/* SQLSource.h - this file is part of SOGo
 *
 * Copyright (C) 2009 Inverse inc.
 *
 * Author: Ludovic Marcotte <lmarcotte@inverse.ca>
 *
 * This file is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * This file is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

#import <Foundation/NSArray.h>
#import <Foundation/NSObject.h>
#import <Foundation/NSDictionary.h>
#import <Foundation/NSString.h>
#import <Foundation/NSValue.h>
#import <Foundation/NSURL.h>

#import <NGExtensions/NSObject+Logs.h>

#import <GDLContentStore/GCSChannelManager.h>
#import <GDLContentStore/NSURL+GCS.h>
#import <GDLAccess/EOAdaptorChannel.h>
#import <GDLAccess/EOAdaptorContext.h>
#import <GDLAccess/EOAttribute.h>

#include <openssl/evp.h>
#include <openssl/md5.h>

#include "SQLSource.h"

/**
 * The view MUST contain the following columns:
 *
 * c_uid      - will be used for authentication - it's a username or username@domain.tld)
 * c_name     - which can be identical to c_uid - will be used to uniquely identify entries)
 * c_password - password of the user, plain-text or md5 encoded for now
 * c_cn       - the user's common name
 * mail       - hte user's mail address
 *
 * Other columns can be defined - see LDAPSource.m for the complete list.
 *
 *
 * A SQL source can be defined like this:
 *
 *  {   
 *    id = zot;
 *    type = sql;
 *    viewURL = "http://sogo:sogo@127.0.0.1:5432/sogo/sogo_view";
 *    canAuthenticate = YES;
 *    isAddressBook = YES;
 *    userPasswordAlgorithm = md5;
 *  }
 *
 */

@implementation SQLSource

+ (id) sourceFromUDSource: (NSDictionary *) udSource
                 inDomain: (NSString *) domain
{
  return [[[self alloc] initFromUDSource: udSource
                                inDomain: domain] autorelease];
}

- (id) init
{
  if ((self = [super init]))
    {
      _sourceID = nil;
      _mailFields = nil;
      _userPasswordAlgorithm = nil;
      _viewURL = nil;
    }

  return self;
}

- (void) dealloc
{
  [_sourceID release];
  [_mailFields release];
  [_userPasswordAlgorithm release];
  [_viewURL release];
   
  [super dealloc];
}

- (id) initFromUDSource: (NSDictionary *) udSource
               inDomain: (NSString *) sourceDomain
{
  self = [self init];

  ASSIGN(_sourceID, [udSource objectForKey: @"id"]);
  ASSIGN(_mailFields, [udSource objectForKey: @"MailFieldNames"]);
  ASSIGN(_userPasswordAlgorithm, [udSource objectForKey: @"userPasswordAlgorithm"]);

  if (!_userPasswordAlgorithm)
    _userPasswordAlgorithm = @"none";

  if ([udSource objectForKey: @"viewURL"])
    _viewURL = [[NSURL alloc] initWithString: [udSource objectForKey: @"viewURL"]];

#warning this domain code has no effect yet
  if ([sourceDomain length])
    ASSIGN (_domain, sourceDomain);

  if (!_viewURL)
    {
      [self autorelease];
      return nil;
    }

  return self;
}

- (NSString *) domain
{
  return _domain;
}

- (BOOL) _isPassword: (NSString *) plainPassword
             equalTo: (NSString *) encryptedPassword
{
  if ([_userPasswordAlgorithm caseInsensitiveCompare: @"none"] == NSOrderedSame)
    {
      return [plainPassword isEqualToString: encryptedPassword];
    }
  else if ([_userPasswordAlgorithm caseInsensitiveCompare: @"md5"] == NSOrderedSame)
    {
      NSString *s;

      unsigned char md[MD5_DIGEST_LENGTH];
      char buf[80];
      int i;

      memset(md, 0, MD5_DIGEST_LENGTH);
      memset(buf, 0, 80);

      EVP_Digest([plainPassword UTF8String], strlen([plainPassword UTF8String]), md, NULL, EVP_md5(), NULL);
      for (i = 0; i < MD5_DIGEST_LENGTH; i++)
	sprintf(&(buf[i*2]), "%02x", md[i]);

      s = [NSString stringWithUTF8String: buf];
      return [s isEqualToString: encryptedPassword];
    }


  [self errorWithFormat: @"Unsupported user-password algorithm: %@", _userPasswordAlgorithm];

  return NO;
}

- (BOOL) checkLogin: (NSString *) login
	andPassword: (NSString *) password
{
  EOAdaptorChannel *channel;
  GCSChannelManager *cm;
  NSException *ex;
  NSString *sql;
  BOOL rc;

  rc = NO;

  cm = [GCSChannelManager defaultChannelManager];
  channel = [cm acquireOpenChannelForURL: _viewURL];
  if (channel)
    {  
      sql = [NSString stringWithFormat: (@"SELECT c_password"
                                         @" FROM %@"
                                         @" WHERE c_uid = '%@'"),
                      [_viewURL gcsTableName], login];

      ex = [channel evaluateExpressionX: sql];
      if (!ex)
        {
          NSDictionary *row;
          NSArray *attrs;
          NSString *value;
          
          attrs = [channel describeResults: NO];
          row = [channel fetchAttributes: attrs  withZone: NULL];
          value = [row objectForKey: @"c_password"];
      
          rc = [self _isPassword: password  equalTo: value];
	  [channel cancelFetch];
        }
      else
        [self errorWithFormat: @"could not run SQL '%@': %@", sql, ex];
      [cm releaseChannel: channel];
    }
  else
    [self errorWithFormat:@"failed to acquire channel for URL: %@",
          [_viewURL absoluteString]];

  return rc;
}

- (NSDictionary *) _lookupContactEntry: (NSString *) theID
                         considerEmail: (BOOL) b
{
  EOAdaptorChannel *channel;
  GCSChannelManager *cm;
  NSException *ex;
  NSString *sql;
  NSMutableDictionary *response;

  response = nil;

  cm = [GCSChannelManager defaultChannelManager];
  channel = [cm acquireOpenChannelForURL: _viewURL];
  if (channel)
    {
      if (!b)
        sql = [NSString stringWithFormat: (@"SELECT *"
                                           @" FROM %@"
                                           @" WHERE c_uid = '%@'"),
                        [_viewURL gcsTableName], theID];
      else
        sql = [NSString stringWithFormat: (@"SELECT *"
                                           @" FROM %@"
                                           @" WHERE c_uid = '%@' OR"
                                           @" LOWER(mail) = '%@'"),
                        [_viewURL gcsTableName], theID, [theID lowercaseString]];

      ex = [channel evaluateExpressionX: sql];
      if (!ex)
        {
          response = [[channel fetchAttributes: [channel describeResults: NO]
                                      withZone: NULL] mutableCopy];
          [response autorelease];
	  [channel cancelFetch];

          // We have to do this here since we do not manage modules
          // constraints right now over a SQL backend.
          [response setObject: [NSNumber numberWithBool: YES] forKey: @"CalendarAccess"];
          [response setObject: [NSNumber numberWithBool: YES] forKey: @"MailAccess"];
        }
      else
        [self errorWithFormat: @"could not run SQL '%@': %@", sql, ex];
      [cm releaseChannel: channel];
    }
  else
    [self errorWithFormat:@"failed to acquire channel for URL: %@",
          [_viewURL absoluteString]];

  return response;
}


- (NSDictionary *) lookupContactEntry: (NSString *) theID
{
  return [self _lookupContactEntry: theID  considerEmail: NO];
}

- (NSDictionary *) lookupContactEntryWithUIDorEmail: (NSString *) entryID
{
  return [self _lookupContactEntry: entryID  considerEmail: YES];
}

- (NSArray *) allEntryIDs
{
  EOAdaptorChannel *channel;
  NSMutableArray *results;
  GCSChannelManager *cm;
  NSException *ex;
  NSString *sql;
  
  results = [NSMutableArray array];

  cm = [GCSChannelManager defaultChannelManager];
  channel = [cm acquireOpenChannelForURL: _viewURL];
  if (channel)
    {
      sql = [NSString stringWithFormat: @"SELECT c_uid FROM %@",
                      [_viewURL gcsTableName]];

      ex = [channel evaluateExpressionX: sql];
      if (!ex)
        {
          NSDictionary *row;
          NSArray *attrs;
          NSString *value;

          attrs = [channel describeResults: NO];
          
          while ((row = [channel fetchAttributes: attrs withZone: NULL]))
            {
              value = [row objectForKey: @"c_uid"];
              if (value)
                [results addObject: value];
            }
        }
      else
        [self errorWithFormat: @"could not run SQL '%@': %@", sql, ex];
      [cm releaseChannel: channel];
    }
  else
    [self errorWithFormat:@"failed to acquire channel for URL: %@",
          [_viewURL absoluteString]];

  
  return results;
}

- (NSArray *) fetchContactsMatching: (NSString *) filter
{
  EOAdaptorChannel *channel;
  NSMutableArray *results;
  GCSChannelManager *cm;
  NSException *ex;
  NSString *sql, *lowerFilter;
  
  results = [NSMutableArray array];

  cm = [GCSChannelManager defaultChannelManager];
  channel = [cm acquireOpenChannelForURL: _viewURL];
  if (channel)
    {
      lowerFilter = [filter lowercaseString];
      sql = [NSString stringWithFormat: (@"SELECT *"
                                         @" FROM %@"
                                         @" WHERE LOWER(c_cn) LIKE '%%%@%%'"
                                         @"    OR LOWER(mail) LIKE '%%%@%%'"),
                      [_viewURL gcsTableName],
                      lowerFilter, lowerFilter];

      ex = [channel evaluateExpressionX: sql];
      if (!ex)
        {
          NSDictionary *row;
          NSArray *attrs;

          attrs = [channel describeResults: NO];

          while ((row = [channel fetchAttributes: attrs withZone: NULL]))
            [results addObject: row];
        }
      else
        [self errorWithFormat: @"could not run SQL '%@': %@", sql, ex];
      [cm releaseChannel: channel];
    }
  else
    [self errorWithFormat:@"failed to acquire channel for URL: %@",
          [_viewURL absoluteString]];
  
  return results;
}

- (NSString *) sourceID
{
  return _sourceID;
}

@end