const api = require('../../utils/api')
const app = getApp()

Page({
    data: {
        statusBarHeight: 44,
        navBarHeight: 44,
        totalNavHeight: 88,
        posters: [],
        currentPosterIndex: 0,
        qrCodeUrl: '',
        referralCode: '',
        canvasWidth: 1080,
        canvasHeight: 1920,
        isLoading: true,
        userInfo: null
    },

    onLoad(options) {
        const systemInfo = wx.getSystemInfoSync()
        const statusBarHeight = systemInfo.statusBarHeight || 44
        const menuButton = wx.getMenuButtonBoundingClientRect()
        const navBarHeight = menuButton.height + (menuButton.top - statusBarHeight) * 2
        const totalNavHeight = statusBarHeight + navBarHeight

        this.setData({
            statusBarHeight,
            navBarHeight,
            totalNavHeight,
            userInfo: app.globalData.userInfo || wx.getStorageSync('user_info')
        })

        this.loadData();
    },

    async loadData() {
        try {
            // 1. 获取推荐码
            const statsRes = await api.commission.getStats();
            let referralCode = 'default';
            if (statsRes.success && statsRes.data) {
                referralCode = statsRes.data.referralCode;
                this.setData({ referralCode });
            }

            // 2. 设置小程序二维码地址
            // scene 格式必须为 r=XXX 才能被 app.js 正确解析
            const baseUrl = app.globalData.baseUrl || 'https://ai-c.maimanji.com';
            const qrCodeUrl = `${baseUrl}/api/user/qrcode?scene=r=${referralCode}&page=pages/index/index`;
            this.setData({ qrCodeUrl });

            // 3. 获取动态海报背景列表
            const assetRes = await api.pageAssets.getAssets('posters');
            if (assetRes && assetRes.success && assetRes.data && assetRes.data.length > 0) {
                const posters = assetRes.data.map(item => {
                    let url = (item.asset_url || '').trim();
                    // 如果是相对路径，补充完整域名
                    if (url && !url.startsWith('http')) {
                        url = baseUrl + (url.startsWith('/') ? '' : '/') + url;
                    }
                    return {
                        id: item.asset_key,
                        url: url,
                        qrBottom: 4.5, // 对应 1920 高度下的位置
                        qrRight: 8 // 对应 1080 宽度下的位置
                    };
                });
                this.setData({ posters, isLoading: false });
            } else {
                // 兜底默认海报
                this.setData({
                    posters: [
                        { id: 'default', url: 'https://ai-c.maimanji.com/uploads/assets/poster-1.png', qrBottom: 4.5, qrRight: 8 }
                    ],
                    isLoading: false
                });
            }
        } catch (err) {
            console.error('[promote-poster] loadData failed:', err);
            this.setData({ isLoading: false });
        }
    },

    onPosterChange(e) {
        this.setData({ currentPosterIndex: e.detail.current })
    },

    onImageError(e) {
        console.error('[promote-poster] 海报图加载失败:', e.detail.errMsg);
        wx.showToast({ title: '海报背景加载失败', icon: 'none' });
    },

    onQrError(e) {
        console.error('[promote-poster] 二维码加载失败:', e.detail.errMsg);
        wx.showToast({ title: '二维码加载失败', icon: 'none' });
    },

    /**
     * 下载文件辅助函数
     */
    downloadFile(url) {
        return new Promise((resolve, reject) => {
            wx.downloadFile({
                url,
                success: res => {
                    if (res.statusCode === 200) resolve(res.tempFilePath);
                    else reject(new Error('Download failed: ' + url));
                },
                fail: err => {
                    console.error('Download failed:', url, err);
                    reject(err);
                }
            });
        });
    },

    async savePoster() {
        if (this.data.posters.length === 0) return;
        
        wx.showLoading({ title: '生成中...', mask: true });

        try {
            const template = this.data.posters[this.data.currentPosterIndex];
            
            // 1. 下载资源
            const [bgPath, qrPath] = await Promise.all([
                this.downloadFile(template.url),
                this.downloadFile(this.data.qrCodeUrl)
            ]);

            // 2. 初始化 Canvas
            const query = wx.createSelectorQuery()
            query.select('#posterCanvas')
                .fields({ node: true, size: true })
                .exec(async (res) => {
                    if (!res[0] || !res[0].node) {
                        wx.hideLoading();
                        wx.showToast({ title: 'Canvas初始化失败', icon: 'none' });
                        return;
                    }

                    const canvas = res[0].node
                    const ctx = canvas.getContext('2d')
                    const dpr = wx.getSystemInfoSync().pixelRatio
                    
                    const canvasW = 1080;
                    const canvasH = 1920;
                    
                    canvas.width = canvasW * dpr
                    canvas.height = canvasH * dpr
                    ctx.scale(dpr, dpr)

                    // 3. 绘制背景
                    const bgImg = canvas.createImage();
                    bgImg.src = bgPath;
                    await new Promise((resolve, reject) => {
                        bgImg.onload = resolve;
                        bgImg.onerror = reject;
                    });
                    ctx.drawImage(bgImg, 0, 0, canvasW, canvasH);

                    // 4. 绘制二维码
                    const qrImg = canvas.createImage();
                    qrImg.src = qrPath;
                    await new Promise((resolve, reject) => {
                        qrImg.onload = resolve;
                        qrImg.onerror = reject;
                    });
                    
                    // 识别白框位置：根据 1080x1920 设计稿，白框在右下角
                    // 二维码尺寸 260x260
                    const qrW = 260;
                    const qrX = 720; // 1080 - 100 - 260
                    const qrY = 1580; // 1920 - 80 - 260

                    // 绘制二维码背景（白框内可能需要微调，这里先绘制一个纯白背景确保清晰）
                    ctx.fillStyle = '#FFFFFF';
                    ctx.beginPath();
                    this.roundRect(ctx, qrX - 5, qrY - 5, qrW + 10, qrW + 10, 10);
                    ctx.fill();

                    ctx.drawImage(qrImg, qrX, qrY, qrW, qrW);

                    // 6. 导出
                    setTimeout(() => {
                        wx.canvasToTempFilePath({
                            canvas: canvas,
                            success: (fileRes) => {
                                wx.saveImageToPhotosAlbum({
                                    filePath: fileRes.tempFilePath,
                                    success: () => {
                                        wx.hideLoading();
                                        wx.showToast({ title: '已保存到相册', icon: 'success' })
                                    },
                                    fail: (err) => {
                                        wx.hideLoading();
                                        if (err.errMsg.indexOf('auth deny') !== -1) {
                                            wx.showModal({
                                                title: '提示',
                                                content: '请授权保存图片到相册',
                                                success: (sm) => {
                                                    if (sm.confirm) wx.openSetting();
                                                }
                                            });
                                        } else {
                                            wx.showToast({ title: '保存失败', icon: 'none' })
                                        }
                                    }
                                })
                            },
                            fail: (err) => {
                                console.error('canvasToTempFilePath fail:', err);
                                wx.hideLoading();
                                wx.showToast({ title: '生成图片失败', icon: 'none' });
                            }
                        })
                    }, 300);
                })
        } catch (err) {
            console.error('[promote-poster] savePoster error:', err);
            wx.hideLoading();
            wx.showToast({ title: '海报资源加载失败', icon: 'none' });
        }
    },

    roundRect(ctx, x, y, w, h, r) {
        ctx.moveTo(x + r, y);
        ctx.arcTo(x + w, y, x + w, y + h, r);
        ctx.arcTo(x + w, y + h, x, y + h, r);
        ctx.arcTo(x, y + h, x, y, r);
        ctx.arcTo(x, y, x + w, y, r);
    },

    onShareAppMessage() {
        const title = "发现一个超赞的AI情感陪伴官，快来看看吧！";
        const imageUrl = this.data.posters[this.data.currentPosterIndex]?.url || '';
        return {
            title: title,
            path: `/pages/index/index?referralCode=${this.data.referralCode}`,
            imageUrl: imageUrl
        }
    },

    goBack() {
        wx.navigateBack();
    }
});