/**
 * 导出动画弹出框
 */
class ExportView {
    constructor() {
        this.canvas = null;
        this.ctx = null;
        this.previewPlaceholder = null;
        this.referenceInput = null;
        this.referencePreview = null;
        this.referenceUpload = null;
        this.cancelBtn = null;
        this.confirmBtn = null;
        this.referenceImage = null;
        this.spritesheetData = null;
        
        this.init();
    }

    init() {
        this.canvas = document.getElementById('spritesheetCanvas');
        this.ctx = this.canvas?.getContext('2d');
        this.previewPlaceholder = document.getElementById('previewPlaceholder');
        this.referenceInput = document.getElementById('referenceInput');
        this.referencePreview = document.getElementById('referencePreview');
        this.referenceUpload = document.getElementById('referenceUpload');
        this.cancelBtn = document.getElementById('exportCancelBtn');
        this.confirmBtn = document.getElementById('exportConfirmBtn');
        
        this.bindEvents();
        
        // 初始时禁用确定按钮
        if (this.confirmBtn) {
            this.confirmBtn.disabled = true;
        }
    }

    bindEvents() {
        // 取消按钮
        this.cancelBtn?.addEventListener('click', () => {
            this.close();
        });

        // 确定按钮
        this.confirmBtn?.addEventListener('click', () => {
            this.downloadSpritesheet();
        });

        // 参考图上传区点击
        this.referenceUpload?.addEventListener('click', () => {
            this.referenceInput?.click();
        });

        // 参考图选择
        this.referenceInput?.addEventListener('change', (e) => {
            const file = e.target.files[0];
            if (file) {
                this.loadReferenceImage(file);
            }
        });

        // 拖拽上传参考图
        this.referenceUpload?.addEventListener('dragover', (e) => {
            e.preventDefault();
            e.stopPropagation();
            this.referenceUpload.style.borderColor = '#667eea';
        });

        this.referenceUpload?.addEventListener('dragleave', (e) => {
            e.preventDefault();
            e.stopPropagation();
            this.referenceUpload.style.borderColor = '';
        });

        this.referenceUpload?.addEventListener('drop', (e) => {
            e.preventDefault();
            e.stopPropagation();
            this.referenceUpload.style.borderColor = '';
            
            const file = e.dataTransfer.files[0];
            if (file && file.type.startsWith('image/')) {
                this.loadReferenceImage(file);
            }
        });

        // 监听来自父窗口的消息
        window.addEventListener('message', (event) => {
            if (event.data && event.data.type === 'generate-spritesheet') {
                // console.log('[ExportView] 收到生成Spritesheet消息:', event.data);
                this.generateSpritesheet(event.data.folderName, event.data.frames);
            }
        });
    }

    loadReferenceImage(file) {
        const reader = new FileReader();
        reader.onload = (e) => {
            this.referenceImage = new Image();
            this.referenceImage.onload = () => {
                this.referencePreview.innerHTML = '';
                this.referencePreview.classList.add('has-image');
                this.referencePreview.appendChild(this.referenceImage);
                // console.log('[ExportView] 参考图已加载');
            };
            this.referenceImage.src = e.target.result;
        };
        reader.readAsDataURL(file);
    }

    async generateSpritesheet(folderName, frames) {
        // console.log('[ExportView] 开始生成Spritesheet');
        // console.log('[ExportView]   文件夹:', folderName);
        // console.log('[ExportView]   帧数:', frames?.length);
        
        if (!frames || frames.length === 0) {
            // console.error('[ExportView] 没有帧数据');
            return;
        }

        try {
            // 加载所有帧
            const images = await Promise.all(
                frames.map(frameUrl => {
                    return new Promise((resolve, reject) => {
                        const img = new Image();
                        img.crossOrigin = 'anonymous';
                        img.onload = () => resolve(img);
                        img.onerror = reject;
                        img.src = frameUrl;
                    });
                })
            );

            // console.log('[ExportView] 所有帧已加载');

            // 计算spritesheet尺寸
            const frameWidth = images[0].width;
            const frameHeight = images[0].height;
            const cols = Math.ceil(Math.sqrt(images.length));
            const rows = Math.ceil(images.length / cols);

            this.canvas.width = frameWidth * cols;
            this.canvas.height = frameHeight * rows;

            // console.log('[ExportView] 画布尺寸:', this.canvas.width, 'x', this.canvas.height);

            // 绘制所有帧
            images.forEach((img, index) => {
                const col = index % cols;
                const row = Math.floor(index / cols);
                const x = col * frameWidth;
                const y = row * frameHeight;
                this.ctx.drawImage(img, x, y);
            });

            // 保存数据用于下载
            this.spritesheetData = {
                folderName: folderName,
                canvas: this.canvas
            };

            // 显示预览
            this.canvas.classList.add('show');
            this.previewPlaceholder.classList.add('hide');
            
            // 启用确定按钮
            if (this.confirmBtn) {
                this.confirmBtn.disabled = false;
            }

            // console.log('[ExportView] ✓ Spritesheet生成完成');
        } catch (error) {
            // console.error('[ExportView] 生成Spritesheet失败:', error);
            this.previewPlaceholder.textContent = '生成失败';
        }
    }

    downloadSpritesheet() {
        if (!this.spritesheetData) {
            // console.warn('[ExportView] 没有可下载的数据');
            return;
        }

        // console.log('[ExportView] 开始下载Spritesheet');

        this.canvas.toBlob((blob) => {
            const url = URL.createObjectURL(blob);
            const a = document.createElement('a');
            a.href = url;
            a.download = `${this.spritesheetData.folderName}_spritesheet.png`;
            a.click();
            URL.revokeObjectURL(url);

            // console.log('[ExportView] ✓ 下载已触发');
            
            // 下载后关闭弹出框
            this.close();
        }, 'image/png');
    }

    close() {
        // console.log('[ExportView] 关闭导出弹出框');
        // 通知父窗口关闭
        if (window.parent && window.parent !== window) {
            window.parent.postMessage({
                type: 'close-export-view'
            }, '*');
        }
    }
}

// 初始化
window.ExportView = new ExportView();