): KeybindingsManager {
    return new KeybindingsManager(config);
  }

  private static loadFromFile(path: string): KeybindingsConfig {
    if (!existsSync(path)) return {};
    try {
      return JSON.parse(readFileSync(path, "utf-8"));
    } catch {
      return {};
    }
  }

  private buildMaps(): void {
    this.appActionToKeys.clear();

    // Set defaults for app actions
    for (const [action, keys] of Object.entries(DEFAULT_APP_KEYBINDINGS)) {
      const keyArray = Array.isArray(keys) ? keys : [keys];
      this.appActionToKeys.set(action as AppAction, [...keyArray]);
    }

    // Override with user config (app actions only)
    for (const [action, keys] of Object.entries(this.config)) {
      if (keys === undefined || !isAppAction(action)) continue;
      const keyArray = Array.isArray(keys) ? keys : [keys];
      this.appActionToKeys.set(action, keyArray);
    }
  }

  /**
   * Check if input matches an app action.
   */
  matches(data: string, action: AppAction): boolean {
    const keys = this.appActionToKeys.get(action);
    if (!keys) return false;
    for (const key of keys) {
      if (matchesKey(data, key)) return true;
    }
    return false;
  }

  /**
   * Get keys bound to an app action.
   */
  getKeys(action: AppAction): KeyId[] {
    return this.appActionToKeys.get(action) ?? [];
  }

  /**
   * Get the full effective config.
   */
  getEffectiveConfig(): Required<KeybindingsConfig> {
    const result = { ...DEFAULT_KEYBINDINGS };
    for (const [action, keys] of Object.entries(this.config)) {
      if (keys !== undefined) {
        (result as KeybindingsConfig)[action as KeyAction] = keys;
      }
    }
    return result;
  }
}

// Re-export for convenience
export type { EditorAction, KeyId };