import { IPC_EVENTS, WINDOW_NAMES } from './constants';
import { invokeIpc } from './host-api';
import type { RuntimePlatform, WindowIdentity, WindowName } from '../types/runtime';

function normalizePlatform(platform: string | undefined | null): RuntimePlatform {
  const value = platform?.toLowerCase() ?? '';
  if (value === 'win32' || value.includes('win')) return 'win32';
  if (value === 'darwin' || value.includes('mac')) return 'darwin';
  if (value === 'linux') return 'linux';
  if (value) return 'unknown';
  return 'web';
}

export function hasIpcBridge(): boolean {
  return typeof window !== 'undefined' && Boolean(window.api?.invoke);
}

export function detectRuntimePlatform(): RuntimePlatform {
  if (typeof window === 'undefined') return 'unknown';
  const exposedPlatform = window.api?.platform;
  if (exposedPlatform) return normalizePlatform(exposedPlatform);
  if (typeof navigator !== 'undefined') {
    const nav = navigator as Navigator & { userAgentData?: { platform?: string } };
    return normalizePlatform(nav.platform || nav.userAgentData?.platform);
  }
  return window.api ? 'unknown' : 'web';
}

function readWindowIdFromBridge(): string | number | null {
  if (typeof window.api?.getCurrentWindowId === 'function') {
    return window.api.getCurrentWindowId();
  }

  return null;
}

export function detectWindowName(windowId?: string | number | null): WindowName {
  if (typeof windowId === 'string') {
    const normalized = windowId.toLowerCase();
    if (normalized.includes('setting')) return WINDOW_NAMES.SETTING;
    if (normalized.includes('dialog')) return WINDOW_NAMES.DIALOG;
    if (normalized.includes('loading')) return WINDOW_NAMES.LOADING;
  }
  return WINDOW_NAMES.MAIN;
}

export async function resolveWindowIdentity(): Promise<WindowIdentity> {
  const platform = detectRuntimePlatform();
  const isElectron = platform !== 'web' && platform !== 'unknown';

  if (!hasIpcBridge()) {
    return {
      platform,
      windowId: null,
      windowName: WINDOW_NAMES.MAIN,
      isElectron,
    };
  }

  let windowId: string | number | null = null;
  try {
    windowId = readWindowIdFromBridge();
    if (windowId === null) {
      windowId = await invokeIpc<string | number | null>(IPC_EVENTS.GET_WINDOW_ID);
    }
  } catch {
    windowId = null;
  }

  return {
    platform,
    windowId,
    windowName: detectWindowName(windowId),
    isElectron,
  };
}