// Generated by CoffeeScript 1.6.2
var Tail, environment, events, fs,
  __bind = function(fn, me){ return function(){ return fn.apply(me, arguments); }; },
  __hasProp = {}.hasOwnProperty,
  __extends = function(child, parent) { for (var key in parent) { if (__hasProp.call(parent, key)) child[key] = parent[key]; } function ctor() { this.constructor = child; } ctor.prototype = parent.prototype; child.prototype = new ctor(); child.__super__ = parent.prototype; return child; };

events = require("events");

fs = require('fs');

environment = process.env['NODE_ENV'] || 'development';

Tail = (function(_super) {
  __extends(Tail, _super);

  Tail.prototype.readBlock = function() {
    var block, stream,
      _this = this;

    if (this.queue.length >= 1) {
      block = this.queue.shift();
      if (block.end > block.start) {
        stream = fs.createReadStream(this.filename, {
          start: block.start,
          end: block.end - 1,
          encoding: "utf-8"
        });
        stream.on('error', function(error) {
          console.log("Tail error:" + error);
          return _this.emit('error', error);
        });
        stream.on('end', function() {
          if (_this.queue.length >= 1) {
            return _this.internalDispatcher.emit("next");
          }
        });
        return stream.on('data', function(data) {
          var chunk, parts, _i, _len, _results;

          _this.buffer += data;
          parts = _this.buffer.split(_this.separator);
          _this.buffer = parts.pop();
          _results = [];
          for (_i = 0, _len = parts.length; _i < _len; _i++) {
            chunk = parts[_i];
            _results.push(_this.emit("line", chunk));
          }
          return _results;
        });
      }
    }
  };

  function Tail(filename, separator, fsWatchOptions) {
    var stats,
      _this = this;

    this.filename = filename;
    this.separator = separator != null ? separator : '\n';
    this.fsWatchOptions = fsWatchOptions != null ? fsWatchOptions : {};
    this.readBlock = __bind(this.readBlock, this);
    this.buffer = '';
    this.internalDispatcher = new events.EventEmitter();
    this.queue = [];
    this.isWatching = false;
    stats = fs.statSync(this.filename);
    this.pos = stats.size;
    this.internalDispatcher.on('next', function() {
      return _this.readBlock();
    });
    this.watch();
  }

  Tail.prototype.watch = function() {
    var _this = this;

    if (this.isWatching) {
      return;
    }
    this.isWatching = true;
    if (fs.watch) {
      return this.watcher = fs.watch(this.filename, this.fsWatchOptions, function(e) {
        return _this.watchEvent(e);
      });
    } else {
      return fs.watchFile(this.filename, this.fsWatchOptions, function(curr, prev) {
        return _this.watchFileEvent(curr, prev);
      });
    }
  };

  Tail.prototype.watchEvent = function(e) {
    var stats,
      _this = this;

    if (e === 'change') {
      stats = fs.statSync(this.filename);
      if (stats.size < this.pos) {
        this.pos = stats.size;
      }
      if (stats.size > this.pos) {
        this.queue.push({
          start: this.pos,
          end: stats.size
        });
        this.pos = stats.size;
        if (this.queue.length === 1) {
          return this.internalDispatcher.emit("next");
        }
      }
    } else if (e === 'rename') {
      this.unwatch();
      return setTimeout((function() {
        return _this.watch();
      }), 1000);
    }
  };

  Tail.prototype.watchFileEvent = function(curr, prev) {
    if (curr.size > prev.size) {
      this.queue.push({
        start: prev.size,
        end: curr.size
      });
      if (this.queue.length === 1) {
        return this.internalDispatcher.emit("next");
      }
    }
  };

  Tail.prototype.unwatch = function() {
    if (fs.watch && this.watcher) {
      this.watcher.close();
      this.pos = 0;
    } else {
      fs.unwatchFile(this.filename);
    }
    this.isWatching = false;
    return this.queue = [];
  };

  return Tail;

})(events.EventEmitter);

exports.Tail = Tail;
