/*
  Copyright (C) 2000-2005 SKYRIX Software AG

  This file is part of SOPE.

  SOPE 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.

  SOPE 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 SOPE; see the file COPYING.  If not, write to the
  Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  02111-1307, USA.
*/

#include <NGObjWeb/WOAdaptor.h>
#include <NGObjWeb/WOCoreApplication.h>
#include <NGObjWeb/WORequest.h>
#include <NGObjWeb/WOResponse.h>
#include <NGObjWeb/WOCookie.h>

#include "common.h"
#include "WORunLoop.h"
#include "NGHttp+WO.h"

#if LIB_FOUNDATION_LIBRARY
#  import <Foundation/UnixSignalHandler.h>
#else
#  include "UnixSignalHandler.h"
#endif

//#define USE_POOLS 1

#if USE_POOLS
#  warning extensive pools are enabled ...
#endif

#include "WOHttpAdaptor.h"
#include "WORecordRequestStream.h"
#include "WOHttpTransaction.h"

#include <unistd.h>
#include <sys/wait.h>

@interface WOHttpAdaptor(Server)

/* accessors */

- (id<NGPassiveSocket>)socket;
- (id<NGSocketAddress>)serverAddress;

- (void)setSendTimeout:(NSTimeInterval)_timeout;
- (NSTimeInterval)sendTimeout;
- (void)setReceiveTimeout:(NSTimeInterval)_timeout;
- (NSTimeInterval)receiveTimeout;

@end /* WOHttpAdaptor */

@interface WOCoreApplication(Port)
- (NSNumber *)port;
@end

@implementation WOHttpAdaptor

static NGLogger *logger                      = nil;
static NGLogger *perfLogger                  = nil;
static BOOL     WOHttpAdaptor_LogStream      = NO;
static BOOL     WOContactSNS                 = NO;
static BOOL     WOCoreOnHTTPAdaptorException = NO;
static NSString *WOPort                      = nil;
static int      WOHttpAdaptorSendTimeout     = 10;
static int      WOHttpAdaptorReceiveTimeout  = 10;
static int      WOHttpAdaptorForkCount       = 0;
static id       allow                        = nil;
static BOOL     debugOn                      = NO;

+ (BOOL)optionLogStream {
  return WOHttpAdaptor_LogStream;
}
+ (BOOL)optionLogPerf {
  return perfLogger != nil ? YES : NO;
}

+ (int)version {
  return [super version] + 1 /* v2 */;
}
+ (void)initialize {
  NSUserDefaults  *ud;
  NGLoggerManager *lm;
  static BOOL     didInit = NO;

  if (didInit) return;
  didInit = YES;

  NSAssert2([super version] == 1,
            @"invalid superclass (%@) version %i !",
            NSStringFromClass([self superclass]), [super version]);

  ud = [NSUserDefaults standardUserDefaults];
  lm = [NGLoggerManager defaultLoggerManager];
  
  logger     = [lm loggerForClass:self];
  perfLogger = [lm loggerForDefaultKey:@"WOProfileHttpAdaptor"];

  WOHttpAdaptor_LogStream = [ud boolForKey:@"WOHttpAdaptor_LogStream"];

  // TODO: those two should be queried on demand to allow different defaults
  WOPort       = [[ud stringForKey:@"WOPort"] copy];
  WOContactSNS = [[ud objectForKey:@"WOContactSNS"] boolValue];

  WOCoreOnHTTPAdaptorException = 
    [[ud objectForKey:@"WOCoreOnHTTPAdaptorException"] boolValue] ? 1 : 0;
  
  WOHttpAdaptorSendTimeout    = 
    [ud integerForKey:@"WOHttpAdaptorSendTimeout"];
  WOHttpAdaptorReceiveTimeout = 
    [ud integerForKey:@"WOHttpAdaptorReceiveTimeout"];
  
  if (allow == nil) {
    if ((allow = [ud objectForKey:@"WOHttpAllowHost"]) == nil) {
      allow = [NSArray arrayWithObjects:
                         @"localhost", @"localhost.localdomain",
		         @"127.0.0.1", nil];
    }
    
    if (![allow isKindOfClass:[NSArray class]])
      allow = [NSArray arrayWithObject:allow];
      
    allow = [allow copy];
  }
  
  WOHttpAdaptorForkCount = 
    [[ud objectForKey:@"WOHttpAdaptorForkCount"] intValue];
  
  if (WOCoreOnHTTPAdaptorException)
    [logger warnWithFormat:@"will dump core on HTTP adaptor exception!"];
}

- (id)autoBindAddress {
  NGInternetSocketAddress *addr;
  addr = [[NGInternetSocketAddress alloc] initWithPort:0 onHost:@"127.0.0.1"];
  return [addr autorelease];
}

- (void)_registerForSignals {
#if !defined(__MINGW32__)
  UnixSignalHandler *us = [UnixSignalHandler sharedHandler];
      
  [us addObserver:self selector:@selector(handleSIGPIPE:)
      forSignal:SIGPIPE immediatelyNotifyOnSignal:NO];
#endif
}

- (id<NGSocketAddress>)addressFromDefaultsOfApplication:(WOCoreApplication*)_a{
  id<NGSocketAddress> lAddress = nil;
  const char *cstr;
  
  if ([WOPort isEqualToString:@"auto"]) {
    if ((lAddress = [self autoBindAddress]) != nil)
      return lAddress;
  }
  
  if ((cstr = [WOPort cString]) != NULL) {
    if (isdigit(*cstr) && index(cstr, ':') == NULL) {
      NSNumber *p;
          
      p = [(WOCoreApplication *)[_a class] port];
      if (p == nil) p = (id)WOPort;
          
      lAddress =
	[NGInternetSocketAddress wildcardAddressWithPort:[p intValue]];
      if (lAddress != nil)
	return lAddress;
    }
  }
  
  return NGSocketAddressFromString(WOPort);
}

- (id<NGSocketAddress>)addressFromArguments:(NSDictionary *)_args {
  id<NGSocketAddress> lAddress = nil;
  NSString *arg = nil;
  const char *cstr;
      
  if ((arg = [_args objectForKey:@"-p"]) != nil)
    return [NGInternetSocketAddress wildcardAddressWithPort:[arg intValue]];
  
  if ((arg = [_args objectForKey:@"-WOPort"]) == nil)
    return nil;
  
  lAddress = nil;
  if ([arg isEqualToString:@"auto"])
    lAddress = [self autoBindAddress];
        
  if ((lAddress == nil) && (cstr = [arg cString])) {
    if (isdigit(*cstr)) {
      lAddress =
	[NGInternetSocketAddress wildcardAddressWithPort:[arg intValue]];
    }
  }
  if (lAddress == nil)
    lAddress = NGSocketAddressFromString(arg);
  return lAddress;
}

- (id)initWithName:(NSString *)_name
  arguments:(NSDictionary *)_args
  application:(WOCoreApplication *)_application
{
  if ((self = [super initWithName:_name
                     arguments:_args
                     application:_application])) {
    id arg = nil;
    
    if ([[_application recordingPath] length] > 0)
      WOHttpAdaptor_LogStream = YES;
    
    [self _registerForSignals];
    
    if ([_args count] < 1)
      self->address = [self addressFromDefaultsOfApplication:_application];
    else
      self->address = [self addressFromArguments:_args];
    
    self->address = [self->address retain];
    
    if (self->address == nil) {
      [_application errorWithFormat:
                      @"got no address for HTTP server (using arg '%@')", arg];
      [self release];
      return nil;
    }
    
    if (!WOContactSNS) {
      [_application logWithFormat:@"%@ listening on address %@",
                      NSStringFromClass([self class]),
                      [(id)self->address stringValue]];
    }
    
    self->lock = [[NSRecursiveLock alloc] init];
    
    self->maxThreadCount = [[WOCoreApplication workerThreadCount] intValue];
    
    [self setSendTimeout:WOHttpAdaptorSendTimeout];
    [self setReceiveTimeout:WOHttpAdaptorReceiveTimeout];
  }
  return self;
}

- (void)dealloc {
  [[UnixSignalHandler    sharedHandler] removeObserver:self];
  [[NSNotificationCenter defaultCenter] removeObserver:self];
  [self->lock    release];
  [self->socket  release];
  [self->address release];
  [super dealloc];
}

/* accessors */

- (id<NGSocketAddress>)socketAddress {
  /* used by sns */
  return self->address;
}

/* forking */

static pid_t *childPIDs       = NULL;
static BOOL  isForkMaster     = YES;

- (void)forkChildren {
  unsigned i;

  if (WOHttpAdaptorForkCount == 0)
    return;

  [self logWithFormat:@"Note: forking %d children for socket processing.",
	  WOHttpAdaptorForkCount];
  
#if !defined(__MINGW32__)
  [[UnixSignalHandler sharedHandler]
    addObserver:self selector:@selector(handleSIGCHLD:)
    forSignal:SIGCHLD immediatelyNotifyOnSignal:NO];
#endif
  
  childPIDs = calloc(WOHttpAdaptorForkCount + 1, sizeof(pid_t));
  for (i = 0; i < WOHttpAdaptorForkCount; i++) {
    childPIDs[i] = fork();
    
    if (childPIDs[i] == 0) {
      /* child */
      isForkMaster = NO;
      return;
    }
    else if (childPIDs[i] > 0)
      printf("Note: successfully forked child: %i\n", childPIDs[i]);
    else
      [self errorWithFormat:@"failed to fork child %i.", i];
  }
}
- (void)killChildren {
  int i;
  
  if (!isForkMaster)
    return;
  
  for (i = 0; i < WOHttpAdaptorForkCount; i++) {
    if (childPIDs[i] != 0)
      kill(childPIDs[i], SIGKILL);
  }
}

- (void)checkStatusOfChildren {
  /*
    Note: currently this does not refork crashed processes. Reforking is harder
          than it may sound because the crash can happen at arbitary execution
	  states.
	  That is, the "master process" is not virgin anymore, eg it might have
	  open database connections.
	  
	  So the solution might be to refork the whole cluster once a minimum
	  backend threshold is reached.
  */
  unsigned int i;
  
  if (!isForkMaster)
    return;
  
  for (i = 0; i < WOHttpAdaptorForkCount; i++) {
    pid_t result;
    int   status;
    
    if (childPIDs[i] == 0)
      continue;
    
    result = waitpid(childPIDs[i], &status, WNOHANG);
    if (result == 0) /* did not exit yet */
      continue;
    
    if (result == -1) { /* error */
      [self errorWithFormat:@"failed to get status of child %i: %s", 
	      childPIDs[i], strerror(errno)];
      continue;
    }

    [self logWithFormat:@"Note: child %i terminated.", childPIDs[i]];
    childPIDs[i] = 0;
  }
}

/* events */

- (void)handleSIGPIPE:(int)_signal {
  [self warnWithFormat:@"caught SIGPIPE !"];
}
- (void)handleSIGCHLD:(int)_signal {
  [self checkStatusOfChildren];
}

- (void)registerForEvents {
  int backlog;
  
  backlog = [[WOCoreApplication listenQueueSize] intValue];
  
  if (backlog == 0)
    backlog = 5;
  
  [self->socket release]; self->socket = nil;
  
  self->socket =
    [[NGPassiveSocket alloc] initWithDomain:[self->address domain]];
  
  [self->socket bindToAddress:self->address];
  
  if ([[self->address domain] isEqual:[NGInternetSocketDomain domain]]) {
    if ([(NGInternetSocketAddress *)self->address port] == 0) {
      /* let the kernel choose an IP address */
      
      [self debugWithFormat:@"bound to wildcard: %@", self->address];
      [self debugWithFormat:@"got local: %@", [self->socket localAddress]];
      
      self->address = [[self->socket localAddress] retain];
      
      [self logWithFormat:@"bound to kernel assigned address %@: %@",
              self->address, self->socket];
    }
  }
  
  [self->socket listenWithBacklog:backlog];
  
  [[NSNotificationCenter defaultCenter]
                         addObserver:self selector:@selector(acceptConnection:)
                         name:NSFileObjectBecameActiveNotificationName
                         object:self->socket];
  [(WORunLoop *)[WORunLoop currentRunLoop]
              addFileObject:self->socket
              activities:NSPosixReadableActivity
              forMode:NSDefaultRunLoopMode];
  
  [self forkChildren];
}
- (void)unregisterForEvents {
  [self killChildren];
  
  [(WORunLoop *)[WORunLoop currentRunLoop]
              removeFileObject:self->socket forMode:NSDefaultRunLoopMode];
  [[NSNotificationCenter defaultCenter] removeObserver:self];
  
  [self->lock   release]; self->lock   = nil;
  [self->socket release]; self->socket = nil;
}

/* debugging */

- (BOOL)isDebuggingEnabled {
  return debugOn;
}

/* description */

- (NSString *)description {
  return [NSString stringWithFormat:@"<%@[0x%08X]: address=%@>",
                     NSStringFromClass([self class]), self,
                     self->address];
}

/* Server */

/* accessors */

- (id<NGPassiveSocket>)socket {
  return self->socket;
}
- (id<NGSocketAddress>)serverAddress {
  return [self->socket localAddress];
}

- (void)setSendTimeout:(NSTimeInterval)_timeout {
  self->sendTimeout = _timeout;
}
- (NSTimeInterval)sendTimeout {
  return self->sendTimeout;
}

- (void)setReceiveTimeout:(NSTimeInterval)_timeout {
  self->receiveTimeout = _timeout;
}
- (NSTimeInterval)receiveTimeout {
  return self->receiveTimeout;
}

- (void)setMaxThreadCount:(int)_count {
  self->maxThreadCount = _count;
}
- (int)maxThreadCount {
  return self->maxThreadCount;
}

/* run-loop */

- (void)_serverCatched:(NSException *)_exc {
  [self errorWithFormat:@"http server caught: %@", _exc];
  if (WOCoreOnHTTPAdaptorException) abort();
}

- (BOOL)runConnection:(id<NGActiveSocket>)_socket {
  WOHttpTransaction *tx;
  
  if (_socket == nil) {
    [self errorWithFormat:@"got no socket for transaction ??"];
    return NO;
  }
  
  tx = [[WOHttpTransaction alloc] initWithSocket:_socket
                                  application:self->application];
  
  if (![tx run])
    [self _serverCatched:[tx lastException]];
  
  [tx release];
  
  if ([self->application isTerminating])
    self->isTerminated = YES;
  
  return YES;
}

- (void)_handleAcceptedConnection:(NGActiveSocket *)_connection {
#if USE_POOLS
  NSAutoreleasePool *pool = nil;
#endif
  NSTimeInterval t;
  
  if (perfLogger)
    *(&t) = [[NSDate date] timeIntervalSince1970];
  
  [self->lock lock];
  self->activeThreadCount++;
  [self->lock unlock];
  
#if USE_POOLS
  pool = [[NSAutoreleasePool alloc] init];
#endif
  {
    [*(&_connection) autorelease];
    
    NS_DURING {
      [_connection setReceiveTimeout:self->receiveTimeout];
      [_connection setSendTimeout:self->sendTimeout];
      
      [self runConnection:_connection];
    }
    NS_HANDLER {
      [self _serverCatched:localException];
    }
    NS_ENDHANDLER;
  }
#if USE_POOLS
  [pool release]; pool = nil;
#endif

  [self->lock lock];
  self->activeThreadCount--;
  [self->lock unlock];

  if (perfLogger) {
    t = [[NSDate date] timeIntervalSince1970] - t;
    [perfLogger logWithFormat:@"handling of request took %4.3fs.",
                  t < 0.0 ? -1.0 : t];
  }
}

- (NSArray *)allowedHostNames {
  return allow;
}

- (id<NGActiveSocket>)_checkAccessOnConnection:(id<NGActiveSocket>)_connection{
  static NGInternetSocketDomain *ipDomain = nil;
  id<NGSocketAddress> remote;

  if ((remote = [_connection remoteAddress]) == nil) {
    [self errorWithFormat:@"missing remote address for connection: %@",
            _connection];
    return nil;
  }

  if (ipDomain == nil)
    ipDomain = [[NGInternetSocketDomain domain] retain];
  
  /* always allow access for Unix domain sockets */
  if (![[remote domain] isEqual:ipDomain])
    return _connection;
  
  {
    /* check access */
    NGInternetSocketAddress *ipAddr = (id)remote;
    NSArray *allow = nil;
    unsigned i, count;
    NSString *rh, *ra;
    
    allow = [self allowedHostNames];
    
    rh = [ipAddr hostName];
    ra = [ipAddr address];
    
    /* first check address */
    
    for (i = 0, count = [allow count]; i < count; i++) {
      NSString *h;
      
      h = [[allow objectAtIndex:i] stringValue];
      if ([h isEqualToString:ra])
        return _connection;
    }
    
    /* now check DNS names */
    
    for (i = 0, count = [allow count]; i < count; i++) {
      NSString *h;
      
      h = [[allow objectAtIndex:i] stringValue];
      if ([h isEqualToString:rh])
        return _connection;
    }
    
    [self errorWithFormat:@"ACCESS DENIED: %@", ipAddr];
    _connection = nil;
  }
  
  return _connection;
}

- (void)acceptConnection:(id)_notification {
#if USE_POOLS
  NSAutoreleasePool *pool;
  *(&pool) = [[NSAutoreleasePool alloc] init];
#endif
  {
    NGActiveSocket *connection;
    
    NS_DURING {
      *(&connection) = (NGActiveSocket *)[self->socket accept];
      if (connection == nil)
        [self _serverCatched:[self->socket lastException]];
      else
        [self debugWithFormat:@"accepted connection: %@", connection];
    }
    NS_HANDLER {
      connection = nil;
      [self _serverCatched:localException];
    }
    NS_ENDHANDLER;
    
    connection = (NGActiveSocket *)[self _checkAccessOnConnection:connection];
    
    if (connection != nil) {
      if (self->maxThreadCount <= 1) {
        NS_DURING
          [self _handleAcceptedConnection:[connection retain]];
        NS_HANDLER
          [self _serverCatched:localException];
        NS_ENDHANDLER;
      }
      else {
        [NSThread detachNewThreadSelector:@selector(_handleAcceptedConnection:)
                  toTarget:self
                  withObject:[connection retain]];
        [self logWithFormat:@"detached new thread for request."];
        //[NSThread sleepUntilDate:[NSDate dateWithTimeIntervalSinceNow:10]];
      }
      connection = nil;
    }
  }
#if USE_POOLS
  [pool release]; pool = nil;
#endif
  
  if (self->isTerminated) {
    if (self->socket) {
      [[NSNotificationCenter defaultCenter]
                             removeObserver:self
                             name:NSFileObjectBecameActiveNotificationName
                             object:self->socket];
      [self->socket close];
      [self->socket release]; self->socket = nil;
    }
    [self logWithFormat:@"adaptor stops application: %@ ...",
            self->application];
    exit(0);
  }
}

@end /* WOHttpAdaptor */