//

//  MGTwitterEngine.m

//  MGTwitterEngine

//

//  Created by Matt Gemmell on 10/02/2008.

//  Copyright 2008 Instinctive Code.

//

#import "MGTwitterEngine.h"

#import "MGTwitterHTTPURLConnection.h"

#import "NSData+Base64.h"

#define USE_LIBXML 0

#import "MGTwitterStatusesParser.h"

#import "MGTwitterUsersParser.h"

#import "MGTwitterMessagesParser.h"

#import "MGTwitterMiscParser.h"

#define TWITTER_DOMAIN          @"twitter.com"

#define HTTP_POST_METHOD        @"POST"

#define HTTP_MULTIPART_METHOD	@"MULTIPART" //adium

#define MULTIPART_FORM_BOUNDARY	@"bf5faadd239c17e35f91e6dafe1d2f96" //adium

#define MAX_MESSAGE_LENGTH      140 // Twitter recommends tweets of max 140 chars

#define MAX_LOCATION_LENGTH		31

#define DEFAULT_CLIENT_NAME     @"MGTwitterEngine"

#define DEFAULT_CLIENT_VERSION  @"1.0"

#define DEFAULT_CLIENT_URL      @"http://mattgemmell.com/source"

#define DEFAULT_CLIENT_TOKEN	@"mgtwitterengine"

#define URL_REQUEST_TIMEOUT     50.0 // Twitter usually fails quickly if it's going to fail at all.

#define DEFAULT_TWEET_COUNT		20

@interface MGTwitterEngine (PrivateMethods)

// Utility methods

- (NSDateFormatter *)_HTTPDateFormatter;

- (NSString *)_queryStringWithBase:(NSString *)base parameters:(NSDictionary *)params prefixed:(BOOL)prefixed;

- (NSDate *)_HTTPToDate:(NSString *)httpDate;

- (NSString *)_dateToHTTP:(NSDate *)date;

- (NSString *)_encodeString:(NSString *)string;

// Connection/Request methods

- (NSString *)_sendRequestWithMethod:(NSString *)method 

                                path:(NSString *)path 

                     queryParameters:(NSDictionary *)params

                                body:(id)body 

                         requestType:(MGTwitterRequestType)requestType 

                        responseType:(MGTwitterResponseType)responseType;

// Parsing methods

- (void)_parseXMLForConnection:(MGTwitterHTTPURLConnection *)connection;

// Delegate methods

- (BOOL) _isValidDelegateForSelector:(SEL)selector;

@end

@implementation MGTwitterEngine

#pragma mark Constructors

+ (MGTwitterEngine *)twitterEngineWithDelegate:(NSObject *)theDelegate

{

    return [[[MGTwitterEngine alloc] initWithDelegate:theDelegate] autorelease];

}

- (MGTwitterEngine *)initWithDelegate:(NSObject *)newDelegate

{

    if ((self = [super init])) {

        _delegate = newDelegate; // deliberately weak reference

        _connections = [[NSMutableDictionary alloc] initWithCapacity:0];

        _clientName = [DEFAULT_CLIENT_NAME retain];

        _clientVersion = [DEFAULT_CLIENT_VERSION retain];

        _clientURL = [DEFAULT_CLIENT_URL retain];

		_clientSourceToken = [DEFAULT_CLIENT_TOKEN retain];

		_APIDomain = [TWITTER_DOMAIN retain];

        _secureConnection = YES;

		_clearsCookies = NO;

    }

    return self;

}

- (void)dealloc

{

    _delegate = nil;

    [[_connections allValues] makeObjectsPerformSelector:@selector(cancel)];

    [_connections release];

	[_accessToken release];

	[_consumer release];

    [_username release];

    [_password release];

    [_clientName release];

    [_clientVersion release];

    [_clientURL release];

    [_clientSourceToken release];

	[_APIDomain release];

    [super dealloc];

}

#pragma mark Configuration and Accessors

+ (NSString *)version

{

    // 1.0.0 = 22 Feb 2008

    // 1.0.1 = 26 Feb 2008

    // 1.0.2 = 04 Mar 2008

    // 1.0.3 = 04 Mar 2008

	// 1.0.4 = 11 Apr 2008

	// 1.0.5 = 06 Jun 2008

	// 1.0.6 = 05 Aug 2008

	// 1.0.7 = 28 Sep 2008

	// 1.0.8 = 01 Oct 2008

    return @"1.0.8";

}

- (NSString *)username

{

    return [[_username retain] autorelease];

}

- (NSString *)password

{

    return [[_password retain] autorelease];

}

- (void)setUsername:(NSString *)newUsername password:(NSString *)newPassword

{

    // Set new credentials.

    [_username release];

    _username = [newUsername retain];

    [_password release];

    _password = [newPassword retain];

	if ([self clearsCookies]) {

		// Remove all cookies for twitter, to ensure next connection uses new credentials.

		NSString *urlString = [NSString stringWithFormat:@"%@://%@", 

							   (_secureConnection) ? @"https" : @"http", 

							   _APIDomain];

		NSURL *url = [NSURL URLWithString:urlString];

		NSHTTPCookieStorage *cookieStorage = [NSHTTPCookieStorage sharedHTTPCookieStorage];

		NSEnumerator *enumerator = [[cookieStorage cookiesForURL:url] objectEnumerator];

		NSHTTPCookie *cookie = nil;

		while ((cookie = [enumerator nextObject])) {

			[cookieStorage deleteCookie:cookie];

		}

	}

}

- (NSString *)clientName

{

    return [[_clientName retain] autorelease];

}

- (NSString *)clientVersion

{

    return [[_clientVersion retain] autorelease];

}

- (NSString *)clientURL

{

    return [[_clientURL retain] autorelease];

}

- (NSString *)clientSourceToken

{

    return [[_clientSourceToken retain] autorelease];

}

- (void)setClientName:(NSString *)name version:(NSString *)version URL:(NSString *)url token:(NSString *)token;

{

    [_clientName release];

    _clientName = [name retain];

    [_clientVersion release];

    _clientVersion = [version retain];

    [_clientURL release];

    _clientURL = [url retain];

    [_clientSourceToken release];

    _clientSourceToken = [token retain];

}

- (NSString *)APIDomain

{

	return [[_APIDomain retain] autorelease];

}

- (void)setAPIDomain:(NSString *)domain

{

	[_APIDomain release];

	if (!domain || [domain length] == 0) {

		_APIDomain = [TWITTER_DOMAIN retain];

	} else {

		_APIDomain = [domain retain];

	}

}

- (BOOL)usesSecureConnection

{

    return _secureConnection;

}

- (void)setUsesSecureConnection:(BOOL)flag

{

    _secureConnection = flag;

}

- (BOOL)clearsCookies

{

	return _clearsCookies;

}

- (void)setClearsCookies:(BOOL)flag

{

	_clearsCookies = flag;

}

#pragma mark Connection methods

- (int)numberOfConnections

{

    return [_connections count];

}

- (NSArray *)connectionIdentifiers

{

    return [_connections allKeys];

}

- (void)closeConnection:(NSString *)identifier

{

    MGTwitterHTTPURLConnection *connection = [_connections objectForKey:identifier];

    if (connection) {

        [connection cancel];

        [_connections removeObjectForKey:identifier];

    }

}

- (void)closeAllConnections

{

    [[_connections allValues] makeObjectsPerformSelector:@selector(cancel)];

    [_connections removeAllObjects];

}

#pragma mark Utility methods

- (NSDateFormatter *)_HTTPDateFormatter

{

    // Returns a formatter for dates in HTTP format (i.e. RFC 822, updated by RFC 1123).

    // e.g. "Sun, 06 Nov 1994 08:49:37 GMT"

	NSDateFormatter *dateFormatter = [[[NSDateFormatter alloc] init] autorelease];

	//[dateFormatter setDateFormat:@"%a, %d %b %Y %H:%M:%S GMT"]; // won't work with -init, which uses new (unicode) format behaviour.

	[dateFormatter setFormatterBehavior:NSDateFormatterBehavior10_4];

	[dateFormatter setDateFormat:@"EEE, dd MMM yyyy HH:mm:ss GMT"];

	return dateFormatter;

}

- (NSString *)_queryStringWithBase:(NSString *)base parameters:(NSDictionary *)params prefixed:(BOOL)prefixed

{

    // Append base if specified.

    NSMutableString *str = [NSMutableString stringWithCapacity:0];

    if (base) {

        [str appendString:base];

    }

    // Append each name-value pair.

    if (params) {

        int i;

        NSArray *names = [params allKeys];

        for (i = 0; i < [names count]; i++) {

            if (i == 0 && prefixed) {

                [str appendString:@"?"];

            } else if (i > 0) {

                [str appendString:@"&"];

            }

            NSString *name = [names objectAtIndex:i];

            [str appendString:[NSString stringWithFormat:@"%@=%@", 

             name, [self _encodeString:[params objectForKey:name]]]];

        }

    }

    return str;

}

- (NSDate *)_HTTPToDate:(NSString *)httpDate

{

    NSDateFormatter *dateFormatter = [self _HTTPDateFormatter];

    return [dateFormatter dateFromString:httpDate];

}

- (NSString *)_dateToHTTP:(NSDate *)date

{

    NSDateFormatter *dateFormatter = [self _HTTPDateFormatter];

    return [dateFormatter stringFromDate:date];

}

- (NSString *)_encodeString:(NSString *)string

{

    NSString *result = (NSString *)CFURLCreateStringByAddingPercentEscapes(NULL, 

                                                                 (CFStringRef)string, 

                                                                 NULL, 

                                                                 (CFStringRef)@";/?:@&=$+{}<>,",

                                                                 kCFStringEncodingUTF8);

    return [result autorelease];

}

- (NSString *)getImageAtURL:(NSString *)urlString

{

    // This is a method implemented for the convenience of the client, 

    // allowing asynchronous downloading of users' Twitter profile images.

	NSString *encodedUrlString = [urlString stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];

    NSURL *url = [NSURL URLWithString:encodedUrlString];

    if (!url) {

        return nil;

    }

    // Construct an NSMutableURLRequest for the URL and set appropriate request method.

    NSMutableURLRequest *theRequest = [NSMutableURLRequest requestWithURL:url 

                                                              cachePolicy:NSURLRequestReloadIgnoringCacheData 

                                                          timeoutInterval:URL_REQUEST_TIMEOUT];

    // Create a connection using this request, with the default timeout and caching policy, 

    // and appropriate Twitter request and response types for parsing and error reporting.

    MGTwitterHTTPURLConnection *connection;

    connection = [[MGTwitterHTTPURLConnection alloc] initWithRequest:theRequest 

                                                            delegate:self 

                                                         requestType:MGTwitterImageRequest 

                                                        responseType:MGTwitterImage];

    if (!connection) {

        return nil;

    } else {

        [_connections setObject:connection forKey:[connection identifier]];

        [connection release];

    }

    return [connection identifier];

}

#pragma mark Request sending methods

#define SET_AUTHORIZATION_IN_HEADER 1

/* See Adium Additions/Changes below—oauth support */

#if 0

- (NSString *)_sendRequestWithMethod:(NSString *)method 

                                path:(NSString *)path 

                     queryParameters:(NSDictionary *)params 

                                body:(id)body 

                         requestType:(MGTwitterRequestType)requestType 

                        responseType:(MGTwitterResponseType)responseType

{

    // Construct appropriate URL string.

    NSString *fullPath = path;

    if (params) {

        fullPath = [self _queryStringWithBase:fullPath parameters:params prefixed:YES];

    }

#if SET_AUTHORIZATION_IN_HEADER

    NSString *urlString = [NSString stringWithFormat:@"%@://%@/%@", 

                           (_secureConnection) ? @"https" : @"http",

                           _APIDomain, fullPath];

#else    

    NSString *urlString = [NSString stringWithFormat:@"%@://%@:%@@%@/%@", 

                           (_secureConnection) ? @"https" : @"http", 

                           [self _encodeString:_username], [self _encodeString:_password], 

                           _APIDomain, fullPath];

#endif

    NSURL *finalURL = [NSURL URLWithString:urlString];

    if (!finalURL) {

        return nil;

    }

    // Construct an NSMutableURLRequest for the URL and set appropriate request method.

    NSMutableURLRequest *theRequest = [NSMutableURLRequest requestWithURL:finalURL 

                                                              cachePolicy:NSURLRequestReloadIgnoringCacheData 

                                                          timeoutInterval:URL_REQUEST_TIMEOUT];

	if(method && [method isEqualToString:HTTP_MULTIPART_METHOD]) {

		method = HTTP_POST_METHOD;

		[theRequest setValue:[NSString stringWithFormat:@"multipart/form-data; boundary=%@", MULTIPART_FORM_BOUNDARY] forHTTPHeaderField:@"Content-type"];

	}

    if (method) {

        [theRequest setHTTPMethod:method];

    }

    [theRequest setHTTPShouldHandleCookies:NO];

    // Set headers for client information, for tracking purposes at Twitter.

    [theRequest setValue:_clientName    forHTTPHeaderField:@"X-Twitter-Client"];

    [theRequest setValue:_clientVersion forHTTPHeaderField:@"X-Twitter-Client-Version"];

    [theRequest setValue:_clientURL     forHTTPHeaderField:@"X-Twitter-Client-URL"];

#if SET_AUTHORIZATION_IN_HEADER

	if ([self username] && [self password]) {

		// Set header for HTTP Basic authentication explicitly, to avoid problems with proxies and other intermediaries

		NSString *authStr = [NSString stringWithFormat:@"%@:%@", [self username], [self password]];

		NSData *authData = [authStr dataUsingEncoding:NSASCIIStringEncoding];

		NSString *authValue = [NSString stringWithFormat:@"Basic %@", [authData base64EncodingWithLineLength:80]];

		[theRequest setValue:authValue forHTTPHeaderField:@"Authorization"];

	}

#endif

    // Set the request body if this is a POST request.

    BOOL isPOST = (method && [method isEqualToString:HTTP_POST_METHOD]);

    if (isPOST) {

        // Set request body, if specified (hopefully so), with 'source' parameter if appropriate.

		if([body isKindOfClass:[NSString class]]) {

			NSString *finalBody = @"";

			if (body) {

				finalBody = [finalBody stringByAppendingString:body];

			}

			if (_clientSourceToken) {

				finalBody = [finalBody stringByAppendingString:[NSString stringWithFormat:@"%@source=%@", 

																(body) ? @"&" : @"?" , 

																_clientSourceToken]];

			}

			if (finalBody) {

				[theRequest setHTTPBody:[finalBody dataUsingEncoding:NSUTF8StringEncoding]];

			}

		} else if ([body isKindOfClass:[NSData class]]) {

			[theRequest setHTTPBody:body];

		}

    }

    // Create a connection using this request, with the default timeout and caching policy, 

    // and appropriate Twitter request and response types for parsing and error reporting.

    MGTwitterHTTPURLConnection *connection;

    connection = [[MGTwitterHTTPURLConnection alloc] initWithRequest:theRequest 

                                                            delegate:self 

                                                         requestType:requestType 

                                                        responseType:responseType];

    if (!connection) {

        return nil;

    } else {

        [_connections setObject:connection forKey:[connection identifier]];

        [connection release];

    }

    return [connection identifier];

}

#endif

#pragma mark Parsing methods

- (void)_parseXMLForConnection:(MGTwitterHTTPURLConnection *)connection

{

    NSString *identifier = [[[connection identifier] copy] autorelease];

    NSData *xmlData = [[[connection data] copy] autorelease];

    MGTwitterRequestType requestType = [connection requestType];

    MGTwitterResponseType responseType = [connection responseType];

#if USE_LIBXML

	NSURL *URL = [connection URL];

    switch (responseType) {

        case MGTwitterStatuses:

        case MGTwitterStatus:

            [MGTwitterStatusesLibXMLParser parserWithXML:xmlData delegate:self 

                              connectionIdentifier:identifier requestType:requestType 

                                      responseType:responseType URL:URL];

            break;

        case MGTwitterUsers:

        case MGTwitterUser:

            [MGTwitterUsersLibXMLParser parserWithXML:xmlData delegate:self 

                           connectionIdentifier:identifier requestType:requestType 

                                   responseType:responseType URL:URL];

            break;

        case MGTwitterDirectMessages:

        case MGTwitterDirectMessage:

            [MGTwitterMessagesLibXMLParser parserWithXML:xmlData delegate:self 

                              connectionIdentifier:identifier requestType:requestType 

                                      responseType:responseType URL:URL];

            break;

		case MGTwitterMiscellaneous:

			[MGTwitterMiscLibXMLParser parserWithXML:xmlData delegate:self 

						  connectionIdentifier:identifier requestType:requestType 

								  responseType:responseType URL:URL];

			break;

        default:

            break;

    }

#else

    // Determine which type of parser to use.

    switch (responseType) {

        case MGTwitterStatuses:

        case MGTwitterStatus:

            [MGTwitterStatusesParser parserWithXML:xmlData delegate:self 

                              connectionIdentifier:identifier requestType:requestType 

                                      responseType:responseType];

            break;

        case MGTwitterUsers:

        case MGTwitterUser:

            [MGTwitterUsersParser parserWithXML:xmlData delegate:self 

                           connectionIdentifier:identifier requestType:requestType 

                                   responseType:responseType];

            break;

        case MGTwitterDirectMessages:

        case MGTwitterDirectMessage:

            [MGTwitterMessagesParser parserWithXML:xmlData delegate:self 

                              connectionIdentifier:identifier requestType:requestType 

                                      responseType:responseType];

            break;

		case MGTwitterMiscellaneous:

			[MGTwitterMiscParser parserWithXML:xmlData delegate:self 

						  connectionIdentifier:identifier requestType:requestType 

								  responseType:responseType];

			break;

        default:

            break;

    }

#endif

}

#pragma mark Delegate methods

- (BOOL) _isValidDelegateForSelector:(SEL)selector

{

	return ((_delegate != nil) && [_delegate respondsToSelector:selector]);

}

#pragma mark MGTwitterParserDelegate methods

- (void)parsingSucceededForRequest:(NSString *)identifier 

                    ofResponseType:(MGTwitterResponseType)responseType 

                 withParsedObjects:(NSArray *)parsedObjects

{

    // Forward appropriate message to _delegate, depending on responseType.

    switch (responseType) {

        case MGTwitterStatuses:

        case MGTwitterStatus:

			if ([self _isValidDelegateForSelector:@selector(statusesReceived:forRequest:)])

				[_delegate statusesReceived:parsedObjects forRequest:identifier];

            break;

        case MGTwitterUsers:

        case MGTwitterUser:

			if ([self _isValidDelegateForSelector:@selector(userInfoReceived:forRequest:)])

				[_delegate userInfoReceived:parsedObjects forRequest:identifier];

            break;

        case MGTwitterDirectMessages:

        case MGTwitterDirectMessage:

			if ([self _isValidDelegateForSelector:@selector(directMessagesReceived:forRequest:)])

				[_delegate directMessagesReceived:parsedObjects forRequest:identifier];

            break;

		case MGTwitterMiscellaneous:

			if ([self _isValidDelegateForSelector:@selector(miscInfoReceived:forRequest:)])

				[_delegate miscInfoReceived:parsedObjects forRequest:identifier];

			break;

        default:

            break;

    }

}

- (void)parsingFailedForRequest:(NSString *)requestIdentifier 

                 ofResponseType:(MGTwitterResponseType)responseType 

                      withError:(NSError *)error

{

	if ([self _isValidDelegateForSelector:@selector(requestFailed:withError:)])

		[_delegate requestFailed:requestIdentifier withError:error];

}

#pragma mark NSURLConnection delegate methods

- (void)connection:(NSURLConnection *)connection didReceiveAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge

{

	if ([challenge previousFailureCount] == 0 && ![challenge proposedCredential] && !_useOAuth && _password && _username) {

		NSURLCredential *credential = [NSURLCredential credentialWithUser:_username password:_password 

															  persistence:NSURLCredentialPersistenceForSession];

		[[challenge sender] useCredential:credential forAuthenticationChallenge:challenge];

	} else {

		[[challenge sender] continueWithoutCredentialForAuthenticationChallenge:challenge];

	}

}

- (void)connection:(MGTwitterHTTPURLConnection *)connection didReceiveResponse:(NSURLResponse *)response

{

    // This method is called when the server has determined that it has enough information to create the NSURLResponse.

    // it can be called multiple times, for example in the case of a redirect, so each time we reset the data.

    [connection resetDataLength];

    // Get response code.

    NSHTTPURLResponse *resp = (NSHTTPURLResponse *)response;

    int statusCode = [resp statusCode];

    if (statusCode >= 400) {

        // Assume failure, and report to delegate.

        NSError *error = [NSError errorWithDomain:@"HTTP" code:statusCode userInfo:nil];

		if ([self _isValidDelegateForSelector:@selector(requestFailed:withError:)])

			[_delegate requestFailed:[connection identifier] withError:error];

        // Destroy the connection.

        [connection cancel];

        [_connections removeObjectForKey:[connection identifier]];

    } else if (statusCode == 304 || [connection responseType] == MGTwitterGeneric) {

        // Not modified, or generic success.

		if ([self _isValidDelegateForSelector:@selector(requestSucceeded:)])

			[_delegate requestSucceeded:[connection identifier]];

        if (statusCode == 304) {

            [self parsingSucceededForRequest:[connection identifier] 

                              ofResponseType:[connection responseType] 

                           withParsedObjects:[NSArray array]];

        }

        // Destroy the connection.

        [connection cancel];

        [_connections removeObjectForKey:[connection identifier]];

    }

    if (NO) {

        // Display headers for debugging.

        NSHTTPURLResponse *resp = (NSHTTPURLResponse *)response;

        NSLog(@"(%d) [%@]:\r%@", 

              [resp statusCode], 

              [NSHTTPURLResponse localizedStringForStatusCode:[resp statusCode]], 

              [resp allHeaderFields]);

    }

}

- (void)connection:(MGTwitterHTTPURLConnection *)connection didReceiveData:(NSData *)data

{

    // Append the new data to the receivedData.

    [connection appendData:data];

}

- (void)connection:(MGTwitterHTTPURLConnection *)connection didFailWithError:(NSError *)error

{

    // Inform delegate.

	if ([self _isValidDelegateForSelector:@selector(requestFailed:withError:)])

		[_delegate requestFailed:[connection identifier] withError:error];

    // Release the connection.

    [_connections removeObjectForKey:[connection identifier]];

}

- (void)connectionDidFinishLoading:(MGTwitterHTTPURLConnection *)connection

{

    // Inform delegate.

	if ([self _isValidDelegateForSelector:@selector(requestSucceeded:)])

		[_delegate requestSucceeded:[connection identifier]];

    NSData *receivedData = [connection data];

    if (receivedData) {

        if (NO) {

            // Dump data as string for debugging.

            NSString *dataString = [NSString stringWithUTF8String:[receivedData bytes]];

            NSLog(@"Succeeded! Received %d bytes of data:\r\r%@", [receivedData length], dataString);

        }

        if (NO) {

            // Dump XML to file for debugging.

            NSString *dataString = [NSString stringWithUTF8String:[receivedData bytes]];

            [dataString writeToFile:[@"~/Desktop/twitter_messages.xml" stringByExpandingTildeInPath] 

                         atomically:NO encoding:NSUnicodeStringEncoding error:NULL];

        }

        if ([connection responseType] == MGTwitterImage) {

			// Create image from data.

#if TARGET_OS_IPHONE

            UIImage *image = [[[UIImage alloc] initWithData:[connection data]] autorelease];

#else

            NSImage *image = [[[NSImage alloc] initWithData:[connection data]] autorelease];