// server/utils/textRegionCropper.js
import sharp from 'sharp';
import fse from 'fs-extra';
import * as path from 'path';

class TextRegionCropper {
    constructor() {
        this.logger = {
            info: (msg, ...args) => console.log(`✂️ [裁剪] ${msg}`, ...args),
            debug: (msg, ...args) => console.log(`🐛 [裁剪] ${msg}`, ...args),
            error: (msg, ...args) => console.error(`❌ [裁剪] ${msg}`, ...args)
        };
        // 确保裁剪调试目录存在
        this.cropDebugDir = path.join(process.cwd(), 'temp', 'crop_debug');
        fse.ensureDirSync(this.cropDebugDir);
    }

    async cropTextRegion(imageBuffer, box, regionIndex) {
        const timestamp = Date.now();
        try {
            const metadata = await sharp(imageBuffer).metadata();
            const imgWidth = metadata.width;
            const imgHeight = metadata.height;

            // 计算文本框的边界
            const left = Math.min(box.x1, box.x2, box.x3, box.x4);
            const top = Math.min(box.y1, box.y2, box.y3, box.y4);
            const right = Math.max(box.x1, box.x2, box.x3, box.x4);
            const bottom = Math.max(box.y1, box.y2, box.y3, box.y4);

            const originalWidth = right - left;
            const originalHeight = bottom - top;

            // 四边各扩大5像素
            const expandPixels = 5;

            const expandedLeft = Math.max(0, left - expandPixels);
            const expandedTop = Math.max(0, top - expandPixels);
            const expandedRight = Math.min(imgWidth - 1, right + expandPixels);
            const expandedBottom = Math.min(imgHeight - 1, bottom + expandPixels);

            const expandedWidth = expandedRight - expandedLeft;
            const expandedHeight = expandedBottom - expandedTop;

            if (expandedWidth <= 0 || expandedHeight <= 0) {
                this.logger.debug(`区域 ${regionIndex}: 无效的裁剪区域`);
                return null;
            }

            const croppedBuffer = await sharp(imageBuffer)
                .extract({
                    left: Math.floor(expandedLeft),
                    top: Math.floor(expandedTop),
                    width: Math.floor(expandedWidth),
                    height: Math.floor(expandedHeight)
                })
                .png()
                .toBuffer();

            // 保存裁剪后的图像用于调试
            const cropPath = path.join(this.cropDebugDir, `crop-${regionIndex}-${timestamp}.png`);
            await fse.writeFile(cropPath, croppedBuffer);
            this.logger.debug(`区域 ${regionIndex}: 裁剪 ${Math.floor(expandedWidth)}x${Math.floor(expandedHeight)} -> ${cropPath}`);

            return {
                buffer: croppedBuffer,
                boxInfo: {
                    original: { left, top, right, bottom, width: originalWidth, height: originalHeight },
                    expanded: {
                        left: expandedLeft,
                        top: expandedTop,
                        right: expandedRight,
                        bottom: expandedBottom,
                        width: expandedWidth,
                        height: expandedHeight
                    }
                }
            };

        } catch (error) {
            this.logger.error(`区域 ${regionIndex}: 裁剪失败`, error);
            return null;
        }
    }

    async rotateImage(imageBuffer, degrees) {
        return await sharp(imageBuffer)
            .rotate(degrees)
            .png()
            .toBuffer();
    }

    calculateExpansion(originalWidth, originalHeight, expansionFactor = 1.2) {
        return {
            width: originalWidth * expansionFactor,
            height: originalHeight * expansionFactor
        };
    }

    validateCropRegion(left, top, width, height, imgWidth, imgHeight) {
        if (width <= 0 || height <= 0) {
            return false;
        }
        if (left < 0 || top < 0) {
            return false;
        }
        if (left + width > imgWidth || top + height > imgHeight) {
            return false;
        }
        return true;
    }
}

export default TextRegionCropper;