//
//  DropboxV2ObjC.m
//  FMC Planner 2
//
//  Created by Kilian Hofmann on 29.03.16.
//  Copyright © 2016 Kilian Hofmann. All rights reserved.
//

#import "DropboxV2ObjC.h"

@implementation DropboxV2ObjC

- (DropboxV2ObjC *)init
{
    self = [super init];
    self.rootDirectory = @"";
    self.kJSONNullObject = [@"null" dataUsingEncoding:NSASCIIStringEncoding];
    self.kDropboxProtectionSpace =
        [[NSURLProtectionSpace alloc] initWithHost:@"dropbox"
                                              port:443
                                          protocol:@"HTTP"
                                             realm:nil
                              authenticationMethod:@"OAuth2"];
    return self;
}

#pragma mark - OAuth stuff
// TODO: Alert on error
- (BOOL)authorizeUserWithToke:(NSURL *)token completion:(void (^)(void))handler
{
    NSScanner *scan = [NSScanner scannerWithString:token.absoluteString];
    NSString *error = [[NSString alloc] init];
    [scan scanUpToString:@"&error=" intoString:&error];
    if (![error isEqualToString:token.absoluteString]) {
        handler();
        return false;
    }

    // No error, refine token
    NSString *tokenUnrefined = [[NSString alloc] init];
    scan = [NSScanner scannerWithString:token.absoluteString];
    [scan scanUpToString:@"&" intoString:&tokenUnrefined];
    NSString *tokenRefined = [tokenUnrefined substringFromIndex:21];
    _token = tokenRefined;
    NSURLCredential *credential = [NSURLCredential
        credentialWithUser:@"Dropbox"
                  password:_token
               persistence:NSURLCredentialPersistencePermanent];
    [[NSURLCredentialStorage sharedCredentialStorage]
             setCredential:credential
        forProtectionSpace:_kDropboxProtectionSpace];
    handler();
    return true;
}

// TODO: Alert on error
- (void)deauthorizeUser
{
    NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init];
    request.URL = [NSURL
        URLWithString:@"https://api.dropboxapi.com/1/disable_access_token"];
    [request addValue:[NSString stringWithFormat:@"Bearer %@", _token]
                          .precomposedStringWithCanonicalMapping
        forHTTPHeaderField:(@"Authorization")
                               .precomposedStringWithCanonicalMapping];
    [request addValue:(@"application/json")
                          .precomposedStringWithCanonicalMapping
        forHTTPHeaderField:(@"Content-Type")
                               .precomposedStringWithCanonicalMapping];
    request.HTTPMethod = @"POST";
    request.HTTPBody = _kJSONNullObject;

    [NSURLConnection
        sendAsynchronousRequest:request
                          queue:[[NSOperationQueue alloc] init]
              completionHandler:^(NSURLResponse *response, NSData *data,
                                  NSError *error) {
                  if ([[NSJSONSerialization JSONObjectWithData:data
                                                       options:0
                                                         error:nil]
                          isEqualToDictionary:@{}]) {
                      NSDictionary *credentials =
                          [[NSURLCredentialStorage sharedCredentialStorage]
                              credentialsForProtectionSpace:
                                  _kDropboxProtectionSpace];
                      NSURLCredential *credential =
                          [credentials.objectEnumerator nextObject];
                      [[NSURLCredentialStorage sharedCredentialStorage]
                            removeCredential:credential
                          forProtectionSpace:_kDropboxProtectionSpace];
                  }

              }];
}

#pragma mark - File and directory operations
/**
 * Pass nil as path for root dir
 * @return Content of directory at path or nil if error
 */
// !!!: Cannot be asynchronous
// TODO: Alert on error
- (NSArray *)contentsOfPath:(NSString *)path
{

    if (path == nil) {
        path = _rootDirectory;
    }
    else {
        path = [path
            stringByAppendingString:[NSString stringWithFormat:@"/%@", path]];
    }

    NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init];
    request.URL =
        [NSURL URLWithString:@"https://api.dropboxapi.com/2/files/list_folder"];
    [request addValue:[NSString stringWithFormat:@"Bearer %@", _token]
                          .precomposedStringWithCanonicalMapping
        forHTTPHeaderField:(@"Authorization")
                               .precomposedStringWithCanonicalMapping];
    [request addValue:(@"application/json")
                          .precomposedStringWithCanonicalMapping
        forHTTPHeaderField:(@"Content-Type")
                               .precomposedStringWithCanonicalMapping];
    request.HTTPMethod = @"POST";
    NSData *data = [NSJSONSerialization dataWithJSONObject:@{
        @"path" : path.precomposedStringWithCanonicalMapping
    }
                                                   options:0
                                                     error:nil];
    NSString *temp =
        [[NSString alloc] initWithData:data encoding:NSASCIIStringEncoding];
    temp = [temp stringByReplacingOccurrencesOfString:@"\\/" withString:@"/"];
    request.HTTPBody = [temp dataUsingEncoding:NSASCIIStringEncoding];
    NSURLResponse *response = nil;
    NSError *error = nil;
    id dataOut =
        [self parseJSON:[NSURLConnection sendSynchronousRequest:request
                                              returningResponse:&response
                                                          error:&error]];
    if ([dataOut isKindOfClass:[NSDictionary class]]) {
        return [dataOut valueForKey:@"entries"];
    }
    else {
        return nil;
    }
}

// TODO: Alert on error
- (void)downloadFromDropbox:(NSArray *)files
{
    NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init];
    request.URL = [NSURL
        URLWithString:@"https://content.dropboxapi.com/2/files/download"];
    [request addValue:[NSString stringWithFormat:@"Bearer %@", _token]
                          .precomposedStringWithCanonicalMapping
        forHTTPHeaderField:(@"Authorization")
                               .precomposedStringWithCanonicalMapping];
    [request addValue:(@"").precomposedStringWithCanonicalMapping
        forHTTPHeaderField:(@"Content-Type")];
    request.HTTPMethod = @"POST";
    request.HTTPBody = nil;

    // File Path
    for (NSString *string in files) {
        NSData *data = [NSJSONSerialization dataWithJSONObject:@{
            @"path" : [NSString stringWithFormat:@"/%@", string]
                          .precomposedStringWithCanonicalMapping
        }
                                                       options:0
                                                         error:nil];
        NSString *temp =
            [[NSString alloc] initWithData:data encoding:NSASCIIStringEncoding];
        temp =
            [temp stringByReplacingOccurrencesOfString:@"\\/" withString:@"/"];

        [request addValue:temp.precomposedStringWithCanonicalMapping
            forHTTPHeaderField:(@"Dropbox-API-Arg")
                                   .precomposedStringWithCanonicalMapping];

        [NSURLConnection
            sendAsynchronousRequest:request
                              queue:[[NSOperationQueue alloc] init]
                  completionHandler:^(NSURLResponse *response, NSData *data,
                                      NSError *error) {
                      if (error == nil) {
                          [data writeToFile:[SharedDeclerations
                                                savePathForFile:string]
                                 atomically:YES];
                      }

                  }];
    }
}

// TODO: Alert on error
- (void)uploadToDropbox:(NSArray *)files
{
    NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init];
    request.URL =
        [NSURL URLWithString:@"https://content.dropboxapi.com/2/files/upload"];
    [request addValue:[NSString stringWithFormat:@"Bearer %@", _token]
                          .precomposedStringWithCanonicalMapping
        forHTTPHeaderField:(@"Authorization")
                               .precomposedStringWithCanonicalMapping];
    [request addValue:(@"application/octet-stream")
                          .precomposedStringWithCanonicalMapping
        forHTTPHeaderField:(@"Content-Type")];
    request.HTTPMethod = @"POST";

    // File Path
    for (NSString *string in files) {
        NSData *data = [NSJSONSerialization dataWithJSONObject:@{
            @"path" : [NSString stringWithFormat:@"/%@", string]
                          .precomposedStringWithCanonicalMapping,
            @"mode" : @"overwrite".precomposedStringWithCanonicalMapping,
        }
                                                       options:0
                                                         error:nil];
        NSString *temp =
            [[NSString alloc] initWithData:data encoding:NSASCIIStringEncoding];
        temp =
            [temp stringByReplacingOccurrencesOfString:@"\\/" withString:@"/"];

        [request addValue:temp.precomposedStringWithCanonicalMapping
            forHTTPHeaderField:(@"Dropbox-API-Arg")
                                   .precomposedStringWithCanonicalMapping];

        request.HTTPBody = [NSData
            dataWithContentsOfFile:[SharedDeclerations savePathForFile:string]];

        [NSURLConnection
            sendAsynchronousRequest:request
                              queue:[[NSOperationQueue alloc] init]
                  completionHandler:^(NSURLResponse *response, NSData *data,
                                      NSError *error){
                  }];
    }
}

#pragma mark - Other operations

// !!!: Cannot be asynchronous
// TODO: Alert on error
- (NSDictionary *)getUserInfo
{
    NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init];
    request.URL =
        [NSURL URLWithString:
                   @"https://api.dropboxapi.com/2/users/get_current_account"];
    [request addValue:[NSString stringWithFormat:@"Bearer %@", _token]
                          .precomposedStringWithCanonicalMapping
        forHTTPHeaderField:(@"Authorization")
                               .precomposedStringWithCanonicalMapping];
    [request addValue:(@"application/json")
                          .precomposedStringWithCanonicalMapping
        forHTTPHeaderField:(@"Content-Type")
                               .precomposedStringWithCanonicalMapping];
    request.HTTPMethod = @"POST";
    request.HTTPBody = _kJSONNullObject;

    NSURLResponse *response = nil;
    NSError *error = nil;
    id data = [self parseJSON:[NSURLConnection sendSynchronousRequest:request
                                                    returningResponse:&response
                                                                error:&error]];
    if ([data isKindOfClass:[NSDictionary class]]) {
        return data;
    }
    else {
        return nil;
    }
}

#pragma mark - Helper methods

- (id)parseJSON:(NSData *)data
{
    NSError *error = nil;
    id object =
        [NSJSONSerialization JSONObjectWithData:data options:0 error:&error];
    if (error == nil) {
        return object;
    }
    else {
        return
            [[NSString alloc] initWithData:data encoding:NSASCIIStringEncoding];
    }
}

@end