/**
 * Copyright (c) 2015-present, Facebook, Inc.
 * All rights reserved.
 *
 * This source code is licensed under the BSD-style license found in the
 * LICENSE file in the root directory of this source tree. An additional grant
 * of patent rights can be found in the PATENTS file in the same directory.
 */

#import "FBWebServer.h"

#import "RoutingConnection.h"
#import "RoutingHTTPServer.h"

#import "FBCommandHandler.h"
#import "FBErrorBuilder.h"
#import "FBExceptionHandler.h"
#import "FBRouteRequest.h"
#import "FBRuntimeUtils.h"
#import "FBSession.h"
#import "FBUnknownCommands.h"
#import "FBConfiguration.h"
#import "FBLogger.h"

static NSString *const FBServerURLBeginMarker = @"ServerURLHere->";
static NSString *const FBServerURLEndMarker = @"<-ServerURLHere";

@interface FBHTTPConnection : RoutingConnection
@end

@implementation FBHTTPConnection

- (void)handleResourceNotFound
{
  [FBLogger logFmt:@"Received request for %@ which we do not handle", self.requestURI];
  [super handleResourceNotFound];
}

@end


@interface FBWebServer ()
@property (nonatomic, strong) FBExceptionHandler *exceptionHandler;
@property (nonatomic, strong) RoutingHTTPServer *server;
@property (atomic, assign) BOOL keepAlive;
@end

@implementation FBWebServer

+ (NSArray<Class<FBCommandHandler>> *)collectCommandHandlerClasses
{
  NSArray *handlersClasses = FBClassesThatConformsToProtocol(@protocol(FBCommandHandler));
  NSMutableArray *handlers = [NSMutableArray array];
  for (Class aClass in handlersClasses) {
    if ([aClass respondsToSelector:@selector(shouldRegisterAutomatically)]) {
      if (![aClass shouldRegisterAutomatically]) {
        continue;
      }
    }
    [handlers addObject:aClass];
  }
  return handlers.copy;
}

- (void)startServing
{
  [FBLogger logFmt:@"Built at %s %s", __DATE__, __TIME__];
  self.exceptionHandler = [FBExceptionHandler new];
  [self startHTTPServer];

  self.keepAlive = YES;
  NSRunLoop *runLoop = [NSRunLoop mainRunLoop];
  while (self.keepAlive &&
         [runLoop runMode:NSDefaultRunLoopMode beforeDate:[NSDate distantFuture]]);
}

- (void)startHTTPServer
{
  self.server = [[RoutingHTTPServer alloc] init];
  [self.server setRouteQueue:dispatch_get_main_queue()];
  [self.server setInterface:FBConfiguration.sharedConfiguration.serverInterface];
  [self.server setDefaultHeader:@"Server" value:@"WebDriverAgent/1.0"];
  [self.server setDefaultHeader:@"Access-Control-Allow-Origin" value:@"*"];
  [self.server setDefaultHeader:@"Access-Control-Allow-Headers" value:@"Content-Type, X-Requested-With"];
  [self.server setConnectionClass:[FBHTTPConnection self]];

  [self registerRouteHandlers:[self.class collectCommandHandlerClasses]];
  [self registerServerKeyRouteHandlers];

  NSRange serverPortRange = FBConfiguration.sharedConfiguration.bindingPortRange;
  NSError *error;
  BOOL serverStarted = NO;

  for (NSUInteger index = 0; index < serverPortRange.length; index++) {
    NSInteger port = serverPortRange.location + index;
    [self.server setPort:(UInt16)port];

    serverStarted = [self attemptToStartServer:self.server onPort:port withError:&error];
    if (serverStarted) {
      break;
    }

    [FBLogger logFmt:@"Failed to start web server on port %ld with error %@", (long)port, [error description]];
  }

  if (!serverStarted) {
    [FBLogger logFmt:@"Last attempt to start web server failed with error %@", [error description]];
    abort();
  }
  [FBLogger logFmt:@"%@http://%@:%d%@", FBServerURLBeginMarker, @"localhost", [self.server port], FBServerURLEndMarker];
}

- (void)stopServing
{
  [FBSession.activeSession kill];
  if (self.server.isRunning) {
    [self.server stop:NO];
  }
  self.keepAlive = NO;
}

- (BOOL)attemptToStartServer:(RoutingHTTPServer *)server onPort:(NSInteger)port withError:(NSError **)error
{
  server.port = (UInt16)port;
  NSError *innerError = nil;
  BOOL started = [server start:&innerError];
  if (!started) {
    if (!error) {
      return NO;
    }

    NSString *description = @"Unknown Error when Starting server";
    if ([innerError.domain isEqualToString:NSPOSIXErrorDomain] && innerError.code == EADDRINUSE) {
      description = [NSString stringWithFormat:@"Unable to start web server on port %ld", (long)port];
    }
    return
    [[[[FBErrorBuilder builder]
       withDescription:description]
      withInnerError:innerError]
     buildError:error];
  }
  return YES;
}

- (void)registerRouteHandlers:(NSArray *)commandHandlerClasses
{
  for (Class<FBCommandHandler> commandHandler in commandHandlerClasses) {
    NSArray *routes = [commandHandler routes];
    for (FBRoute *route in routes) {
      [self.server handleMethod:route.verb
                       withPath:route.path
                          block:^(RouteRequest *request, RouteResponse *response) {
        NSDictionary *arguments = nil;
        if ([request.body length]) {
          NSError *error = nil;
          arguments = [NSJSONSerialization JSONObjectWithData:request.body
                                                      options:NSJSONReadingMutableContainers
                                                        error:&error];
          if (nil != error) {
            [FBLogger logFmt:@"%@", error.localizedDescription];
          }
        }
        FBRouteRequest *routeParams = [FBRouteRequest
          routeRequestWithURL:request.url
          parameters:request.params
          arguments:arguments ?: @{}
        ];

        [FBLogger verboseLog:routeParams.description];

        @try {
          [route mountRequest:routeParams intoResponse:response];
        }
        @catch (NSException *exception) {
          [self handleException:exception forResponse:response];
        }
      }];
    }
  }
}

- (void)handleException:(NSException *)exception forResponse:(RouteResponse *)response
{
  [self.exceptionHandler handleException:exception forResponse:response];
}

- (void)registerServerKeyRouteHandlers
{
  [self.server get:@"/health" withBlock:^(RouteRequest *request, RouteResponse *response) {
    [response respondWithString:@"I-AM-ALIVE"];
  }];

  [self.server delete:@"/" withBlock:^(RouteRequest *request, RouteResponse *response) {
    @try {
      [FBSession.activeSession kill];
    } @finally {
      [response respondWithString:@"Shutting down"];
      [self.delegate webServerDidRequestShutdown:self];
    }
  }];

  [self registerRouteHandlers:@[FBUnknownCommands.class]];
}

@end