var camp = require('camp').start({
  documentRoot: __dirname,
  port: +process.env.PORT||+process.argv[2]||80
});
var https = require('https');
var request = require('request');
var fs = require('fs');
var LruCache = require('./lru-cache.js');
var badge = require('./badge.js');
var svg2img = require('./svg-to-img.js');
var semver = require('semver');
var serverStartTime = new Date((new Date()).toGMTString());

var validTemplates = ['default', 'flat'];

// Analytics

var redis;
// Use Redis by default.
var useRedis = true;
if (process.env.REDISTOGO_URL) {
  var redisToGo = require('url').parse(process.env.REDISTOGO_URL);
  redis = require('redis').createClient(redisToGo.port, redisToGo.hostname);
  redis.auth(redisToGo.auth.split(':')[1]);
} else {
  redis = require('redis').createClient();
}
redis.on('error', function() {
  useRedis = false;
});

var analytics = {};

var analyticsAutoSaveFileName = './analytics.json';
var analyticsAutoSavePeriod = 10000;
setInterval(function analyticsAutoSave() {
  if (useRedis) {
    redis.set(analyticsAutoSaveFileName, JSON.stringify(analytics));
  } else {
    fs.writeFileSync(analyticsAutoSaveFileName, JSON.stringify(analytics));
  }
}, analyticsAutoSavePeriod);

// Auto-load analytics.
function analyticsAutoLoad() {
  if (useRedis) {
    redis.get(analyticsAutoSaveFileName, function(err, value) {
      if (err == null && value != null) {
        // if/try/return trick:
        // if error, then the rest of the function is run.
        try {
          analytics = JSON.parse(value);
          return;
        } catch(e) {}
      }
      // In case something happens on the 36th.
      analytics.vendorMonthly = new Array(36);
      analytics.rawMonthly = new Array(36);
      resetMonthlyAnalytics(analytics.vendorMonthly);
      resetMonthlyAnalytics(analytics.rawMonthly);
    });
  } else {
    // Not using Redis.
    try {
      analytics = JSON.parse(fs.readFileSync(analyticsAutoSaveFileName));
    } catch(e) {
      // In case something happens on the 36th.
      analytics.vendorMonthly = new Array(36);
      analytics.rawMonthly = new Array(36);
      resetMonthlyAnalytics(analytics.vendorMonthly);
      resetMonthlyAnalytics(analytics.rawMonthly);
    }
  }
}

var lastDay = (new Date()).getDate();
function resetMonthlyAnalytics(monthlyAnalytics) {
  for (var i = 0; i < monthlyAnalytics.length; i++) {
    monthlyAnalytics[i] = 0;
  }
}
function incrMonthlyAnalytics(monthlyAnalytics) {
  var currentDay = (new Date()).getDate();
  // If we changed month, reset empty days.
  while (lastDay !== currentDay) {
    // Assumption: at least a hit a month.
    lastDay = (lastDay + 1) % monthlyAnalytics.length;
    monthlyAnalytics[lastDay] = 0;
  }
  monthlyAnalytics[currentDay]++;
}

analyticsAutoLoad();
camp.ajax.on('analytics/v1', function(json, end) { end(analytics); });

// Cache

// We avoid calling the vendor's server for computation of the information in a
// number of badges.
var minAccuracy = 0.75;

// The quotient of (vendor) data change frequency by badge request frequency
// must be lower than this to trigger sending the cached data *before*
// updating our data from the vendor's server.
// Indeed, the accuracy of our badges are:
// A(Δt) = 1 - min(# data change over Δt, # requests over Δt)
//             / (# requests over Δt)
//       = 1 - max(1, df) / rf
var freqRatioMax = 1 - minAccuracy;

// Request cache size of size 1_000_000 (~1GB, 1kB/image).
var requestCache = new LruCache(1000000);

function cache(f) {
  return function getRequest(data, match, end, ask) {
    // Cache management - no cache, so it won't be cached by GitHub's CDN.
    ask.res.setHeader('Cache-Control', 'no-cache, no-store, must-revalidate');
    incrMonthlyAnalytics(analytics.vendorMonthly);

    var cacheIndex = match[0] + '?label=' + data.label + '&style=' + data.style;
    // Should we return the data right away?
    var cached = requestCache.get(cacheIndex);
    var cachedVersionSent = false;
    if (cached !== undefined
        && cached.dataChange / cached.reqs <= freqRatioMax) {
      badge(cached.data.badgeData, makeSend(cached.data.format, ask.res, end));
      cachedVersionSent = true;
    }

    // In case our vendor servers are unresponsive.
    var serverUnresponsive = false;
    var serverResponsive = setTimeout(function() {
      serverUnresponsive = true;
      if (cachedVersionSent) { return; }
      if (requestCache.has(cacheIndex)) {
        var cached = requestCache.get(cacheIndex).data;
        badge(cached.badgeData, makeSend(cached.format, ask.res, end));
        return;
      }
      var badgeData = getBadgeData('vendor', data);
      badgeData.text[1] = 'unresponsive';
      badge(badgeData, makeSend('svg', ask.res, end));
    }, 25000);

    f(data, match, function sendBadge(format, badgeData) {
      if (serverUnresponsive) { return; }
      clearTimeout(serverResponsive);
      // Check for a change in the data.
      var dataHasChanged = false;
      if (cached !== undefined
        && cached.data.badgeData.text[1] !== badgeData.text[1]) {
        dataHasChanged = true;
      }
      // Update information in the cache.
      var updatedCache = {
        reqs: cached? (cached.reqs + 1): 1,
        dataChange: cached? (cached.dataChange + (dataHasChanged? 1: 0))
                          : 1,
        data: { format: format, badgeData: badgeData }
      };
      requestCache.set(cacheIndex, updatedCache);
      if (!cachedVersionSent) {
        badge(badgeData, makeSend(format, ask.res, end));
      }
    });
  };
}

// Vendors.

// Travis integration
camp.route(/^\/travis(-ci)?\/([^\/]+\/[^\/]+)(?:\/(.+))?\.(svg|png|gif|jpg)$/,
cache(function(data, match, sendBadge) {
  var userRepo = match[2];  // eg, espadrine/sc
  var branch = match[3];
  var format = match[4];
  var options = {
    json: true,
    uri: 'https://api.travis-ci.org/repos/' + userRepo + '/builds.json'
  };
  branch = branch || 'master';
  var badgeData = getBadgeData('build', data);
  request(options, function(err, res, json) {
    if (err != null || (json.length !== undefined && json.length === 0)) {
      badgeData.text[1] = 'inaccessible';
      sendBadge(format, badgeData);
      return;
    }
    // Find the latest push on this branch.
    var build = null;
    for (var i = 0; i < json.length; i++) {
      if (json[i].state === 'finished' && json[i].event_type === 'push'
      && json[i].branch === branch) {
        build = json[i];
        break;
      }
    }
    badgeData.text[1] = 'pending';
    if (build === null) {
      sendBadge(format, badgeData);
      return;
    }
    if (build.result === 0) {
      badgeData.colorscheme = 'brightgreen';
      badgeData.text[1] = 'passing';
    } else if (build.result === 1) {
      badgeData.colorscheme = 'red';
      badgeData.text[1] = 'failing';
    }
    sendBadge(format, badgeData);
  });
}));

// Gittip integration.
camp.route(/^\/gittip\/(.*)\.(svg|png|gif|jpg)$/,
cache(function(data, match, sendBadge) {
  var user = match[1];  // eg, `JSFiddle`.
  var format = match[2];
  var apiUrl = 'https://www.gittip.com/' + user + '/public.json';
  var badgeData = getBadgeData('tips', data);
  request(apiUrl, function dealWithData(err, res, buffer) {
    if (err != null) {
      badgeData.text[1] = 'inaccessible';
      sendBadge(format, badgeData);
      return;
    }
    try {
      var data = JSON.parse(buffer);
      var money = parseInt(data.receiving);
      badgeData.text[1] = '$' + metric(money) + '/week';
      if (money === 0) {
        badgeData.colorscheme = 'red';
      } else if (money < 10) {
        badgeData.colorscheme = 'yellow';
      } else if (money < 100) {
        badgeData.colorscheme = 'green';
      } else {
        badgeData.colorscheme = 'brightgreen';
      }
      sendBadge(format, badgeData);
    } catch(e) {
      badgeData.text[1] = 'invalid';
      sendBadge(format, badgeData);
    }
  });
}));

// Packagist integration.
camp.route(/^\/packagist\/(dm|dd|dt)\/(.*)\.(svg|png|gif|jpg)$/,
cache(function(data, match, sendBadge) {
  var info = match[1];  // either `dm` or dt`.
  var userRepo = match[2];  // eg, `doctrine/orm`.
  var format = match[3];
  var apiUrl = 'https://packagist.org/packages/' + userRepo + '.json';
  var badgeData = getBadgeData('downloads', data);
  request(apiUrl, function(err, res, buffer) {
    if (err != null) {
      badgeData.text[1] = 'inaccessible';
      sendBadge(format, badgeData);
    }
    try {
      var data = JSON.parse(buffer);
      switch (info.charAt(1)) {
        case 'm':
          var downloads = data.package.downloads.monthly;
          badgeData.text[1] = metric(downloads) + '/month';
          break;
        case 'd':
          var downloads = data.package.downloads.daily;
          badgeData.text[1] = metric(downloads) + '/day';
          break;
        case 't':
          var downloads = data.package.downloads.total;
          badgeData.text[1] = metric(downloads) + ' total';
          break;
      }
      if (downloads === 0) {
        badgeData.colorscheme = 'red';
      } else if (downloads < 10) {
        badgeData.colorscheme = 'yellow';
      } else if (downloads < 100) {
        badgeData.colorscheme = 'yellowgreen';
      } else if (downloads < 1000) {
        badgeData.colorscheme = 'green';
      } else {
        badgeData.colorscheme = 'brightgreen';
      }
      sendBadge(format, badgeData);
    } catch(e) {
      badgeData.text[1] = 'invalid';
      sendBadge(format, badgeData);
    }
  });
}));

// Packagist version integration.
camp.route(/^\/packagist\/v\/(.*)\.(svg|png|gif|jpg)$/,
cache(function(data, match, sendBadge) {
  var userRepo = match[1];
  var format = match[2];
  var apiUrl = 'https://packagist.org/packages/' + userRepo + '.json';
  var badgeData = getBadgeData('packagist', data);
  request(apiUrl, function(err, res, buffer) {
    if (err != null) {
      badgeData.text[1] = 'inaccessible';
      sendBadge(format, badgeData);
    }
    try {
      var data = JSON.parse(buffer);
      var version;
      var unstable = function(ver) { return /dev/.test(ver); };
      // Grab the latest stable version, or an unstable
      for (var versionName in data.package.versions) {
        var current = data.package.versions[versionName];

        if (version !== undefined) {
          if (unstable(version.version) && !unstable(current.version)) {
            version = current;
          } else if (version.version_normalized < current.version_normalized) {
            version = current;
          }
        } else {
          version = current;
        }
      }
      version = version.version.replace(/^v/, "");
      badgeData.text[1] = version;
      if (/^\d/.test(badgeData.text[1])) {
        badgeData.text[1] = 'v' + version;
      }
      if (version[0] === '0' || /dev/.test(version)) {
        badgeData.colorscheme = 'orange';
      } else {
        badgeData.colorscheme = 'blue';
      }
      sendBadge(format, badgeData);
    } catch(e) {
      badgeData.text[1] = 'invalid';
      sendBadge(format, badgeData);
    }
  });
}));

// Packagist license integration.
camp.route(/^\/packagist\/l\/(.*)\.(svg|png|gif|jpg)$/,
cache(function(data, match, sendBadge) {
  var userRepo = match[1];
  var format = match[2];
  var apiUrl = 'https://packagist.org/packages/' + userRepo + '.json';
  var badgeData = getBadgeData('license', data);
  request(apiUrl, function(err, res, buffer) {
    if (err != null) {
      badgeData.text[1] = 'inaccessible';
      sendBadge(format, badgeData);
    }
    try {
      var data = JSON.parse(buffer);
      // Note: if you change the latest version detection algorithm here,
      // change it above (for the actual version badge).
      var version;
      var unstable = function(ver) { return /dev/.test(ver); };
      // Grab the latest stable version, or an unstable
      for (var versionName in data.package.versions) {
        var current = data.package.versions[versionName];

        if (version !== undefined) {
          if (unstable(version.version) && !unstable(current.version)) {
            version = current;
          } else if (version.version_normalized < current.version_normalized) {
            version = current;
          }
        } else {
          version = current;
        }
      }
      badgeData.text[1] = version.license[0];
      badgeData.colorscheme = 'red';
      sendBadge(format, badgeData);
    } catch(e) {
      badgeData.text[1] = 'invalid';
      sendBadge(format, badgeData);
    }
  });
}));

// npm integration.
camp.route(/^\/npm\/dm\/(.*)\.(svg|png|gif|jpg)$/,
cache(function(data, match, sendBadge) {
  var user = match[1];  // eg, `localeval`.
  var format = match[2];
  var apiUrl = 'https://api.npmjs.org/downloads/point/last-month/' + user;
  var badgeData = getBadgeData('downloads', data);
  request(apiUrl, function(err, res, buffer) {
    if (err != null) {
      badgeData.text[1] = 'inaccessible';
      sendBadge(format, badgeData);
      return;
    }
    try {
      var monthly = JSON.parse(buffer).downloads;
    } catch(e) {
      badgeData.text[1] = 'invalid';
      sendBadge(format, badgeData);
      return;
    }
    badgeData.text[1] = metric(monthly) + '/month';
    if (monthly === 0) {
      badgeData.colorscheme = 'red';
    } else if (monthly < 10) {
      badgeData.colorscheme = 'yellow';
    } else if (monthly < 100) {
      badgeData.colorscheme = 'yellowgreen';
    } else if (monthly < 1000) {
      badgeData.colorscheme = 'green';
    } else {
      badgeData.colorscheme = 'brightgreen';
    }
    sendBadge(format, badgeData);
  });
}));

// npm version integration.
camp.route(/^\/npm\/v\/(.*)\.(svg|png|gif|jpg)$/,
cache(function(data, match, sendBadge) {
  var repo = match[1];  // eg, `localeval`.
  var format = match[2];
  var apiUrl = 'https://registry.npmjs.org/' + repo + '/latest';
  var badgeData = getBadgeData('npm', data);
  // Using the Accept header because of this bug:
  // <https://github.com/npm/npmjs.org/issues/163>
  request(apiUrl, { headers: { 'Accept': '*/*' } }, function(err, res, buffer) {
    if (err != null) {
      badgeData.text[1] = 'inaccessible';
      sendBadge(format, badgeData);
    }
    try {
      var data = JSON.parse(buffer);
      var version = data.version;
      badgeData.text[1] = 'v' + version;
      if (version[0] === '0' || /dev/.test(version)) {
        badgeData.colorscheme = 'orange';
      } else {
        badgeData.colorscheme = 'blue';
      }
      sendBadge(format, badgeData);
    } catch(e) {
      badgeData.text[1] = 'invalid';
      sendBadge(format, badgeData);
    }
  });
}));

// Gem version integration.
camp.route(/^\/gem\/v\/(.*)\.(svg|png|gif|jpg)$/,
cache(function(data, match, sendBadge) {
  var repo = match[1];  // eg, `localeval`.
  var format = match[2];
  var apiUrl = 'https://rubygems.org/api/v1/gems/' + repo + '.json';
  var badgeData = getBadgeData('gem', data);
  request(apiUrl, function(err, res, buffer) {
    if (err != null) {
      badgeData.text[1] = 'inaccessible';
      sendBadge(format, badgeData);
    }
    try {
      var data = JSON.parse(buffer);
      var version = data.version;
      badgeData.text[1] = 'v' + version;
      if (version[0] === '0' || /dev/.test(version)) {
        badgeData.colorscheme = 'orange';
      } else {
        badgeData.colorscheme = 'blue';
      }
      sendBadge(format, badgeData);
    } catch(e) {
      badgeData.text[1] = 'invalid';
      sendBadge(format, badgeData);
    }
  });
}));

// PyPI integration.
camp.route(/^\/pypi\/([^\/]+)\/(.*)\.(svg|png|gif|jpg)$/,
cache(function(data, match, sendBadge) {
  var info = match[1];
  var egg = match[2];  // eg, `gevent`.
  var format = match[3];
  var apiUrl = 'https://pypi.python.org/pypi/' + egg + '/json';
  var badgeData = getBadgeData('pypi', data);
  request(apiUrl, function(err, res, buffer) {
    if (err != null) {
      badgeData.text[1] = 'inaccessible';
      sendBadge(format, badgeData);
    }
    try {
      var data = JSON.parse(buffer);
      if (info.charAt(0) === 'd') {
        badgeData.text[0] = getLabel('downloads', data);
        switch (info.charAt(1)) {
          case 'm':
            var downloads = data.info.downloads.last_month;
            badgeData.text[1] = metric(downloads) + '/month';
            break;
          case 'w':
            var downloads = data.info.downloads.last_week;
            badgeData.text[1] = metric(downloads) + '/week';
            break;
          case 'd':
            var downloads = data.info.downloads.last_day;
            badgeData.text[1] = metric(downloads) + '/day';
            break;
        }
        if (downloads === 0) {
          badgeData.colorscheme = 'red';
        } else if (downloads < 10) {
          badgeData.colorscheme = 'yellow';
        } else if (downloads < 100) {
          badgeData.colorscheme = 'yellowgreen';
        } else if (downloads < 1000) {
          badgeData.colorscheme = 'green';
        } else {
          badgeData.colorscheme = 'brightgreen';
        }
        sendBadge(format, badgeData);
      } else if (info === 'v') {
        var version = data.info.version;
        badgeData.text[1] = 'v' + version;
        if (version[0] === '0' || /dev/.test(version)) {
          badgeData.colorscheme = 'orange';
        } else {
          badgeData.colorscheme = 'blue';
        }
        sendBadge(format, badgeData);
      }
    } catch(e) {
      badgeData.text[1] = 'invalid';
      sendBadge(format, badgeData);
    }
  });
}));

// Coveralls integration.
camp.route(/^\/coveralls\/([^\/]+\/[^\/]+)(?:\/(.+))?\.(svg|png|gif|jpg)$/,
cache(function(data, match, sendBadge) {
  var userRepo = match[1];  // eg, `jekyll/jekyll`.
  var branch = match[2];
  var format = match[3];
  var apiUrl = 'https://coveralls.io/repos/' + userRepo + '/badge.png';
  if (branch) {
    apiUrl += '?branch=' + branch;
  }
  var badgeData = getBadgeData('coverage', data);
  https.get(apiUrl, function(res) {
    // We should get a 302. Look inside the Location header.
    var buffer = res.headers.location;
    if (!buffer) {
      badgeData.text[1] = 'invalid';
      sendBadge(format, badgeData);
      return;
    }
    try {
      var score = buffer.split('_')[1].split('.')[0];
      var percentage = parseInt(score);
      if (percentage !== percentage) {
        // It is NaN, treat it as unknown.
        badgeData.text[1] = 'unknown';
        sendBadge(format, badgeData);
        return;
      }
    } catch(e) {
      badgeData.text[1] = 'malformed';
      sendBadge(format, badgeData);
      return;
    }
    badgeData.text[1] = score + '%';
    if (percentage < 80) {
      badgeData.colorscheme = 'red';
    } else if (percentage < 90) {
      badgeData.colorscheme = 'yellow';
    } else if (percentage < 95) {
      badgeData.colorscheme = 'green';
    } else {
      badgeData.colorscheme = 'brightgreen';
    }
    sendBadge(format, badgeData);
  }).on('error', function(e) {
    badgeData.text[1] = 'inaccessible';
    sendBadge(format, badgeData);
  });
}));

// Code Climate coverage integration
camp.route(/^\/codeclimate\/coverage\/(.+)\.(svg|png|gif|jpg)$/,
cache(function(data, match, sendBadge) {
  var userRepo = match[1];  // eg, `github/triAGENS/ashikawa-core`.
  var format = match[2];
  var options = {
    method: 'HEAD',
    uri: 'https://codeclimate.com/' + userRepo + '/coverage.png'
  };
  var badgeData = getBadgeData('coverage', data);
  request(options, function(err, res) {
    if (err != null) {
      badgeData.text[1] = 'inaccessible';
      sendBadge(format, badgeData);
    }
    try {
      var score = res.headers['content-disposition']
                     .match(/filename="coverage_(.+)\.png"/)[1];
      if (!score) {
        badgeData.text[1] = 'malformed';
        sendBadge(format, badgeData);
        return;
      }
      var percentage = parseInt(score);
      if (percentage !== percentage) {
        // It is NaN, treat it as unknown.
        badgeData.text[1] = 'unknown';
        sendBadge(format, badgeData);
        return;
      }
      badgeData.text[1] = score + '%';
      if (percentage < 80) {
        badgeData.colorscheme = 'red';
      } else if (percentage < 90) {
        badgeData.colorscheme = 'yellow';
      } else if (percentage < 95) {
        badgeData.colorscheme = 'green';
      } else {
        badgeData.colorscheme = 'brightgreen';
      }
      sendBadge(format, badgeData);
    } catch(e) {
      badgeData.text[1] = 'not found';
      sendBadge(format, badgeData);
    }
  });
}));

// Code Climate integration
camp.route(/^\/codeclimate\/(.+)\.(svg|png|gif|jpg)$/,
cache(function(data, match, sendBadge) {
  var userRepo = match[1];  // eg, `github/kabisaict/flow`.
  var format = match[2];
  var options = {
    method: 'HEAD',
    uri: 'https://codeclimate.com/' + userRepo + '.png'
  };
  var badgeData = getBadgeData('code climate', data);
  request(options, function(err, res) {
    if (err != null) {
      badgeData.text[1] = 'inaccessible';
      sendBadge(format, badgeData);
    }
    try {
      var statusMatch = res.headers['content-disposition']
                           .match(/filename="code_climate-(.+)\.png"/);
      if (!statusMatch) {
        badgeData.text[1] = 'unknown';
        sendBadge(format, badgeData);
        return;
      }
      var state = statusMatch[1].replace('-', '.');
      var score = +state;
      badgeData.text[1] = state;
      if (score == 4) {
        badgeData.colorscheme = 'brightgreen';
      } else if (score > 3) {
        badgeData.colorscheme = 'green';
      } else if (score > 2) {
        badgeData.colorscheme = 'yellowgreen';
      } else if (score > 1) {
        badgeData.colorscheme = 'yellow';
      } else {
        badgeData.colorscheme = 'red';
      }
      sendBadge(format, badgeData);
    } catch(e) {
      badgeData.text[1] = 'not found';
      sendBadge(format, badgeData);
    }
  });
}));

// Gemnasium integration
camp.route(/^\/gemnasium\/(.+)\.(svg|png|gif|jpg)$/,
cache(function(data, match, sendBadge) {
  var userRepo = match[1];  // eg, `jekyll/jekyll`.
  var format = match[2];
  var options = 'https://gemnasium.com/' + userRepo + '.svg';
  var badgeData = getBadgeData('dependencies', data);
  request(options, function(err, res, buffer) {
    if (err != null) {
      badgeData.text[1] = 'inaccessible';
      sendBadge(format, badgeData);
    }
    try {
      var nameMatch = buffer.match(/(devD|d)ependencies/)[0];
      var statusMatch = buffer.match(/'12'>(.+)<\/text>\n<\/g>/)[1];
      badgeData.text[0] = nameMatch;
      badgeData.text[1] = statusMatch;
      if (statusMatch === 'up-to-date') {
        badgeData.colorscheme = 'brightgreen';
      } else if (statusMatch === 'out-of-date') {
        badgeData.colorscheme = 'yellow';
      } else if (statusMatch === 'update!') {
        badgeData.colorscheme = 'red';
      } else if (statusMatch === 'none') {
        badgeData.colorscheme = 'brightgreen';
      } else {
        badgeData.text[1] = 'undefined';
      }
      sendBadge(format, badgeData);
    } catch(e) {
      badgeData.text[1] = 'invalid';
      sendBadge(format, badgeData);
      return;
    }
  });
}));

// Hackage version integration.
camp.route(/^\/hackage\/v\/(.*)\.(svg|png|gif|jpg)$/,
cache(function(data, match, sendBadge) {
  var repo = match[1];  // eg, `lens`.
  var format = match[2];
  var apiUrl = 'https://hackage.haskell.org/package/' + repo + '/' + repo + '.cabal';
  var badgeData = getBadgeData('hackage', data);
  request(apiUrl, function(err, res, buffer) {
    if (err != null) {
      badgeData.text[1] = 'inaccessible';
      sendBadge(format, badgeData);
    }
    try {
      var lines = buffer.split("\n");
      var versionLines = lines.filter(function(e) {
        return (/^version:/i).test(e) === true;
      });
      // We don't have to check length of versionLines, because if we throw,
      // we'll render the 'invalid' badge below, which is the correct thing
      // to do.
      var version = versionLines[0].replace(/\s+/, '').split(/:/)[1];
      badgeData.text[1] = 'v' + version;
      if (version[0] === '0') {
        badgeData.colorscheme = 'orange';
      } else {
        badgeData.colorscheme = 'blue';
      }
      sendBadge(format, badgeData);
    } catch(e) {
      badgeData.text[1] = 'invalid';
      sendBadge(format, badgeData);
    }
  });
}));

// CocoaPods version integration.
camp.route(/^\/cocoapods\/v\/(.*)\.(svg|png|gif|jpg)$/,
cache(function(data, match, sendBadge) {
  var spec = match[1];  // eg, AFNetworking
  var format = match[2];
  var apiUrl = 'http://search.cocoapods.org/api/v1/pod/' + spec + '.json';
  var badgeData = getBadgeData('pod', data);
  request(apiUrl, function(err, res, buffer) {
    if (err != null) {
      badgeData.text[1] = 'inaccessible';
      sendBadge(format, badgeData);
    }
    try {
      var data = JSON.parse(buffer);
      var version = data.version;
      version = version.replace(/^v/, "");
      badgeData.text[1] = version;
      if (/^\d/.test(badgeData.text[1])) {
        badgeData.text[1] = 'v' + version;
      }
      if (version[0] === '0' || /dev/.test(version)) {
        badgeData.colorscheme = 'orange';
      } else {
        badgeData.colorscheme = 'blue';
      }
      sendBadge(format, badgeData);
    } catch(e) {
      badgeData.text[1] = 'invalid';
      sendBadge(format, badgeData);
    }
  });
}));

// GitHub tag integration.
camp.route(/^\/github\/tag\/(.*)\/(.*)\.(svg|png|gif|jpg)$/,
cache(function(data, match, sendBadge) {
  var user = match[1];  // eg, visionmedia/express
  var repo = match[2];
  var format = match[3];
  var apiUrl = 'https://api.github.com/repos/' + user + '/' + repo + '/tags';
  var badgeData = getBadgeData('tag', data);
  // A special User-Agent is required:
  // http://developer.github.com/v3/#user-agent-required
  request(apiUrl, { headers: { 'User-Agent': 'Shields.io' } }, function(err, res, buffer) {
    if (err != null) {
      badgeData.text[1] = 'inaccessible';
      sendBadge(format, badgeData);
    }
    try {
      var data = JSON.parse(buffer);
      var tag = data[0].name;
      badgeData.text[1] = tag;
      badgeData.colorscheme = 'blue';
      if (/^v[0-9]/.test(tag)) {
        tag = tag.slice(1);
      }
      if (/^[0-9]/.test(tag)) {
        badgeData.text[1] = 'v' + tag;
        if (tag[0] === '0' || /dev/.test(tag)) {
          badgeData.colorscheme = 'orange';
        }
      }
      sendBadge(format, badgeData);
    } catch(e) {
      badgeData.text[1] = 'invalid';
      sendBadge(format, badgeData);
    }
  });
}));

// GitHub release integration.
camp.route(/^\/github\/release\/(.*)\/(.*)\.(svg|png|gif|jpg)$/,
cache(function(data, match, sendBadge) {
  var user = match[1];  // eg, qubyte/rubidium
  var repo = match[2];
  var format = match[3];
  var apiUrl = 'https://api.github.com/repos/' + user + '/' + repo + '/releases';
  var badgeData = getBadgeData('release', data);
  // A special User-Agent is required:
  // http://developer.github.com/v3/#user-agent-required
  request(apiUrl, { headers: { 'User-Agent': 'Shields.io' } }, function(err, res, buffer) {
    if (err != null) {
      badgeData.text[1] = 'inaccessible';
      sendBadge(format, badgeData);
    }
    try {
      var data = JSON.parse(buffer);
      var latest = (function () {
        var topTag, tagDate, topDate = null;
        for (var i = 0, len = data.length; i < len; i++) {
          if (!data[i].draft) {
            tagDate = new Date(data[i].created_at);
            if (topDate === null || tagDate > topDate) {
              topDate = tagDate;
              topTag = i;
            }
          }
        }
        return data[topTag];
      })();
      var tag = latest.tag_name;
      badgeData.text[1] = tag;
      badgeData.colorscheme = latest.prerelease ? 'orange' : 'blue';
      if (/^v[0-9]/.test(tag)) {
        tag = tag.slice(1);
      }
      if (/^[0-9]/.test(tag)) {
        badgeData.text[1] = 'v' + tag;
        if (tag[0] === '0' || /dev/.test(tag)) {
          badgeData.colorscheme = 'orange';
        }
      }
      sendBadge(format, badgeData);
    } catch(e) {
      badgeData.text[1] = 'invalid';
      sendBadge(format, badgeData);
    }
  });
}));

// Chef cookbook integration.
camp.route(/^\/cookbook\/v\/(.*)\.(svg|png|gif|jpg)$/,
cache(function(data, match, sendBadge) {
  var cookbook = match[1]; // eg, chef-sugar
  var format = match[2];
  var apiUrl = 'https://cookbooks.opscode.com/api/v1/cookbooks/' + cookbook + '/versions/latest';
  var badgeData = getBadgeData('cookbook', data);

  request(apiUrl, function(err, res, buffer) {
    if (err != null) {
      badgeData.text[1] = 'inaccessible';
      sendBadge(format, badgeData);
    }

    try {
      var data = JSON.parse(buffer);
      var version = data.version;
      badgeData.text[1] = 'v' + version;
      if (version[0] === '0' || /dev/.test(version)) {
        badgeData.colorscheme = 'orange';
      } else {
        badgeData.colorscheme = 'blue';
      }
      sendBadge(format, badgeData);
    } catch(e) {
      badgeData.text[1] = 'invalid';
      sendBadge(format, badgeData);
    }
  });
}));

// NuGet version integration.
camp.route(/^\/nuget\/v\/(.*)\.(svg|png|gif|jpg)$/,
cache(function(data, match, sendBadge) {
  var repo = match[1];  // eg, `Nuget.Core`.
  var format = match[2];
  var apiUrl = 'https://www.nuget.org/api/v2/Packages()?$filter=Id%20eq%20%27' + repo + '%27%20and%20IsLatestVersion%20eq%20true';
  var badgeData = getBadgeData('nuget', data);
  request(apiUrl, { headers: { 'Accept': 'application/atom+json,application/json' } }, function(err, res, buffer) {
    if (err != null) {
      badgeData.text[1] = 'inaccessible';
      sendBadge(format, badgeData);
    }
    try {
      var data = JSON.parse(buffer);
      var version = data.d.results[0].NormalizedVersion;
      badgeData.text[1] = 'v' + version;
      if (version[0] === '0') {
        badgeData.colorscheme = 'orange';
      } else {
        badgeData.colorscheme = 'blue';
      }
      sendBadge(format, badgeData);
    } catch(e) {
      badgeData.text[1] = 'invalid';
      sendBadge(format, badgeData);
    }
  });
}));

// TeamCity CodeBetter version integration.
camp.route(/^\/teamcity\/codebetter\/(.*)\.(svg|png|gif|jpg)$/,
cache(function(data, match, sendBadge) {
  var buildType = match[1];  // eg, `bt428`.
  var format = match[2];
  var apiUrl = 'http://teamcity.codebetter.com/app/rest/builds/buildType:(id:' + buildType + ')?guest=1';
  var badgeData = getBadgeData('build', data);
  request(apiUrl, { headers: { 'Accept': 'application/json' } }, function(err, res, buffer) {
    if (err != null) {
      badgeData.text[1] = 'inaccessible';
      sendBadge(format, badgeData);
    }
    try {
      var data = JSON.parse(buffer);
      var status = data.status;
      badgeData.text[1] = (status || '').toLowerCase();
      if (status === 'SUCCESS') {
        badgeData.colorscheme = 'brightgreen'; 
      } else {
        badgeData.colorscheme = 'red'; 
      }
      sendBadge(format, badgeData);
    } catch(e) {
      badgeData.text[1] = 'invalid';
      sendBadge(format, badgeData);
    }
  });
}));

// Puppet Forge
camp.route(/^\/puppetforge\/v\/([^\/]+\/[^\/]+)\.(svg|png|gif|jpg)$/,
cache(function(data, match, sendBadge) {
  var userRepo = match[1];
  var format = match[2];
  var options = {
    json: true,
    uri: 'https://forge.puppetlabs.com/api/v1/releases.json?module=' + userRepo
  };
  var badgeData = getBadgeData('puppetforge', data);
  request(options, function dealWithData(err, res, json) {
    if (err != null || (json.length !== undefined && json.length === 0)) {
      badgeData.text[1] = 'inaccessible';
      sendBadge(format, badgeData);
      return
    }
    try {
      var unstable = function(ver) { return /-[0-9A-Za-z.-]+(?:\+[0-9A-Za-z.-]+)?$/.test(ver); };
      var releases = json[userRepo];
      if (releases.length == 0) {
        badgeData.text[1] = 'none';
        badgeData.colorscheme = 'lightgrey';
        sendBadge(format, badgeData);
        return;
      }
      var version = releases[0].version;
      for (var i = 0; i < releases.length; i++) {
        var current = releases[i].version;
        if (semver.gt(current, version)) {
          version = current;
        }
      }
      if (unstable(version)) {
        badgeData.colorscheme = "yellow";
      } else {
        badgeData.colorscheme = "blue";
      }
      badgeData.text[1] = "v" + version;
      sendBadge(format, badgeData);

    } catch(e) {
      badgeData.text[1] = 'invalid';
      sendBadge(format, badgeData);
    }
  });
}));

// Any badge.
camp.route(/^\/(:|badge\/)(([^-]|--)+)-(([^-]|--)+)-(([^-]|--)+)\.(svg|png|gif|jpg)$/,
function(data, match, end, ask) {
  var subject = escapeFormat(match[2]);
  var status = escapeFormat(match[4]);
  var color = escapeFormat(match[6]);
  var format = match[8];

  incrMonthlyAnalytics(analytics.rawMonthly);

  // Cache management - the badge is constant.
  var cacheDuration = (3600*24*1)|0;    // 1 day.
  ask.res.setHeader('Cache-Control', 'public, max-age=' + cacheDuration);
  if (+(new Date(ask.req.headers['if-modified-since'])) >= +serverStartTime) {
    ask.res.statusCode = 304;
    ask.res.end();  // not modified.
    return;
  }
  ask.res.setHeader('Last-Modified', serverStartTime.toGMTString());

  // Badge creation.
  try {
    var badgeData = {text: [subject, status]};
    if (sixHex(color)) {
      badgeData.colorB = '#' + color;
    } else {
      badgeData.colorscheme = color;
    }
    if (data.style && validTemplates.indexOf(data.style) > -1) {
      badgeData.template = data.style;
    }
    badge(badgeData, makeSend(format, ask.res, end));
  } catch(e) {
    badge({text: ['error', 'bad badge'], colorscheme: 'red'},
      makeSend(format, ask.res, end));
  }
});

// Any badge, old version.
camp.route(/^\/([^\/]+)\/(.+).png$/,
function(data, match, end, ask) {
  var subject = match[1];
  var status = match[2];
  var color = data.color;

  // Cache management - the badge is constant.
  var cacheDuration = (3600*24*1)|0;    // 1 day.
  ask.res.setHeader('Cache-Control', 'public, max-age=' + cacheDuration);
  if (+(new Date(ask.req.headers['if-modified-since'])) >= +serverStartTime) {
    ask.res.statusCode = 304;
    ask.res.end();  // not modified.
    return;
  }
  ask.res.setHeader('Last-Modified', serverStartTime.toGMTString());

  // Badge creation.
  try {
    var badgeData = {text: [subject, status]};
    badgeData.colorscheme = color;
    badge(badgeData, makeSend('png', ask.res, end));
  } catch(e) {
    badge({text: ['error', 'bad badge'], colorscheme: 'red'},
      makeSend('png', ask.res, end));
  }
});

// Redirect the root to the website.
camp.route(/^\/$/, function(data, match, end, ask) {
  ask.res.statusCode = 302;
  ask.res.setHeader('Location', 'http://shields.io');
  ask.res.end();
});

// Escapes `t` using the format specified in
// <https://github.com/espadrine/gh-badges/issues/12#issuecomment-31518129>
function escapeFormat(t) {
  return t
    // Inline single underscore.
    .replace(/([^_])_([^_])/g, '$1 $2')
    // Leading or trailing underscore.
    .replace(/([^_])_$/, '$1 ').replace(/^_([^_])/, ' $1')
    // Double underscore and double dash.
    .replace(/__/g, '_').replace(/--/g, '-');
}

function sixHex(s) { return /^[0-9a-fA-F]{6}$/.test(s); }

function getLabel(label, data) {
  return data.label || label;
}

function getBadgeData(defaultLabel, data) {
  var label = getLabel(defaultLabel, data);
  var template = data.style || 'default';
  if (data.style && validTemplates.indexOf(data.style) > -1) {
    template = data.style;
  };

  return {text:[label, 'n/a'], colorscheme:'lightgrey', template:template};
}

function makeSend(format, askres, end) {
  if (format === 'svg') {
    return function(res) { sendSVG(res, askres, end); };
  } else {
    return function(res) { sendOther(format, res, askres, end); };
  }
}

function sendSVG(res, askres, end) {
  askres.setHeader('Content-Type', 'image/svg+xml;charset=utf-8');
  end(null, {template: streamFromString(res)});
}

function sendOther(format, res, askres, end) {
  askres.setHeader('Content-Type', 'image/' + format);
  svg2img(res, format, askres);
}

var stream = require('stream');
function streamFromString(str) {
  var newStream = new stream.Readable();
  newStream._read = function() { newStream.push(str); newStream.push(null); };
  return newStream;
}

// Given a number, string with appropriate unit in the metric system, SI.
// Note: numbers beyond the peta- cannot be represented as integers in JS.
var metricPrefix = ['k', 'M', 'G', 'T', 'P', 'E', 'Z', 'Y'];
var metricPower = Array.apply(null, Array(metricPrefix.length))
    .map(function(a, i) { return Math.pow(1000, i + 1); });
function metric(n) {
  for (var i = metricPrefix.length - 1; i >= 0; i--) {
    var limit = metricPower[i];
    if (n > limit) {
      n = Math.round(n / limit);
      return ''+n + metricPrefix[i];
    }
  }
  return ''+n;
}