import { BadRequestException, Injectable, Logger } from "@nestjs/common";
import sharp from "sharp";
import type { MediaProcessingResult } from "../../common/interfaces/media.interface";
import type { IMediaProcessorStrategy } from "./media-processor.strategy";

@Injectable()
export class ImageProcessorStrategy implements IMediaProcessorStrategy {
	private readonly logger = new Logger(ImageProcessorStrategy.name);

	canHandle(mimeType: string): boolean {
		return mimeType.startsWith("image/");
	}

	async process(
		buffer: Buffer,
		options: {
			format: "webp" | "avif";
			resize?: { width?: number; height?: number };
		} = { format: "webp" },
	): Promise<MediaProcessingResult> {
		try {
			const { format, resize } = options;
			let pipeline = sharp(buffer);

			if (resize) {
				pipeline = pipeline.resize(resize.width, resize.height, {
					fit: "cover",
					position: "center",
				});
			}

			const metadata = await pipeline.metadata();

			if (format === "webp") {
				pipeline = pipeline.webp({ quality: 80, effort: 6 });
			} else {
				pipeline = pipeline.avif({ quality: 65, effort: 6 });
			}

			const processedBuffer = await pipeline.toBuffer();

			return {
				buffer: processedBuffer,
				mimeType: `image/${format}`,
				extension: format,
				width: metadata.width,
				height: metadata.height,
				size: processedBuffer.length,
			};
		} catch (error) {
			this.logger.error(`Error processing image: ${error.message}`);
			throw new BadRequestException("Failed to process image");
		}
	}
}