// ==UserScript==
// @name         Bilibili MediaSession Helper
// @namespace    http://tampermonkey.net/
// @version      0.4
// @description  Dock metadata to MediaSession API for bilibili.com (Chrome 73+)
// @author       nondanee
// @match        https://*.bilibili.com/*
// @grant        none
// @downloadURL none
// ==/UserScript==

(() => {
	if (!('mediaSession' in navigator)) return
	if (self != top) return

	const updateMetadata = inital =>
		Promise.resolve()
		.then(() => {
			const url = window.location.href
			let id, title, artist, cover
			if (id = (url.match(/live\.bilibili\.com\/(\d+)/) || [])[1]) {
				return fetch(`//api.live.bilibili.com/xlive/web-room/v1/index/getInfoByRoom?room_id=${id}`)
				.then(response => response.json())
				.then(body => body.data)
				.then(data => Object.assign(data.room_info, {artist: data.anchor_info.base_info.uname}))
			}
			else if (id = (url.match(/bilibili\.com\/video\/av(\d+)/) || [])[1]) {
                const {videoData} = window.__INITIAL_STATE__
				return {
                    title: videoData.title,
                    artist: videoData.owner.name,
                    cover: videoData.pic.replace('https:', '').replace('http:', '')
                }
			}
			else if (id = (url.match(/bilibili\.com\/bangumi\/play\/\D+(\d+)/) || [])[1]) {
				const {progress} = window.__PGC_USERSTATE__
				const {epList, mediaInfo} = window.__INITIAL_STATE__
				const epInfo = (epList || []).find(item => (item.id === progress.last_ep_id && inital) || item.id.toString() === id) || window.__INITIAL_STATE__.epInfo
				return {
					title: mediaInfo.title,
					artist: (epInfo.titleFormat + ' ' + epInfo.longTitle).trim(),
					cover: epInfo.cover
				}
			}
		})
		.then(({title, artist, cover}) => {
			const image = new Image()
			image.onload = () => {
				navigator.mediaSession.metadata = new window.MediaMetadata({
					title,
					artist,
					artwork: [{src: cover, sizes: `${image.naturalWidth}x${image.naturalHeight}`, type: 'image/jpeg'}]
				})
			}
			image.src = cover
		})

	updateMetadata(true)

	const _pushState = history.pushState
	history.pushState = function (...props) {
		_pushState.apply(this, props)
		updateMetadata()
	}

	const _replaceState = history.replaceState
	history.replaceState = function (...props) {
		_replaceState.apply(this, props)
		updateMetadata()
	}
})()