import GameLoop from './game-loop/game-loop';

import './index.scss';

import { initAnalytics, trackExport, trackVibeChange } from './analytics';
import { preloadPianoSamples } from './audio/piano-samples';
import { appConfig } from './config';
import { CollapsiblePanelAnimator } from './page/collapsible-panel-animator';
import { ConfigPane } from './page/config-pane';
import { FullScreenHandler } from './page/full-screen-handler';
import { MenuHider } from './page/menu-hider';
import { activeVibe, applyVibeSettings, resetSettings, settings } from './settings';
import { readBrowserStorage, writeBrowserStorage } from './utils/browser-storage';
import { clamp } from './utils/clamp';
import { DeltaTimeCalculator } from './utils/delta-time-calculator';
import { queryRequiredElement, queryRequiredElements } from './utils/dom';
import {
  ErrorHandler,
  getErrorMessage,
  RuntimeError,
  Severity,
} from './utils/error-handler';
import { initializeGpu } from './utils/graphics/initialize-gpu';
import { VIBE_PRESETS } from './vibes';

const clampEraserSize = (value: number): number => {
  const safeValue = Number.isFinite(value) ? value : appConfig.toolbar.eraser.default;
  return Math.min(
    appConfig.toolbar.eraser.max,
    Math.max(appConfig.toolbar.eraser.min, Math.round(safeValue))
  );
};

const getEraserSizeRatio = (size: number): number =>
  (size - appConfig.toolbar.eraser.min) /
  (appConfig.toolbar.eraser.max - appConfig.toolbar.eraser.min);

const clampMirrorSegmentCount = (value: number): number => {
  const safeValue = Number.isFinite(value) ? value : appConfig.toolbar.mirror.default;
  return Math.min(
    appConfig.toolbar.mirror.max,
    Math.max(appConfig.toolbar.mirror.min, Math.round(safeValue))
  );
};

const getMirrorSegmentRatio = (count: number): number =>
  (count - appConfig.toolbar.mirror.min) /
  (appConfig.toolbar.mirror.max - appConfig.toolbar.mirror.min);

const mirrorSegmentNames: Readonly<Record<number, string>> =
  appConfig.toolbar.mirror.names;

const formatMirrorSegmentCount = (count: number): string =>
  count === appConfig.toolbar.mirror.default
    ? appConfig.toolbar.mirror.offLabel
    : `${count} ${mirrorSegmentNames[count] ?? appConfig.toolbar.mirror.fallbackSegmentName}`;

const clampAudioVolume = (value: number): number => {
  const safeValue = Number.isFinite(value) ? value : appConfig.toolbar.volume.default;
  return clamp(safeValue, appConfig.toolbar.volume.min, appConfig.toolbar.volume.max);
};

const getAudioVolumeRatio = (volume: number): number =>
  (volume - appConfig.toolbar.volume.min) /
  (appConfig.toolbar.volume.max - appConfig.toolbar.volume.min);

const getAudioVolumePercent = (volume: number): number =>
  Math.round(getAudioVolumeRatio(volume) * 100);

const readInitialAudioVolume = (): number => {
  const storedVolume = readBrowserStorage(appConfig.storage.audioVolumeKey);
  return storedVolume === null
    ? appConfig.toolbar.volume.default
    : clampAudioVolume(Number(storedVolume));
};

const formatStoredAudioVolume = (volume: number): string =>
  clampAudioVolume(volume).toFixed(2);

type RuntimeUiError = Parameters<
  Parameters<typeof ErrorHandler.addOnErrorListener>[0]
>[0];

const renderRuntimeMessage = (container: HTMLElement, error: RuntimeUiError) => {
  const message = document.createElement('pre');
  message.className = error.severity;
  message.textContent = error.code ? `${error.message}\n${error.code}` : error.message;
  message.setAttribute('role', error.severity === Severity.ERROR ? 'alert' : 'status');
  message.setAttribute(
    'aria-live',
    error.severity === Severity.ERROR ? 'assertive' : 'polite'
  );
  container.append(message);

  if (error.severity === Severity.ERROR) {
    message.tabIndex = -1;
    message.focus({ preventScroll: true });
  }
};

const getRuntimeUiError = (exception: unknown): RuntimeUiError => ({
  severity: Severity.ERROR,
  message: getErrorMessage(exception),
  ...(exception instanceof RuntimeError ? { code: exception.code } : {}),
});

const renderStartupException = (exception: unknown) => {
  const existingContainer = document.querySelector('.errors-container');
  const container =
    existingContainer instanceof HTMLElement
      ? existingContainer
      : document.createElement('div');

  if (!(existingContainer instanceof HTMLElement)) {
    container.className = 'errors-container';
    document.body.append(container);
  }

  container.setAttribute('aria-live', 'assertive');
  renderRuntimeMessage(container, getRuntimeUiError(exception));
};

const queryAppElements = () => ({
  aside: queryRequiredElement('aside', HTMLElement),
  toolbarRow: queryRequiredElement('.toolbar-row', HTMLElement),
  infoButton: queryRequiredElement('button.info', HTMLButtonElement),
  infoElement: queryRequiredElement('.info-page', HTMLElement),
  minimizeFullScreenButton: queryRequiredElement(
    'button.minimize-full-screen',
    HTMLButtonElement
  ),
  maximizeFullScreenButton: queryRequiredElement(
    'button.maximize-full-screen',
    HTMLButtonElement
  ),
  settingsButton: queryRequiredElement('button.settings', HTMLButtonElement),
  soundButton: queryRequiredElement('button.sound', HTMLButtonElement),
  volumeControl: queryRequiredElement('.volume-control', HTMLLabelElement),
  volumeSlider: queryRequiredElement('.volume-slider', HTMLInputElement),
  restartButton: queryRequiredElement('button.restart', HTMLButtonElement),
  canvas: queryRequiredElement('canvas', HTMLCanvasElement),
  eraserPreview: queryRequiredElement('.eraser-preview', HTMLDivElement),
  errorContainer: queryRequiredElement('.errors-container', HTMLElement),
  previousVibe: queryRequiredElement('.previous-vibe', HTMLButtonElement),
  nextVibe: queryRequiredElement('.next-vibe', HTMLButtonElement),
  swatches: queryRequiredElements('.color-swatch', HTMLButtonElement),
  eraserSizeControl: queryRequiredElement('.eraser-size-control', HTMLLabelElement),
  eraserSizeSlider: queryRequiredElement('.eraser-size-slider', HTMLInputElement),
  mirrorSegmentControl: queryRequiredElement('.mirror-segment-control', HTMLLabelElement),
  mirrorSegmentSlider: queryRequiredElement('.mirror-segment-slider', HTMLInputElement),
  export4k: queryRequiredElement('.export-4k', HTMLButtonElement),
  exportStatus: queryRequiredElement('.export-status', HTMLSpanElement),
  prompt: queryRequiredElement('.garden-prompt', HTMLDivElement),
  loadingStatus: queryRequiredElement('.loading-status', HTMLDivElement),
  loadingProgress: queryRequiredElement('.loading-progress', HTMLDivElement),
});

type AppElements = ReturnType<typeof queryAppElements>;

let elements: AppElements;

const setLoadingStage = (label: string, ratio: number) => {
  const percent = Math.round(Math.max(0, Math.min(1, ratio)) * 100);
  elements.loadingStatus.textContent = label;
  elements.loadingProgress.style.setProperty('--loading-progress', `${percent}%`);
  elements.loadingProgress.setAttribute('aria-valuenow', String(percent));
};

let audioVolume = readInitialAudioVolume();
let isAudioMuted =
  readBrowserStorage(appConfig.storage.audioMutedKey) === '1' ||
  audioVolume <= appConfig.toolbar.volume.min;
let isEraserActive = false;

const persistAudioUiState = () => {
  writeBrowserStorage(appConfig.storage.audioMutedKey, isAudioMuted ? '1' : '0');
  writeBrowserStorage(
    appConfig.storage.audioVolumeKey,
    formatStoredAudioVolume(audioVolume)
  );
};

const renderAudioUi = (game: GameLoop | null) => {
  audioVolume = clampAudioVolume(audioVolume);
  const isEffectivelyMuted = isAudioMuted || audioVolume <= appConfig.toolbar.volume.min;
  const volumePercent = getAudioVolumePercent(audioVolume);

  elements.soundButton.classList.toggle('muted', isEffectivelyMuted);
  elements.soundButton.setAttribute('aria-pressed', String(isEffectivelyMuted));
  elements.soundButton.setAttribute(
    'aria-label',
    isEffectivelyMuted ? 'Unmute audio' : 'Mute audio'
  );
  elements.soundButton.title = isEffectivelyMuted ? 'Unmute audio' : 'Mute audio';

  elements.volumeSlider.min = appConfig.toolbar.volume.min.toString();
  elements.volumeSlider.max = appConfig.toolbar.volume.max.toString();
  elements.volumeSlider.step = appConfig.toolbar.volume.step.toString();
  elements.volumeSlider.value = formatStoredAudioVolume(audioVolume);
  elements.volumeSlider.setAttribute(
    'aria-valuetext',
    isEffectivelyMuted ? `Muted, ${volumePercent}%` : `${volumePercent}%`
  );
  elements.volumeControl.classList.toggle('muted', isEffectivelyMuted);
  elements.volumeControl.title = isEffectivelyMuted
    ? `Muted, ${volumePercent}% volume`
    : `${volumePercent}% volume`;
  elements.volumeControl.style.setProperty('--volume-progress', `${volumePercent}%`);

  game?.setAudioVolume(audioVolume);
  game?.setAudioMuted(isEffectivelyMuted);
};

const renderPaletteUi = (game: GameLoop | null) => {
  elements.swatches.forEach((swatch, index) => {
    swatch.style.backgroundColor = activeVibe.colors[index];
    swatch.classList.toggle(
      'active',
      settings.selectedColorIndex === index && !isEraserActive
    );
  });
  elements.eraserSizeControl.classList.toggle('active', isEraserActive);
  game?.setEraseMode(isEraserActive);
  document.documentElement.style.setProperty(
    '--garden-background',
    activeVibe.backgroundColor
  );
};

const renderEraserSizeUi = (game: GameLoop | null) => {
  const size = clampEraserSize(settings.eraserSize);
  if (settings.eraserSize !== size) {
    settings.eraserSize = size;
  }

  elements.eraserSizeSlider.min = appConfig.toolbar.eraser.min.toString();
  elements.eraserSizeSlider.max = appConfig.toolbar.eraser.max.toString();
  elements.eraserSizeSlider.step = appConfig.toolbar.eraser.step.toString();
  elements.eraserSizeSlider.value = size.toString();
  elements.eraserSizeSlider.setAttribute('aria-valuetext', `${size}px`);

  const ratio = getEraserSizeRatio(size);
  const scale =
    appConfig.toolbar.eraser.controlScaleMin +
    (appConfig.toolbar.eraser.controlScaleMax -
      appConfig.toolbar.eraser.controlScaleMin) *
      ratio;
  elements.eraserSizeControl.style.setProperty('--eraser-progress', `${ratio * 100}%`);
  elements.eraserSizeControl.style.setProperty(
    '--eraser-control-scale',
    scale.toFixed(3)
  );
  game?.updateEraserPreview();
};

const renderMirrorSegmentUi = () => {
  const count = clampMirrorSegmentCount(settings.mirrorSegmentCount);
  if (settings.mirrorSegmentCount !== count) {
    settings.mirrorSegmentCount = count;
  }

  elements.mirrorSegmentSlider.min = appConfig.toolbar.mirror.min.toString();
  elements.mirrorSegmentSlider.max = appConfig.toolbar.mirror.max.toString();
  elements.mirrorSegmentSlider.step = appConfig.toolbar.mirror.step.toString();
  elements.mirrorSegmentSlider.value = count.toString();

  const label = formatMirrorSegmentCount(count);
  const ratio = getMirrorSegmentRatio(count);
  elements.mirrorSegmentSlider.setAttribute('aria-valuetext', label);
  elements.mirrorSegmentControl.title = label;
  elements.mirrorSegmentControl.classList.toggle('active', count > 1);
  elements.mirrorSegmentControl.style.setProperty('--mirror-progress', `${ratio * 100}%`);
  elements.mirrorSegmentControl.style.setProperty(
    '--mirror-angle',
    `${(360 / count).toFixed(3)}deg`
  );
};

const main = async () => {
  let hasRuntimeErrorListener = false;
  try {
    initAnalytics();

    let shouldStop = false;
    let game: GameLoop | null = null;
    let configPane: ConfigPane | null = null;

    elements = queryAppElements();
    elements.errorContainer.setAttribute('aria-live', 'assertive');
    ErrorHandler.addOnErrorListener((error) => {
      renderRuntimeMessage(elements.errorContainer, error);
      if (error.severity === Severity.ERROR) {
        document.body.classList.remove('is-loading');
        game?.destroy();
        shouldStop = true;
      }
    });
    hasRuntimeErrorListener = true;

    const syncRuntimeUi = (activeGame = game) => {
      renderEraserSizeUi(game);
      renderMirrorSegmentUi();
      renderPaletteUi(activeGame);
    };

    const infoPageHandler = new CollapsiblePanelAnimator(
      elements.infoButton,
      elements.infoElement,
      elements.aside
    );

    new MenuHider(
      elements.aside,
      () =>
        FullScreenHandler.isInFullScreenMode() &&
        !configPane?.isOpen &&
        !infoPageHandler.isOpen
    );
    new FullScreenHandler(
      elements.minimizeFullScreenButton,
      elements.maximizeFullScreenButton,
      document.body
    );

    const startAudioFromUserGesture = (event: Event) => {
      if (
        isAudioMuted ||
        (event.target instanceof Node && elements.soundButton.contains(event.target))
      ) {
        return;
      }

      game?.startAudio(true);
    };

    window.addEventListener('touchend', startAudioFromUserGesture, {
      capture: true,
      passive: true,
    });
    window.addEventListener('pointerup', startAudioFromUserGesture, {
      capture: true,
      passive: true,
    });
    window.addEventListener('click', startAudioFromUserGesture, { capture: true });
    window.addEventListener('keydown', startAudioFromUserGesture, { capture: true });

    elements.restartButton.addEventListener('click', () => game?.destroy());
    elements.soundButton.addEventListener('click', () => {
      const shouldUnmute = isAudioMuted || audioVolume <= appConfig.toolbar.volume.min;
      if (shouldUnmute && audioVolume <= appConfig.toolbar.volume.min) {
        audioVolume = appConfig.toolbar.volume.default;
      }
      isAudioMuted = !shouldUnmute;
      persistAudioUiState();
      renderAudioUi(game);
      if (!isAudioMuted) {
        game?.startAudio(true);
      }
    });
    elements.volumeSlider.addEventListener('input', () => {
      audioVolume = clampAudioVolume(Number(elements.volumeSlider.value));
      isAudioMuted = audioVolume <= appConfig.toolbar.volume.min;
      persistAudioUiState();
      renderAudioUi(game);
      if (!isAudioMuted) {
        game?.startAudio(true);
      }
    });

    const selectRelativeVibe = (offset: number, source: string) => {
      const current = VIBE_PRESETS.findIndex((vibe) => vibe.id === activeVibe.id);
      const vibe =
        VIBE_PRESETS[(current + VIBE_PRESETS.length + offset) % VIBE_PRESETS.length];
      const activePreset = applyVibeSettings(vibe);
      trackVibeChange({
        vibeId: activePreset.id,
        vibeName: activePreset.name,
        source,
      });
      game?.onVibeChanged();
      syncRuntimeUi();
      configPane?.refresh();
      game?.playVibeChangeAudio(true);
    };

    elements.previousVibe.addEventListener('click', () =>
      selectRelativeVibe(-1, 'previous-button')
    );

    elements.nextVibe.addEventListener('click', () =>
      selectRelativeVibe(1, 'next-button')
    );

    elements.swatches.forEach((swatch, index) => {
      swatch.addEventListener('click', () => {
        settings.selectedColorIndex = index;
        isEraserActive = false;
        renderPaletteUi(game);
        configPane?.refresh();
      });
    });

    const activateEraser = () => {
      isEraserActive = true;
      renderPaletteUi(game);
    };

    elements.eraserSizeControl.addEventListener('pointerdown', activateEraser);
    elements.eraserSizeControl.addEventListener('click', activateEraser);
    elements.eraserSizeSlider.addEventListener('focus', activateEraser);

    elements.eraserSizeSlider.addEventListener('input', () => {
      settings.eraserSize = clampEraserSize(Number(elements.eraserSizeSlider.value));
      isEraserActive = true;
      renderEraserSizeUi(game);
      renderPaletteUi(game);
      configPane?.refresh();
    });

    elements.mirrorSegmentSlider.addEventListener('input', () => {
      settings.mirrorSegmentCount = clampMirrorSegmentCount(
        Number(elements.mirrorSegmentSlider.value)
      );
      isEraserActive = false;
      renderMirrorSegmentUi();
      renderPaletteUi(game);
      configPane?.refresh();
    });

    elements.export4k.addEventListener('click', async () => {
      if (!game || elements.export4k.disabled) {
        return;
      }

      elements.export4k.disabled = true;
      try {
        await game.export4K();
        trackExport({ vibeId: activeVibe.id });
      } catch (error) {
        ErrorHandler.addException(error, { severity: Severity.WARNING });
      } finally {
        elements.export4k.disabled = false;
      }
    });

    renderPaletteUi(game);
    renderEraserSizeUi(game);
    renderMirrorSegmentUi();
    renderAudioUi(game);

    const fontsReady = document.fonts.ready.catch((error) => {
      ErrorHandler.addException(error, {
        fallbackMessage: 'Could not load fonts.',
        severity: Severity.WARNING,
      });
    });
    setLoadingStage('Connecting to GPU…', 0.1);
    const gpu = await initializeGpu();
    configPane = new ConfigPane({
      settingsButton: elements.settingsButton,
      onConfigChange: () => {
        game?.onVibeChanged();
        syncRuntimeUi();
      },
      onOpenChange: () => undefined,
      onRuntimeChange: syncRuntimeUi,
      onRuntimeReset: () => {
        resetSettings();
        game?.onVibeChanged();
        syncRuntimeUi();
      },
      onRestart: () => game?.destroy(),
      onVibeChange: (vibeId) => {
        const vibe = VIBE_PRESETS.find((candidate) => candidate.id === vibeId);
        if (!vibe) {
          return;
        }

        const activePreset = applyVibeSettings(vibe);
        trackVibeChange({
          vibeId: activePreset.id,
          vibeName: activePreset.name,
          source: 'settings',
        });
        game?.onVibeChanged();
        syncRuntimeUi();
        game?.playVibeChangeAudio(false);
      },
    });
    infoPageHandler.onOpen = configPane.close.bind(configPane);
    setLoadingStage('Loading fonts…', 0.3);
    await fontsReady;
    setLoadingStage('Loading piano samples…', 0.45);
    await preloadPianoSamples(({ loadedCount, totalCount }) => {
      const sampleRatio = totalCount > 0 ? loadedCount / totalCount : 1;
      setLoadingStage(
        `Loading piano samples ${loadedCount}/${totalCount}…`,
        0.45 + sampleRatio * 0.3
      );
    });
    setLoadingStage('Compiling shaders…', 0.8);

    const deltaTimeCalculator = new DeltaTimeCalculator();

    let isFirstStart = true;
    while (!shouldStop) {
      game = new GameLoop(elements.canvas, gpu, deltaTimeCalculator, {
        toolbar: elements.toolbarRow,
        prompt: elements.prompt,
        eraserPreview: elements.eraserPreview,
        exportStatus: elements.exportStatus,
      });
      renderPaletteUi(game);
      renderEraserSizeUi(game);
      renderMirrorSegmentUi();
      renderAudioUi(game);

      const startPromise = game.start();
      if (isFirstStart) {
        isFirstStart = false;
        setLoadingStage('Ready', 1);
        requestAnimationFrame(() =>
          requestAnimationFrame(() => document.body.classList.remove('is-loading'))
        );
      }
      await startPromise;
    }
  } catch (e) {
    document.body.classList.remove('is-loading');
    if (hasRuntimeErrorListener) {
      ErrorHandler.addException(e);
    } else {
      renderStartupException(e);
      ErrorHandler.addException(e);
    }
    console.error(e);
  }
};

main();