/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (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.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Mozilla Spellchecker Component.
 *
 * The Initial Developer of the Original Code is
 * David Einstein.
 * Portions created by the Initial Developer are Copyright (C) 2001
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s): David Einstein <Deinst@world.std.com>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

#include "mozPersonalDictionary.h"
#include "nsIUnicharInputStream.h"
#include "nsReadableUtils.h"
#include "nsIFile.h"
#include "nsAppDirectoryServiceDefs.h"
#include "nsICharsetConverterManager.h"
#include "nsICharsetAlias.h"
#include "nsIObserverService.h"
#include "nsIPrefService.h"
#include "nsIPrefBranch.h"
#include "nsIPrefBranch2.h"
#include "nsIWeakReference.h"
#include "nsCRT.h"
#include "nsNetUtil.h"
#include "nsStringEnumerator.h"

#define MOZ_PERSONAL_DICT_NAME "persdict.dat"
static NS_DEFINE_CID(kCharsetConverterManagerCID, NS_ICHARSETCONVERTERMANAGER_CID);

const int kMaxWordLen=256;

/**
 * This is the most braindead implementation of a personal dictionary possible.
 * There is not much complexity needed, though.  It could be made much faster,
 *  and probably should, but I don't see much need for more in terms of interface.
 *
 * Allowing personal words to be associated with only certain dictionaries maybe.
 *
 * TODO:
 * Implement the suggestion record.
 */


NS_IMPL_ISUPPORTS3(mozPersonalDictionary, mozIPersonalDictionary, nsIObserver, nsISupportsWeakReference)

mozPersonalDictionary::mozPersonalDictionary()
 : mDirty(PR_FALSE)
{
}

mozPersonalDictionary::~mozPersonalDictionary()
{
}

nsresult mozPersonalDictionary::Init()
{
  if (!mDictionaryTable.Init() || !mIgnoreTable.Init())
    return NS_ERROR_OUT_OF_MEMORY;

  nsresult rv;
  nsCOMPtr<nsIObserverService> svc = 
           do_GetService("@mozilla.org/observer-service;1", &rv);
   
  if (NS_SUCCEEDED(rv) && svc) 
    rv = svc->AddObserver(this, "profile-do-change", PR_TRUE); // we want to reload the dictionary if the profile switches

  if (NS_FAILED(rv)) return rv;

  Load();
  
  return NS_OK;
}

/* void Load (); */
NS_IMETHODIMP mozPersonalDictionary::Load()
{
  //FIXME Deinst  -- get dictionary name from prefs;
  nsresult res;
  nsCOMPtr<nsIFile> theFile;
  PRBool dictExists;

  res = NS_GetSpecialDirectory(NS_APP_USER_PROFILE_50_DIR, getter_AddRefs(theFile));
  if(NS_FAILED(res)) return res;
  if(!theFile)return NS_ERROR_FAILURE;
  res = theFile->Append(NS_LITERAL_STRING(MOZ_PERSONAL_DICT_NAME));
  if(NS_FAILED(res)) return res;
  res = theFile->Exists(&dictExists);
  if(NS_FAILED(res)) return res;

  if (!dictExists) {
    // Nothing is really wrong...
    return NS_OK;
  }
  
  nsCOMPtr<nsIInputStream> inStream;
  NS_NewLocalFileInputStream(getter_AddRefs(inStream), theFile);
  nsCOMPtr<nsIUnicharInputStream> convStream;
  res = NS_NewUTF8ConverterStream(getter_AddRefs(convStream), inStream, 0);
  if(NS_FAILED(res)) return res;
  
  // we're rereading to get rid of the old data  -- we shouldn't have any, but...
  mDictionaryTable.Clear();

  PRUnichar c;
  PRUint32 nRead;
  PRBool done = PR_FALSE;
  do{  // read each line of text into the string array.
    if( (NS_OK != convStream->Read(&c, 1, &nRead)) || (nRead != 1)) break;
    while(!done && ((c == '\n') || (c == '\r'))){
      if( (NS_OK != convStream->Read(&c, 1, &nRead)) || (nRead != 1)) done = PR_TRUE;
    }
    if (!done){ 
      nsAutoString word;
      while((c != '\n') && (c != '\r') && !done){
        word.Append(c);
        if( (NS_OK != convStream->Read(&c, 1, &nRead)) || (nRead != 1)) done = PR_TRUE;
      }
      mDictionaryTable.PutEntry(word.get());
    }
  } while(!done);
  mDirty = PR_FALSE;
  
  return res;
}

// A little helper function to add the key to the list.
// This is not threadsafe, and only safe if the consumer does not 
// modify the list.
PR_STATIC_CALLBACK(PLDHashOperator)
AddHostToStringArray(nsUniCharEntry *aEntry, void *aArg)
{
  NS_STATIC_CAST(nsStringArray*, aArg)->AppendString(nsDependentString(aEntry->GetKey()));
  return PL_DHASH_NEXT;
}

/* void Save (); */
NS_IMETHODIMP mozPersonalDictionary::Save()
{
  nsCOMPtr<nsIFile> theFile;
  nsresult res;

  if(!mDirty) return NS_OK;

  //FIXME Deinst  -- get dictionary name from prefs;
  res = NS_GetSpecialDirectory(NS_APP_USER_PROFILE_50_DIR, getter_AddRefs(theFile));
  if(NS_FAILED(res)) return res;
  if(!theFile)return NS_ERROR_FAILURE;
  res = theFile->Append(NS_LITERAL_STRING(MOZ_PERSONAL_DICT_NAME));
  if(NS_FAILED(res)) return res;

  nsCOMPtr<nsIOutputStream> outStream;
  NS_NewLocalFileOutputStream(getter_AddRefs(outStream), theFile, PR_CREATE_FILE | PR_WRONLY | PR_TRUNCATE ,0664);

  // get a buffered output stream 4096 bytes big, to optimize writes
  nsCOMPtr<nsIOutputStream> bufferedOutputStream;
  res = NS_NewBufferedOutputStream(getter_AddRefs(bufferedOutputStream), outStream, 4096);
  if (NS_FAILED(res)) return res;

  nsStringArray array(mDictionaryTable.Count());
  mDictionaryTable.EnumerateEntries(AddHostToStringArray, &array);

  PRUint32 bytesWritten;
  nsCAutoString utf8Key;
  for (PRInt32 i = 0; i < array.Count(); ++i ) {
    const nsString *key = array[i];
    CopyUTF16toUTF8(*key, utf8Key);

    bufferedOutputStream->Write(utf8Key.get(), utf8Key.Length(), &bytesWritten);
    bufferedOutputStream->Write("\n", 1, &bytesWritten);
  }
  return res;
}

/* readonly attribute nsIStringEnumerator GetWordList() */
NS_IMETHODIMP mozPersonalDictionary::GetWordList(nsIStringEnumerator **aWords)
{
  NS_ENSURE_ARG_POINTER(aWords);
  *aWords = nsnull;

  nsStringArray *array = new nsStringArray(mDictionaryTable.Count());
  if (!array)
    return NS_ERROR_OUT_OF_MEMORY;

  mDictionaryTable.EnumerateEntries(AddHostToStringArray, array);

  array->Sort();

  return NS_NewAdoptingStringEnumerator(aWords, array);
}

/* boolean Check (in wstring word, in wstring language); */
NS_IMETHODIMP mozPersonalDictionary::Check(const PRUnichar *aWord, const PRUnichar *aLanguage, PRBool *aResult)
{
  NS_ENSURE_ARG_POINTER(aWord);
  NS_ENSURE_ARG_POINTER(aResult);

  *aResult = (mDictionaryTable.GetEntry(aWord) || mIgnoreTable.GetEntry(aWord));
  return NS_OK;
}

/* void AddWord (in wstring word); */
NS_IMETHODIMP mozPersonalDictionary::AddWord(const PRUnichar *aWord, const PRUnichar *aLang)
{
  mDictionaryTable.PutEntry(aWord);
  mDirty = PR_TRUE;
  return NS_OK;
}

/* void RemoveWord (in wstring word); */
NS_IMETHODIMP mozPersonalDictionary::RemoveWord(const PRUnichar *aWord, const PRUnichar *aLang)
{
  mDictionaryTable.RemoveEntry(aWord);
  mDirty = PR_TRUE;
  return NS_OK;
}

/* void IgnoreWord (in wstring word); */
NS_IMETHODIMP mozPersonalDictionary::IgnoreWord(const PRUnichar *aWord)
{
  // avoid adding duplicate words to the ignore list
  if (aWord && !mIgnoreTable.GetEntry(aWord)) 
    mIgnoreTable.PutEntry(aWord);
  return NS_OK;
}

/* void EndSession (); */
NS_IMETHODIMP mozPersonalDictionary::EndSession()
{
  Save(); // save any custom words at the end of a spell check session
  mIgnoreTable.Clear();
  return NS_OK;
}

/* void AddCorrection (in wstring word, in wstring correction); */
NS_IMETHODIMP mozPersonalDictionary::AddCorrection(const PRUnichar *word, const PRUnichar *correction, const PRUnichar *lang)
{
    return NS_ERROR_NOT_IMPLEMENTED;
}

/* void RemoveCorrection (in wstring word, in wstring correction); */
NS_IMETHODIMP mozPersonalDictionary::RemoveCorrection(const PRUnichar *word, const PRUnichar *correction, const PRUnichar *lang)
{
    return NS_ERROR_NOT_IMPLEMENTED;
}

/* void GetCorrection (in wstring word, [array, size_is (count)] out wstring words, out PRUint32 count); */
NS_IMETHODIMP mozPersonalDictionary::GetCorrection(const PRUnichar *word, PRUnichar ***words, PRUint32 *count)
{
    return NS_ERROR_NOT_IMPLEMENTED;
}

/* void observe (in nsISupports aSubject, in string aTopic, in wstring aData); */
NS_IMETHODIMP mozPersonalDictionary::Observe(nsISupports *aSubject, const char *aTopic, const PRUnichar *aData)
{
  if (!nsCRT::strcmp(aTopic, "profile-do-change")) {
    Load();  // load automatically clears out the existing dictionary table
  }

  return NS_OK;
}