//
//  Copyright (c) 2018 Open Whisper Systems. All rights reserved.
//

#import "OWSUploadOperation.h"
#import "MIMETypeUtil.h"
#import "NSError+MessageSending.h"
#import "NSNotificationCenter+OWS.h"
#import "OWSDispatch.h"
#import "OWSError.h"
#import "OWSOperation.h"
#import <PromiseKit/PromiseKit.h>
#import "SSKEnvironment.h"
#import "TSAttachmentStream.h"

#import <SignalCoreKit/Cryptography.h>
#import <YapDatabase/YapDatabaseConnection.h>
#import <SignalUtilitiesKit/SignalUtilitiesKit-Swift.h>

NS_ASSUME_NONNULL_BEGIN

NSString *const kAttachmentUploadProgressNotification = @"kAttachmentUploadProgressNotification";
NSString *const kAttachmentUploadProgressKey = @"kAttachmentUploadProgressKey";
NSString *const kAttachmentUploadAttachmentIDKey = @"kAttachmentUploadAttachmentIDKey";

// Use a slightly non-zero value to ensure that the progress
// indicator shows up as quickly as possible.
static const CGFloat kAttachmentUploadProgressTheta = 0.001f;

@interface OWSUploadOperation ()

@property (readonly, nonatomic) NSString *attachmentId;
@property (readonly, nonatomic) NSString *threadID;
@property (readonly, nonatomic) YapDatabaseConnection *dbConnection;

@end

#pragma mark -

@implementation OWSUploadOperation

- (instancetype)initWithAttachmentId:(NSString *)attachmentId
                            threadID:(NSString *)threadID
                        dbConnection:(YapDatabaseConnection *)dbConnection
{
    self = [super init];
    if (!self) {
        return self;
    }

    self.remainingRetries = 4;

    _attachmentId = attachmentId;
    _threadID = threadID;
    _dbConnection = dbConnection;

    return self;
}

- (void)run
{
    __block TSAttachmentStream *attachmentStream;
    [self.dbConnection readWithBlock:^(YapDatabaseReadTransaction *transaction) {
        attachmentStream = [TSAttachmentStream fetchObjectWithUniqueID:self.attachmentId transaction:transaction];
    }];

    if (!attachmentStream) {
        NSError *error = OWSErrorMakeFailedToSendOutgoingMessageError();
        // Not finding a local attachment is a terminal failure
        error.isRetryable = NO;
        [self reportError:error];
        return;
    }

    if (attachmentStream.isUploaded) {
        OWSLogDebug(@"Attachment previously uploaded.");
        [self reportSuccess];
        return;
    }
    
    [self fireNotificationWithProgress:0];
    
    SNOpenGroup *publicChat = [LKStorage.shared getOpenGroupForThreadID:self.threadID];
    NSString *server = (publicChat != nil) ? publicChat.server : SNFileServerAPI.server;
    
    [[SNFileServerAPI uploadAttachment:attachmentStream withID:self.attachmentId toServer:server]
    .thenOn(dispatch_get_main_queue(), ^() {
        [self reportSuccess];
    })
    .catchOn(dispatch_get_main_queue(), ^(NSError *error) {
        [self reportError:error];
    }) retainUntilComplete];
}

- (void)fireNotificationWithProgress:(CGFloat)aProgress
{
    NSNotificationCenter *notificationCenter = [NSNotificationCenter defaultCenter];

    CGFloat progress = MAX(kAttachmentUploadProgressTheta, aProgress);
    [notificationCenter postNotificationNameAsync:kAttachmentUploadProgressNotification
                                           object:nil
                                         userInfo:@{
                                             kAttachmentUploadProgressKey : @(progress),
                                             kAttachmentUploadAttachmentIDKey : self.attachmentId
                                         }];
}

@end

NS_ASSUME_NONNULL_END