/*
  Copyright (C) 2006-2009 Helge Hess
  Copyright (C) 2006-2009 Adam Williams

  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/WODirectAction.h>

/*
  CalDAV calendar-query REPORT

  Sample request:
    <calendary-query xmlns:D="DAV:">
      <D:prop>
        <D:getetag/>
        <calendar-data/>
      </D:prop>
    </calendar-query>

  Sample response:
    <D:multistatus xmlns:D="DAV:">
      <D:response>
        <D:href>http://localhost/zidestore/dav/donald/Calendar/123.ics</D:href>
        <D:propstat>
          <D:status>HTTP/1.1 200 OK</D:status>
          <D:prop>
            <D:getetag>"abc:1"</D:getetag>
            <calendar-data>BEGIN:VCALENDAR
VERSION:2.0
BEGIN:VEVENT
...
END:VEVENT
END:VCALENDAR
            </calendar-data>
          </D:prop>
        </D:propstat>
      </D:response>
    </D:multistatus>
*/

@class NSString, NSDate, NSArray, NSMutableArray, NSEnumerator;
@class WORequest, WOResponse, WOContext;

@interface SxDavCalendarQuery : WODirectAction
{
  /* nil - not requested, empty - all requested */
  NSMutableArray *calendarDataFields;
  /* is vEventDataFields ever other than empty? */
  NSMutableArray *vEventDataFields;
  NSMutableArray *vTodoDataFields;
  NSMutableArray *requestedWebDAVProperties;
  
  NSString *queryType;
  NSDate   *startDate;
  NSDate   *endDate;

  NSEnumerator *results;
}

- (void)takeValuesFromRequest:(WORequest *)_rq inContext:(WOContext *)_ctx;
- (void)appendToResponse:(WOResponse *)_r      inContext:(WOContext *)_ctx;

- (NSEnumerator *)fetchDatesInContext:(id)_ctx;

@end

#include "SxAppointmentFolder.h"
#include <NGiCal/NSCalendarDate+ICal.h>
#include <SaxObjC/XMLNamespaces.h>
#include <ZSBackend/SxAptManager.h>
#include "common.h"

@implementation SxDavCalendarQuery

static BOOL debugOn = NO;

- (void)dealloc {
  [self->results   release];

  [self->queryType release];
  [self->startDate release];
  [self->endDate   release];

  [self->calendarDataFields        release];
  [self->vEventDataFields          release];
  [self->vTodoDataFields           release];
  [self->requestedWebDAVProperties release];
  [super dealloc];
}

/* action */

- (id)defaultAction {
  // TODO: remember the depth!

  [self takeValuesFromRequest:[self request] inContext:[self context]];
  
  if ([self isDebuggingEnabled]) {
    [self debugWithFormat:@"CalDAV REPORT on: %@", [self clientObject]];
    [self debugWithFormat:@"  type: %@", self->queryType];
    if (self->startDate != nil)
      [self debugWithFormat:@"  range: %@-%@", self->startDate, self->endDate];
  }
  
  if ([self->queryType isEqualToString:@"VEVENT"]) {
    self->results = [[self fetchDatesInContext:[self context]] retain];
    if (self->results == nil)
      [self debugWithFormat:@"got no dates ..."];
    else if ([self->results isKindOfClass:[NSException class]]) {
      [self errorWithFormat:@"failed to fetch: %@", self->results];
      return self->results;
    }
  }
  
  if (self->results == nil)
    self->results = [[[NSArray array] objectEnumerator] retain];
  
  [self appendToResponse:[[self context] response] inContext:[self context]];
  return [[self context] response];
}

/* fetching */

- (SxAptManager *)aptManagerInContext:(id)_ctx {
  return [[self clientObject] aptManagerInContext:_ctx];
}
- (SxAptSetIdentifier *)currentAptSet {
  return [[self clientObject] aptSetID];
}

- (NSEnumerator *)fetchDatesInContext:(id)_ctx {
  id           folder;
  SxAptManager *manager;
  NSArray      *dates;
  SxAptSetIdentifier *sid;
  
  folder  = [self clientObject];
  manager = [self aptManagerInContext:_ctx];
  
  // TODO: consider limit set by client
  sid   = [self currentAptSet];
  dates = [manager gidsOfAppointmentSet:sid];
  [self debugWithFormat:@"for %@ got %d events ...", sid, [dates count]];
  
  return [manager pkeysAndModDatesAndICalsForGlobalIDs:dates];
}

/* generate response */

- (NSString *)hrefForEvent:(id)_event inContext:(WOContext *)_ctx {
  NSString *u;
  id pkey;

  if (![(pkey = [_event valueForKey:@"pkey"]) isNotEmpty])
    return nil;
  
  u = [[self clientObject] baseURLInContext:_ctx];
  return [u stringByAppendingFormat:
        ([u hasSuffix:@"/"] ? @"%@.ics" : @"/%@.ics"), pkey];
}

- (void)appendToResponse:(WOResponse *)_r inContext:(WOContext *)_ctx {
  id event;
  
  [self debugWithFormat:@"generating responses"];
  
  [_r setContentEncoding:NSUTF8StringEncoding];
  [_r setStatus:207 /* multistatus */];
  [_r setHeader:@"text/xml; charset=\"utf-8\"" forKey:@"content-type"];
  
  /* open multistatus */
  [_r appendContentString:@"<?xml version=\"1.0\"?>\n"];
  [_r appendContentString:@"<D:multistatus xmlns:D=\"DAV:\" xmlns=\""];
  [_r appendContentString:XMLNS_CALDAV];
  [_r appendContentString:@"\">\n"];
  
  /* generate events */
  while ((event = [self->results nextObject]) != nil) {
    [_r appendContentString:@"  <D:response>\n"];

    [_r appendContentString:@"    <D:href>"];
    [_r appendContentXMLString:[self hrefForEvent:event inContext:_ctx]];
    [_r appendContentString:@"</D:href>\n"];

    /* successful properties */
    
    [_r appendContentString:@"    <D:propstat>\n"];
    [_r appendContentString:@"      <D:status>HTTP/1.1 200 OK</D:status>\n"];
    [_r appendContentString:@"      <D:prop>\n"];
    
    if ([self isDebuggingEnabled]) {
      [self debugWithFormat:@"RENDER DATE: %@", [event allKeys]];
      if (vEventDataFields != nil)
        [self debugWithFormat:@"vEventDataFields = %@", vEventDataFields];
      else
        [self debugWithFormat:@"vEventDataFields is nil"];
    }

    /* always include etag */
    if ([[event valueForKey:@"pkey"] isNotNull]) {
      [_r appendContentString:@"<D:getetag>"];
      [_r appendContentXMLString:[[event valueForKey:@"pkey"] stringValue]];
      [_r appendContentXMLString:@":"];
      [_r appendContentXMLString:[[event valueForKey:@"version"] stringValue]];
      [_r appendContentString:@"</D:getetag>\n"];
    }
    
    if (vEventDataFields != nil) {
      // TODO: render specific properties if requested ..., we just deliver
      //       everything
      id tmp;
      
      if ([(tmp = [event valueForKey:@"iCalData"]) isNotEmpty]) {
        [_r appendContentString:@"<calendar-data>"];
        [_r appendContentXMLString:@"BEGIN:VCALENDAR\r\n"];
        [_r appendContentXMLString:@"VERSION:2.0\r\n"];
        // TODO: product-id
  
        [_r appendContentXMLString:[tmp stringValue]];

        [_r appendContentXMLString:@"END:VCALENDAR\r\n"];
        [_r appendContentString:@"</calendar-data>\n"];
      }
      else {
        [self errorWithFormat:@"got no iCalendar data for event: %@", event];
      }
    } /* end if vEventDataFields != nil */
    
    [_r appendContentString:@"      </D:prop>\n"];
    [_r appendContentString:@"    </D:propstat>\n"];
    
    // TODO: failed properties?
    
    [_r appendContentString:@"  </D:response>\n"];
  } /* end while */
  
  /* close multistatus */
  [_r appendContentString:@"</D:multistatus>"];
}


/* decoding requests */

// TODO: this is kinda bloated code because some methods in DOM are not
//       implemented yet

- (void)_loadRequestedCalDataProperties:(id<DOMElement>)_base
  list:(NSMutableArray **)_list
{
  id<DOMNodeList> children;
  unsigned i, count;
  
  [self debugWithFormat:@"  loading properties for element: %@", _base];
  
  if (*_list == nil)
    *_list = [[NSMutableArray alloc] initWithCapacity:4];
  
  children = [_base childNodes];
  for (i = 0, count = [children length]; i < count; i++) {
    id<DOMElement> node;
    NSString *n, *an;
    
    node = [children objectAtIndex:i];
    if ([node nodeType] != DOM_ELEMENT_NODE)
      continue;

    if (![[node namespaceURI] isEqualToString:XMLNS_CALDAV]) {
      [self warnWithFormat:@"unexpected XML element/namespace: %@", node];
      continue;
    }
    
    n  = [node localName];
    an = [node attribute:@"name"];
    
    if ([n isEqualToString:@"prop"] && [an isNotEmpty]) {
      /* name is a "same level property" */
      [*_list addObject:an];
    }
    else if ([n isEqualToString:@"comp"] && [an isNotEmpty]) {
        /* name is a component type */
        if ([an isEqualToString:@"VCALENDAR"]) {
          [self _loadRequestedCalDataProperties:node 
                list:&self->calendarDataFields];
        }
        else if ([an isEqualToString:@"VEVENT"]) {
          [self _loadRequestedCalDataProperties:node 
                list:&self->vEventDataFields];
        }
        else if ([an isEqualToString:@"VTODO"]) {
          [self _loadRequestedCalDataProperties:node 
                list:&self->vTodoDataFields];
        }
        else {
          /* component type not recognized */
          [self warnWithFormat:@"unexpected CalDAV component name: %@", node];
        }
    }
    else {
        /* node type not recognized */
        [self warnWithFormat:@"unexpected CalDAV XML element: %@", node];
    }
  } /* end for */
}

- (void)_loadRequestedCalDataProperties:(id<DOMElement>)_props {
  [self debugWithFormat:@"loading caldata properties: %@", _props];
  
  self->calendarDataFields = [[NSMutableArray alloc] initWithCapacity:4];
  [self _loadRequestedCalDataProperties:_props list:&self->calendarDataFields];

  /* was an empty element, so request everything ... */
  if (![self->calendarDataFields isNotEmpty]) {
    self->vEventDataFields = [[NSMutableArray alloc] initWithCapacity:4];
    self->vTodoDataFields  = [[NSMutableArray alloc] initWithCapacity:4];
  }
}

- (void)_loadRequestedProperties:(id<DOMElement>)_props {
  id<DOMNodeList> children;
  unsigned i, count;
  
  [self debugWithFormat:@"loading properties: %@", _props];
  
  children = [_props childNodes];
  for (i = 0, count = [children length]; i < count; i++) {
    id<DOMElement> node;
    NSString *n, *ns;
    
    node = [children objectAtIndex:i];
    if ([node nodeType] != DOM_ELEMENT_NODE)
      continue;

    n  = [node localName];
    ns = [node namespaceURI];

    if ([ns isEqualToString:XMLNS_CALDAV]) {
      if ([n isEqualToString:@"calendar-data"])
        [self _loadRequestedCalDataProperties:node];
      else
        [self warnWithFormat:@"unexpected CalDAV XML element: %@", node];
    }
    else if ([ns isEqualToString:XMLNS_WEBDAV]) {
      if (self->requestedWebDAVProperties == nil) {
        self->requestedWebDAVProperties =
            [[NSMutableArray alloc] initWithCapacity:4];
      }
      [self->requestedWebDAVProperties addObject:n];
    }
    else {
      [self warnWithFormat:@"unexpected XML element/namespace: %@", node];
    }
  } /* end for */
}

- (id<DOMElement>)_elementNamed:(NSString *)_k inParent:(id<DOMElement>)_e {
  id<DOMNodeList> children;
  unsigned i, count;
  
  if (![_e hasChildNodes])
    return nil;
  
  children = [_e childNodes];
  for (i = 0, count = [children length]; i < count; i++) {
    id<DOMElement> node;
    
    node = [children objectAtIndex:i];
    if ([node nodeType] != DOM_ELEMENT_NODE)
      continue;
    
    if ([_k isEqualToString:[node localName]])
      return node;
  }
  return nil;
}

- (void)_loadCalDAVFilter:(id<DOMElement>)_filter {
  // Note: we ignore namespace here to avoid some DOM bugs ...
  id<DOMElement> element;
  NSString *an;

  [self debugWithFormat:@"loading filter: %@", _filter];
  
  /* first we should get a <comp-filter name="VCALENDAR"> */
  
  element = [self _elementNamed:@"comp-filter" inParent:_filter];
  if (element == nil) {
    [self debugWithFormat:@"no filter specified: %@", _filter];
    return;
  }
  if (![(an = [element attribute:@"name"]) isEqualToString:@"VCALENDAR"]) {
    [self errorWithFormat:@"unsupported top-level filter: %@", _filter];
    return;
  }
  
  /* next we should get the component we want (our querytype) */
  
  element = [self _elementNamed:@"comp-filter" inParent:element];
  if (element == nil) {
    [self debugWithFormat:@"no specific component filter: %@", _filter];
    return;
  }
  if (![(an = [element attribute:@"name"]) isNotEmpty]) {
    [self errorWithFormat:@"got no CalDAV query type: %@", _filter];
    return;
  }
  self->queryType = [an copy]; /* this is VTODO, VEVENT etc */
  
  /* check whether a timerange was specified */
  
  if ((element = [self _elementNamed:@"time-range" inParent:element]) != nil) {
    if ([(an = [element attribute:@"start"]) isNotEmpty]) {
      self->startDate =
        [[NSCalendarDate calendarDateWithICalRepresentation:an] copy];
    }
    if ([(an = [element attribute:@"end"]) isNotEmpty]) {
      self->endDate =
        [[NSCalendarDate calendarDateWithICalRepresentation:an] copy];
    }
  }
}

- (void)takeValuesFromRequest:(WORequest *)_rq inContext:(WOContext *)_ctx {
  id<DOMElement>  queryElement;
  id<DOMNodeList> children;
  unsigned i, count;
 
  queryElement = [[_rq contentAsDOMDocument] documentElement];
  [self debugWithFormat:@"process DOM root: %@", queryElement];
  
  children = [queryElement childNodes];
  for (i = 0, count = [children length]; i < count; i++) {
    id<DOMElement> node;
    NSString *n, *ns;
    
    node = [children objectAtIndex:i];
    if ([node nodeType] != DOM_ELEMENT_NODE)
      continue;

    n  = [node localName];
    ns = [node namespaceURI];
    
    if ([ns isEqualToString:XMLNS_WEBDAV]) {
      if ([n isEqualToString:@"prop"])
        [self _loadRequestedProperties:node];
      else
        [self warnWithFormat:@"unexpected WebDAV XML element: %@", node];
    }
    else if ([ns isEqualToString:XMLNS_CALDAV]) {
        if ([n isEqualToString:@"filter"])
          [self _loadCalDAVFilter:node];
        else
          [self warnWithFormat:@"unexpected CalDAV XML element: %@", node];
    }
    else {
      [self warnWithFormat:@"unexpected XML element/namespace: %@", node];
    }
  } /* end for */
}

/* debugging */

- (BOOL)isDebuggingEnabled {
  return debugOn;
}

@end /* SxDavCalendarQuery */