import { type Application, Color, type ColorSource, type Container, Rectangle, Text } from 'pixi.js';
import { resolveObjects } from '../core/model/instance';
import { findObjectHolder } from '../core/model/Project';
import { Button, ui, Widget } from '../ui';
import type { CentreTab, Editor } from './Editor';
import type { EditorState } from './state';

/**
 * Installs `window.__gm`, which the check scripts in tools/ use to find widgets by their
 * visible text and to read editor state.
 */
export function installDebugHook(app: Application, state: EditorState, editor: Editor): void {
  const { viewport, gameView, graphEditor, textureEditor, containerEditor, hierarchy } = editor;
  const centreOf = (widget: { getGlobalPosition(): { x: number; y: number }; w: number; h: number }) => {
    const p = widget.getGlobalPosition();
    return { x: p.x + widget.w / 2, y: p.y + widget.h / 2 };
  };
  /** Centre of the first (or, with `last`, the topmost/last-drawn) visible text equal to `text`. */
  const locate = (text: string, last = false): { x: number; y: number } | null => {
    let found: Text | null = null;
    const walk = (node: Container): void => {
      if ((found && !last) || !node.visible) return;
      if (node instanceof Text && node.text === text) {
        found = node;
        return;
      }
      for (const child of node.children) walk(child);
    };
    walk(app.stage);
    // TypeScript does not track the assignment inside `walk`, hence the disable and the cast.
    // eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
    if (!found) return null;
    const node = found as Text;
    const p = node.getGlobalPosition();
    return { x: p.x + node.width / 2, y: p.y + node.height / 2 };
  };
  /** Fill colour of a visible text, as `#rrggbb` – what tells an override label from a plain one. */
  const textColor = (text: string): string | null => {
    let found: string | null = null;
    const walk = (node: Container): void => {
      if (found !== null || !node.visible) return;
      if (node instanceof Text && node.text === text) {
        found = new Color(node.style.fill as ColorSource).toHex();
        return;
      }
      for (const child of node.children) walk(child);
    };
    walk(app.stage);
    return found;
  };
  /**
   * The visible text of the overlay layer, in drawing order – everything an open popup shows.
   * Menus hide filtered-out entries, so this is also what a search box currently leaves.
   */
  const overlayTexts = (): string[] => {
    const out: string[] = [];
    const walk = (node: Container): void => {
      if (!node.visible) return;
      if (node instanceof Text) {
        if (node.text) out.push(node.text);
        return;
      }
      for (const child of node.children) walk(child);
    };
    walk(ui().overlay);
    return out;
  };
  /**
   * Visible texts drawn wider than the widget that owns them. The owner's box is its declared
   * `w`/`h`, not `getBounds()`: a Pixi container's bounds are the union of its children –
   * including the overflowing text – so every overflow would measure as zero.
   */
  const textOverflows = (all = false): { text: string; owner: string; over: number }[] => {
    const out: { text: string; owner: string; over: number }[] = [];
    const walk = (node: Container, owner: Widget | null, clipped: boolean): void => {
      if (!node.visible) return;
      const isWidget = node instanceof Widget;
      const box = isWidget ? node : owner;
      // A mask further up does not excuse a label spilling out of its own control, so the
      // question restarts at every widget. `Boolean`, not `!== null`: Pixi's mask getter
      // returns `undefined` when nothing masks.
      const masked = (isWidget ? false : clipped) || Boolean(node.mask);
      if (node instanceof Text) {
        if (!box || !node.text || (masked && !all)) return;
        const text = node.getBounds();
        const origin = box.getGlobalPosition();
        const over = Math.max(text.x + text.width - (origin.x + box.w), origin.x - text.x);
        if (over > 1 || all) {
          out.push({ text: node.text, owner: box.constructor.name, over: Math.round(over) });
        }
        return;
      }
      for (const child of node.children) walk(child, box, masked);
    };
    walk(app.stage, null, false);
    return out;
  };
  /**
   * The counterpart of `textOverflows`: buttons whose label was shortened away to nothing, which
   * leaves a control that says nothing at all. An empty `Text` is invisible to the overflow walk.
   */
  const labelsDropped = (): { text: string; owner: string; w: number }[] => {
    const out: { text: string; owner: string; w: number }[] = [];
    const walk = (node: Container): void => {
      if (!node.visible) return;
      if (node instanceof Button && node.text && !node.shownText) {
        out.push({ text: node.text, owner: node.constructor.name, w: node.w });
      }
      for (const child of node.children) walk(child);
    };
    walk(app.stage);
    return out;
  };
  /** Screen rectangle of the open popup (the backdrop is not a widget), or null when none is. */
  const overlayRect = (): { x: number; y: number; w: number; h: number } | null => {
    const popups = ui().overlay.children.filter((node): node is Widget => node instanceof Widget);
    const popup = popups[popups.length - 1];
    if (!popup) return null;
    const p = popup.getGlobalPosition();
    return { x: p.x, y: p.y, w: popup.w, h: popup.h };
  };
  /**
   * A holder's objects the way the editor sees them: the content of placed containers is resolved
   * from the template, so it is nowhere in `holder.objects` (see `model/instance.ts`).
   */
  const objectsOf = (holderId: string) => {
    const holder = findObjectHolder(state.project, holderId);
    return holder ? resolveObjects(state.project, holder) : [];
  };
  (window as unknown as { __gm: unknown }).__gm = {
    state,
    objectsOf,
    sceneObjects: () => (state.activeScene ? objectsOf(state.activeScene.id) : []),
    locate,
    textColor,
    overlayTexts,
    overlayRect,
    textOverflows,
    labelsDropped,
    viewportCenter: () => centreOf(viewport),
    viewportInfo: () => viewport.debugInfo(),
    gameInfo: () => gameView.debugInfo(),
    layerOf: (id: string) => viewport.layerOf(id),
    drawOrder: () => viewport.drawOrder(),
    objectScreen: (id: string) => viewport.objectScreen(id),
    objectRect: (id: string) => viewport.objectRect(id),
    /** The same for the Game tab – through the camera, so what the player sees. */
    gameScreen: (id: string) => gameView.objectScreen(id),
    graph: {
      current: () => graphEditor.currentAssetId,
      portAt: (nodeId: string, port: string, isOutput: boolean) =>
        graphEditor.canvas.portGlobal(nodeId, port, isOutput),
      nodeAt: (nodeId: string) => graphEditor.canvas.nodeGlobal(nodeId),
      dropTarget: () => graphEditor.canvas.pendingDropTarget(),
      // The canvas, not the whole tab: a centre measured through the header sits above the
      // drawing area.
      center: () => centreOf(graphEditor.canvas),
      pickerWidth: () => graphEditor.pickerWidth,
    },
    texture: {
      current: () => textureEditor.currentAssetId,
      pickerWidth: () => textureEditor.pickerWidth,
      /** Where an image pixel of the shown sheet sits on screen (frames are dragged in image coordinates). */
      pointAt: (x: number, y: number) => textureEditor.imageToScreen(x, y),
    },
    container: {
      current: () => containerEditor.currentAssetId,
      pickerWidth: () => containerEditor.pickerWidth,
      center: () => centreOf(containerEditor),
      rect: () => containerEditor.canvasRect(),
      /** Where a template object is drawn, so a check can click or sample it. */
      objectScreen: (id: string) => containerEditor.objectScreen(id),
    },
    world: () => editor.worldSnapshot(),
    /** Rows the hierarchy shows – collapsed subtrees are not in here. */
    hierarchyOrder: () => hierarchy.rowOrder(),
    hierarchyChevron: (id: string) => hierarchy.chevronPosition(id),
    hierarchyRowColor: (id: string) => hierarchy.rowColor(id),
    hierarchyExpandAll: () => hierarchy.expandAll(),
    hierarchyCollapseAll: () => hierarchy.collapseAll(),
    /** The colour actually on screen at a point, as `#rrggbb` – what was drawn, not what the model says. */
    pixelAt: (x: number, y: number) => {
      const { pixels } = app.renderer.extract.pixels({
        target: app.stage,
        frame: new Rectangle(x, y, 1, 1),
      });
      const hex = (value: number | undefined) => (value ?? 0).toString(16).padStart(2, '0');
      return `#${hex(pixels[0])}${hex(pixels[1])}${hex(pixels[2])}`;
    },
    fps: () => editor.fps,
    tab: () => editor.tab,
    showTab: (tab: CentreTab) => editor.showTab(tab),
  };
}