/*
 * Copyright (C) 2026 Fluxer Contributors
 *
 * This file is part of Fluxer.
 *
 * Fluxer is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Fluxer is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with Fluxer. If not, see <https://www.gnu.org/licenses/>.
 */

import assert from 'node:assert/strict';
import fs from 'node:fs/promises';
import type {LoggerInterface} from '@fluxer/logger/src/LoggerInterface';
import {toBodyData} from '@fluxer/media_proxy/src/lib/BinaryUtils';
import type {FFmpegUtilsType} from '@fluxer/media_proxy/src/lib/FFmpegUtils';
import type {MimeTypeUtils} from '@fluxer/media_proxy/src/lib/MimeTypeUtils';
import type {S3Utils} from '@fluxer/media_proxy/src/lib/S3Utils';
import type {HonoEnv} from '@fluxer/media_proxy/src/types/HonoEnv';
import type {Context} from 'hono';
import {HTTPException} from 'hono/http-exception';
import sharp from 'sharp';
import {temporaryFile} from 'tempy';
import * as v from 'valibot';

const ThumbnailRequestSchema = v.object({
	type: v.literal('upload'),
	upload_filename: v.string(),
});

interface ThumbnailControllerDeps {
	s3Utils: S3Utils;
	mimeTypeUtils: MimeTypeUtils;
	ffmpegUtils: FFmpegUtilsType;
	logger: LoggerInterface;
	bucketUploads: string;
}

export function createThumbnailHandler(deps: ThumbnailControllerDeps) {
	const {s3Utils, mimeTypeUtils, ffmpegUtils, logger, bucketUploads} = deps;
	const {readS3Object} = s3Utils;
	const {getMimeType, getMediaCategory} = mimeTypeUtils;
	const {createThumbnail} = ffmpegUtils;

	return async (ctx: Context<HonoEnv>): Promise<Response> => {
		try {
			const body = await ctx.req.json();
			const {upload_filename} = v.parse(ThumbnailRequestSchema, body);

			const {data} = await readS3Object(bucketUploads, upload_filename);

			assert(data instanceof Buffer);

			const mimeType = getMimeType(data, upload_filename);
			if (!mimeType) {
				throw new HTTPException(400, {message: 'Unable to determine file type'});
			}

			const mediaType = getMediaCategory(mimeType);
			if (mediaType !== 'video') {
				throw new HTTPException(400, {message: 'Not a video file'});
			}

			const ext = mimeType.split('/')[1] || 'mp4';
			const tempVideoPath = temporaryFile({extension: ext});
			ctx.get('tempFiles').push(tempVideoPath);
			await fs.writeFile(tempVideoPath, data);

			const thumbnailPath = await createThumbnail(tempVideoPath);
			ctx.get('tempFiles').push(thumbnailPath);

			const thumbnailData = await fs.readFile(thumbnailPath);
			const processedThumbnail = await sharp(thumbnailData).jpeg({quality: 80}).toBuffer();

			return ctx.body(toBodyData(processedThumbnail), {
				headers: {
					'Content-Type': 'image/jpeg',
				},
			});
		} catch (error) {
			logger.error({error}, 'Failed to generate thumbnail');
			throw new HTTPException(404);
		}
	};
}