var ltx = require('ltx');
var http = require('http');
var fs = require('fs');
var url = require('url');


var running = 0, queue = [];

var SUFFIXES = [".mp4", ".webm", ".mp3", "_hq.mp4"];
var WEB_SUFFIXES = [".mp4", ".webm", ".mp3"];

function resolveSizes(urls, cb) {
    if (running > 0) {
	queue.push(function() {
	    resolveSizes(urls, cb);
	});
	return;
    }
    running++;

    urls = urls.map(url.parse);

    var pending = 0, results = [],
	done = function() {
	    if (pending < 1) {
		results = results.sort(function(r1, r2) {
		    var ui1 = urls.indexOf(r1.url);
		    var ui2 = urls.indexOf(r2.url);
		    if (ui1 < ui2)
			return -1;
		    else if (ui1 > ui2)
			return 1;
		    else
			return 0;
		});
		cb(results);

		running--;
		var f = queue.shift();
		f && f();
	    }
	};

    urls.forEach(function(u) {
	var req = http.request({ method: 'HEAD',
				 path: u.pathname,
				 hostname: u.host });
	req.end();
	req.on('response', function(res) {
	    if (res.statusCode === 200) {
		results.push({ url: url.format(u),
			       size: res.headers['content-length'] });
	    } else {
		console.error("HTTP " + res.statusCode + " " + u.pathname);
	    }
	    pending--;
	    done();
	});
	pending++;
    });
    done();
}

function mimeByExt(url) {
    var ext = url.split('.').pop();
    var type = ({ avi: 'video/avi',
		  mp3: 'audio/mpeg',
		  mp4: 'video/mp4',
		  webm: 'video/webm',
		  ogv: 'video/ogg',
		  flv: 'video/x-flv' })[ext];
    return type || 'application/octet-stream';
}

function processEvent(event) {
    var base = 'http://ftp.c3d2.de/datenspuren/2013/' + event.outputName;
    var urls = WEB_SUFFIXES.map(function(fmt) {
	return base + fmt;
    });
    resolveSizes(urls, function(infos) {
	infos = infos.filter(function(i) {
	    return i.size !== undefined;
	});

	if (infos.length < 1) {
	    console.warn("<!-- No resources for " + event.id + ": " + event.title + " -->");
	    return;
	}
	var resAttrs = {
	    title: event.title,
	    size: infos[0].size,
	    type: mimeByExt(infos[0].url),
	    url: infos[0].url,
	    preview: base + ".gif",
	    poster: base + ".jpg"
	};
	if (event.id != "0000") {
	    resAttrs['details-link'] = "http://datenspuren.de/2013/fahrplan/events/" +
		event.id + ".html";
	    resAttrs['feedback-link'] = "https://frab.cccv.de/en/DS2013/public/events/" +
		event.id + "/feedback/new";
	}
	var res = new ltx.Element('resource', resAttrs);
	infos.slice(1).forEach(function(info) {
	    res.c('alternative', { size: info.size,
				   type: mimeByExt(info.url),
				   url: info.url });
	});
	console.info(res.toString());
    });
}

function printMetadata(event) {
    var metaparameters = "";
    function addMeta(k, v) {
	metaparameters +=
	    " -metadata " + k + "=\"" +
	    v.replace(/"/g, '\\"') + "\"";
    }
    addMeta('title', event.title);
    addMeta('subtitle', event.subtitle);
    addMeta('album', "Datenspuren 2012");
    addMeta('artist', "Datenspuren");
    addMeta('author', "Datenspuren");
    addMeta('language', "deu");
    addMeta('year', "2012");
    addMeta('composer', event.persons.join(", "));
    addMeta('description', event.abstract || event.description);
    SUFFIXES.forEach(function(suffix) {
	console.log("avconv -i " + event.inputName + suffix + " -codec copy" + metaparameters + " -y " + event.outputName + suffix);
    });
}

function slugify(title) {
    return title.toLowerCase().
	replace(/\s*[–\-\:].*/, "").
	replace(/[\.!\?\/]/g, "").
	replace(/Ä/g, "Ae").
	replace(/Ö/g, "Oe").
	replace(/Ü/g, "Ue").
	replace(/ä/g, "ae").
	replace(/ö/g, "oe").
	replace(/ü/g, "ue").
	replace(/ß/g, "ss").
	replace(/ẞ/g, "SS").
	replace(/\s+/g, "_");
}

function makeEvent(event) {
    event.inputName = event.id;
    event.outputName = event.id + "_" + slugify(event.title);
    return event;
}

var scheduleFile = fs.readFileSync('../content/static/datenspuren/2013/fahrplan/schedule.xml');
var schedule = ltx.parse(scheduleFile);
schedule.getChildren('day').forEach(function(dayEl) {
    var dayEvents = [];
    var roomIdx = 0;
    dayEl.getChildren('room').forEach(function(roomEl) {
	roomEl.getChildren('event').forEach(function(eventEl) {
	    var persons = [];
	    eventEl.getChildren('persons').forEach(function(personsEl) {
		personsEl.getChildren('person').forEach(function(personEl) {
		    persons.push(personEl.getText());
		});
	    });
	    dayEvents.push(makeEvent(
		{ id: eventEl.attrs.id,
		  time: eventEl.getChildText('start'),
		  room: roomIdx,
		  title: eventEl.getChildText('title'),
		  subtitle: eventEl.getChildText('subtitle'),
		  slug: eventEl.getChildText('slug'),
		  abstract: eventEl.getChildText('abstract'),
		  description: eventEl.getChildText('description'),
		  persons: persons
		}));
	});
	roomIdx++;
    });
    dayEvents = dayEvents.sort(function(e1, e2) {
	return (e1.time < e2.time) ? -1 :
	    ((e1.time > e2.time) ? 1 : e1.room - e2.room);
    });
    dayEvents.forEach(printMetadata);
    dayEvents.forEach(processEvent);
});