/* Single audio play Pane

**

*/

const UI = require('solid-ui')

const ns = UI.ns

const kb = UI.store

module.exports = {

icon: UI.icons.iconBase + 'noun_534313.svg',

name: 'audio',

// Does the subject deserve an audio play pane?

label: function (subject) {

var kb = UI.store

var typeURIs = kb.findTypeURIs(subject)

var prefix = $rdf.Util.mediaTypeClass('audio/*').uri.split('*')[0]

for (var t in typeURIs) {

if (t.startsWith(prefix)) return 'Play audio'

}

return null

},

render: function (subject, dom) {

var options = {autoplay: false, chain: true, chainAlbums: true, loop: false}

var removeExtension = function (str) {

var dot = str.lastIndexOf('.')

if (dot < 0) return str // if any

var slash = str.lastIndexOf('/')

if (dot < slash) return str

return str.slice(0, dot)

}

// True if there is another file like song.mp3 when this is "song 1.mp3"

// or this is song.m4a

//

var looksRedundant = function (x) {

var folder = kb.any(undefined, ns.ldp('contains'), x)

if (!folder) return false

var contents = kb.each(folder, ns.ldp('contains'))

if (contents.length < 2) return false

var thisName = x.uri

for (var k = 0; k < contents.length; k++) {

var otherName = contents[k].uri

if (thisName.length > otherName.length && thisName.startsWith(removeExtension(otherName))) {

return true

}

if (thisName.endsWith('.m4a') && otherName.endsWith('.mp3') &&

removeExtension(thisName) === removeExtension(otherName)) {

return true

}

}

return false

}

// Alternative methods could include:

// Accesing metadata in the audio contol, or paring the audio file

var guessNames = function (x) {

var a = x.uri.split('/').slice(-3) // Hope artist, album, track

var decode = function (str) {

try {

return decodeURIComponent(str)

} catch (e) {

return str

}

}

artistRow.textContent = decode(a[0])

albumRow.textContent = decode(a[1])

trackRow.textContent = decode(removeExtension(a[2]))

}

var moveOn = function (current, level) {

return new Promise(function (resolve, reject) {

level = level || 0

if (!options.chain) return resolve(null)

// Ideally navigate graph else cheat with URI munging:

var folder = kb.any(undefined, ns.ldp('contains'), current) || current.dir()

if (!folder) return resolve(null)

kb.fetcher.load(folder).then(function (xhr) {

var contents = kb.each(folder, ns.ldp('contains')) // @@ load if not loaded

// if (contents.length < 2) return resolve(null) NO might move on from 1-track album

var j

contents.sort() // sort by URI which hopefully will get tracks in order

for (var i = 0; i < contents.length; i++) {

if (current.uri === contents[i].uri) {

j = (i + 1) % contents.length

if (j === 0) {

if (!options.chainAlbums) {

if (options.loop) {

return resolve(contents[j])

}

return resolve(null) // No more music needed

} else { // chain albums

if (level === 1 || !options.chainAlbums) return resolve(null) // limit of navigating treee

moveOn(folder, level + 1).then(function (folder2) {

if (folder2) {

kb.fetcher.load(folder2).then(function (xhr) {

var contents = kb.each(folder2, ns.ldp('contains'))

if (contents.length === 0) return resolve(null)

contents.sort()

console.log('New Album: ' + folder2)

return resolve(contents[0]) // Start off new album

})

}

})

}

} else {

return resolve(contents[j])

}

}

} // for

})

})

}

var endedListener = function (event) {

var current = kb.sym(event.target.getAttribute('src'))

if (!options.chain) return

var tryNext = function (cur) {

var current = cur

moveOn(current).then(function (next) {

if (!next) {

console.log('No successor to ' + current)

return

}

if (!looksRedundant(next)) {

console.log('Moving on to ' + next)

guessNames(next)

controlRow.appendChild(audioControl(next, true)) // Force autoplay

controlRow.removeChild(event.target)

} else {

console.log('Ignoring redundant ' + next)

tryNext(next)

}

})

}

tryNext(current)

}

var audioControl = function (song, autoplay) {

var audio = dom.createElement('audio')

audio.setAttribute('controls', 'yes')

audio.setAttribute('src', song.uri)

if (autoplay) {

audio.setAttribute('autoplay', 'autoplay') // Make this a personal preference

}

audio.addEventListener('ended', endedListener, false)

return audio

}

var div = dom.createElement('div')

var table = div.appendChild(dom.createElement('table'))

var labelStyle = 'padding: 0.3em; color:white; background-color: black;'

var artistRow = table.appendChild(dom.createElement('tr'))

artistRow.style.cssText = labelStyle

var albumRow = table.appendChild(dom.createElement('tr'))

albumRow.style.cssText = labelStyle

var trackRow = table.appendChild(dom.createElement('tr'))

trackRow.style.cssText = labelStyle

var controlRow = table.appendChild(dom.createElement('tr'))

guessNames(subject)

controlRow.appendChild(audioControl(subject, options.autoplay))

if (!kb.holds(undefined, ns.ldp('contains'), subject) && subject.dir()) {

kb.fetcher.load(subject.dir()) // Prefetch enclosing @@ or playlist

}

return div

}

}

// ends