import { AudioCodec, MediaContainer, VideoCodec, VideoEncodingSetting } from "music-server-shared/types";
import { createRFC6381String } from "music-server-shared/utils";
import { probeFile, readStream } from "./utils";

function secondsToFfmpeg(seconds: number): string {
	// Ensure seconds is non-negative
	if (seconds < 0) {
		throw new Error("Seconds must be a non-negative number");
	}

	// Extract hours, minutes, seconds, and milliseconds
	const hours = Math.floor(seconds / 3600);
	const minutes = Math.floor((seconds % 3600) / 60);
	const secs = Math.floor(seconds % 60);

	// Calculate the fractional part for milliseconds
	const milliseconds = Math.floor((seconds - Math.floor(seconds)) * 1000);

	// Pad numbers with leading zeros
	const hoursStr = hours.toString().padStart(2, "0");
	const minutesStr = minutes.toString().padStart(2, "0");
	const secondsStr = secs.toString().padStart(2, "0");
	const millisecondsStr = milliseconds.toString().padStart(3, "0");

	return `${hoursStr}:${minutesStr}:${secondsStr}.${millisecondsStr}`;
}

export function convertWithFFmpeg(
	filePath: string,
	audioBitrate: number,
	videoBitrate: number,
	container: MediaContainer,
	requestedAudioCodec: AudioCodec,
	requestedVideoCodec: VideoCodec,
	requestedVideoEncodingSetting: VideoEncodingSetting,
	seekTo: number | undefined,
) {
	const mimeType = createRFC6381String(container, requestedVideoCodec, requestedAudioCodec);

	let audioCodec = undefined;
	switch (requestedAudioCodec) {
		case AudioCodec.aac:
			audioCodec = "aac";
			break;
		case AudioCodec.mp3: {
			audioCodec = "libmp3lame";
			break;
		}
		case AudioCodec.opus: {
			audioCodec = "libopus";
			break;
		}
		case AudioCodec.vorbis: {
			audioCodec = "libvorbis";
			break;
		}
		default: {
			throw new Error(`Unsupported audio codec: ${requestedAudioCodec}`);
		}
	}

	let maxWidth = undefined;
	if (videoBitrate <= 210000) {
		maxWidth = 860;
	} else if (videoBitrate < 420000) {
		maxWidth = 1000;
	} else if (videoBitrate < 1500000) {
		maxWidth = 1280;
	} else if (videoBitrate < 2000000) {
		maxWidth = 1920;
	} else if (videoBitrate < 10000000) {
		maxWidth = 3840;
	}

	let containerSettings = undefined;
	if (container === MediaContainer.mp4) {
		containerSettings = [
			"-avoid_negative_ts",
			"make_zero",
			"-movflags",
			"+frag_keyframe+empty_moov+default_base_moof+faststart",
			"-g",
			"300",
		];
	}

	const videoEncodingSettings: string[] = [];
	let videoCodec = undefined;
	let extraVideoSettings = undefined;
	//only convert video if transcoding is requesting so
	if (videoCodec !== VideoCodec.none) {
		extraVideoSettings = [
			//make sure pixel format is browser compatible
			"-pix_fmt",
			"yuv420p",
			//automatically deinterlace video to double fps if video is interlaced
			//scale video down based on bitrate
			"-vf",
			`yadif=deint=1:mode=1${maxWidth ? `, scale='if(gt(iw,${maxWidth}),${maxWidth},iw)':-2` : ""}`,
			"-g",
			"600",
		];

		switch (requestedVideoCodec) {
			case VideoCodec.av1:
				videoCodec = "libsvtav1"; //TODO: support hardware encoding
				switch (requestedVideoEncodingSetting) {
					case VideoEncodingSetting.veryfast:
						videoEncodingSettings.push("-preset", "8");
						break;
					case VideoEncodingSetting.fast:
						videoEncodingSettings.concat("-preset", "7");
						break;
					case VideoEncodingSetting.balanced:
						videoEncodingSettings.concat("-preset", "6");
						break;
					case VideoEncodingSetting.quality:
						videoEncodingSettings.concat("-preset", "5");
						break;
					default: {
						throw new Error(`Unsupported video encoding setting: ${requestedVideoEncodingSetting}`);
					}
				}
				break;
			case VideoCodec.h264:
				videoCodec = "libx264"; //TODO: support hardware encoding
				videoEncodingSettings.concat(["-profile", "high"]);
				switch (requestedVideoEncodingSetting) {
					case VideoEncodingSetting.veryfast:
						videoEncodingSettings.push("-preset", "veryfast");
						break;
					case VideoEncodingSetting.fast:
						videoEncodingSettings.concat("-preset", "fast");
						break;
					case VideoEncodingSetting.balanced:
						videoEncodingSettings.concat("-preset", "medium");
						break;
					case VideoEncodingSetting.quality:
						videoEncodingSettings.concat("-preset", "slow");
						break;
					default: {
						throw new Error(`Unsupported video encoding setting: ${requestedVideoEncodingSetting}`);
					}
				}
				break;
			case VideoCodec.h265:
				videoCodec = "libx265"; //TODO: support hardware encoding
				videoEncodingSettings.concat(["-profile", "main"]);
				switch (requestedVideoEncodingSetting) {
					case VideoEncodingSetting.veryfast:
						videoEncodingSettings.push("-preset", "veryfast");
						break;
					case VideoEncodingSetting.fast:
						videoEncodingSettings.concat("-preset", "fast");
						break;
					case VideoEncodingSetting.balanced:
						videoEncodingSettings.concat("-preset", "medium");
						break;
					case VideoEncodingSetting.quality:
						videoEncodingSettings.concat("-preset", "slow");
						break;
					default: {
						throw new Error(`Unsupported video encoding setting: ${requestedVideoEncodingSetting}`);
					}
				}
				break;
			case VideoCodec.vp9:
				videoCodec = "libvpx-vp9";
				switch (requestedVideoEncodingSetting) {
					case VideoEncodingSetting.veryfast:
						videoEncodingSettings.concat("-deadline", "realtime", "-cpu-used", "5");
						break;
					case VideoEncodingSetting.fast:
						videoEncodingSettings.concat("-deadline", "realtime", "-cpu-used", "4");
						break;
					case VideoEncodingSetting.balanced:
						videoEncodingSettings.concat("-deadline", "good", "-cpu-used", "2");
						break;
					case VideoEncodingSetting.quality:
						videoEncodingSettings.concat("-deadline", "good", "-cpu-used", "2");
						break;
					default: {
						throw new Error(`Unsupported video encoding setting: ${requestedVideoEncodingSetting}`);
					}
				}
				break;
		}
	}
	const seekParams = seekTo === undefined ? [] : ["-ss", secondsToFfmpeg(seekTo)];
	const args = ["ffmpeg"]
		.concat(seekParams) //put seek first to do a fast keyframe seek
		.concat(["-i", filePath])
		.concat(containerSettings || [])
		.concat(
			videoCodec
				? ["-c:v", videoCodec, "-b:v", videoBitrate.toString()] //TODO: better bitrate selection
						.concat(extraVideoSettings || [])
						.concat(videoEncodingSettings)
				: ["-vn"],
		)
		.concat(videoEncodingSettings)
		.concat(["-c:a", audioCodec, "-b:a", audioBitrate.toString()])
		.concat(["-f", container, "-"]);
	const cmd = Bun.spawn(args, {
		stdin: "ignore",
		stdout: "pipe",
		stderr: "pipe",
		onExit: async (subprocess: Bun.Subprocess<"ignore", "pipe", "pipe">, exitCode: number | null) => {
			if (exitCode !== 0 && exitCode !== null) {
				console.error("ffmpeg failed with status code", exitCode);
				console.error(new TextDecoder().decode(await readStream(subprocess.stderr as ReadableStream)));
			}
		},
	});
	return { cmd, mimeType };
}