hook.js

const cache = require('./cache')
const parse = require('url').parse
const crypto = require('./crypto')
const request = require('./request')
const match = require('./provider/match')

const hook = {
	request: {
		before: () => {},
		after: () => {},
	},
	connect: {
		before: () => {}
	},
	negotiate: {
		before: () => {}
	},
	target: {
		host: [],
		path: []
	}
}

hook.target.host = [
	'music.163.com',
	'interface.music.163.com',
	'interface3.music.163.com',
	'apm.music.163.com',
	'apm3.music.163.com',
	// 'mam.netease.com',
	// 'api.iplay.163.com', // look living
	// 'ac.dun.163yun.com',
	// 'crash.163.com',
	// 'clientlog.music.163.com',
	// 'clientlog3.music.163.com'
]

hook.target.path = [
	'/api/v3/playlist/detail',
	'/api/v3/song/detail',
	'/api/v6/playlist/detail',
	'/api/album/play',
	'/api/artist/privilege',
	'/api/album/privilege',
	'/api/v1/artist',
	'/api/v1/artist/songs',
	'/api/artist/top/song',
	'/api/v1/album',
	'/api/album/v3/detail',
	'/api/playlist/privilege',
	'/api/song/enhance/player/url',
	'/api/song/enhance/player/url/v1',
	'/api/song/enhance/download/url',
	'/batch',
	'/api/batch',
	'/api/v1/search/get',
	'/api/cloudsearch/pc',
	'/api/v1/playlist/manipulate/tracks',
	'/api/song/like',
	'/api/v1/play/record',
	'/api/playlist/v4/detail',
	'/api/v1/radio/get',
	'/api/v1/discovery/recommend/songs'
]

hook.request.before = ctx => {
	const req = ctx.req
	req.url = (req.url.startsWith('http://') ? '' : (req.socket.encrypted ? 'https:' : 'http:') + '//' + (hook.target.host.includes(req.headers.host) ? req.headers.host : null)) + req.url
	const url = parse(req.url)
	if([url.hostname, req.headers.host].some(host => hook.target.host.includes(host)) && req.method == 'POST' && (url.path == '/api/linux/forward' || url.path.startsWith('/eapi/'))){
		return request.read(req)
		.then(body => req.body = body)
		.then(body => {
			if('x-napm-retry' in req.headers) delete req.headers['x-napm-retry']
			req.headers['X-Real-IP'] = '118.88.88.88'
			if(req.url.includes('stream')) return // look living eapi can not be decrypted
			if(body){
				let data = null
				let netease = {}
				netease.pad = (body.match(/%0+$/) || [''])[0]
				netease.forward = (url.path == '/api/linux/forward')
				if(netease.forward){
					data = JSON.parse(crypto.linuxapi.decrypt(Buffer.from(body.slice(8, body.length - netease.pad.length), 'hex')).toString())
					netease.path = parse(data.url).path
					netease.param = data.params
				}
				else{
					data = crypto.eapi.decrypt(Buffer.from(body.slice(7, body.length - netease.pad.length), 'hex')).toString().split('-36cd479b6b5-')
					netease.path = data[0]
					netease.param = JSON.parse(data[1])
				}
				netease.path = netease.path.replace(/\/\d*$/, '')
				ctx.netease = netease
				// console.log(netease.path, netease.param)

				if(netease.path == '/api/song/enhance/download/url')
					return pretendPlay(ctx)
			}
		})
		.catch(error => console.log(error, ctx.req.url))
	}
	if((hook.target.host.includes(url.hostname)) && url.path.startsWith('/weapi/')){
		ctx.req.headers['X-Real-IP'] = '118.88.88.88'
		ctx.netease = {web: true, path: url.path.replace(/^\/weapi\//, '/api/').replace(/\?.+$/, '').replace(/\/\d*$/, '')}
	}
	else if(req.url.includes('package')){
		try{
			let data = req.url.split('package/').pop().split('/')
			let url = parse(crypto.base64.decode(data[0]))
			let id = data[1].replace('.mp3', '')
			req.url = url.href
			req.headers['host'] = url.hostname
			ctx.package = {id}
			ctx.decision = 'proxy'
		}
		catch(error){
			ctx.error = error
			ctx.decision = 'close'
		}
	}
}

hook.request.after = ctx => {
	const netease = ctx.netease
	const package = ctx.package
	const proxyRes = ctx.proxyRes
	if(netease && hook.target.path.includes(netease.path) && proxyRes.statusCode == 200){
		return request.read(proxyRes, true)
		.then(buffer => proxyRes.body = buffer)
		.then(buffer => {
			const patch = string => string.replace(/([^\\]"\s*:\s*)(\d{16,})(\s*[}|,])/g, '$1"$2L"$3') // for js precision
			try{
				netease.encrypted = false
				netease.jsonBody = JSON.parse(patch(buffer.toString()))
			}
			catch(error){
				netease.encrypted = true
				netease.jsonBody = JSON.parse(patch(crypto.eapi.decrypt(buffer).toString()))
			}

			if(netease.path.includes('manipulate') && [401, 512].includes(netease.jsonBody.code) && !netease.web)
				return tryCollect(ctx)
			else if(netease.path == '/api/song/like' && [401, 512].includes(netease.jsonBody.code) && !netease.web)
				return tryLike(ctx)
			else if(netease.path.includes('url'))
				return tryMatch(ctx)
		})
		.then(() => {
			if('transfer-encoding' in proxyRes.headers) delete proxyRes.headers['transfer-encoding']
			if('content-encoding' in proxyRes.headers) delete proxyRes.headers['content-encoding']
			if('content-length' in proxyRes.headers) delete proxyRes.headers['content-length']

			const inject = (key, value) => {
				if(typeof(value) === 'object' && value != null){
					if('fee' in value) value['fee'] = 0
					if('st' in value && 'pl' in value && 'dl' in value && 'subp' in value){ // batch modify
						value['st'] = 0
						value['subp'] = 1
						value['pl'] = (value['pl'] == 0) ? 320000 : value['pl']
						value['dl'] = (value['dl'] == 0) ? 320000 : value['dl']
					}
				}
				return value
			}

			let body = JSON.stringify(netease.jsonBody, inject)
			body = body.replace(/([^\\]"\s*:\s*)"(\d{16,})L"(\s*[}|,])/g, '$1$2$3') // for js precision
			proxyRes.body = (netease.encrypted ? crypto.eapi.encrypt(Buffer.from(body)) : body)
		})
		.catch(error => console.log(error, ctx.req.url))
	}
	else if(package){
		if(/p\d+c*.music.126.net/.test(ctx.req.url)){
			proxyRes.headers['content-type'] = 'audio/mpeg'
		}
	}
}

hook.connect.before = ctx => {
	let url = parse('https://' + ctx.req.url)
	if([url.hostname, ctx.req.headers.host].some(host => hook.target.host.includes(host))){
		if(url.port == 80){
			ctx.req.url = `${global.address || 'localhost'}:${global.port[0]}`
			ctx.req.local = true
		}
		else if(global.port[1]){
			ctx.req.url = `${global.address || 'localhost'}:${global.port[1]}`
			ctx.req.local = true
		}
		else{
			ctx.decision = 'blank'
		}
	}
}

hook.negotiate.before = ctx => {
	let url = parse('https://' + ctx.req.url)
	let socket = ctx.socket
	let target = hook.target.host
	if(ctx.req.local || ctx.decision) return
	if(target.includes(socket.sni) && !target.includes(url.hostname)){
		hook.target.host = Array.from(new Set([url.hostname].concat(target)))
		ctx.decision = 'blank'
	}
}

const pretendPlay = ctx => {
	const req = ctx.req
	const netease = ctx.netease
	let turn = 'http://music.163.com/api/song/enhance/player/url'
	let query = null
	if(netease.linux){
		netease.param = {
			ids: `["${netease.param.id}"]`,
			br: netease.param.br
		}
		query = crypto.linuxapi.encryptRequest(turn, netease.param)
	}
	else{
		netease.param = {
			ids: `["${netease.param.id}"]`,
			br: netease.param.br,
			e_r: netease.param.e_r,
			header: netease.param.header
		}
		query = crypto.eapi.encryptRequest(turn, netease.param)
	}
	req.url = query.url
	req.body = query.body + netease.pad
}

const tryCollect = ctx => {
	const req = ctx.req
	const netease = ctx.netease
	let trackId = (netease.param.trackIds instanceof Array ? netease.param.trackIds : JSON.parse(netease.param.trackIds))[0]
	return request('POST', 'http://music.163.com/api/playlist/manipulate/tracks', req.headers, `trackIds=[${trackId},${trackId}]&pid=${netease.param.pid}&op=${netease.param.op}`).then(response => response.json())
	.then(jsonBody => {
		netease.jsonBody = jsonBody
	})
	.catch(() => {})
}

const tryLike = ctx => {
	const req = ctx.req
	const netease = ctx.netease
	let pid, userId, trackId = netease.param.trackId
	return request('GET', 'http://music.163.com/api/v1/user/info', req.headers).then(response => response.json())
	.then(jsonBody => {
		userId = jsonBody.userPoint.userId
		return request('GET', `http://music.163.com/api/user/playlist?uid=${userId}&limit=1`, req.headers).then(response => response.json())
	})
	.then(jsonBody => {
		pid = jsonBody.playlist[0].id
		return request('POST', 'http://music.163.com/api/playlist/manipulate/tracks', req.headers, `trackIds=[${trackId},${trackId}]&pid=${pid}&op=add`).then(response => response.json())
	})
	.then(jsonBody => {
		if(jsonBody.code == 200 || jsonBody.code == 502){
			netease.jsonBody = {code: 200, playlistId: pid}
		}
	})
	.catch(() => {})
}

const computeHash = task => request('GET', task.url).then(response => crypto.md5.pipe(response))

const tryMatch = ctx => {
	const netease = ctx.netease
	const jsonBody = netease.jsonBody
	let tasks = [], target = 0

	const inject = item => {
		item.flag = 0
		if((item.code != 200 || item.freeTrialInfo) && (target == 0 || item.id == target)){
			return match(item.id)
			.then(song => {
				item.url = global.endpoint ? `${global.endpoint}/package/${crypto.base64.encode(song.url)}/${item.id}.mp3` : song.url
				item.md5 = song.md5 || crypto.md5.digest(song.url)
				item.size = song.size
				item.code = 200
				item.br = 320000
				item.type = 'mp3'
				return song
			})
			.then(song => {
				if(!netease.path.includes('download') || song.md5) return
				const newer = (base, target) => {
					let difference =
						Array.from([base, target])
						.map(version => version.split('.').slice(0, 3).map(number => parseInt(number) || 0))
						.reduce((aggregation, current) => !aggregation.length ? current.map(element => [element]) : aggregation.map((element, index) => element.concat(current[index])), [])
						.filter(pair => pair[0] != pair[1])[0]
					return !difference || difference[0] <= difference[1]
				}
				const limit = {android: '0.0.0', osx: '2.0.0'}
				const task = {key: song.url.replace(/\?.*$/, ''), url: song.url}
				try{
					let header = netease.param.header
					header = typeof(header) === 'string' ? JSON.parse(header) : header
					let os = header.os, version = header.appver
					if(os in limit && newer(limit[os], version))
						return cache(computeHash, task, 7 * 24 * 60 * 60 * 1000).then(value => item.md5 = value)
				}
				catch(e){}
			})
			.catch(() => {})
		}
		else if(item.code == 200 && netease.web){
			item.url = item.url.replace(/(m\d+?)(?!c)\.music\.126\.net/, '$1c.music.126.net')
		}
	}

	if(!jsonBody.data instanceof Array){
		tasks = [inject(jsonBody.data)]
	}
	else if(netease.path.includes('download')){
		jsonBody.data = jsonBody.data[0]
		tasks = [inject(jsonBody.data)]
	}
	else{
		target = netease.web ? 0 : parseInt((netease.param.ids instanceof Array ? netease.param.ids : JSON.parse(netease.param.ids))[0].toString().replace('_0', '')) // reduce time cost
		tasks = jsonBody.data.map(item => inject(item))
	}
	return Promise.all(tasks).catch(() => {})
}

module.exports = hook