import { _decorator, Component, director, Label, Node, Color, EventTouch, UITransform, Sprite, SpriteFrame, Texture2D, ImageAsset, Rect, Size, resources } from 'cc';
import { ConfigMgr } from '../data/ConfigMgr';
import { CCJsonLoader } from './CCJsonLoader';
import { StorySceneCtrl } from '../ui/StorySceneCtrl';
import {
    ensureCanvasSize,
    createLabel,
    createButton,
    createSprite,
    createSolidRect,
} from './MainMenuEntry';
import { DESIGN_WIDTH, DESIGN_HEIGHT } from '../common/Constants';
import { IStoryPageConfig } from '../data/Interfaces';

const { ccclass, property } = _decorator;

/**
 * StoryIntro scene entry (task 9.1 hookup, req 19.x).
 *
 * Attach to the root of `StoryIntro.scene`. Inspector:
 *   - labelNode: optional — if left empty and `autoBuildUI` is true, a
 *     centered Label and a bottom-right "Skip" button are auto-created.
 *   - storyId: story id in `configs/stories.json` (default `chapter_1_intro`).
 *
 * Tap anywhere → accelerate / advance (req 19.3).
 * "Skip" button → finish immediately (req 19.4).
 */
@ccclass('StorySceneEntry')
export class StorySceneEntry extends Component {
    @property({ type: Node, tooltip: '打字机 Label 节点 (可留空，自动创建)' })
    public labelNode: Node | null = null;

    @property({ tooltip: '对应 configs/stories.json 中的 id' })
    public storyId: string = 'chapter_1_intro';

    @property({ tooltip: '是否自动创建 Label / Skip 按钮 / 背景遮罩' })
    public autoBuildUI: boolean = true;

    private ctrl: StorySceneCtrl | undefined;
    private bgNode: Node | null = null;

    protected async onLoad(): Promise<void> {
        // Always ensure the illustration bgNode exists (even if the scene
        // was hand-built in the editor and labelNode is already bound).
        if (!this.bgNode) {
            this.ensureBgNode();
        }

        if (this.autoBuildUI && !this.labelNode) {
            this.buildDefaultUI();
        }
        // Full-screen tap accelerator: listen on the host node itself.
        this.node.on(Node.EventType.TOUCH_END, () => this.onTap(), this);

        const cfg = await this.loadStoryConfig();
        this.ctrl = new StorySceneCtrl(cfg, undefined, {
            onTextChanged: (text) => this.updateLabel(text),
            onPageEntered: (page) => this.swapIllustration(page),
            onFinished: () => director.loadScene('Level_1_1'),
        });
        const outcome = this.ctrl.start();
        if (outcome === 'already_seen') {
            director.loadScene('Level_1_1');
        }
    }

    protected update(dt: number): void {
        this.ctrl?.tick(dt);
    }

    /** Tap handler (called by auto-built full-screen listener or external). */
    public onTap(): void {
        this.ctrl?.onTap();
    }

    /** Bound to the "Skip" button. */
    public onSkip(): void {
        this.ctrl?.onSkip();
    }

    private updateLabel(text: string): void {
        if (!this.labelNode) return;
        const label = this.labelNode.getComponent(Label);
        if (label) label.string = text;
    }

    private async loadStoryConfig() {
        const mgr = new ConfigMgr(new CCJsonLoader());
        await mgr.load();
        return mgr.story(this.storyId);
    }

    /** Ensure the full-screen illustration layer exists. Called even when
     *  the scene was hand-built in the editor (labelNode already bound). */
    private ensureBgNode(): void {
        ensureCanvasSize(this.node);
        this.bgNode = new Node('StoryIllustration');
        this.bgNode.layer = this.node.layer;
        // Added before any scrim/label nodes so it renders behind them.
        this.node.addChild(this.bgNode);
        const bgUt = this.bgNode.addComponent(UITransform);
        bgUt.setContentSize(DESIGN_WIDTH, DESIGN_HEIGHT);
        const bgSp = this.bgNode.addComponent(Sprite);
        bgSp.sizeMode = Sprite.SizeMode.CUSTOM;
        this.bgNode.setPosition(0, 0, 0);
    }

    private buildDefaultUI(): void {
        // bgNode is already created by ensureBgNode() — just build the
        // text overlay, scrim and skip button.

        // Dark scrim below the text area for readability.
        createSolidRect(
            this.node,
            0,
            -DESIGN_HEIGHT / 2 + 110,
            DESIGN_WIDTH,
            180,
            new Color(0, 0, 0, 170),
        );

        // Central typewriter label (sits on top of the scrim).
        this.labelNode = createLabel(this.node, '', 0, -DESIGN_HEIGHT / 2 + 110, 26, Color.WHITE);
        const ut = this.labelNode.getComponent(UITransform);
        if (ut) ut.setContentSize(DESIGN_WIDTH - 80, 160);
        const lb = this.labelNode.getComponent(Label);
        if (lb) lb.enableWrapText = true;

        // Skip button at bottom-right.
        const skipX = DESIGN_WIDTH / 2 - 90;
        const skipY = -DESIGN_HEIGHT / 2 + 40;
        createButton(this.node, 'Skip >>', skipX, skipY, 140, 50, () => this.onSkip());
    }

    /** Swap the full-screen illustration when the controller enters a new page. */
    private swapIllustration(page: IStoryPageConfig): void {
        if (!this.bgNode) return;
        const sp = this.bgNode.getComponent(Sprite);
        if (!sp) return;
        const path = page.illustration;
        // Strategy 1: direct SpriteFrame load (works with sprite-frame meta).
        resources.load(path, SpriteFrame, (err, sf) => {
            if (!err && sf) {
                if (this.bgNode && this.bgNode.isValid) sp.spriteFrame = sf as SpriteFrame;
                return;
            }
            // Strategy 2: ImageAsset → Texture2D → SpriteFrame fallback.
            resources.load(path, ImageAsset, (err2, imgAsset) => {
                if (err2 || !imgAsset) {
                    console.warn(`[StorySceneEntry] failed to load illustration '${path}':`, err, err2);
                    return;
                }
                if (!this.bgNode || !this.bgNode.isValid) return;
                const tex = new Texture2D();
                tex.image = imgAsset as ImageAsset;
                const frame = new SpriteFrame();
                frame.texture = tex;
                frame.rect = new Rect(0, 0, tex.width, tex.height);
                frame.originalSize = new Size(tex.width, tex.height);
                sp.spriteFrame = frame;
            });
        });
    }
}