jamp3/src/lib/id3v2/frames/id3v2.frame.version.ts

mp3, id3v1, id3v2 - reader & writer

import {IID3V2} from '../id3v2.types';
import {FrameDefs} from './id3v2.frame.defs';

export function upgrade23DateFramesTov24Date(dateFrames: Array<IID3V2.Frame>): IID3V2.Frame | undefined {
	const year = dateFrames.find(f => ['TYER', 'TYE'].indexOf(f.id) >= 0);
	const date = dateFrames.find(f => ['TDAT', 'TDA'].indexOf(f.id) >= 0);
	const time = dateFrames.find(f => ['TIME', 'TIM'].indexOf(f.id) >= 0);
	if (!year && !date && !time) {
		return;
	}
	const result: Array<string> = [];
	if (year && year.value && year.value.hasOwnProperty('text')) {
		result.push((<IID3V2.FrameValue.Text>year.value).text);
	}
	if (date && date.value && date.value.hasOwnProperty('text')) {
		result.push((<IID3V2.FrameValue.Text>date.value).text);
	}
	if (time && time.value && time.value.hasOwnProperty('text')) {
		result.push((<IID3V2.FrameValue.Text>time.value).text);
	}
	return {
		id: 'TDRC',
		title: 'Recording time',
		value: {text: result.join('-')}
	};
}

function downgradeFrame(id: string, dest: number): string | null {
	const downgradeKey = Object.keys(FrameDefs).find(key => FrameDefs[key].upgrade === id);
	if (!downgradeKey) {
		// debug('ensureID3v2FrameVersionDef', 'Missing v2.' + def.versions + ' -> v2.' + dest + ' mapping', id);
		return null;
	}
	const fdown = FrameDefs[downgradeKey];
	if (fdown.versions.includes(dest)) {
		return downgradeKey;
	}
	return (fdown.versions[0] > dest) ? ensureID3v2FrameVersionDef(downgradeKey, dest) : null;
}

function upgradeFrame(upgradeKey: string | undefined, dest: number): string | null {
	if (!upgradeKey) {
		// debug('ensureID3v2FrameVersionDef', 'Missing v2.' + def.versions + ' -> v2.' + dest + ' mapping', id);
		return null;
	}
	const fup = FrameDefs[upgradeKey];
	if (fup.versions.includes(dest)) {
		return upgradeKey;
	}
	return (fup.versions[0] < dest) ? ensureID3v2FrameVersionDef(upgradeKey, dest) : null;
}

export function ensureID3v2FrameVersionDef(id: string, dest: number): string | null {
	const def = FrameDefs[id];
	if (!def) {
		// TODO: matcher?
		return null;
	}
	if (def.versions.includes(dest)) {
		return id;
	}
	if (def.versions[0] > dest) {
		return downgradeFrame(id, dest);
	}
	return upgradeFrame(def.upgrade, dest);
}