//
//  APIClient.m
//  Juick
//
//  Created by Vitaly Takmazov on 22/08/16.
//  Copyright © 2016 com.juick. All rights reserved.
//
#import "APIClient.h"
#import "Message.h"
#import "Chat.h"

@interface APIClient ()
@property(nonatomic, strong) NSOperationQueue *backgroundQueue;
@property(nonatomic, strong) NSURL *baseURL;
@property(nonatomic, strong) NSURLSession *urlSession;
@property(nonatomic, strong) NSURLProtectionSpace *apiProtectionSpace;
-(void) get:(NSString *)path params:(NSDictionary *)params callback:(void(^)(NSDictionary *, NSError *))callback;
@end

@implementation APIClient

@synthesize credential = _credential;

+(APIClient *) sharedClient {
    static APIClient *sharedAPIClient = nil;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        sharedAPIClient = [[self alloc] init];
    });
    return sharedAPIClient;
}

-(id)init {
    if (self = [super init]) {
        NSString *baseURLString = [[NSBundle mainBundle] objectForInfoDictionaryKey:@"base_url"];
        NSLog(@"Initializing with %@ base URL", baseURLString);
        self.baseURL = [NSURL URLWithString:baseURLString];
        self.apiProtectionSpace = [[NSURLProtectionSpace alloc] initWithHost:self.baseURL.host port:0 protocol:NSURLProtectionSpaceHTTPS realm:@"Juick" authenticationMethod:NSURLAuthenticationMethodHTTPBasic];
        self.backgroundQueue = [NSOperationQueue new];
        self.urlSession = [NSURLSession sessionWithConfiguration:[NSURLSessionConfiguration defaultSessionConfiguration] delegate:self delegateQueue:self.backgroundQueue];
        
        self.dateFormatter = [[NSDateFormatter alloc] init];
        self.dateFormatter.dateFormat = @"yyyy-MM-dd HH:mm:ss";
        [self.dateFormatter setTimeZone:[NSTimeZone timeZoneWithName:@"UTC"]];
    }
    return self;
}

-(void) pullNextFromPath:(NSString *)path  params:(NSDictionary *) params callback:(void(^)(NSArray<Message *> *, NSError *))callback {
    [self get:path params:params callback:^(NSDictionary *response, NSError *error) {
        NSMutableArray *messages = [NSMutableArray new];
        if (!error) {
            [((NSArray *)response) enumerateObjectsUsingBlock:^(id  _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
                [messages addObject:[Message fromJSON:obj]];
            }];
        }
        callback(messages, error);
    }];
}

-(void) postMessage:(NSString *)text result:(void (^)(Message *, NSError *))callback {
    [self post:@"post" params:@{
        @"body": text
    } callback:^(NSDictionary *response, NSError *err) {
        Message *result;
        if (!err) {
            result = [Message fromJSON:response[@"newMessage"]];
        }
        callback(result, err);
    }];
}

-(void) postReplyToThread:(NSNumber *)mid inReplyTo:(NSNumber *)rid text:(NSString *)text result:(void(^)(Message *, NSError *))callback {
    [self post:@"comment" params:@{
        @"mid": mid,
        @"rid": [NSString stringWithFormat:@"%ld", [rid integerValue]],
        @"body": text
    } callback:^(NSDictionary *response, NSError *err) {
        Message *reply;
        if (!err) {
            NSLog(@"Success!");
            reply = [Message fromJSON:response];
        }
        callback(reply, err);
    }];
}

-(void) postPMToUser:(NSString *)uname text:(NSString *)text result:(void (^)(NSError *))callback {
    [self.backgroundQueue addOperationWithBlock:^{
        [self post:@"pm" params:@{
            @"uname": uname,
            @"body": text
        } callback:^(NSDictionary *response, NSError *err) {
            callback(err);
        }];
    }];
}

-(void) fetchChats:(void (^)(NSArray *, NSError *))callback {
    [self get:@"groups_pms" params:nil callback:^(NSDictionary *response, NSError *err) {
        NSMutableArray *groups = [NSMutableArray new];
        NSArray *pms = [response objectForKey:@"pms"];
        [pms enumerateObjectsUsingBlock:^(id  _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
            [groups addObject:[Chat fromJSON:obj]];
        }];
        callback(groups, err);
    }];
}

-(void) fetchChatWithUser:(NSString *)uname callback:(void (^)(NSArray *, NSError *))callback {
    NSDictionary *params = @{@"uname": uname};
    [self get:@"pm" params:params callback:^(NSDictionary *response, NSError *err) {
        NSMutableArray *messages = [NSMutableArray new];
        if (!err) {
            NSArray *messagesList = (NSArray *)response;
            [messagesList enumerateObjectsUsingBlock:^(id  _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
                [messages addObject:[Message fromJSON:obj]];
            }];
        }
        callback(messages, err);
    }];
}
 
-(void) authenticate:(void (^)(User *user, NSError *error))callback {
    [self get:@"me" params:nil callback:^(NSDictionary *response, NSError *error) {
        User *user;
        if (!error) {
            user = [User fromJSON:response];
        }
        callback(user, error);
    }];
}

-(void) getUserByName:(NSString *) name callback:(void(^)(User *))callback {
    NSDictionary *params = @{@"uname": name};
    [self get:@"users" params:params callback:^(NSDictionary *response, NSError *err) {
        if (!err) {
            callback([User fromJSON:[(NSArray *)response firstObject]]);
        } else {
            callback(nil);
        }
    }];
}

-(void) refreshDeviceRegistration:(DeviceRegistration *)registrationData callback:(void (^)(BOOL))callback {
    NSURL *notificationsUrl = [NSURL URLWithString:@"notifications" relativeToURL:self.baseURL];
    NSError *error;
    NSDictionary *token = [registrationData toJSON];
    NSData *jsonData = [NSJSONSerialization dataWithJSONObject:@[token] options:kNilOptions error:&error];
    [self fetchDataWithURL:notificationsUrl data:jsonData boundary:nil callback:^(NSData *response, NSError *err) {
        callback(!err);
    }];
}


- (NSURLCredential *)credential {
    NSDictionary *credentials = [[NSURLCredentialStorage sharedCredentialStorage] credentialsForProtectionSpace:self.apiProtectionSpace];
    return [credentials.objectEnumerator nextObject];
}

- (void)setCredential:(NSURLCredential *)credential {
    if (credential) {
        [[NSURLCredentialStorage sharedCredentialStorage] removeCredential:_credential forProtectionSpace:self.apiProtectionSpace options:@{NSURLCredentialStorageRemoveSynchronizableCredentials:@YES}];
        [[NSURLCredentialStorage sharedCredentialStorage] setCredential:credential forProtectionSpace:self.apiProtectionSpace];
    } else {
        [[NSURLCredentialStorage sharedCredentialStorage] removeCredential:_credential forProtectionSpace:self.apiProtectionSpace];
    }
}


-(BOOL) isAuthenticated {
    NSString *password = self.credential.password;
    return password != nil;
}

- (void)URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task didReceiveChallenge:(NSURLAuthenticationChallenge *)challenge completionHandler:(void (^)(NSURLSessionAuthChallengeDisposition, NSURLCredential * _Nullable))completionHandler {
    if (challenge.protectionSpace.authenticationMethod == NSURLAuthenticationMethodHTTPBasic) {
        if (self.isAuthenticated) {
            completionHandler(NSURLSessionAuthChallengeUseCredential, self.credential);
            return;
        }
    }
    completionHandler(NSURLSessionAuthChallengePerformDefaultHandling, nil);
}

-(void) fetchDataWithURL:(NSURL *) url data:(NSData *)postData boundary:(NSString *)boundary callback:(void(^)(NSData *, NSError *))callback {
    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
    if (boundary) {
        request.HTTPMethod = @"POST";
        request.HTTPBody = postData;
        NSString *contentType = [NSString stringWithFormat:@"multipart/form-data; boundary=%@", boundary];
        [request setValue:contentType forHTTPHeaderField: @"Content-Type"];
    } else if (postData) {
        request.HTTPMethod = @"PUT";
        request.HTTPBody = postData;
        [request setValue:@"application/json" forHTTPHeaderField: @"Content-Type"];
    } else {
        request.HTTPMethod = @"GET";
    }
    
    NSURLSessionDataTask *task = [self.urlSession dataTaskWithRequest:request completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {
        NSInteger statusCode = ((NSHTTPURLResponse *)response).statusCode;
        if (!response || statusCode != 200) {
            NSError *err = [NSError errorWithDomain:@"JuickErrorDomain"
                                               code:statusCode
                                           userInfo:nil];
            [[NSOperationQueue mainQueue] addOperationWithBlock:^{
                callback(nil, err);
            }];
        } else {
            [[NSOperationQueue mainQueue] addOperationWithBlock:^{
                callback(data, error);
            }];
        }
    }];
    [self.backgroundQueue addOperationWithBlock:^{
        [task resume];
    }];
}

-(NSURL *) url:(NSURL *)url withParameters:(NSDictionary *)params {
    NSURLComponents *parametersUrl = [NSURLComponents componentsWithURL:url resolvingAgainstBaseURL:YES];
    NSMutableArray *items = [NSMutableArray array];
    for (NSString * key in params) {
        NSString *value = [NSString stringWithFormat:@"%@", params[key]];
        [items addObject:[NSURLQueryItem queryItemWithName:key value:value]];
    }
    [parametersUrl setQueryItems:items];
    return [parametersUrl URL];
}

-(NSData *) multipartData:(NSDictionary *)params withBoundary:(NSString *)boundary {
    NSMutableData *body = [NSMutableData data];
    for (NSString *key in params) {
        [body appendData:[[NSString stringWithFormat:@"--%@\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];
        [body appendData:[[NSString stringWithFormat:@"Content-Disposition: form-data; name=%@\r\n\r\n", key] dataUsingEncoding:NSUTF8StringEncoding]];
        [body appendData:[[NSString stringWithFormat:@"%@\r\n", params[key]] dataUsingEncoding:NSUTF8StringEncoding]];
    }
    [body appendData:[[NSString stringWithFormat:@"--%@--", boundary] dataUsingEncoding:NSUTF8StringEncoding]];
    return body;
}

-(void) get:(NSString *) path params:(NSDictionary *)params callback:(void(^)(NSDictionary *, NSError *))callback {
    NSURL *url = [NSURL URLWithString:path relativeToURL:self.baseURL];
    NSURL *requestUrl = params ? [self url:url withParameters:params] : url;
    [self fetchDataWithURL:requestUrl data:nil boundary:nil callback:^(NSData *data, NSError *err) {
        if (err) {
            callback(nil, err);
        } else {
            NSError *jsonError;
            NSDictionary *jsonData = [NSJSONSerialization JSONObjectWithData:data options:0 error:&jsonError];
            if (jsonError) {
                callback(nil, jsonError);
            } else {
                callback(jsonData, nil);
            }
        }
    }];
}

-(void) post:(NSString *) path params:(NSDictionary *)params callback:(void(^)(NSDictionary *, NSError *))callback {
    NSURL *url = [NSURL URLWithString:path relativeToURL:self.baseURL];
    NSString *boundary = [NSString stringWithFormat:@"Boundary-%@", [[NSUUID UUID] UUIDString]];
    [self fetchDataWithURL:url data:[self multipartData:params withBoundary:boundary] boundary:boundary callback:^(NSData *data, NSError *err) {
        if (!err) {
            NSError *jsonError;
            NSDictionary *jsonData = [NSJSONSerialization JSONObjectWithData:data options:0 error:&jsonError];
            if (jsonError) {
                callback(nil, jsonError);
            } else {
                callback(jsonData, nil);
            }
        } else {
            callback(nil, err);
        }
    }];
}

-(void) fetchImageWithURL:(NSURL *) url callback:(void(^)(NSData *))callback {
    [self fetchDataWithURL:url data:nil boundary:nil callback:^(NSData *data, NSError *err) {
        if (err) {
            callback(nil);
        } else {
            callback(data);
        }
    }];
}

+(NSString *) messagesUrl {
    return @"messages";
}

+(NSString *) discussionsUrl {
    return @"messages/discussions";
}

+(NSString *) threadUrl {
    return @"thread";
}

+(NSString *) feedUrl {
    return @"home";
}

@end