var fs = require("fs");
var crypto = require("crypto");

var FileDocumentStore = function() {
  this.basePath = "/data";
  this.expire = null;
};

FileDocumentStore.md5 = function(str) {
  var md5sum = crypto.createHash("md5");
  md5sum.update(str);
  return md5sum.digest("hex");
};

FileDocumentStore.prototype.set = function(key, data, callback) {
  try {
    var _this = this;
    fs.mkdir(this.basePath, "700", function() {
      var fn = _this.basePath + "/" + FileDocumentStore.md5(key);
      fs.writeFile(fn, data, "utf8", function(err) {
        if (err) {
          callback(false);
        }
        else {
          callback(true);
        }
      });
    });
  } catch(err) {
    callback(false);
  }
};

FileDocumentStore.prototype.get = function(key, callback) {
  var _this = this;
  var fn = _this.basePath + "/" + FileDocumentStore.md5(key);
  fs.readFile(fn, "utf8", function(err, data) {
    if (err) {
      callback(false);
    }
    else {
      callback(data);
    }
  });
};

module.exports = FileDocumentStore;