#!/usr/bin/env node

"use strict";

var hlsdump = require('commander');
hlsdump.version('0.0.0')
   .usage('[options] <url>')
   .option('-o, --output <path>', 'target file')
   .option('-u, --udp [host:port]', 'relay TS over UDP', function(val) {
     var r = { host:'localhost', port:1234 };
     if (val) {
       var s = val.split(':');
       if (s.length === 1) {
         r.port = parseInt(s[0], 10);
       } else {
         r.host = s[0];
         r.port = parseInt(s[1], 10);
       }
     }
     return r;
   })
   .option('-b, --buffer-size <bytes>|full', 'try to buffer <bytes> of input data (implies -s)', function(val) {
     if (val === 'full') return 0x80000000-1;
     return parseInt(val, 0);
   })
   .option('-s, --sync', 'clock sync using stream PCR')
   .option('-f, --full-stream', 'fetch all stream data')
   .option('-c, --concurrent <count>', 'fetch using concurrent connections', parseInt)
   .option('-a, --user-agent <string>', 'HTTP User-Agent')
   .option('-i, --info-port <port>', 'report status using HTTP + json', parseInt)
   .parse(process.argv);

var util = require('util'),
    url = require('url'),
    fs = require('fs'),
    http = require('http');

var streamprocess = require('streamprocess'),
    oncemore = require('oncemore');
var reader = require('../lib/reader'),
    tssmooth = require('../lib/tssmooth'),
    tsblast = require('../lib/tsblast');

try {
  var Passthrough = require('stream').Passthrough;
  assert(Passthrough);
} catch (e) {
  var Passthrough = require('readable-stream/passthrough');
}

var stats = require('measured').createCollection();

var src = hlsdump.args[0];
if (!src) return hlsdump.help();

if (hlsdump.bufferSize) hlsdump.sync = true;

var r = reader(src, {highWaterMark:(hlsdump.concurrent || 1) - 1, fullStream:hlsdump.fullStream});

var totalDuration = 0, currentSegment = -1;
var reading = false;

streamprocess(r, function (obj, done) {
  var meta = obj.meta;
  var duration = obj.segment.duration;
  var size = meta.size;
  var stream = oncemore(obj.stream);
  totalDuration += duration;

  console.error('piping segment', meta.url);

  var stopwatch = stats.timer('fetchTime').start();
  stream.once('close', 'end', 'error', function(err) {
    stopwatch.end();
  });

  reading = true;
  currentSegment = obj.seq;
  stream.pipe(buffer, { end: false });
  if (size === -1 || !hooked) {
    size = 0;
    obj.stream.on('data', function(chunk) {
      size += chunk.length;
      if (!hooked && size >= hlsdump.bufferSize)
        hook(buffer);
    });
  }

  stream.once('end', 'error', function(err) {
    reading = false;
    console.error('segment done at '+totalDuration.toFixed(0)+' seconds, avg bitrate (kbps):', (size / (duration * 1024/8)).toFixed(1));
    if (err) {
      stats.meter('streamErrors').mark();
      console.error('stream error', err.stack || err);
    }
    hook(buffer);
    done();
  });
});

r.once('index', function() {
  // wait until first index is returned before attaching error listener.
  // this will enable initials errors to throw
  r.on('error', function(err) {
    console.error('reader error', err.stack || err);
  });
});

r.on('end', function() {
  console.error('done');
});

var buffer = new Passthrough({highWaterMark:hlsdump.bufferSize});
var outputs = [];

if (hlsdump.udp)
  outputs.push(tsblast(hlsdump.udp));

if (hlsdump.output) {
  if (hlsdump.output === '-')
    outputs.push(process.stdout);
  else
    outputs.push(fs.createWriteStream(hlsdump.output));
}

// the hook is used to prebuffer
var hooked = false;
function hook(stream) {
  if (hooked) return;

  console.error('hooking output');

  var s = stream;
  if (hlsdump.sync) {
    var smooth = tssmooth();
    smooth.on('unpipe', function() {
      this.unpipe();
    });
    smooth.on('warning', function(err) {
      console.error('smoothing error', err);
    });
    s = s.pipe(smooth);
  }

  outputs.forEach(function (o) {
    s.pipe(o);
  });

  hooked = true;
}

if (!hlsdump.sync)
  hook(buffer);

// setup stat tracking
stats.gauge('bufferBytes', function() { return buffer._readableState.length/* + buffer._writableState.length*/; });
stats.gauge('currentSegment', function() { return currentSegment; });
stats.gauge('index.first', function() { return r.index ? r.index.first_seq_no : -1; });
stats.gauge('index.last', function() { return r.index ? r.index.lastSeqNo() : -1; });
stats.gauge('totalDuration', function() { return totalDuration; });

stats.meter('streamErrors');

if (hlsdump.infoPort) {
  http.createServer(function (req, res) {
    if (req.method === 'GET') {
      var data = JSON.stringify(stats, null, ' ');
      res.writeHead(200, {
        'Content-Type': 'application/json',
        'Content-Length': data.length
      });
      res.write(data);
    }
    res.end();
  }).listen(hlsdump.infoPort);
}