import { spawn, spawnSync } from 'node:child_process';
import { fileURLToPath } from 'node:url';
import { chromium } from 'playwright';
import {
  desktopBrowserContextOptions,
  desktopBrowserViewport
} from './desktop-browser-viewport.mjs';

const battleId = 'first-battle-zhuo-commandery';
const renderer = process.env.VERIFY_BATTLE_KEYBOARD_RENDERER;
if (!renderer) {
  for (const requestedRenderer of ['canvas', 'webgl']) {
    const result = spawnSync(
      process.execPath,
      [fileURLToPath(import.meta.url)],
      {
        cwd: process.cwd(),
        env: {
          ...process.env,
          VERIFY_BATTLE_KEYBOARD_RENDERER: requestedRenderer
        },
        stdio: 'inherit'
      }
    );
    if (result.status !== 0) {
      process.exit(result.status ?? 1);
    }
  }
  process.exit(0);
}
assert(
  renderer === 'canvas' || renderer === 'webgl',
  `Unsupported renderer: ${renderer}`
);
const baseUrl =
  process.env.VERIFY_BATTLE_KEYBOARD_URL ??
  'http://127.0.0.1:41796/heros_web/';
const targetUrl = withDebugOptions(baseUrl, renderer);

let serverProcess;
let browser;

try {
  serverProcess = await ensureLocalServer(targetUrl);
  browser = await chromium.launch({
    headless: process.env.VERIFY_BATTLE_KEYBOARD_HEADLESS !== '0'
  });
  const context = await browser.newContext(desktopBrowserContextOptions);
  const page = await context.newPage();
  page.setDefaultTimeout(30000);

  const pageErrors = [];
  const consoleErrors = [];
  page.on('pageerror', (error) => pageErrors.push(error.stack ?? error.message));
  page.on('console', (message) => {
    if (message.type() === 'error') {
      consoleErrors.push(message.text());
    }
  });

  await page.goto(targetUrl, {
    waitUntil: 'domcontentloaded',
    timeout: 90000
  });
  await page.evaluate(() => window.localStorage.clear());
  await page.reload({
    waitUntil: 'domcontentloaded',
    timeout: 90000
  });
  await waitForDebugApi(page);
  await assertDesktopViewport(page);
  await assertRendererAndBasePath(page, renderer);

  await page.evaluate((requestedBattleId) => {
    window.__HEROS_DEBUG__?.goToBattle(requestedBattleId);
  }, battleId);
  await page.waitForFunction(
    (requestedBattleId) => {
      const battle = window.__HEROS_DEBUG__?.battle();
      const activeScenes = window.__HEROS_DEBUG__?.activeScenes?.() ?? [];
      return (
        battle?.battleId === requestedBattleId &&
        battle.phase === 'deployment' &&
        battle.mapBackgroundReady === true &&
        ['ready', 'degraded'].includes(battle.combatAssets?.status) &&
        activeScenes.length === 1 &&
        activeScenes[0] === 'BattleScene'
      );
    },
    battleId,
    { timeout: 90000 }
  );

  await installPointerInputRecorder(page);
  let state = await readBattleState(page);
  assertFirstBattleObjectiveDefinitions(state.objectiveDefinitions);
  assertDeploymentKeyboardFocus(state.deploymentKeyboard, 'start');
  assertDeploymentKeyboardOrder(state.deploymentKeyboard);

  await page.keyboard.press('Tab');
  await waitForDeploymentFocus(page, state.deploymentKeyboard.items[0].id);
  state = await readBattleState(page);
  assertDeploymentKeyboardFocus(
    state.deploymentKeyboard,
    state.deploymentKeyboard.items[0].id
  );

  await page.keyboard.press('Shift+Tab');
  await waitForDeploymentFocus(page, 'start');
  state = await readBattleState(page);
  assertDeploymentKeyboardFocus(state.deploymentKeyboard, 'start');

  await page.keyboard.press('ArrowRight');
  await waitForDeploymentFocus(page, state.deploymentKeyboard.items[0].id);
  state = await readBattleState(page);
  assertDeploymentKeyboardFocus(
    state.deploymentKeyboard,
    state.deploymentKeyboard.items[0].id
  );

  await page.keyboard.press('ArrowLeft');
  await waitForDeploymentFocus(page, 'start');
  state = await readBattleState(page);
  assertDeploymentKeyboardFocus(state.deploymentKeyboard, 'start');

  const firstDeploymentItemId = state.deploymentKeyboard.items[0].id;
  const secondDeploymentItemId = state.deploymentKeyboard.items[1].id;
  await page.keyboard.down('ArrowRight');
  await waitForDeploymentFocus(page, firstDeploymentItemId);
  await page.keyboard.down('ArrowRight');
  await waitForDeploymentFocus(page, secondDeploymentItemId);
  await page.keyboard.up('ArrowRight');
  await page.keyboard.press('ArrowLeft');
  await waitForDeploymentFocus(page, firstDeploymentItemId);
  await page.keyboard.press('ArrowLeft');
  await waitForDeploymentFocus(page, 'start');

  await dispatchKeyDownWithoutKeyUp(page, 'Tab', 'Tab');
  await waitForDeploymentFocus(page, firstDeploymentItemId);
  await page.evaluate(() => {
    window.dispatchEvent(new Event('blur'));
  });
  await page.keyboard.press('Tab');
  await waitForDeploymentFocus(page, secondDeploymentItemId);
  await page.keyboard.press('Shift+Tab');
  await waitForDeploymentFocus(page, firstDeploymentItemId);
  await page.keyboard.press('Shift+Tab');
  await waitForDeploymentFocus(page, 'start');

  await page.screenshot({
    path: `dist/verification-battle-keyboard-deployment-focus-${renderer}.png`,
    fullPage: true
  });

  await page.keyboard.press('Enter');
  await page.waitForFunction(
    (requestedBattleId) => {
      const battle = window.__HEROS_DEBUG__?.battle();
      return battle?.battleId === requestedBattleId && battle.phase === 'idle';
    },
    battleId,
    { timeout: 30000 }
  );

  await page.waitForFunction(
    () => {
      const battle = window.__HEROS_DEBUG__?.battle();
      return (
        battle?.phase === 'idle' &&
        battle.activeBattleEvent === null &&
        battle.firstBattleTutorial?.active === true &&
        battle.firstBattleTutorial.step === 'select-unit'
      );
    },
    undefined,
    { timeout: 30000 }
  );

  state = await readBattleState(page);
  const tutorialPath = state.firstBattleTutorial?.path;
  assert(
    tutorialPath?.unitId &&
      tutorialPath.from &&
      tutorialPath.moveTile &&
      tutorialPath.targetId &&
      tutorialPath.targetTile,
    `Expected a complete first-battle tutorial path: ${JSON.stringify(state.firstBattleTutorial)}`
  );

  state = await focusBattleCursorAt(page, tutorialPath.from, {
    expectedMode: 'unit',
    expectedUnitId: tutorialPath.unitId
  });
  assertIdleUnitKeyboardFocus(state, tutorialPath.unitId, tutorialPath.from);

  await page.screenshot({
    path: `dist/verification-battle-keyboard-idle-focus-${renderer}.png`,
    fullPage: true
  });

  await page.keyboard.press('Enter');
  await page.waitForFunction(
    (expectedUnitId) => {
      const battle = window.__HEROS_DEBUG__?.battle();
      return (
        battle?.phase === 'moving' &&
        battle.selectedUnitId === expectedUnitId &&
        battle.firstBattleTutorial?.step === 'move'
      );
    },
    tutorialPath.unitId
  );

  state = await focusBattleCursorAt(page, tutorialPath.moveTile, {
    expectedMode: 'move'
  });
  assertBattleCursor(state.keyboardBattleCursor, tutorialPath.moveTile, 'move');
  await page.keyboard.press('Enter');
  await page.waitForFunction(
    (expectedUnitId) => {
      const battle = window.__HEROS_DEBUG__?.battle();
      return (
        battle?.phase === 'command' &&
        battle.selectedUnitId === expectedUnitId &&
        battle.pendingMove?.unitId === expectedUnitId &&
        battle.firstBattleTutorial?.step === 'attack-command' &&
        battle.commandMenuKeyboard?.visible === true
      );
    },
    tutorialPath.unitId,
    { timeout: 30000 }
  );

  await focusMenuItem(page, 'attack');
  state = await readBattleState(page);
  assertCommandMenuFocus(state.commandMenuKeyboard, 'command');
  assert(
    state.commandMenuKeyboard.focusedItem.id === 'attack',
    `Expected attack to receive keyboard focus: ${JSON.stringify(state.commandMenuKeyboard)}`
  );
  await page.keyboard.press('Enter');
  await page.waitForFunction(
    (expectedUnitId) => {
      const battle = window.__HEROS_DEBUG__?.battle();
      return (
        battle?.phase === 'targeting' &&
        battle.selectedUnitId === expectedUnitId &&
        battle.firstBattleTutorial?.step === 'target-preview'
      );
    },
    tutorialPath.unitId
  );

  state = await focusBattleCursorAt(page, tutorialPath.targetTile, {
    expectedMode: 'damage',
    expectedUnitId: tutorialPath.targetId
  });
  assertBattleCursor(
    state.keyboardBattleCursor,
    tutorialPath.targetTile,
    'damage',
    tutorialPath.targetId
  );
  await page.keyboard.press('Enter');
  await page.waitForFunction(
    (expectedTargetId) => {
      const battle = window.__HEROS_DEBUG__?.battle();
      return (
        battle?.firstBattleTutorial?.targetPreviewLocked === true &&
        battle.combatExchangePreview?.defenderId === expectedTargetId
      );
    },
    tutorialPath.targetId
  );

  state = await readBattleState(page);
  assert(
    state.combatExchangePreview?.attackerId === tutorialPath.unitId &&
      state.combatExchangePreview.defenderId === tutorialPath.targetId &&
      Number.isFinite(state.combatExchangePreview.attackDamage) &&
      Number.isFinite(state.combatExchangePreview.attackHitRate),
    `Expected a keyboard-selected attack forecast before confirmation: ${JSON.stringify(state.combatExchangePreview)}`
  );

  await page.screenshot({
    path: `dist/verification-battle-keyboard-attack-preview-${renderer}.png`,
    fullPage: true
  });

  await page.keyboard.press('Enter');
  await page.waitForFunction(
    (unitId) => {
      const battle = window.__HEROS_DEBUG__?.battle();
      return (
        battle?.actedUnitIds?.includes(unitId) &&
        battle.commandMenuKeyboard?.visible === false &&
        battle.firstBattleTutorial?.active === false
      );
    },
    tutorialPath.unitId,
    { timeout: 30000 }
  );

  const completed = await page.evaluate((unitId) => {
    const state = window.__HEROS_DEBUG__?.battle();
    const qa = window.__HEROS_KEYBOARD_COMMAND_QA__;
    return {
      selectedUnitId: state?.selectedUnitId ?? null,
      pendingMove: state?.pendingMove ?? null,
      acted: state?.actedUnitIds?.includes(unitId) ?? false,
      commandMenu: state?.commandMenuKeyboard ?? null,
      phase: state?.phase ?? null,
      tutorialActive: state?.firstBattleTutorial?.active ?? null,
      pointerInputCount: qa?.pointerInputCount ?? -1
    };
  }, tutorialPath.unitId);
  assert(
    completed.acted &&
      completed.commandMenu?.visible === false &&
      completed.tutorialActive === false,
    `Keyboard attack confirmation must complete exactly one first action: ${JSON.stringify(completed)}`
  );
  assert(
    completed.pointerInputCount === 0,
    `Deployment-to-attack keyboard flow emitted mouse/pointer input: ${JSON.stringify(completed)}`
  );

  state = await waitForAutoFocusedUnitWithKeyboard(page);
  const handoffUnit = state.units?.find(
    (unit) => unit.id === state.selectedUnitId
  );
  assert(
    handoffUnit?.id === 'zhang-fei' &&
      handoffUnit.faction === 'ally' &&
      handoffUnit.hp > 0 &&
      handoffUnit.acted === false,
    `Expected the first completed action to hand keyboard focus to Zhang Fei: ${JSON.stringify({
      selectedUnitId: state.selectedUnitId,
      units: state.units
    })}`
  );

  await focusBattleCursorAt(
    page,
    { x: handoffUnit.x, y: handoffUnit.y },
    { expectedMode: 'move' }
  );
  await page.keyboard.press('Enter');
  await page.waitForFunction(
    (unitId) => {
      const battle = window.__HEROS_DEBUG__?.battle();
      return (
        battle?.selectedUnitId === unitId &&
        battle.pendingMove?.unitId === unitId &&
        battle.commandMenuKeyboard?.visible === true
      );
    },
    handoffUnit.id
  );
  await focusMenuItem(page, 'wait');
  await page.keyboard.press('Enter');
  await page.waitForFunction(
    (unitId) => {
      const battle = window.__HEROS_DEBUG__?.battle();
      return (
        battle?.actedUnitIds?.includes(unitId) &&
        battle.commandMenuKeyboard?.visible === false
      );
    },
    handoffUnit.id
  );

  state = await waitForAutoFocusedUnitWithKeyboard(page);
  const menuUnit = state.units?.find(
    (unit) => unit.id === state.selectedUnitId
  );
  assert(
    menuUnit?.id === 'liu-bei' &&
      menuUnit.faction === 'ally' &&
      menuUnit.hp > 0 &&
      menuUnit.acted === false,
    `Expected Zhang Fei's wait to hand keyboard focus to Liu Bei: ${JSON.stringify({
      selectedUnitId: state.selectedUnitId,
      units: state.units
    })}`
  );

  await focusBattleCursorAt(
    page,
    { x: menuUnit.x, y: menuUnit.y },
    { expectedMode: 'move' }
  );
  await page.keyboard.press('Enter');
  await page.waitForFunction(
    (unitId) => {
      const battle = window.__HEROS_DEBUG__?.battle();
      return (
        battle?.selectedUnitId === unitId &&
        battle.pendingMove?.unitId === unitId &&
        battle.commandMenuKeyboard?.visible === true &&
        battle.commandMenuKeyboard.mode === 'command'
      );
    },
    menuUnit.id
  );

  state = await readBattleState(page);
  assertCommandMenuFocus(state.commandMenuKeyboard, 'command');
  const commandItems = state.commandMenuKeyboard.items;
  const attackCommand = commandItems.find(({ id }) => id === 'attack');
  const strategyCommand = commandItems.find(({ id }) => id === 'strategy');
  assert(
    attackCommand?.available === false &&
      strategyCommand?.available === true &&
      state.commandMenuKeyboard.focusedItem.id === 'strategy',
    `Default command focus must skip unavailable attack and land on strategy: ${JSON.stringify(state.commandMenuKeyboard)}`
  );

  const availableCommandIds = commandItems
    .filter(({ available }) => available)
    .map(({ id }) => id);
  const strategyIndex = availableCommandIds.indexOf('strategy');
  const previousCommandId =
    availableCommandIds[
      (strategyIndex - 1 + availableCommandIds.length) %
        availableCommandIds.length
    ];
  await page.keyboard.press('Shift+Tab');
  state = await readBattleState(page);
  assert(
    state.commandMenuKeyboard?.focusedItem?.id === previousCommandId,
    `Shift+Tab must wrap to the previous available command: ${JSON.stringify(state.commandMenuKeyboard)}`
  );
  await page.keyboard.press('Tab');
  state = await readBattleState(page);
  assert(
    state.commandMenuKeyboard?.focusedItem?.id === 'strategy',
    `Tab must return to strategy without visiting disabled attack: ${JSON.stringify(state.commandMenuKeyboard)}`
  );

  await page.keyboard.press('Enter');
  await page.waitForFunction(() => {
    const keyboard = window.__HEROS_DEBUG__?.battle()?.commandMenuKeyboard;
    return keyboard?.visible === true && keyboard.mode === 'usable';
  });
  state = await readBattleState(page);
  assertCommandMenuFocus(state.commandMenuKeyboard, 'usable');
  assert(
    state.commandMenuKeyboard.items.some(({ available }) => !available) &&
      state.commandMenuKeyboard.focusedItem.available === true,
    `Usable focus must skip unavailable choices: ${JSON.stringify(state.commandMenuKeyboard)}`
  );

  await page.keyboard.press('Shift+Tab');
  state = await readBattleState(page);
  assert(
    state.commandMenuKeyboard?.focusedItem?.available === true,
    `Usable Shift+Tab must keep focus on an available choice: ${JSON.stringify(state.commandMenuKeyboard)}`
  );
  await page.keyboard.press('Escape');
  await page.waitForFunction(() => {
    const keyboard = window.__HEROS_DEBUG__?.battle()?.commandMenuKeyboard;
    return (
      keyboard?.visible === true &&
      keyboard.mode === 'command' &&
      keyboard.focusedItem?.id === 'strategy'
    );
  });
  state = await readBattleState(page);
  assert(
    state.selectedUnitId === menuUnit.id &&
      state.pendingMove?.unitId === menuUnit.id,
    `Esc must return one menu level without clearing the unit or pending move: ${JSON.stringify(state)}`
  );

  await focusMenuItem(page, 'wait');
  await page.keyboard.press('Enter');
  await page.waitForFunction(
    (unitId) => {
      const battle = window.__HEROS_DEBUG__?.battle();
      return (
        battle?.actedUnitIds?.includes(unitId) &&
        battle.commandMenuKeyboard?.visible === false
      );
    },
    menuUnit.id
  );

  const finalInputState = await page.evaluate(() => {
    const qa = window.__HEROS_KEYBOARD_COMMAND_QA__;
    if (qa?.recordPointerInput) {
      window.removeEventListener(
        'mousedown',
        qa.recordPointerInput,
        true
      );
      window.removeEventListener(
        'pointerdown',
        qa.recordPointerInput,
        true
      );
    }
    if (qa?.recordKeyboardInput) {
      window.removeEventListener(
        'keydown',
        qa.recordKeyboardInput,
        true
      );
    }
    return {
      pointerInputCount: qa?.pointerInputCount ?? -1,
      keyboardInputCount: qa?.keyboardInputs?.length ?? 0
    };
  });
  assert(
    finalInputState.pointerInputCount === 0 &&
      finalInputState.keyboardInputCount > 0,
    `Full keyboard regression flow must complete with zero pointer input: ${JSON.stringify(finalInputState)}`
  );
  assert(
    pageErrors.length === 0,
    `Unexpected browser errors: ${JSON.stringify(pageErrors.slice(-5))}`
  );
  assert(
    consoleErrors.length === 0,
    `Unexpected console errors: ${JSON.stringify(consoleErrors.slice(-5))}`
  );

  console.log(
    `Verified ${renderer} keyboard-only first-battle flow at ${desktopBrowserViewport.width}x${desktopBrowserViewport.height} DPR1 under /heros_web/: ` +
      'deployment focus cycles with Tab/Shift+Tab and held arrows, focus-loss recovery works without keyup, Enter starts the recommended deployment, ' +
      'idle ally selection, movement, attack forecast, and confirmation complete one action; disabled command and usable choices are skipped, ' +
      'submenu Escape preserves the pending move, and a second action completes with zero pointer input.'
  );
} finally {
  await browser?.close();
  await stopServerProcess(serverProcess);
}

function withDebugOptions(url, requestedRenderer) {
  const parsed = new URL(url);
  parsed.searchParams.set('debug', '1');
  parsed.searchParams.set('renderer', requestedRenderer);
  parsed.searchParams.set('debugCombatAssetWatchdogMs', '250');
  return parsed.toString();
}

async function dispatchKeyDownWithoutKeyUp(page, key, code) {
  await page.evaluate(
    ({ requestedKey, requestedCode }) => {
      window.dispatchEvent(
        new KeyboardEvent('keydown', {
          key: requestedKey,
          code: requestedCode,
          bubbles: true,
          cancelable: true
        })
      );
    },
    { requestedKey: key, requestedCode: code }
  );
}

async function installPointerInputRecorder(page) {
  await page.evaluate(() => {
    const recordPointerInput = () => {
      window.__HEROS_KEYBOARD_COMMAND_QA__.pointerInputCount += 1;
    };
    const recordKeyboardInput = (event) => {
      window.__HEROS_KEYBOARD_COMMAND_QA__.keyboardInputs.push({
        code: event.code,
        key: event.key,
        shiftKey: event.shiftKey,
        repeat: event.repeat
      });
    };
    window.__HEROS_KEYBOARD_COMMAND_QA__ = {
      pointerInputCount: 0,
      recordPointerInput,
      recordKeyboardInput,
      keyboardInputs: []
    };
    window.addEventListener('mousedown', recordPointerInput, true);
    window.addEventListener('pointerdown', recordPointerInput, true);
    window.addEventListener('keydown', recordKeyboardInput, true);
  });
}

function assertDeploymentKeyboardOrder(keyboard) {
  const ids = keyboard?.items?.map(({ id }) => id) ?? [];
  const firstSlotIndex = ids.findIndex((id) => id.startsWith('slot:'));
  const lastUnitIndex = ids.findLastIndex((id) => id.startsWith('unit:'));
  assert(
    ids.length >= 4 &&
      ids.at(-2) === 'restore' &&
      ids.at(-1) === 'start' &&
      lastUnitIndex >= 0 &&
      firstSlotIndex > lastUnitIndex &&
      ids.slice(0, firstSlotIndex).every((id) => id.startsWith('unit:')) &&
      ids
        .slice(firstSlotIndex, -2)
        .every((id) => id.startsWith('slot:')),
    `Expected deployment order roles -> slots -> restore -> start: ${JSON.stringify(keyboard)}`
  );
}

function assertFirstBattleObjectiveDefinitions(objectives) {
  assert(
    Array.isArray(objectives) && objectives.length === 4,
    `Expected exactly four first-battle objective definitions: ${JSON.stringify(objectives)}`
  );

  const byId = Object.fromEntries(
    objectives.map((objective) => [objective.id, objective])
  );
  assert(
    byId.leader?.kind === 'defeat-leader' &&
      byId.leader.rewardGold === 200,
    `Expected the commander objective to reward 200 gold: ${JSON.stringify(byId.leader)}`
  );
  assert(
    byId['liu-bei']?.kind === 'keep-unit-alive' &&
      byId['liu-bei'].rewardGold === 100,
    `Expected the Liu Bei survival objective to reward 100 gold: ${JSON.stringify(byId['liu-bei'])}`
  );
  assert(
    byId.village?.kind === 'secure-terrain' &&
      byId.village.terrain === 'village' &&
      byId.village.targetTile?.radius === 4 &&
      byId.village.rewardGold === 210,
    `Expected the village objective to expose radius 4 and reward 210 gold: ${JSON.stringify(byId.village)}`
  );
  assert(
    byId.quick?.kind === 'quick-victory' &&
      byId.quick.maxTurn === 15 &&
      byId.quick.rewardGold === 120,
    `Expected the quick-victory objective to expose 15 turns and reward 120 gold: ${JSON.stringify(byId.quick)}`
  );
}

function assertDeploymentKeyboardFocus(keyboard, expectedId) {
  const focusedItem = keyboard?.focusedItem;
  const matchingItem = keyboard?.items?.find(({ id }) => id === expectedId);
  const guidanceText = keyboard?.guidance?.text ?? '';
  assert(
    keyboard?.visible === true &&
      focusedItem?.id === expectedId &&
      focusedItem.available !== false &&
      matchingItem?.focused === true &&
      keyboard.items.filter(({ focused }) => focused).length === 1 &&
      focusedItem.bounds &&
      boundsInsideViewport(focusedItem.bounds) &&
      (focusedItem.lineWidth ?? matchingItem.lineWidth ?? 0) >= 3 &&
      guidanceText.includes('Tab') &&
      guidanceText.includes('Enter') &&
      guidanceText.includes('Esc') &&
      boundsInsideViewport(keyboard.guidance?.bounds),
    `Expected visible deployment keyboard focus and guidance on ${expectedId}: ${JSON.stringify(keyboard)}`
  );
}

async function waitForDeploymentFocus(page, expectedId) {
  try {
    await page.waitForFunction(
      (id) =>
        window.__HEROS_DEBUG__?.battle()?.deploymentKeyboard?.focusedItem
          ?.id === id,
      expectedId
    );
  } catch (error) {
    const diagnostic = await page.evaluate(() => ({
      deploymentKeyboard: window.__HEROS_DEBUG__?.battle()?.deploymentKeyboard,
      keyboardInputs: window.__HEROS_KEYBOARD_COMMAND_QA__?.keyboardInputs ?? []
    }));
    throw new Error(
      `Timed out waiting for deployment keyboard focus ${expectedId}: ${JSON.stringify(diagnostic)}`,
      { cause: error }
    );
  }
}

async function focusBattleCursorAt(
  page,
  expectedTile,
  { expectedMode, expectedUnitId } = {}
) {
  for (let attempt = 0; attempt < 96; attempt += 1) {
    const state = await readBattleState(page);
    const cursor = state?.keyboardBattleCursor;
    const cursorUnitId =
      cursor?.unitId ??
      cursor?.targetId ??
      state?.units?.find(
        (unit) =>
          unit.hp > 0 &&
          unit.x === cursor?.x &&
          unit.y === cursor?.y
      )?.id;
    if (
      cursor?.x === expectedTile.x &&
      cursor?.y === expectedTile.y &&
      (!expectedMode || cursor.mode === expectedMode) &&
      (!expectedUnitId || cursorUnitId === expectedUnitId)
    ) {
      return state;
    }
    await page.keyboard.press('Tab');
    await page.waitForTimeout(20);
  }
  throw new Error(
    `Could not focus ${expectedMode ?? 'battle'} cursor at ${expectedTile.x},${expectedTile.y} for ${expectedUnitId ?? 'any unit'}.`
  );
}

function assertIdleUnitKeyboardFocus(state, expectedUnitId, expectedTile) {
  const focusedUnit = state?.units?.find(
    (unit) =>
      unit.hp > 0 &&
      unit.x === state.keyboardBattleCursor?.x &&
      unit.y === state.keyboardBattleCursor?.y
  );
  assert(
    state?.phase === 'idle' &&
      state.selectedUnitId === null &&
      state.keyboardBattleCursor?.mode === 'unit' &&
      focusedUnit?.id === expectedUnitId &&
      focusedUnit.faction === 'ally' &&
      focusedUnit.acted === false &&
      state.keyboardBattleCursor.x === expectedTile.x &&
      state.keyboardBattleCursor.y === expectedTile.y,
    `Expected one keyboard-focused actionable ally before selection: ${JSON.stringify({
      cursor: state?.keyboardBattleCursor,
      focusedUnit,
      selectedUnitId: state?.selectedUnitId,
      phase: state?.phase
    })}`
  );
}

function assertBattleCursor(cursor, expectedTile, expectedMode, expectedTargetId) {
  assert(
    cursor?.mode === expectedMode &&
      cursor.x === expectedTile.x &&
      cursor.y === expectedTile.y &&
      (!expectedTargetId ||
        cursor.targetId === expectedTargetId ||
        cursor.unitId === expectedTargetId),
    `Expected ${expectedMode} keyboard cursor at ${expectedTile.x},${expectedTile.y}: ${JSON.stringify(cursor)}`
  );
}

async function waitForAutoFocusedUnitWithKeyboard(page) {
  for (let attempt = 0; attempt < 300; attempt += 1) {
    const state = await readBattleState(page);
    const selected = state?.units?.find(
      (unit) => unit.id === state.selectedUnitId
    );
    if (
      state?.phase === 'moving' &&
      state.activeFaction === 'ally' &&
      !state.activeBattleEvent &&
      selected?.faction === 'ally' &&
      selected.hp > 0 &&
      selected.acted === false
    ) {
      return state;
    }
    if (state?.activeBattleEvent) {
      await page.keyboard.press('Enter');
    }
    await page.waitForTimeout(100);
  }
  const state = await readBattleState(page);
  throw new Error(
    `Could not reach the next auto-focused ally after a keyboard action: ${JSON.stringify({
      phase: state?.phase,
      activeFaction: state?.activeFaction,
      activeBattleEvent: state?.activeBattleEvent,
      combatCutIn: state?.combatCutIn,
      selectedUnitId: state?.selectedUnitId,
      keyboardBattleCursor: state?.keyboardBattleCursor,
      actedUnitIds: state?.actedUnitIds
    })}`
  );
}

async function focusMenuItem(page, expectedId) {
  for (let attempt = 0; attempt < 8; attempt += 1) {
    const keyboard = await page.evaluate(
      () => window.__HEROS_DEBUG__?.battle()?.commandMenuKeyboard
    );
    assertCommandMenuFocus(keyboard, keyboard?.mode);
    if (keyboard.focusedItem.id === expectedId) {
      return;
    }
    const target = keyboard.items.find(({ id }) => id === expectedId);
    assert(
      target?.available,
      `Expected ${expectedId} to be keyboard-selectable: ${JSON.stringify(keyboard)}`
    );
    await page.keyboard.press('Tab');
  }
  throw new Error(`Could not focus command menu item ${expectedId}.`);
}

function assertCommandMenuFocus(keyboard, expectedMode) {
  assert(
    keyboard?.visible === true &&
      keyboard.mode === expectedMode &&
      keyboard.focusedItem?.available === true &&
      keyboard.focusedItem.bounds &&
      keyboard.focusedItem.lineWidth >= 3 &&
      keyboard.focusMarker?.visible === true &&
      keyboard.focusMarker.text === '▶' &&
      keyboard.focusMarker.bounds &&
      boundsInside(keyboard.focusMarker.bounds, keyboard.focusedItem.bounds) &&
      keyboard.guidance?.text.includes('↑↓/Tab') &&
      keyboard.guidance.text.includes('Enter') &&
      keyboard.guidance.text.includes('Esc') &&
      boundsInsideViewport(keyboard.guidance.bounds),
    `Expected one visible non-color keyboard focus and on-screen controls guidance: ${JSON.stringify(keyboard)}`
  );
  assert(
    keyboard.items.filter(({ focused }) => focused).length === 1,
    `Expected exactly one focused menu item: ${JSON.stringify(keyboard)}`
  );
}

async function readBattleState(page) {
  return page.evaluate(() => window.__HEROS_DEBUG__?.battle());
}

function boundsInside(inner, outer) {
  return (
    inner.x >= outer.x - 1 &&
    inner.y >= outer.y - 1 &&
    inner.x + inner.width <= outer.x + outer.width + 1 &&
    inner.y + inner.height <= outer.y + outer.height + 1
  );
}

function boundsInsideViewport(bounds) {
  return (
    bounds &&
    bounds.x >= 0 &&
    bounds.y >= 0 &&
    bounds.x + bounds.width <= desktopBrowserViewport.width &&
    bounds.y + bounds.height <= desktopBrowserViewport.height
  );
}

async function waitForDebugApi(page) {
  await page.waitForFunction(
    () =>
      Boolean(
        window.__HEROS_DEBUG__?.activeScenes &&
          window.__HEROS_DEBUG__?.goToBattle
      ),
    undefined,
    { timeout: 90000 }
  );
}

async function assertDesktopViewport(page) {
  const viewport = await page.evaluate(() => {
    const canvas = document.querySelector('canvas');
    return {
      width: window.innerWidth,
      height: window.innerHeight,
      dpr: window.devicePixelRatio,
      zoom: window.visualViewport?.scale ?? 1,
      canvas: canvas
        ? { width: canvas.width, height: canvas.height }
        : null
    };
  });
  assert(
    viewport.width === desktopBrowserViewport.width &&
      viewport.height === desktopBrowserViewport.height &&
      viewport.dpr === 1 &&
      viewport.zoom === 1 &&
      viewport.canvas?.width === desktopBrowserViewport.width &&
      viewport.canvas?.height === desktopBrowserViewport.height,
    `Expected explicit 1920x1080 CSS viewport, 100% zoom, and DPR1: ${JSON.stringify(viewport)}`
  );
}

async function assertRendererAndBasePath(page, requestedRenderer) {
  const runtime = await page.evaluate(() => ({
    pathname: window.location.pathname,
    rendererType: window.__HEROS_GAME__?.renderer?.type ?? null,
    rendererName:
      window.__HEROS_GAME__?.renderer?.constructor?.name ?? null
  }));
  const expectedRendererType = requestedRenderer === 'canvas' ? 1 : 2;
  assert(
    runtime.pathname === '/heros_web/' &&
      runtime.rendererType === expectedRendererType,
    `Expected ${requestedRenderer} under /heros_web/: ${JSON.stringify(runtime)}`
  );
}

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

  const parsed = new URL(url);
  if (!['localhost', '127.0.0.1', '0.0.0.0'].includes(parsed.hostname)) {
    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 || '41796',
      '--strictPort'
    ],
    {
      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 attempt = 0; attempt < 120; attempt += 1) {
    if (await canReach(url)) {
      return child;
    }
    await delay(250);
  }

  await stopServerProcess(child);
  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));
}

async function stopServerProcess(child) {
  if (!child || child.exitCode !== null) {
    return;
  }

  const exited = new Promise((resolve) => {
    child.once('exit', resolve);
  });
  child.kill();
  await Promise.race([exited, delay(5000)]);
  if (child.exitCode === null) {
    child.kill('SIGKILL');
    await Promise.race([exited, delay(2000)]);
  }
}

function assert(condition, message) {
  if (!condition) {
    throw new Error(message);
  }
}