GoogleDriveAlternateVideos.coffee

client      = require('./client')
apirequest  = require('../node_modules/googleapis/lib/apirequest')

get_alternate_videos = (docid, callback) ->
    parameters = {
        options: {
            url: "https://docs.google.com/get_video_info?docid={docid}",
            method: "GET"},
        context: client.drive,
        params: {
            docid: docid },
        requiredParams: ["docid"],
        pathParams: ["docid"]}

    mediaUrls = []

    apirequest parameters, (err, body, resp) ->
        if err != null
            # TODO: Handle error...
            return 

        urls = decodeURIComponent decodeURIComponent body
        urls = urls.replace ///\&url\=https:\/\////g, '\@'

        itagDB = {}
        containerDB = {'x-flv':'flv', 'webm': 'webm', 'mp4;+codecs="avc1.42001E,+mp4a.40.2"': 'mp4'}

        reg = ///(\d+)/(\d+)x(\d+)/(\d+/\d+/\d+)\&?\,?///g
        match = reg.exec urls
        while match != null
            itag        = match[1]
            codec       = match[4]

            itagDB[itag] = {
                width:  match[2],
                height: match[3],
                codec:  codec
            }

            # Rename some codecs
            if codec == '9/0/115'
                itagDB[itag]['codec'] = 'h.264/aac'
            else if codec == '99/0/0'
                itagDB[itag]['codec'] = 'VP8/vorbis'
            
            # Find next match
            match = reg.exec urls

        reg   = ///\@([^\@]+)///g
        match = reg.exec urls
        while match != null
            videoURL = 'https://'+match[1]
            reg2 = ///itag\=(\d+)[\s\S]*?type\=video\/([^\&]+)\&quality\=(\w+)///g
            q = reg2.exec videoURL
            while q != null
                itag        = q[1]
                container   = q[2]
                quality     = q[3]

                # Add new video to list
                mediaUrls.push {
                    quality:    quality,
                    width:      itagDB[itag].width,
                    height:     itagDB[itag].height,
                    codec:      itagDB[itag].codec,
                    container:  container,
                    extension:  containerDB[container],
                    url:        videoURL}

                # Next match
                q = reg2.exec videoURL

            # Next match
            match = reg.exec urls

        # Print out results
        console.log "Found "+mediaUrls.length+" alternate videos"

        # Call the callback
        if callback
            callback mediaUrls