//
//  P4NetworkOperation.m
//  Perforce
//
//  Created by Adam Czubernat on 08/01/2014.
//  Copyright (c) 2014 Perforce Software, Inc. All rights reserved.
//

#import "P4NetworkOperation.h"

@interface P4NetworkOperation () <NSURLConnectionDelegate> {
	// Internal state
	BOOL started, executing, finished, cancelled;

	void (^receive)(P4NetworkOperation *operation);
	void (^completion)(P4NetworkOperation *operation);
	
	NSString *MIMEType;
	NSDictionary *HTTPHeaders;
	NSInteger HTTPStatus;
}
- (void)cancelOperation;
- (void)completeOperation;
@end

@implementation P4NetworkOperation
@synthesize success, error;

#pragma mark - Overrides

- (void)start {
	started = YES;
	
	if ([self isCancelled]) {
		[self cancelOperation];
		return;
	}

	[self willChangeValueForKey:@"isExecuting"];
	executing = YES;
	[self didChangeValueForKey:@"isExecuting"];
		
	// Create connection
	connection = [[NSURLConnection alloc]
				  initWithRequest:request
				  delegate:self
				  startImmediately:NO];
	
	data = [[NSMutableData alloc] init];
	
	// Force runloop for events passing
	[connection scheduleInRunLoop:[NSRunLoop mainRunLoop] forMode:NSRunLoopCommonModes];
	[connection start];
}

- (void)cancel {
	[super cancel];
	[self cancelOperation];
}

- (BOOL)isConcurrent {
	return YES;
}

- (BOOL)isExecuting {
    return executing;
}

- (BOOL)isFinished {
    return finished;
}

- (void)dealloc {
	PSLogm(@"");
}

#pragma mark - Public

+ (P4NetworkOperation *)operation {
	return [[P4NetworkOperation alloc] init];
}

+ (P4NetworkOperation *)operationWithRequest:(NSURLRequest *)urlRequest receive:(P4NetworkBlock_t)receive completion:(P4NetworkBlock_t)completion {
	P4NetworkOperation *operation = [[P4NetworkOperation alloc] init];
	[operation setRequest:urlRequest receive:receive completion:completion];
	return operation;
}

+ (P4NetworkOperation *)operationWithUrl:(NSString *)url HTTPMethod:(NSString *)method HTTPHeaders:(NSDictionary *)headers HTTPBody:(NSData *)body receive:(P4NetworkBlock_t)receive completion:(P4NetworkBlock_t)completion {

	NSMutableURLRequest *request;
	request = [NSMutableURLRequest
			   requestWithURL:[NSURL URLWithString:url]
			   cachePolicy:NSURLRequestReloadIgnoringCacheData
			   timeoutInterval:60.0f];
	
	[request setHTTPShouldHandleCookies:YES];
	[request setHTTPMethod:method];
	[request setHTTPBody:body];
	
	// Add headers to request
	for (NSString *field in headers)
		[request setValue:[headers objectForKey:field] forHTTPHeaderField:field];

	// Add length header
	[request
	 setValue:[NSString stringWithFormat:@"%ld", [body length]]
	 forHTTPHeaderField:@"Content-Length"];
	
	P4NetworkOperation *operation = [[P4NetworkOperation alloc] init];
	[operation setRequest:request receive:receive completion:completion];
	
	return operation;
}

- (NSData *)data { return data; }

- (NSString *)MIMEType { return MIMEType; }

- (NSDictionary *)HTTPHeaders { return HTTPHeaders; }

- (NSInteger)HTTPStatus { return HTTPStatus; }

- (NSDate *)HTTPDate {

	static NSDateFormatter *formatter;
	if (!formatter) {
		formatter = [[NSDateFormatter alloc] init];
		NSLocale *locale = [[NSLocale alloc] initWithLocaleIdentifier:@"en_US"];
		[formatter setLocale:locale];
		[formatter setDateFormat:@"EEE, d MMM y HH:mm:ss ZZZ"];
	}

	NSString *stringDate = [HTTPHeaders objectForKey:@"Date"];
	if (!stringDate)
		return nil;
	
	return [formatter dateFromString:stringDate];
}

- (NSURLResponse *)HTTPResponse { return HTTPResponse; }

- (CGFloat)progress { return progress; }

- (long)completed { return completed; }

- (long)length { return length; }

- (NSURLRequest *)request {
	return request;
}

- (void)setRequest:(NSURLRequest *)urlRequest receive:(P4NetworkBlock_t)onReceive completion:(P4NetworkBlock_t)onCompletion {
	
	// Don't create new request if connection is already running
	if (executing)
		return;
	
	// Copy passed request
	request = [urlRequest copy];
	
	// Copy passed blocks
	receive = [onReceive copy];			// Copy blocks from stack to heap, stack
	completion = [onCompletion copy];	// otherwise would be drained when calling
										// function returns.
	// Clear variables
	connection = nil;
	success = NO;
	error = nil;
	data = nil;
	MIMEType = nil;
	HTTPHeaders = nil;
    HTTPResponse = nil;
	HTTPStatus = 0;
	progress = 0.0f;
	completed = 0;
	length = 0;
}

#pragma mark - Private

- (void)cancelOperation {
	
	@synchronized(self) {
		if (cancelled)
			return;
		cancelled = YES;
	}
	
	[connection cancel];
	connection = nil;
	
	// Imitate error situation
	[self connection:nil didFailWithError:
	 [NSError errorWithDomain:NSCocoaErrorDomain code:NSUserCancelledError userInfo:nil]];
}

- (void)completeOperation {
	if (started)
		[self willChangeValueForKey:@"isFinished"];
    [self willChangeValueForKey:@"isExecuting"];
    executing = NO;
    finished = YES;
    [self didChangeValueForKey:@"isExecuting"];
	if (started)
		[self didChangeValueForKey:@"isFinished"];
	
	if (completion)
		completion(self);
}

#pragma mark - NSURLConnection delegate

- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)response {
	
	length = [response expectedContentLength];
	completed = 0;
	progress = 0.0f;

    HTTPResponse = (NSHTTPURLResponse *)response;
	MIMEType = [HTTPResponse MIMEType];
	HTTPHeaders = [HTTPResponse allHeaderFields];
	HTTPStatus = [HTTPResponse statusCode];
	
	if (receive)
		receive(self);
}

- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)receivedData {
	
//	if (outputFile)
//		data = receivedData; // Store new chunk of data
//	else
	[(NSMutableData *)data appendData:receivedData]; // Append new data
	
	// Add received bytecount into completedLength
	completed += receivedData.length;
	
	// Compute progress
	if (length == NSURLResponseUnknownLength)
		progress = 0.0;
	else
		progress = completed / (CGFloat) length;
	
	if (receive)
		receive(self);
}

- (void)connection:(NSURLConnection *)failedConnection didFailWithError:(NSError *)failError {
	connection = nil;
	success = NO;
	
	if (failError)
		error = failError;
	
	[self completeOperation];
}

- (void)connectionDidFinishLoading:(NSURLConnection *)finishedConnection {
	connection = nil;
	success = YES;

	if ((HTTPStatus >= 400 && HTTPStatus < 500) ||	// Client error
        (HTTPStatus >= 500 && HTTPStatus < 600)) {	// Server error		
		if (!error)
			error = [NSError errorWithDomain:NSCocoaErrorDomain code:HTTPStatus userInfo:@{
				  NSLocalizedDescriptionKey : [NSHTTPURLResponse localizedStringForStatusCode:HTTPStatus]
			}];
		success = NO;
	}
	
	[self completeOperation];
}

@end