import { spawn } from 'node:child_process';
import { chromium } from 'playwright';

const targetUrl = process.env.VERIFY_URL ?? 'http://localhost:5173/';

let serverProcess;
let browser;

try {
  serverProcess = await ensureLocalServer(targetUrl);

  browser = await chromium.launch({ headless: true });
  const page = await browser.newPage({ viewport: { width: 1280, height: 720 } });

  await page.goto(targetUrl, { waitUntil: 'networkidle' });
  await page.evaluate(() => window.localStorage.clear());
  await page.reload({ waitUntil: 'networkidle' });
  await page.waitForSelector('canvas');
  await page.waitForFunction(() => window.__HEROS_GAME__ !== undefined);
  await page.waitForFunction(() => window.__HEROS_DEBUG__ !== undefined);
  await page.waitForTimeout(500);

  const debugBeforeBattle = await page.evaluate(() => window.__HEROS_DEBUG__?.activeScenes() ?? []);
  if (!debugBeforeBattle.includes('TitleScene')) {
    throw new Error(`Expected TitleScene before starting. Active scenes: ${debugBeforeBattle.join(', ')}`);
  }

  await page.mouse.click(962, 240);
  await page.waitForTimeout(250);

  for (let i = 0; i < 20; i += 1) {
    const isBattleActive = await page.evaluate(() => {
      const activeScenes = window.__HEROS_GAME__?.scene.getScenes(true) ?? [];
      return activeScenes.some((scene) => scene.scene.key === 'BattleScene');
    });

    if (isBattleActive) {
      break;
    }

    await page.keyboard.press('Space');
    await page.waitForTimeout(220);
  }

  await page.waitForFunction(() => {
    const activeScenes = window.__HEROS_GAME__?.scene.getScenes(true) ?? [];
    return activeScenes.some((scene) => scene.scene.key === 'BattleScene');
  });

  await page.keyboard.press('F9');
  await page.waitForTimeout(100);
  await page.screenshot({ path: 'dist/verification-battle.png', fullPage: true });

  const result = await page.evaluate(() => {
    const canvas = document.querySelector('canvas');
    const activeScenes = window.__HEROS_DEBUG__?.activeScenes() ?? [];
    const battleState = window.__HEROS_DEBUG__?.battle();

    return {
      activeScenes,
      battleState,
      canvasWidth: canvas?.width ?? 0,
      canvasHeight: canvas?.height ?? 0
    };
  });

  if (result.canvasWidth !== 1280 || result.canvasHeight !== 720) {
    throw new Error(`Unexpected canvas size: ${result.canvasWidth}x${result.canvasHeight}`);
  }

  if (!result.activeScenes.includes('BattleScene')) {
    throw new Error(`BattleScene was not active. Active scenes: ${result.activeScenes.join(', ')}`);
  }

  if (!result.battleState || result.battleState.scene !== 'BattleScene') {
    throw new Error(`Debug battle state was not available: ${JSON.stringify(result.battleState)}`);
  }

  if (result.battleState.battleId !== 'first-battle-zhuo-commandery') {
    throw new Error(`Expected first battle scenario id: ${JSON.stringify(result.battleState)}`);
  }

  const actionTexturesLoaded = await page.evaluate(() => {
    const textures = window.__HEROS_GAME__?.textures;
    return [
      'unit-liu-bei-actions',
      'unit-guan-yu-actions',
      'unit-zhang-fei-actions',
      'unit-rebel-actions',
      'unit-rebel-archer-actions',
      'unit-rebel-cavalry-actions',
      'unit-rebel-leader-actions'
    ].every((key) => textures?.exists(key));
  });
  if (!actionTexturesLoaded) {
    throw new Error('Expected all unit action textures to be loaded.');
  }

  await page.waitForTimeout(700);
  await page.mouse.click(260, 300, { button: 'right' });
  await page.waitForTimeout(120);
  await page.mouse.click(182, 213);
  await page.waitForTimeout(120);
  await page.mouse.click(400, 213);
  await page.waitForTimeout(180);

  const battleSlotSave = await page.evaluate(() => {
    const raw = window.localStorage.getItem('heros-web:battle:first-battle-zhuo-commandery:slot-1');
    return raw ? JSON.parse(raw) : undefined;
  });
  if (!battleSlotSave || battleSlotSave.battleId !== 'first-battle-zhuo-commandery') {
    throw new Error(`Expected slot 1 battle save from save UI: ${JSON.stringify(battleSlotSave)}`);
  }

  await page.mouse.click(260, 300, { button: 'right' });
  await page.waitForTimeout(120);
  await page.mouse.click(182, 247);
  await page.waitForTimeout(120);
  await page.mouse.click(400, 213);
  await page.waitForFunction(() => window.__HEROS_DEBUG__?.battle()?.scene === 'BattleScene');

  const cameraBeforeScroll = result.battleState.camera;
  if (
    !cameraBeforeScroll ||
    cameraBeforeScroll.mapWidth <= cameraBeforeScroll.visibleColumns ||
    cameraBeforeScroll.mapHeight <= cameraBeforeScroll.visibleRows
  ) {
    throw new Error(`Expected a scrollable battle map: ${JSON.stringify(cameraBeforeScroll)}`);
  }

  await page.mouse.move(872, 360);
  await page.waitForTimeout(520);
  const cameraAfterEdgeScroll = await page.evaluate(() => window.__HEROS_DEBUG__?.battle()?.camera);
  if (!cameraAfterEdgeScroll || cameraAfterEdgeScroll.x <= cameraBeforeScroll.x) {
    throw new Error(`Expected edge scrolling to move camera right: ${JSON.stringify({ cameraBeforeScroll, cameraAfterEdgeScroll })}`);
  }

  await page.mouse.click(1138, 553);
  await page.waitForTimeout(160);
  const cameraAfterMiniMapClick = await page.evaluate(() => window.__HEROS_DEBUG__?.battle()?.camera);
  if (
    !cameraAfterMiniMapClick ||
    cameraAfterMiniMapClick.x < cameraAfterMiniMapClick.mapWidth - cameraAfterMiniMapClick.visibleColumns ||
    cameraAfterMiniMapClick.y !== 0
  ) {
    throw new Error(`Expected minimap click to move camera to the northeast: ${JSON.stringify(cameraAfterMiniMapClick)}`);
  }

  const readyUnits = result.battleState.units.filter((unit) => !unit.acted);
  if (!readyUnits.some((unit) => unit.animating && unit.animationKey?.includes('-idle-'))) {
    throw new Error(`Expected ready units to loop idle frames: ${JSON.stringify(readyUnits)}`);
  }

  await page.keyboard.press('F9');
  await page.waitForTimeout(100);

  await page.evaluate(() => window.__HEROS_DEBUG__?.forceBattleOutcome('victory'));
  await page.waitForFunction(() => {
    const state = window.__HEROS_DEBUG__?.battle();
    return state?.battleOutcome === 'victory' && state?.phase === 'resolved' && state?.resultVisible === true;
  });

  const victoryState = await page.evaluate(() => window.__HEROS_DEBUG__?.battle());
  const livingEnemiesAfterVictory = victoryState.units.filter((unit) => unit.faction === 'enemy' && unit.hp > 0);
  if (livingEnemiesAfterVictory.length > 0) {
    throw new Error(`Expected no living enemies after forced victory: ${JSON.stringify(livingEnemiesAfterVictory)}`);
  }

  await page.screenshot({ path: 'dist/verification-battle-result-victory.png', fullPage: true });

  await page.mouse.click(738, 642);
  await page.waitForFunction(() => {
    const activeScenes = window.__HEROS_DEBUG__?.activeScenes() ?? [];
    return activeScenes.includes('CampScene');
  });
  await page.screenshot({ path: 'dist/verification-camp.png', fullPage: true });

  const campState = await page.evaluate(() => window.__HEROS_DEBUG__?.camp());
  if (!campState || campState.scene !== 'CampScene' || campState.report?.rewardGold <= 0) {
    throw new Error(`Expected CampScene report after victory: ${JSON.stringify(campState)}`);
  }

  await page.mouse.click(830, 38);
  await page.waitForTimeout(120);
  await page.mouse.click(974, 482);
  await page.waitForTimeout(260);

  const campStateAfterDialogue = await page.evaluate(() => window.__HEROS_DEBUG__?.camp());
  if (!campStateAfterDialogue.report?.completedCampDialogues?.length) {
    throw new Error(`Expected camp dialogue to award bond exp: ${JSON.stringify(campStateAfterDialogue)}`);
  }

  const campaignSaveAfterDialogue = await page.evaluate(() => {
    const raw = window.localStorage.getItem('heros-web:campaign-state');
    return raw ? JSON.parse(raw) : undefined;
  });
  if (
    !campaignSaveAfterDialogue ||
    campaignSaveAfterDialogue.step !== 'first-camp' ||
    campaignSaveAfterDialogue.latestBattleId !== 'first-battle-zhuo-commandery' ||
    !campaignSaveAfterDialogue.battleHistory?.['first-battle-zhuo-commandery'] ||
    !campaignSaveAfterDialogue.completedCampDialogues?.length ||
    Object.keys(campaignSaveAfterDialogue.inventory ?? {}).length === 0
  ) {
    throw new Error(`Expected campaign save to persist camp progress: ${JSON.stringify(campaignSaveAfterDialogue)}`);
  }

  const campaignSlotAfterDialogue = await page.evaluate(() => {
    const raw = window.localStorage.getItem('heros-web:campaign-state:slot-1');
    return raw ? JSON.parse(raw) : undefined;
  });
  if (!campaignSlotAfterDialogue || campaignSlotAfterDialogue.latestBattleId !== 'first-battle-zhuo-commandery') {
    throw new Error(`Expected campaign slot 1 to persist progress: ${JSON.stringify(campaignSlotAfterDialogue)}`);
  }

  await page.evaluate(() => window.__HEROS_GAME__?.scene.start('TitleScene'));
  await page.waitForFunction(() => {
    const activeScenes = window.__HEROS_DEBUG__?.activeScenes() ?? [];
    return activeScenes.includes('TitleScene');
  });
  await page.mouse.click(962, 310);
  await page.waitForFunction(() => {
    const activeScenes = window.__HEROS_DEBUG__?.activeScenes() ?? [];
    return activeScenes.includes('CampScene');
  });

  await page.evaluate(() => window.__HEROS_DEBUG__?.goToBattle());
  await page.waitForFunction(() => {
    const state = window.__HEROS_DEBUG__?.battle();
    return state?.scene === 'BattleScene' && state?.battleOutcome === null && state?.phase === 'idle';
  });

  await page.evaluate(() => window.__HEROS_DEBUG__?.forceBattleOutcome('defeat'));
  await page.waitForFunction(() => {
    const state = window.__HEROS_DEBUG__?.battle();
    return state?.battleOutcome === 'defeat' && state?.phase === 'resolved' && state?.resultVisible === true;
  });

  const defeatState = await page.evaluate(() => window.__HEROS_DEBUG__?.battle());
  const liuBei = defeatState.units.find((unit) => unit.id === 'liu-bei');
  if (!liuBei || liuBei.hp > 0) {
    throw new Error(`Expected Liu Bei to be defeated after forced defeat: ${JSON.stringify(liuBei)}`);
  }

  console.log(`Verified title-to-battle flow, result states, and debug API at ${targetUrl}`);
} finally {
  await browser?.close();
  if (serverProcess && !serverProcess.killed) {
    serverProcess.kill();
  }
}

async function ensureLocalServer(url) {
  if (await canReach(url)) {
    return undefined;
  }

  const parsed = new URL(url);
  const isLocal = ['localhost', '127.0.0.1', '0.0.0.0'].includes(parsed.hostname);
  if (!isLocal) {
    throw new Error(`No server responded at ${url}`);
  }

  const stderr = [];
  const child = spawn(process.execPath, ['node_modules/vite/bin/vite.js', '--host', '127.0.0.1', '--port', parsed.port || '5173'], {
    cwd: process.cwd(),
    env: process.env,
    stdio: ['ignore', 'pipe', 'pipe']
  });

  child.stderr.on('data', (chunk) => stderr.push(chunk.toString()));
  child.stdout.on('data', () => {});

  for (let i = 0; i < 80; i += 1) {
    if (await canReach(url)) {
      return child;
    }
    await delay(250);
  }

  child.kill();
  throw new Error(`Vite server did not start at ${url}\n${stderr.join('')}`);
}

async function canReach(url) {
  try {
    const response = await fetch(url, { signal: AbortSignal.timeout(1000) });
    return response.ok;
  } catch {
    return false;
  }
}

function delay(ms) {
  return new Promise((resolve) => setTimeout(resolve, ms));
}