/*
  Copyright (C) 2000-2004 SKYRIX Software AG

  This file is part of OGo

  OGo is free software; you can redistribute it and/or modify it under
  the terms of the GNU Lesser General Public License as published by the
  Free Software Foundation; either version 2, or (at your option) any
  later version.

  OGo 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 Lesser General Public
  License for more details.

  You should have received a copy of the GNU Lesser General Public
  License along with OGo; see the file COPYING.  If not, write to the
  Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  02111-1307, USA.
*/
// $Id$


#include "AgenorUserManager.h"
#include <NGLdap/NGLdap.h>
#include "SOGoLRUCache.h"

@interface AgenorUserManager (PrivateAPI)
- (NGLdapConnection *)ldapConnection;

- (void)_cacheCN:(NSString *)_cn forUID:(NSString *)_uid;
- (NSString *)_cachedCNForUID:(NSString *)_uid;
- (void)_cacheServer:(NSString *)_server forUID:(NSString *)_uid;
- (NSString *)_cachedServerForUID:(NSString *)_uid;
  
@end


@implementation AgenorUserManager

static BOOL     debugOn     = NO;
static BOOL     useLDAP     = NO;
static NSString *ldapHost   = nil;
static NSString *ldapBaseDN = nil;

+ (void)initialize {
  static BOOL didInit = NO;
  NSUserDefaults *ud;

  if(didInit)
    return;
  didInit = YES;
  ud = [NSUserDefaults standardUserDefaults];
  debugOn = [ud boolForKey:@"SOGoUserManagerDebugEnabled"];
  useLDAP = [ud boolForKey:@"SOGoUserManagerUsesLDAP"];
  if(useLDAP) {
    ldapHost   = [[ud stringForKey:@"SOGoLDAPHost"] retain];
    ldapBaseDN = [[ud stringForKey:@"SOGoLDAPBaseDN"] retain];
  }
}

+ (id)sharedUserManager {
  static id mgr = nil;
  if(mgr == nil) {
    mgr = [[self alloc] init];
  }
  return mgr;
}

- (id)init {
  self = [super init];
  if(self) {
    self->serverCache = [[SOGoLRUCache alloc] initWithCacheSize:10000];
    self->cnCache     = [[SOGoLRUCache alloc] initWithCacheSize:10000];
  }
  return self;
}

- (void)dealloc {
  [self->serverCache release];
  [self->cnCache     release];
  [super dealloc];
}

- (NGLdapConnection *)ldapConnection {
  static NGLdapConnection *ldapConnection = nil;
  if(!ldapConnection) {
    ldapConnection = [[NGLdapConnection alloc] initWithHostName:ldapHost];
#if 0
    [ldapConnection setUseCache:YES];
#endif
  }
  return ldapConnection;
}

- (void)_cacheCN:(NSString *)_cn forUID:(NSString *)_uid {
  [self->cnCache addObject:_cn forKey:_uid];
}

- (NSString *)_cachedCNForUID:(NSString *)_uid {
  return [self->cnCache objectForKey:_uid];
}

- (void)_cacheServer:(NSString *)_server forUID:(NSString *)_uid {
  [self->serverCache addObject:_server forKey:_uid];
}

- (NSString *)_cachedServerForUID:(NSString *)_uid {
  return [self->serverCache objectForKey:_uid];
}


/*
 The uid field is in bijection this the email adress :
 this field can be construct from the email. Email are uniques.
 
 So, we can use email adresse from identifier. 
 The field is made like this :
 _ if the email is equipement.gouv.fr then the login
 is the part before the @
 for example : fisrtName.lastName
 _ if the email is not equipement.gouv.fr then the login
 is the full email adress where @ is change to . (dot)
 for example : fisrtName.lastName.subDomain.domain.tld
 
 NOTE: mapping email -> uid is easy, but can also generate uid's not known
       to the system (i.e. for private addressbook entries, obvious).
       The reverse mapping can work _only_ if "firstName.lastname." is
       guaranteed, because the second dot would be mapped to '@'. This
       is probably error prone.
       Only LDAP fetches would guarantee correctness in both cases.
*/

- (NSString *)getUIDForEmail:(NSString *)_email {
  NSRange r;
  NSString *domain;

  if(!_email || [_email length] == 0)
    return nil;

  r = [_email rangeOfString:@"@"];
  if(r.length == 0)
    return nil;
  domain = [_email substringFromIndex:NSMaxRange(r)];
  if(![domain isEqualToString:@"equipement.gouv.fr"])
      return _email;
  return [_email substringToIndex:r.location];
}

- (NSString *)getEmailForUID:(NSString *)_uid {
  NSRange r;

  if(!_uid || [_uid length] == 0)
    return nil;
  r = [_uid rangeOfString:@"@"];
  if(r.length > 0)
      return _uid;
  return [NSString stringWithFormat:@"%@@equipement.gouv.fr", _uid];
}

- (NSString *)getCNForUID:(NSString *)_uid {
  if(useLDAP) {
    static NSArray   *cnAttrs = nil;
    NGLdapConnection *conn;
    EOQualifier      *q;
    NSEnumerator     *resultEnum;
    NGLdapEntry      *entry;
    NGLdapAttribute  *cnAttr;
    NSString         *cn;

    if(!cnAttrs) {
      cnAttrs = [[NSArray alloc] initWithObjects:@"cn", nil];
    }
    
    if((cn = [self _cachedCNForUID:_uid]))
      return cn;

    q = [EOQualifier qualifierWithQualifierFormat:@"uid = %@", _uid];
    
    conn = [self ldapConnection];
    resultEnum = [conn deepSearchAtBaseDN:ldapBaseDN
                       qualifier:q
                       attributes:cnAttrs];
    entry = [resultEnum nextObject];
    if(!entry) {
      if(debugOn) {
        NSLog(@"%s Didn't find LDAP entry for uid '%@'!",
              __PRETTY_FUNCTION__,
              _uid);
      }
      return nil;
    }
    cnAttr = [entry attributeWithName:@"cn"];
    if(!cnAttr && debugOn) {
      NSLog(@"%s LDAP entry for uid '%@' has no common name?",
            __PRETTY_FUNCTION__,
            _uid);
    }
    cn = [cnAttr stringValueAtIndex:0];
    [self _cacheCN:cn forUID:_uid];
    return cn;
  }
  else {
    NSString *s;
    NSRange  r;
    
    s = _uid;
    if ([s length] < 10)
      return s;
    
    // TODO: algorithm might be inappropriate, depends on the actual UID
    r = [s rangeOfString:@"."];
    if (r.length == 0)
      return s;
    
    return [s substringToIndex:r.location];
  }
}

- (NSString *)getIMAPAccountStringForUID:(NSString *)_uid {
  NSString *server;
  
  server = [self getServerForUID:_uid];
  if(!server)
    return nil;
  return [NSString stringWithFormat:@"%@@%@", _uid, server];
}

- (NSString *)getServerForUID:(NSString *)_uid {
  /*
   First of all : for a particular user IMAP and SMTP are served on the same
   host.
   
   The name of the machine is determined by applying a regex on every values of
   the mineqMelRoutage LDAP attribute.
   The regex is :   .*%.*@(.*\.melanie2\.i2$)
   It extracts the substring that follows '@', ends with 'melanie2', on
   adresses which have a '%' before the '@'
   
   Example: helge.hesse%opengroupware.org@servername1.melanie2.i2
   -> servername1.melanie2.i2
   
   If only one server name is found by applying the regex on every value of the
   attribute, then this name is the IMAP/SMTP server for that user.
   Note that this is the case when we got a unique (well formed) value for the
   attribute.
   If the regex finds more than one servername when applied to the differents
   values, then the IMAP/SMTP server name is to be found in the
   mineqMelServeurPrincipal attribute of the user.
   */
  if(useLDAP) {
    static NSArray   *attrs = nil;
    NGLdapConnection *conn;
    EOQualifier      *q;
    NSEnumerator     *resultEnum;
    NGLdapEntry      *entry;
    NGLdapAttribute  *attr;
    NSMutableArray   *serverCandidates;
    NSString         *server;

    if(!attrs) {
      attrs = [[NSArray alloc] initWithObjects:@"mineqMelRoutage",
                                               @"mineqMelServeurPrincipal",
                                               nil];
    }

    if((server = [self _cachedServerForUID:_uid]))
      return server;

    q = [EOQualifier qualifierWithQualifierFormat:@"uid = %@", _uid];
    
    conn = [self ldapConnection];
    resultEnum = [conn deepSearchAtBaseDN:ldapBaseDN
                       qualifier:q
                       attributes:attrs];
    /* we just expect one entry, thus drop the rest */
    entry = [resultEnum nextObject];
    if(!entry) {
      if(debugOn) {
        NSLog(@"%s Didn't find LDAP entry for uid '%@'!",
              __PRETTY_FUNCTION__,
              _uid);
      }
      return nil;
    }
    attr = [entry attributeWithName:@"mineqMelRoutage"];
    if(attr) {
      unsigned i, count;
      
      count = [attr count];
      serverCandidates = [NSMutableArray arrayWithCapacity:count];
      for(i = 0; i < count; i++) {
        NSRange r;
        NSString *route;

        route = [attr stringValueAtIndex:i];
        r = [route rangeOfString:@".melanie2.i2" options:NSBackwardsSearch];
        if(r.length > 0) {
          unsigned length;

          /* be clever */
          length = [route length];
          r = NSMakeRange(0, length - r.length);
          r = [route rangeOfString:@"@" options:NSBackwardsSearch range:r];
          if(r.length > 0) {
            unsigned start;
            NSRange serverNameRange;
            
            start = NSMaxRange(r);
            serverNameRange = NSMakeRange(start, length - start);
            r = NSMakeRange(0, length - start);
            r = [route rangeOfString:@"%" options:NSBackwardsSearch range:r];
            if(r.length > 0) {
              NSString *serverName;
              
              serverName = [route substringWithRange:serverNameRange];
              [serverCandidates addObject:serverName];
            }
          }
        }
      }
    }
    else {
      if(debugOn) {
      NSLog(@"%s LDAP entry for uid '%@' has no mineqMelRoutage entry?",
            __PRETTY_FUNCTION__,
            _uid);
      }
      serverCandidates = nil;
    }
    if([serverCandidates count] == 1) {
      server = [serverCandidates objectAtIndex:0];
    }

    /* last resort */
    if(!server) {
      attr = [entry attributeWithName:@"mineqMelServeurPrincipal"];
      if([attr count] > 0)
        server = [attr stringValueAtIndex:0];
    }

    if(!server) {
      if(debugOn) {
        NSLog(@"%s no chance of getting at server info for user '%@', "
              @"tried everything. Sorry.",
              __PRETTY_FUNCTION__,
              _uid);
      }
      return nil;
    }

    [self _cacheServer:server forUID:_uid];
    return server;
  }
  else {
    return @"mail.opengroupware.org";
  }
}

@end