import { Pane, type BindingParams, type FolderApi } from 'tweakpane';

import {
  appConfig,
  type GardenRuntimeSettings,
  type NumberControlConfig,
} from '../config';
import { activeVibe, settings } from '../settings';
import { VIBE_PRESETS } from '../vibes';

type PaneContainer = Pick<FolderApi, 'addBinding' | 'addButton' | 'addFolder'>;
type ColorReactionKey = (typeof colorReactionRows)[number]['keys'][number];

const colorReactionRows = [
  {
    colorIndex: 0,
    label: '1',
    keys: ['color1ToColor1', 'color1ToColor2', 'color1ToColor3'],
  },
  {
    colorIndex: 1,
    label: '2',
    keys: ['color2ToColor1', 'color2ToColor2', 'color2ToColor3'],
  },
  {
    colorIndex: 2,
    label: '3',
    keys: ['color3ToColor1', 'color3ToColor2', 'color3ToColor3'],
  },
] as const;

const colorReactionKeySet = new Set<string>(
  colorReactionRows.flatMap((row) => [...row.keys])
);

const isColorReactionKey = (key: string): key is ColorReactionKey =>
  colorReactionKeySet.has(key);

interface ConfigPaneOptions {
  onConfigChange: () => void;
  onOpenChange?: (isOpen: boolean) => void;
  onRestart: () => void;
  onRuntimeChange: () => void;
  onRuntimeReset: () => void;
  onVibeChange: (vibeId: string) => void;
  settingsButton: HTMLButtonElement;
}

const isPlainObject = (value: unknown): value is Record<string, unknown> =>
  typeof value === 'object' && value !== null;

const isBindablePrimitive = (value: unknown): value is boolean | number | string =>
  ['boolean', 'number', 'string'].includes(typeof value);

const isColorString = (value: unknown): value is string =>
  typeof value === 'string' && /^#[0-9a-f]{6}$/i.test(value);

const toLabel = (value: string): string =>
  value
    .replace(/\[(\d+)\]/g, ' $1')
    .replace(/([A-Z])/g, ' $1')
    .replace(/[-_]/g, ' ')
    .replace(/\s+/g, ' ')
    .trim();

const normalizeNumber = (value: number, config: NumberControlConfig): number => {
  if (config.options) {
    const optionValues = Object.values(config.options);
    if (optionValues.includes(value)) {
      return value;
    }
    return optionValues.includes(0) ? 0 : (optionValues[0] ?? config.min);
  }

  const finiteValue = Number.isFinite(value) ? value : config.min;
  const clampedValue = Math.min(config.max, Math.max(config.min, finiteValue));
  return config.integer ? Math.round(clampedValue) : clampedValue;
};

const getNumberBindingParams = (
  key: keyof GardenRuntimeSettings & string,
  config: NumberControlConfig
): BindingParams => ({
  label: config.label ?? toLabel(key),
  min: config.min,
  max: config.max,
  options: config.options,
  step: config.step,
});

export class ConfigPane {
  private readonly container: HTMLDivElement;
  private readonly pane: Pane;
  private readonly colorReactionSelects = new Map<ColorReactionKey, HTMLSelectElement>();
  private readonly colorReactionSwatches: Array<{
    colorIndex: number;
    element: HTMLElement;
  }> = [];
  private readonly state = {
    activeVibeId: activeVibe.id,
  };

  public constructor(private readonly options: ConfigPaneOptions) {
    this.container = document.createElement('div');
    this.container.className = 'config-pane-container';
    Object.assign(this.container.style, {
      boxSizing: 'border-box',
      maxHeight: 'calc(100vh - 24px)',
      pointerEvents: 'none',
      position: 'fixed',
      right: 'max(12px, env(safe-area-inset-right, 0px))',
      top: 'max(12px, env(safe-area-inset-top, 0px))',
      width:
        'min(420px, calc(100vw - 24px - env(safe-area-inset-left, 0px) - env(safe-area-inset-right, 0px)))',
      zIndex: '20',
    });
    document.body.appendChild(this.container);

    this.pane = new Pane({
      container: this.container,
      title: appConfig.tuningPane.title,
      expanded: true,
    });
    this.pane.hidden = appConfig.tuningPane.startHidden;
    this.pane.element.classList.add('config-pane');
    this.pane.element.style.boxSizing = 'border-box';
    this.pane.element.style.maxHeight = 'calc(100vh - 24px)';
    this.pane.element.style.overflowY = 'auto';
    this.pane.element.style.pointerEvents = 'auto';
    this.pane.element.style.width = '100%';

    this.options.settingsButton.addEventListener('click', this.toggle);

    const tabs = this.pane.addTab({
      pages: [{ title: 'Runtime' }, { title: 'Config' }],
    });

    this.setUpRuntimeTab(tabs.pages[0]);
    this.setUpConfigTab(tabs.pages[1]);
    this.syncOpenState();
  }

  public get isOpen(): boolean {
    return !this.pane.hidden;
  }

  public refresh(): void {
    this.state.activeVibeId = activeVibe.id;
    this.pane.refresh();
    this.syncColorReactionMatrix();
    this.syncOpenState();
  }

  private readonly toggle = () => {
    this.pane.hidden = !this.pane.hidden;
    this.syncOpenState();
  };

  private setHidden(isHidden: boolean): void {
    this.pane.hidden = isHidden;
    this.syncOpenState();
  }

  private setUpRuntimeTab(container: PaneContainer): void {
    container
      .addBinding(this.state, 'activeVibeId', {
        label: 'active vibe',
        options: Object.fromEntries(
          VIBE_PRESETS.map((vibe) => [vibe.name, vibe.id])
        ) as Record<string, string>,
      })
      .on('change', ({ value }) => {
        this.options.onVibeChange(value);
        this.refresh();
      });

    container
      .addButton({
        title: 'Reset runtime settings',
      })
      .on('click', () => {
        this.options.onRuntimeReset();
        this.refresh();
      });

    container
      .addButton({
        title: 'Restart simulation',
      })
      .on('click', () => this.options.onRestart());

    const folders = new Map<string, PaneContainer>();
    let hasAddedColorReactionMatrix = false;
    Object.entries(appConfig.runtimeSettings.controls).forEach(([key, config]) => {
      const settingKey = key as keyof GardenRuntimeSettings & string;
      settings[settingKey] = normalizeNumber(settings[settingKey], config);

      if (isColorReactionKey(key)) {
        if (!hasAddedColorReactionMatrix) {
          this.addColorReactionMatrix(container);
          hasAddedColorReactionMatrix = true;
        }
        return;
      }

      const folder =
        folders.get(config.folder) ??
        container.addFolder({
          title: config.folder,
          expanded: config.folder !== 'Runtime',
        });
      folders.set(config.folder, folder);

      folder
        .addBinding(settings, settingKey, getNumberBindingParams(settingKey, config))
        .on('change', () => {
          const nextValue = normalizeNumber(settings[settingKey], config);
          if (nextValue !== settings[settingKey]) {
            settings[settingKey] = nextValue;
            this.pane.refresh();
          }
          this.options.onRuntimeChange();
        });
    });
    this.syncColorReactionMatrix();
  }

  private addColorReactionMatrix(container: PaneContainer): void {
    const folder = container.addFolder({
      title: 'Color Reactions',
      expanded: true,
    });
    folder.element.classList.add('color-reaction-folder');

    const content = Array.from(folder.element.children).find((child) =>
      child.classList.contains('tp-fldv_c')
    );
    if (!(content instanceof HTMLElement)) {
      return;
    }

    const doc = folder.element.ownerDocument;
    const matrix = doc.createElement('div');
    matrix.className = 'color-reaction-matrix';

    matrix.appendChild(this.createColorReactionCorner(doc));
    colorReactionRows.forEach((row) => {
      matrix.appendChild(this.createColorReactionHeader(doc, row.colorIndex, row.label));
    });

    colorReactionRows.forEach((row) => {
      matrix.appendChild(this.createColorReactionHeader(doc, row.colorIndex, row.label));
      row.keys.forEach((key, columnIndex) => {
        matrix.appendChild(
          this.createColorReactionCell(doc, key, row.colorIndex, columnIndex)
        );
      });
    });

    content.appendChild(matrix);
    this.syncColorReactionMatrix();
  }

  private createColorReactionCorner(doc: Document): HTMLDivElement {
    const corner = doc.createElement('div');
    corner.className = 'color-reaction-matrix__corner';
    corner.textContent = 'agent';
    return corner;
  }

  private createColorReactionHeader(
    doc: Document,
    colorIndex: number,
    label: string
  ): HTMLDivElement {
    const header = doc.createElement('div');
    header.className = 'color-reaction-matrix__header';

    const swatch = doc.createElement('span');
    swatch.className = 'color-reaction-matrix__swatch';
    this.colorReactionSwatches.push({ colorIndex, element: swatch });
    header.appendChild(swatch);

    const text = doc.createElement('span');
    text.textContent = label;
    header.appendChild(text);

    return header;
  }

  private createColorReactionCell(
    doc: Document,
    key: ColorReactionKey,
    sourceColorIndex: number,
    targetColorIndex: number
  ): HTMLLabelElement {
    const cell = doc.createElement('label');
    cell.className = 'color-reaction-matrix__cell';

    const select = doc.createElement('select');
    select.setAttribute(
      'aria-label',
      `Color ${sourceColorIndex + 1} agents reacting to color ${targetColorIndex + 1}`
    );

    const config = appConfig.runtimeSettings.controls[key];
    Object.entries(config.options ?? {}).forEach(([label, value]) => {
      const option = doc.createElement('option');
      option.value = String(value);
      option.textContent = label;
      select.appendChild(option);
    });

    select.addEventListener('change', () => {
      settings[key] = normalizeNumber(Number(select.value), config);
      select.value = String(settings[key]);
      this.options.onRuntimeChange();
    });

    this.colorReactionSelects.set(key, select);
    cell.appendChild(select);

    return cell;
  }

  private syncColorReactionMatrix(): void {
    this.colorReactionSelects.forEach((select, key) => {
      const config = appConfig.runtimeSettings.controls[key];
      settings[key] = normalizeNumber(settings[key], config);
      select.value = String(settings[key]);
    });

    this.colorReactionSwatches.forEach(({ colorIndex, element }) => {
      element.style.backgroundColor = activeVibe.colors[colorIndex] ?? '#ffffff';
    });
  }

  private setUpConfigTab(container: PaneContainer): void {
    this.addObjectBindings(
      container,
      appConfig as unknown as Record<string, unknown>,
      []
    );
  }

  private addObjectBindings(
    container: PaneContainer,
    source: Record<string, unknown>,
    path: Array<string>
  ): void {
    Object.entries(source).forEach(([key, value]) => {
      if (isBindablePrimitive(value)) {
        this.addPrimitiveBinding(container, source, key, value);
        return;
      }

      if (Array.isArray(value)) {
        const folder = container.addFolder({
          title: toLabel(`${key}[]`),
          expanded: path.length < appConfig.tuningPane.expandedDepth,
        });
        value.forEach((item, index) => {
          if (isBindablePrimitive(item)) {
            this.addPrimitiveBinding(
              folder,
              value as unknown as Record<string, unknown>,
              `${index}`,
              item
            );
            return;
          }

          if (isPlainObject(item)) {
            this.addObjectBindings(
              folder.addFolder({
                title: `[${index}]`,
                expanded: false,
              }),
              item,
              [...path, key, String(index)]
            );
          }
        });
        return;
      }

      if (isPlainObject(value)) {
        this.addObjectBindings(
          container.addFolder({
            title: toLabel(key),
            expanded: path.length < appConfig.tuningPane.expandedDepth,
          }),
          value,
          [...path, key]
        );
      }
    });
  }

  private addPrimitiveBinding(
    container: PaneContainer,
    source: Record<string, unknown>,
    key: string,
    value: boolean | number | string
  ): void {
    const params: BindingParams = {
      label: toLabel(key),
      ...(isColorString(value) ? { color: { type: 'int' } } : {}),
      ...(key === 'quality' ? { options: { major: 'major', minor: 'minor' } } : {}),
    };

    container
      .addBinding(source, key, params)
      .on('change', () => this.options.onConfigChange());
  }

  private syncButton(): void {
    this.options.settingsButton.classList.toggle('active', this.isOpen);
    this.options.settingsButton.setAttribute('aria-expanded', String(this.isOpen));
    this.options.settingsButton.setAttribute(
      'aria-label',
      this.isOpen ? 'Hide config overlay' : 'Show config overlay'
    );
    this.options.settingsButton.title = this.isOpen
      ? 'Hide config overlay'
      : 'Show config overlay';
  }

  private syncOpenState(): void {
    this.syncButton();
    this.options.onOpenChange?.(this.isOpen);
  }

  public close(): void {
    this.setHidden(true);
  }
}