/**
 * This module provides all API functions
 */

/*
 * 2011 Peter 'Pita' Martischka (Primary Technology Ltd)
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS-IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

var ERR = require("async-stacktrace");
var customError = require("../utils/customError");
var padManager = require("./PadManager");
var padMessageHandler = require("../handler/PadMessageHandler");
var readOnlyManager = require("./ReadOnlyManager");
var groupManager = require("./GroupManager");
var authorManager = require("./AuthorManager");
var sessionManager = require("./SessionManager");
var async = require("async");
var exportHtml = require("../utils/ExportHtml");
var importHtml = require("../utils/ImportHtml");
var cleanText = require("./Pad").cleanText;
var PadDiff = require("../utils/padDiff");

/**********************/
/**GROUP FUNCTIONS*****/
/**********************/

exports.listAllGroups = groupManager.listAllGroups;
exports.createGroup = groupManager.createGroup;
exports.createGroupIfNotExistsFor = groupManager.createGroupIfNotExistsFor;
exports.deleteGroup = groupManager.deleteGroup;
exports.listPads = groupManager.listPads;
exports.createGroupPad = groupManager.createGroupPad;

/**********************/
/**PADLIST FUNCTION****/
/**********************/

exports.listAllPads = padManager.listAllPads;

/**********************/
/**AUTHOR FUNCTIONS****/
/**********************/

exports.createAuthor = authorManager.createAuthor;
exports.createAuthorIfNotExistsFor = authorManager.createAuthorIfNotExistsFor;
exports.getAuthorName = authorManager.getAuthorName;
exports.listPadsOfAuthor = authorManager.listPadsOfAuthor;
exports.padUsers = padMessageHandler.padUsers;
exports.padUsersCount = padMessageHandler.padUsersCount;

/**********************/
/**SESSION FUNCTIONS***/
/**********************/

exports.createSession = sessionManager.createSession;
exports.deleteSession = sessionManager.deleteSession;
exports.getSessionInfo = sessionManager.getSessionInfo;
exports.listSessionsOfGroup = sessionManager.listSessionsOfGroup;
exports.listSessionsOfAuthor = sessionManager.listSessionsOfAuthor;

/************************/
/**PAD CONTENT FUNCTIONS*/
/************************/

/**
getText(padID, [rev]) returns the text of a pad 

Example returns:

{code: 0, message:"ok", data: {text:"Welcome Text"}}
{code: 1, message:"padID does not exist", data: null}
*/
exports.getText = function(padID, rev, callback)
{
  //check if rev is set
  if(typeof rev == "function")
  {
    callback = rev;
    rev = undefined;
  }
  
  //check if rev is a number
  if(rev !== undefined && typeof rev != "number")
  {
    //try to parse the number
    if(!isNaN(parseInt(rev)))
    {
      rev = parseInt(rev);
    }
    else
    {
      callback(new customError("rev is not a number", "apierror"));
      return;
    }
  }
  
  //ensure this is not a negativ number
  if(rev !== undefined && rev < 0)
  {
    callback(new customError("rev is a negativ number","apierror"));
    return;
  }
  
  //ensure this is not a float value
  if(rev !== undefined && !is_int(rev))
  {
    callback(new customError("rev is a float value","apierror"));
    return;
  }
  
  //get the pad
  getPadSafe(padID, true, function(err, pad)
  {
    if(ERR(err, callback)) return;
    
    //the client asked for a special revision
    if(rev !== undefined)
    {
      //check if this is a valid revision
      if(rev > pad.getHeadRevisionNumber())
      {
        callback(new customError("rev is higher than the head revision of the pad","apierror"));
        return;
      }
      
      //get the text of this revision
      pad.getInternalRevisionAText(rev, function(err, atext)
      {
        if(ERR(err, callback)) return;
        
        data = {text: atext.text};
        
        callback(null, data);
      })
    }
    //the client wants the latest text, lets return it to him
    else
    {
      callback(null, {"text": pad.text()});
    }
  });
}

/**
setText(padID, text) sets the text of a pad 

Example returns:

{code: 0, message:"ok", data: null}
{code: 1, message:"padID does not exist", data: null}
{code: 1, message:"text too long", data: null}
*/
exports.setText = function(padID, text, callback)
{    
  //text is required
  if(typeof text != "string")
  {
    callback(new customError("text is no string","apierror"));
    return;
  }

  //get the pad
  getPadSafe(padID, true, function(err, pad)
  {
    if(ERR(err, callback)) return;
    
    //set the text
    pad.setText(text);
    
    //update the clients on the pad
    padMessageHandler.updatePadClients(pad, callback);
  });
}

/**
getHTML(padID, [rev]) returns the html of a pad 

Example returns:

{code: 0, message:"ok", data: {text:"Welcome <strong>Text</strong>"}}
{code: 1, message:"padID does not exist", data: null}
*/
exports.getHTML = function(padID, rev, callback)
{
  if(typeof rev == "function")
  {
    callback = rev;
    rev = undefined; 
  }

  if (rev !== undefined && typeof rev != "number")
  {
    if (!isNaN(parseInt(rev)))
    {
      rev = parseInt(rev);
    }
    else
    {
      callback(new customError("rev is not a number","apierror"));
      return;
    }
  }

  if(rev !== undefined && rev < 0)
  {
     callback(new customError("rev is a negative number","apierror"));
     return;
  }

  if(rev !== undefined && !is_int(rev))
  {
    callback(new customError("rev is a float value","apierror"));
    return;
  }

  getPadSafe(padID, true, function(err, pad)
  {
    if(ERR(err, callback)) return;
    
    //the client asked for a special revision
    if(rev !== undefined)
    {
      //check if this is a valid revision
      if(rev > pad.getHeadRevisionNumber())
      {
        callback(new customError("rev is higher than the head revision of the pad","apierror"));
        return;
      }
     
      //get the html of this revision 
      exportHtml.getPadHTML(pad, rev, function(err, html)
      {
          if(ERR(err, callback)) return;
          data = {html: html};
          callback(null, data);
      });
    }
    //the client wants the latest text, lets return it to him
    else
    {
      exportHtml.getPadHTML(pad, undefined, function (err, html)
      {
        if(ERR(err, callback)) return;
        data = {html: html};
        callback(null, data);
      });
    }
  });
}

exports.setHTML = function(padID, html, callback)
{
  //get the pad
  getPadSafe(padID, true, function(err, pad)
  {
    if(ERR(err, callback)) return;

    // add a new changeset with the new html to the pad
    importHtml.setPadHTML(pad, cleanText(html));

    //update the clients on the pad
    padMessageHandler.updatePadClients(pad, callback);

  });
}

/******************/
/**CHAT FUNCTIONS */
/******************/

/**
getChatHistory(padId, start, end), returns a part of or the whole chat-history of this pad

Example returns:

{"code":0,"message":"ok","data":{"messages":[{"text":"foo","userId":"a.foo","time":1359199533759,"userName":"test"},
                                             {"text":"bar","userId":"a.foo","time":1359199534622,"userName":"test"}]}}

{code: 1, message:"start is higher or equal to the current chatHead", data: null}

{code: 1, message:"padID does not exist", data: null}
*/
exports.getChatHistory = function(padID, start, end, callback)
{
  if(start && end)
  {
    if(start < 0)
    {
      callback(new customError("start is below zero","apierror"));
      return;
    }
    if(end < 0)
    {
      callback(new customError("end is below zero","apierror"));
      return;
    }
    if(start > end)
    {
      callback(new customError("start is higher than end","apierror"));
      return;
    }
  }
  
  //get the pad
  getPadSafe(padID, true, function(err, pad)
  {
    if(ERR(err, callback)) return;
    var chatHead = pad.chatHead;
    
    // fall back to getting the whole chat-history if a parameter is missing
    if(!start || !end)
    {
	  start = 0;
	  end = pad.chatHead;
    }
    
    if(start >= chatHead && chatHead > 0)
    {
      callback(new customError("start is higher or equal to the current chatHead","apierror"));
      return;
    }
    if(end > chatHead)
    {
      callback(new customError("end is higher than the current chatHead","apierror"));
      return;
    }
    
    // the the whole message-log and return it to the client
    pad.getChatMessages(start, end,
      function(err, msgs)
      {
        if(ERR(err, callback)) return;
        callback(null, {messages: msgs});
      });
  });
}

/*****************/
/**PAD FUNCTIONS */
/*****************/

/**
getRevisionsCount(padID) returns the number of revisions of this pad 

Example returns:

{code: 0, message:"ok", data: {revisions: 56}}
{code: 1, message:"padID does not exist", data: null}
*/
exports.getRevisionsCount = function(padID, callback)
{
  //get the pad
  getPadSafe(padID, true, function(err, pad)
  {
    if(ERR(err, callback)) return;
    
    callback(null, {revisions: pad.getHeadRevisionNumber()});
  });
}

/**
getLastEdited(padID) returns the timestamp of the last revision of the pad

Example returns:

{code: 0, message:"ok", data: {lastEdited: 1340815946602}}
{code: 1, message:"padID does not exist", data: null}
*/
exports.getLastEdited = function(padID, callback)
{
  //get the pad
  getPadSafe(padID, true, function(err, pad)
  {
    if(ERR(err, callback)) return;
    pad.getLastEdit(function(err, value) {
      if(ERR(err, callback)) return;
      callback(null, {lastEdited: value});
    });
  });
}

/**
createPad(padName [, text]) creates a new pad in this group 

Example returns:

{code: 0, message:"ok", data: null}
{code: 1, message:"pad does already exist", data: null}
*/
exports.createPad = function(padID, text, callback)
{  
  //ensure there is no $ in the padID
  if(padID && padID.indexOf("$") != -1)
  {
    callback(new customError("createPad can't create group pads","apierror"));
    return;
  }
  
  //create pad
  getPadSafe(padID, false, text, function(err)
  {
    if(ERR(err, callback)) return;
    callback();
  });
}

/**
deletePad(padID) deletes a pad 

Example returns:

{code: 0, message:"ok", data: null}
{code: 1, message:"padID does not exist", data: null}
*/
exports.deletePad = function(padID, callback)
{
  getPadSafe(padID, true, function(err, pad)
  {
    if(ERR(err, callback)) return;
    
    pad.remove(callback);
  });
}

/**
getReadOnlyLink(padID) returns the read only link of a pad 

Example returns:

{code: 0, message:"ok", data: null}
{code: 1, message:"padID does not exist", data: null}
*/
exports.getReadOnlyID = function(padID, callback)
{
  //we don't need the pad object, but this function does all the security stuff for us
  getPadSafe(padID, true, function(err)
  {
    if(ERR(err, callback)) return;
    
    //get the readonlyId
    readOnlyManager.getReadOnlyId(padID, function(err, readOnlyId)
    {
      if(ERR(err, callback)) return;
      callback(null, {readOnlyID: readOnlyId});
    });
  });
}

/**
setPublicStatus(padID, publicStatus) sets a boolean for the public status of a pad 

Example returns:

{code: 0, message:"ok", data: null}
{code: 1, message:"padID does not exist", data: null}
*/
exports.setPublicStatus = function(padID, publicStatus, callback)
{
  //ensure this is a group pad
  if(padID && padID.indexOf("$") == -1)
  {
    callback(new customError("You can only get/set the publicStatus of pads that belong to a group","apierror"));
    return;
  }

  //get the pad
  getPadSafe(padID, true, function(err, pad)
  {
    if(ERR(err, callback)) return;
    
    //convert string to boolean
    if(typeof publicStatus == "string")
      publicStatus = publicStatus == "true" ? true : false;
    
    //set the password
    pad.setPublicStatus(publicStatus);
    
    callback();
  });
}

/**
getPublicStatus(padID) return true of false 

Example returns:

{code: 0, message:"ok", data: {publicStatus: true}}
{code: 1, message:"padID does not exist", data: null}
*/
exports.getPublicStatus = function(padID, callback)
{
  //ensure this is a group pad
  if(padID && padID.indexOf("$") == -1)
  {
    callback(new customError("You can only get/set the publicStatus of pads that belong to a group","apierror"));
    return;
  }
  
  //get the pad
  getPadSafe(padID, true, function(err, pad)
  {
    if(ERR(err, callback)) return;
    
    callback(null, {publicStatus: pad.getPublicStatus()});
  });
}

/**
setPassword(padID, password) returns ok or a error message 

Example returns:

{code: 0, message:"ok", data: null}
{code: 1, message:"padID does not exist", data: null}
*/
exports.setPassword = function(padID, password, callback)
{
  //ensure this is a group pad
  if(padID && padID.indexOf("$") == -1)
  {
    callback(new customError("You can only get/set the password of pads that belong to a group","apierror"));
    return;
  }
  
  //get the pad
  getPadSafe(padID, true, function(err, pad)
  {
    if(ERR(err, callback)) return;
    
    //set the password
    pad.setPassword(password == "" ? null : password);
    
    callback();
  });
}

/**
isPasswordProtected(padID) returns true or false 

Example returns:

{code: 0, message:"ok", data: {passwordProtection: true}}
{code: 1, message:"padID does not exist", data: null}
*/
exports.isPasswordProtected = function(padID, callback)
{
  //ensure this is a group pad
  if(padID && padID.indexOf("$") == -1)
  {
    callback(new customError("You can only get/set the password of pads that belong to a group","apierror"));
    return;
  }

  //get the pad
  getPadSafe(padID, true, function(err, pad)
  {
    if(ERR(err, callback)) return;
    
    callback(null, {isPasswordProtected: pad.isPasswordProtected()});
  });
}

/**
listAuthorsOfPad(padID) returns an array of authors who contributed to this pad 

Example returns:

{code: 0, message:"ok", data: {authorIDs : ["a.s8oes9dhwrvt0zif", "a.akf8finncvomlqva"]}
{code: 1, message:"padID does not exist", data: null}
*/
exports.listAuthorsOfPad = function(padID, callback)
{
  //get the pad
  getPadSafe(padID, true, function(err, pad)
  {
    if(ERR(err, callback)) return;
    
    callback(null, {authorIDs: pad.getAllAuthors()});
  });
}

/**
sendClientsMessage(padID, msg) sends a message to all clients connected to the
pad, possibly for the purpose of signalling a plugin.

Note, this will only accept strings from the HTTP API, so sending bogus changes
or chat messages will probably not be possible.

The resulting message will be structured like so:

{
  type: 'COLLABROOM',
  data: {
    type: <msg>,
    time: <time the message was sent>
  }
}

Example returns:

{code: 0, message:"ok"}
{code: 1, message:"padID does not exist"}
*/

exports.sendClientsMessage = function (padID, msg, callback) {
  getPadSafe(padID, true, function (err, pad) {
    if (ERR(err, callback)) {
      return;
    } else {
      padMessageHandler.handleCustomMessage(padID, msg, callback);
    }
  } );
}

/**
checkToken() returns ok when the current api token is valid

Example returns:

{"code":0,"message":"ok","data":null}
{"code":4,"message":"no or wrong API Key","data":null}
*/
exports.checkToken = function(callback)
{
  callback();
}

/**
getChatHead(padID) returns the chatHead (last number of the last chat-message) of the pad

Example returns:

{code: 0, message:"ok", data: {chatHead: 42}}
{code: 1, message:"padID does not exist", data: null}
*/
exports.getChatHead = function(padID, callback)
{
  //get the pad
  getPadSafe(padID, true, function(err, pad)
  {
    if(ERR(err, callback)) return;
    callback(null, {chatHead: pad.chatHead});
  });
}

/**
createDiffHTML(padID, startRev, endRev) returns an object of diffs from 2 points in a pad

Example returns:

{"code":0,"message":"ok","data":{"html":"<style>\n.authora_HKIv23mEbachFYfH {background-color: #a979d9}\n.authora_n4gEeMLsv1GivNeh {background-color: #a9b5d9}\n.removed {text-decoration: line-through; -ms-filter:'progid:DXImageTransform.Microsoft.Alpha(Opacity=80)'; filter: alpha(opacity=80); opacity: 0.8; }\n</style>Welcome to Etherpad Lite!<br><br>This pad text is synchronized as you type, so that everyone viewing this page sees the same text. This allows you to collaborate seamlessly on documents!<br><br>Get involved with Etherpad at <a href=\"http&#x3a;&#x2F;&#x2F;etherpad&#x2e;org\">http:&#x2F;&#x2F;etherpad.org</a><br><span class=\"authora_HKIv23mEbachFYfH\">aw</span><br><br>","authors":["a.HKIv23mEbachFYfH",""]}}
{"code":4,"message":"no or wrong API Key","data":null}
*/
exports.createDiffHTML = function(padID, startRev, endRev, callback){
  //check if rev is a number
  if(startRev !== undefined && typeof startRev != "number")
  {
    //try to parse the number
    if(!isNaN(parseInt(startRev)))
    {
      startRev = parseInt(startRev, 10);
    }
    else
    {
      callback({stop: "startRev is not a number"});
      return;
    }
  }
 
  //check if rev is a number
  if(endRev !== undefined && typeof endRev != "number")
  {
    //try to parse the number
    if(!isNaN(parseInt(endRev)))
    {
      endRev = parseInt(endRev, 10);
    }
    else
    {
      callback({stop: "endRev is not a number"});
      return;
    }
  }
 
  //get the pad
  getPadSafe(padID, true, function(err, pad)
  {
    if(err){
      return callback(err);
    }
 
    try {
      var padDiff = new PadDiff(pad, startRev, endRev);
    } catch(e) {
      return callback({stop:e.message});
    }
    var html, authors;
 
    async.series([
      function(callback){
        padDiff.getHtml(function(err, _html){
          if(err){
            return callback(err);
          }
 
          html = _html;
          callback();
        });
      },
      function(callback){
        padDiff.getAuthors(function(err, _authors){
          if(err){
            return callback(err);
          }
 
          authors = _authors;
          callback();
        });
      }
    ], function(err){
      callback(err, {html: html, authors: authors})
    });
  });
}

/******************************/
/** INTERNAL HELPER FUNCTIONS */
/******************************/

//checks if a number is an int
function is_int(value)
{ 
  return (parseFloat(value) == parseInt(value)) && !isNaN(value)
}

//gets a pad safe
function getPadSafe(padID, shouldExist, text, callback)
{
  if(typeof text == "function")
  {
    callback = text;
    text = null;
  }

  //check if padID is a string
  if(typeof padID != "string")
  {
    callback(new customError("padID is not a string","apierror"));
    return;
  }
  
  //check if the padID maches the requirements
  if(!padManager.isValidPadId(padID))
  {
    callback(new customError("padID did not match requirements","apierror"));
    return;
  }
  
  //check if the pad exists
  padManager.doesPadExists(padID, function(err, exists)
  {
    if(ERR(err, callback)) return;
    
    //does not exist, but should
    if(exists == false && shouldExist == true)
    {
      callback(new customError("padID does not exist","apierror"));
    }
    //does exists, but shouldn't
    else if(exists == true && shouldExist == false)
    {
      callback(new customError("padID does already exist","apierror"));
    }
    //pad exists, let's get it
    else
    {
      padManager.getPad(padID, text, callback);
    }
  });
}