/*
  Copyright (C) 2000-2007 SKYRIX Software AG
  Copyright (C) 2007      Helge Hess

  This file is part of OpenGroupware.org.

  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.
*/

#include <NGObjWeb/WODynamicElement.h>

/*
  SkyExternalLink

  Dynamic element which allows to jump to external links. This is implemented
  as a redirect and avoids that the link target sees the OGo session ID in the
  'referer' header.

  bindings:
    href, target, string, title
  does this:
    <a href="$externalLinkAction?url=$href" target="$target" title="$title">
    $string<content></a>
*/

@interface SkyExternalLink : WODynamicElement
{
  WOAssociation *href;
  WOAssociation *target;
  WOAssociation *string;
  WOAssociation *title;

  WOElement *template;
}

@end

#include "common.h"
#include <NGExtensions/NSString+misc.h>

@implementation SkyExternalLink

static NSString *server          = nil;
static BOOL     hideInvalidLinks = NO;
static BOOL     validateLinks    = NO;

+ (void)initialize {
  NSUserDefaults *ud = [NSUserDefaults standardUserDefaults];

  if (server == nil)
    server = [[ud stringForKey:@"SkyExternalLinkAction"] copy];
  
  hideInvalidLinks = [ud boolForKey:@"SkyExternalLinkHideInvalid"]  ? 1 : 0;
  validateLinks    = [ud boolForKey:@"SkyExternalLinkCheckInvalid"] ? 1 : 0;
}

- (id)initWithName:(NSString *)_name
  associations:(NSDictionary *)_config
  template:(WOElement *)_t
{
  if ((self = [super initWithName:_name associations:_config template:_t])) {
    self->template = [_t retain];
    self->href     = OWGetProperty(_config, @"href");
    self->target   = OWGetProperty(_config, @"target");
    self->string   = OWGetProperty(_config, @"string");
    self->title    = OWGetProperty(_config, @"title");
  }
  return self;
}

- (void)dealloc {
  [self->href     release];
  [self->target   release];
  [self->string   release];
  [self->title    release];
  [self->template release];
  [super dealloc];
}

/* request processing */

- (void)takeValuesFromRequest:(WORequest *)_req inContext:(WOContext *)_ctx {
  [self->template takeValuesFromRequest:_req inContext:_ctx];
}

- (id)invokeActionForRequest:(WORequest *)_req inContext:(WOContext *)_ctx {
  return [self->template invokeActionForRequest:_req inContext:_ctx];
}

/* response generation */

- (NSString *)externalLinkAction {
  return server;
}
- (BOOL)hideInvalidLinks {
  return hideInvalidLinks ? YES : NO;
}
- (BOOL)checkIfValid {
  return validateLinks ? YES : NO;
}

/* is a valid external link? */
- (BOOL)isLinkValid:(NSString *)_link {
  if (![_link isNotEmpty]) 
    return NO;
  if ([self checkIfValid]) {
    NSURL *url = [NSURL URLWithString:_link];
    if (![[url host] isNotEmpty]) {
#if 0
      NSLog(@"%s: did't find host in external link: %@",
            __PRETTY_FUNCTION__, _link);
#endif
      return NO;
    }
  }
  return YES;
}

- (void)appendToResponse:(WOResponse *)_response inContext:(WOContext *)_ctx {
  WOComponent *comp;
  NSString    *link, *s;
  BOOL        valid;
  
  if ([[_ctx request] isFromClientComponent])
    return;

  comp  = [_ctx component];
  link  = [self->href stringValueInComponent:comp];
  
  if (![link hasPrefix:@"/"] && ([link rangeOfString:@"://"].length == 0)) {
    link = [link isNotEmpty] 
      ? (id)[@"http://" stringByAppendingString:link] : nil;
  }
  
  valid = [self isLinkValid:link];
  
  if (valid) {
    NSDictionary *qd;
    NSString     *da;
    NSString     *ta, *ti;
    // append link
    [_response appendContentString:@"<a href=\""];
    
    da = [self externalLinkAction];
    // use an external server to redirect links
    if ([da isNotEmpty]) {
      da = [da stringByAppendingString:@"?url="];
      da = [da stringByAppendingString:[link stringByEscapingURL]];
    }
    else {
      // build query dictionary for direct action
      qd = [NSDictionary dictionaryWithObjectsAndKeys:
                           link, @"url",
                         nil];
      // build direct action
      da = [_ctx directActionURLForActionNamed:@"viewExternalLink"
                 queryDictionary:qd];
    }
    [_response appendContentString:da];
    [_response appendContentCharacter:'\"'];
      
    /* appending target */
    [_response appendContentString:@" target=\""];
    ta = [self->target stringValueInComponent:comp];
    if (![ta isNotEmpty]) ta = @"OGo External Link Frame";
    [_response appendContentString:ta];
    [_response appendContentCharacter:'\"'];
      
    /* appending title */
    [_response appendContentString:@" title=\""];
    ti = [self->title stringValueInComponent:comp];
    if (![ti isNotEmpty])
      ti = [@"External Link: " stringByAppendingString:link];
    [_response appendContentString:ti];
    [_response appendContentCharacter:'\"'];

    [self appendExtraAttributesToResponse:_response inContext:_ctx];

    [_response appendContentCharacter:'>'];
      
    /* append string */
    s = [self->string stringValueInComponent:comp];
    if ([s isNotEmpty]) [_response appendContentHTMLString:s];

    /* append embedded content */
    [self->template appendToResponse:_response inContext:_ctx];
  }
  else if (![self hideInvalidLinks]) {
    s = [self->string stringValueInComponent:comp];
    if ([s isNotEmpty]) [_response appendContentHTMLString:s];
  }
  
  if (valid) {
    // close link  
    [_response appendContentString:@"</a>"];
  }
}

@end /* SkyExternalLink */