import { app, BrowserWindow, ipcMain, Tray, Menu, nativeImage } from 'electron';
import path from 'path';
import fs   from 'fs';
import https from 'https';
import { TunnelAgent } from './agent/TunnelAgent';

function loadEnv(): void
{
  const envPath = path.join( __dirname, '..', '..', '.env' );
  try
  {
    const lines = fs.readFileSync( envPath, 'utf-8' ).split( /\r?\n/ );
    for ( const line of lines )
    {
      const trimmed = line.trim();
      if ( !trimmed || trimmed.startsWith( '#' ) ) continue;
      const eq  = trimmed.indexOf( '=' );
      if ( eq === -1 ) continue;
      const key = trimmed.slice( 0, eq ).trim();
      const val = trimmed.slice( eq + 1 ).trim().replace( /^["']|["']$/g, '' );
      if ( key && !( key in process.env ) ) process.env[ key ] = val;
    }
  }
  catch { /* no .env — rely on inherited env */ }
}

loadEnv();

const AUTH_HOST         = 'https://account.rokojori.com';
const TUNNEL_SERVER_URL = process.env.TUNNEL_SERVER_URL ?? 'https://tunnel.rokojori.com';

// ── Tokens ────────────────────────────────────────────────────────────────────

interface Tokens { accessToken: string; refreshToken: string; }

function tokenFile(): string { return path.join( app.getPath( 'userData' ), 'tokens.json' ); }

function loadTokens(): Tokens | null
{
  try { return JSON.parse( fs.readFileSync( tokenFile(), 'utf-8' ) ) as Tokens; }
  catch { return null; }
}

function saveTokens( t: Tokens ): void { fs.writeFileSync( tokenFile(), JSON.stringify( t ), 'utf-8' ); }
function clearTokens(): void { try { fs.unlinkSync( tokenFile() ); } catch { /* already gone */ } }

// ── HTTP helpers ──────────────────────────────────────────────────────────────

function postJson( url: string, body: unknown ): Promise<unknown>
{
  return new Promise( ( resolve, reject ) =>
  {
    const data   = JSON.stringify( body );
    const parsed = new URL( url );
    const req    = https.request(
      {
        hostname: parsed.hostname,
        path:     parsed.pathname,
        method:   'POST',
        headers:  { 'Content-Type': 'application/json', 'Content-Length': Buffer.byteLength( data ) },
      },
      res =>
      {
        let raw = '';
        res.on( 'data', ( chunk: string ) => { raw += chunk; } );
        res.on( 'end', () => { try { resolve( JSON.parse( raw ) ); } catch { reject( new Error( raw ) ); } } );
      }
    );
    req.on( 'error', reject );
    req.write( data );
    req.end();
  } );
}

async function apiFetch( apiPath: string, options: RequestInit = {} ): Promise<Response>
{
  const url = `${ TUNNEL_SERVER_URL }${ apiPath }`;
  return fetch( url,
  {
    ...options,
    headers:
    {
      'Content-Type':  'application/json',
      'Authorization': `Bearer ${ currentTokens?.accessToken ?? '' }`,
      ...( options.headers ?? {} ),
    },
  } );
}

// ── State ─────────────────────────────────────────────────────────────────────

let currentTokens: Tokens | null = null;
let mainWindow:    BrowserWindow | null = null;
let loginWindow:   BrowserWindow | null = null;
let tray:          Tray | null = null;
const agents = new Map<string, TunnelAgent>();

// ── Tray ──────────────────────────────────────────────────────────────────────

function buildTray(): void
{
  const iconPath = path.join( __dirname, '..', '..', 'assets', 'tray-icon.png' );
  const icon     = fs.existsSync( iconPath )
    ? nativeImage.createFromPath( iconPath )
    : nativeImage.createEmpty();

  tray = new Tray( icon );
  tray.setToolTip( 'Rokojori Tunnel Agent' );

  const menu = Menu.buildFromTemplate(
  [
    { label: 'Show Window', click: showMainWindow },
    { type:  'separator' },
    {
      label: 'Disconnect All',
      click: () =>
      {
        for ( const [ id, agent ] of agents )
        {
          agent.stop();
          mainWindow?.webContents.send( 'tunnel:status', id, false );
        }
        agents.clear();
      },
    },
    { type: 'separator' },
    { label: 'Quit', role: 'quit' },
  ] );

  tray.setContextMenu( menu );
  tray.on( 'double-click', showMainWindow );
  tray.on( 'click',        showMainWindow ); // Windows single-click
}

function showMainWindow(): void
{
  if ( mainWindow ) { mainWindow.show(); mainWindow.focus(); }
  else createMainWindow();
}

// ── Windows ───────────────────────────────────────────────────────────────────

function createLoginWindow(): void
{
  loginWindow = new BrowserWindow(
  {
    width: 420, height: 520, resizable: false,
    webPreferences: { nodeIntegration: false, contextIsolation: true, preload: path.join( __dirname, 'preload.js' ) },
    title: 'Tunnel Agent — Sign in',
  } );
  loginWindow.loadFile( path.join( __dirname, 'login.html' ) );
  loginWindow.on( 'closed', () => { loginWindow = null; } );
}

function createMainWindow(): void
{
  mainWindow = new BrowserWindow(
  {
    width: 400, height: 560, minWidth: 320, minHeight: 400,
    webPreferences: { nodeIntegration: false, contextIsolation: true, preload: path.join( __dirname, 'preload.js' ) },
    title: 'Tunnel Agent',
  } );
  mainWindow.loadFile( path.join( __dirname, 'window.html' ) );
  mainWindow.on( 'closed', () => { mainWindow = null; } );
}

// ── IPC ───────────────────────────────────────────────────────────────────────

function registerIPC(): void
{
  // Login
  ipcMain.handle( 'auth:login', async ( _e, email: string, password: string ) =>
  {
    try
    {
      const result = await postJson( `${ AUTH_HOST }/api/auth/login`, { email, password } ) as Record<string, unknown>;
      if ( result.accessToken && result.refreshToken )
      {
        currentTokens = { accessToken: result.accessToken as string, refreshToken: result.refreshToken as string };
        saveTokens( currentTokens );
        return { ok: true };
      }
      return { ok: false, error: ( result.error as string ) ?? 'Login failed' };
    }
    catch ( err ) { return { ok: false, error: String( err ) }; }
  } );

  ipcMain.on( 'auth:login-success', () =>
  {
    loginWindow?.close();
    createMainWindow();
    if ( !tray ) buildTray();
  } );

  // List tunnels
  ipcMain.handle( 'tunnels:list', async () =>
  {
    const res     = await apiFetch( '/api/tunnels' );
    const tunnels = await res.json() as Array<Record<string, unknown>>;
    return tunnels.map( t => ( { ...t, agentActive: agents.get( t.id as string )?.isActive() ?? false } ) );
  } );

  // Connect
  ipcMain.handle( 'tunnel:connect', async ( _e, tunnelId: string ) =>
  {
    if ( agents.has( tunnelId ) ) return;

    const res    = await apiFetch( `/api/tunnels/${ tunnelId }` );
    const tunnel = await res.json() as { localPort: number };

    const agent = new TunnelAgent(
    {
      tunnelId,
      token:     currentTokens!.accessToken,
      localPort: tunnel.localPort,
      serverUrl: TUNNEL_SERVER_URL,
    } );

    agent.onStatus = ( active ) =>
      mainWindow?.webContents.send( 'tunnel:status', tunnelId, active );

    agents.set( tunnelId, agent );
    agent.start();
  } );

  // Disconnect
  ipcMain.handle( 'tunnel:disconnect', ( _e, tunnelId: string ) =>
  {
    const agent = agents.get( tunnelId );
    agent?.stop();
    agents.delete( tunnelId );
    mainWindow?.webContents.send( 'tunnel:status', tunnelId, false );
  } );

  // Add tunnel
  ipcMain.handle( 'tunnel:add', async ( _e, data: object ) =>
  {
    const res = await apiFetch( '/api/tunnels', { method: 'POST', body: JSON.stringify( data ) } );
    if ( !res.ok )
    {
      const err = await res.json() as { error: string };
      throw new Error( err.error ?? 'Failed to create tunnel' );
    }
    return res.json();
  } );

  // Delete tunnel
  ipcMain.handle( 'tunnel:delete', async ( _e, tunnelId: string ) =>
  {
    agents.get( tunnelId )?.stop();
    agents.delete( tunnelId );
    await apiFetch( `/api/tunnels/${ tunnelId }`, { method: 'DELETE' } );
  } );
}

// ── Startup ───────────────────────────────────────────────────────────────────

app.whenReady().then( () =>
{
  registerIPC();

  currentTokens = loadTokens();

  if ( currentTokens )
  {
    createMainWindow();
    buildTray();
  }
  else
  {
    createLoginWindow();
  }

  app.on( 'activate', () =>
  {
    if ( BrowserWindow.getAllWindows().length === 0 )
    {
      if ( currentTokens ) createMainWindow();
      else createLoginWindow();
    }
  } );
} );

// Stay alive in tray when all windows are closed
app.on( 'window-all-closed', () => { /* tray keeps the app alive */ } );

app.on( 'before-quit', () =>
{
  for ( const agent of agents.values() ) agent.stop();
  agents.clear();
} );