Joshua Paine

// Copyright (C) 2007 Damien Katz <damien_katz@yahoo.com>.

// This file is licenced under a Creative Commons Attribution 3.0 Unported
// Licence <http://creativecommons.org/licenses/by/3.0/>.

// A simple class to represent a database. Uses XMLHttpRequest
// to interface with the CouchDB server.

// Modified by Joshua Paine to use Helma's helma.Http object with a few
// added compatibility features in place of XMLHttpRequest.
// And to specify a hostname and port.
// And changed obj.toJSONString() -> obj.toJSON().

app.addRepository('modules/helma/Http.js');

function CouchDB(name,host,port) {
  this.host = host ? host : 'localhost';
  this.port = port ? port : 5984;
  this.name = name
  this.url = "http://"+this.host+":"+this.port+"/" + encodeURIComponent(name) +"/";
  xhr = CouchDB.new_XMLHttpRequest();

  // Creates the database on the server
  this.createDb = function() {
    xhr.open("PUT", this.url, false);
    xhr.send(null);
    if (xhr.status != 201)
      throw xhr.responseText.parseJSON();
    return xhr.responseText.parseJSON();
  }

  // Deletes the database on the server
  this.deleteDb = function() {
    xhr.open("DELETE", this.url, false);
    xhr.send(null);
    if (xhr.status == 404)
      return false;
    if (xhr.status != 202)
      throw xhr.responseText.parseJSON();
    return xhr.responseText.parseJSON();
  }

  // Save a document to the database
  this.save = function(doc, options) {
    if (doc._id == undefined)
      xhr.open("POST", this.url + encodeOptions(options), false);
    else
      xhr.open("PUT", this.url  + encodeURIComponent(doc._id)
        + encodeOptions(options), false);
    xhr.send(doc.toJSON());
    if (xhr.status != 201)
      throw xhr.responseText.parseJSON();
    var result = xhr.responseText.parseJSON();
    // set the _id and _rev members on the input object, for caller convenience.
    doc._id = result.id;
    doc._rev = result.rev;
    return result;
  }

  // Open a document from the database
  this.open = function(docId, options) {
    xhr.open("GET", this.url + encodeURIComponent(docId)
        + encodeOptions(options), false);
    xhr.send(null);
    if (xhr.status == 404)
      return null;
    if (xhr.status != 200)
      throw xhr.responseText.parseJSON();
    return xhr.responseText.parseJSON();
  }

  // Deletes a document from the database
  this.deleteDoc = function(doc) {
    xhr.open("DELETE", this.url + encodeURIComponent(doc._id)
        + "?rev=" + doc._rev, false);
    xhr.send(null);
    if (xhr.status != 202)
      throw xhr.responseText.parseJSON();
    var result = xhr.responseText.parseJSON();
    doc._rev = result.rev; //record rev in input document
    doc._deleted = true;
    return result;
  }

  this.bulkSave = function(docs, options) {
    xhr.open("POST", this.url + "_bulk_docs" + encodeOptions(options), false);
    xhr.send(docs.toJSON());
    if (xhr.status != 201)
      throw xhr.responseText.parseJSON();
    return xhr.responseText.parseJSON();
  }

  // Applies the map function to the contents of database and returns the results.
  this.query = function(mapFun, options) {
    xhr.open("POST", this.url + "_temp_view" + encodeOptions(options), false);
    // specify the query language we are using
    xhr.setRequestHeader("content-type", "text/javascript");
    if (typeof(mapFun) != "string")
      mapFun = mapFun.toSource ? mapFun.toSource() : "(" + mapFun.toString() + ")";
    xhr.send(mapFun);
    if (xhr.status != 200)
      throw xhr.responseText.parseJSON();
    return xhr.responseText.parseJSON();
  }

  this.view = function(viewname, options) {
    xhr.open("GET", this.url + "_view/" + viewname
        + encodeOptions(options), false);
    xhr.send(null);
    if (xhr.status == 404)
      return null;
    if (xhr.status != 200)
      throw xhr.responseText.parseJSON();
    return xhr.responseText.parseJSON();
  }

  // gets information about the database
  this.info = function() {
    xhr.open("GET", this.url, false);
    xhr.send(null);
    if (xhr.status != 200)
      throw xhr.responseText.parseJSON();
    return xhr.responseText.parseJSON();
  }

  this.allDocs = function(options) {
    xhr.open("GET", this.url + "_all_docs" + encodeOptions(options), false);
    xhr.send(null);
    if (xhr.status != 200)
      throw xhr.responseText.parseJSON();
    return xhr.responseText.parseJSON();
  }

  // Convert a options object to an url query string.
  // ex: {key:'value',key2:'value2'} becomes '?key="value"&key2="value2"'
  function encodeOptions(options) {
    var buf = []
    if (typeof(options) == "object" && options !== null) {
      for (var name in options) {
        if (!options.hasOwnProperty(name)) continue;
        var value = options[name];
        if (name == "key" || name == "startkey" || name == "endkey") {
          value = toJSON(value);
        }
        buf.push(encodeURIComponent(name) + "=" + encodeURIComponent(value));
      }
    }
    if (!buf.length) {
      return "";
    }
    return "?" + buf.join("&");
  }

  function toJSON(obj) {
    if (obj === null) {
      return "null";
    }
    return obj.toJSON()
  }
}

CouchDB.new_XMLHttpRequest = function() {
  var h = new helma.Http();
  return h;
}

helma.Http.prototype.open = function(method,url) {
        this.xhrUrl = url;
        this.setMethod(method);
}

helma.Http.prototype.send = function(content) {
        this.setContent(content);
        var response = this.getUrl(this.xhrUrl);
        this.status = response.code;
        this.responseText = response.content ? response.content : '';
}

helma.Http.prototype.setRequestHeader = function(name, value) {
        return this.setHeader(name,value);
}