//
//  OfflineFetchStories.m
//  NewsBlur
//
//  Created by Samuel Clay on 7/15/13.
//  Copyright (c) 2013 NewsBlur. All rights reserved.
//

#import "OfflineFetchStories.h"
#import "NewsBlurAppDelegate.h"
#import "FMDatabase.h"
#import "FMDatabaseAdditions.h"
#import "SBJson4.h"
#import "NSObject+SBJSON.h"
#import "NewsBlur-Swift.h"

@implementation OfflineFetchStories

@synthesize appDelegate;

- (void)main {
    dispatch_sync(dispatch_get_main_queue(), ^{
        self.appDelegate = [NewsBlurAppDelegate sharedAppDelegate];
    });

    while (YES) {
        BOOL fetched = [self fetchStories];
        if (!fetched) break;
    }
}

- (BOOL)fetchStories {
    if (self.isCancelled) {
        NSLog(@"FetchStories is canceled.");
        return NO;
    }
    
    
    BOOL offlineAllowed = [[[NSUserDefaults standardUserDefaults]
                            objectForKey:@"offline_allowed"] boolValue];
    if (!offlineAllowed ||
        ![self.appDelegate isReachableForOffline]) {
        dispatch_async(dispatch_get_main_queue(), ^{
            [self.appDelegate.feedsViewController showDoneNotifier];
            [self.appDelegate.feedsViewController hideNotifier];
        });
        return NO;
    }
    
    NSArray *hashes = [self unfetchedStoryHashes];
    
    if ([hashes count] == 0) {
//        NSLog(@"Finished downloading unread stories. %d total", appDelegate.totalUnfetchedStoryCount);
        dispatch_async(dispatch_get_main_queue(), ^{
//            [UIApplication sharedApplication].networkActivityIndicatorVisible = NO;
            
            if ([[NSUserDefaults standardUserDefaults] boolForKey:@"offline_text_download"]) {
                [self.appDelegate.feedsViewController showCachingNotifier:@"Text" progress:0 hoursBack:1];
                [self.appDelegate startOfflineFetchText];
            } else if ([[NSUserDefaults standardUserDefaults] boolForKey:@"offline_image_download"]) {
                [self.appDelegate.feedsViewController showCachingNotifier:@"Images" progress:0 hoursBack:1];
                [self.appDelegate startOfflineFetchImages];
            } else {
                [self.appDelegate.feedsViewController showDoneNotifier];
                [self.appDelegate.feedsViewController hideNotifier];
                [self.appDelegate finishBackground];
            }
        });
        return NO;
    }
    
    __block NSCondition *lock = [NSCondition new];

    [lock lock];
    NSString *urlString = [NSString stringWithFormat:@"%@/reader/river_stories?include_hidden=true&page=0&h=%@",
                           self.appDelegate.url, [hashes componentsJoinedByString:@"&h="]];
    AFHTTPSessionManager *manager = [AFHTTPSessionManager manager];
    manager.responseSerializer = [AFJSONResponseSerializer serializer];
    manager.completionQueue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0);
    
    [manager GET:urlString parameters:nil progress:nil success:^(NSURLSessionDataTask * _Nonnull task, id  _Nullable responseObject) {
        [self storeAllUnreadStories:responseObject withHashes:hashes];
        [lock signal];
    } failure:^(NSURLSessionDataTask * _Nullable task, NSError * _Nonnull error) {
        NSLog(@"Failed fetch all unreads: %@", error);
        [lock signal];
    }];
    
//    dispatch_async(dispatch_get_main_queue(), ^{
//        [UIApplication sharedApplication].networkActivityIndicatorVisible = YES;
//    });
    
    [lock waitUntilDate:[NSDate dateWithTimeIntervalSinceNow:30]];
    [lock unlock];
    
    return YES;
}

- (NSArray *)unfetchedStoryHashes {
    NSMutableArray *hashes = [NSMutableArray array];
    __weak __typeof(&*self)weakSelf = self;
    
    [appDelegate.database inTransaction:^(FMDatabase *db, BOOL *rollback) {
        __strong __typeof(&*weakSelf)strongSelf = weakSelf;
        if (!strongSelf) return;
        NSString *commonQuery = @"FROM unread_hashes u "
        "LEFT OUTER JOIN stories s ON (s.story_hash = u.story_hash) "
        "WHERE s.story_hash IS NULL";
        int count = [db intForQuery:[NSString stringWithFormat:@"SELECT COUNT(1) %@", commonQuery]];
        if (self.appDelegate.totalUnfetchedStoryCount == 0) {
            self.appDelegate.totalUnfetchedStoryCount = count;
            self.appDelegate.remainingUnfetchedStoryCount = self.appDelegate.totalUnfetchedStoryCount;
        } else {
            self.appDelegate.remainingUnfetchedStoryCount = count;
        }
        
        int limit = 100;
        NSString *order;
        if ([[[NSUserDefaults standardUserDefaults] objectForKey:@"default_order"] isEqualToString:@"oldest"]) {
            order = @"ASC";
        } else {
            order = @"DESC";
        }
        FMResultSet *cursor = [db executeQuery:[NSString stringWithFormat:@"SELECT u.story_hash %@ ORDER BY u.story_timestamp %@ LIMIT %d", commonQuery, order, limit]];
        
        while ([cursor next]) {
            [hashes addObject:[cursor objectForColumnName:@"story_hash"]];
        }
        
        [cursor close];
        [strongSelf updateProgress];
    }];
    
    return hashes;
}

- (void)updateProgress {
    if (self.isCancelled) return;
    
    NSInteger start = (int)[[NSDate date] timeIntervalSince1970];
    NSInteger end = appDelegate.latestFetchedStoryDate;
    NSInteger seconds = start - (end ? end : start);
    __block NSInteger hours = (int)round(seconds / 60.f / 60.f);
    
    __block float progress = 0.f;
    if (appDelegate.totalUnfetchedStoryCount) {
        progress = 1.f - ((float)appDelegate.remainingUnfetchedStoryCount /
                          (float)appDelegate.totalUnfetchedStoryCount);
    }
    __weak __typeof(&*self)weakSelf = self;
    dispatch_async(dispatch_get_main_queue(), ^{
//        NSLog(@"appDelegate.remainingUnfetchedStoryCount %d (%f)", appDelegate.remainingUnfetchedStoryCount, progress);
        __strong __typeof(&*weakSelf)strongSelf = weakSelf;
        if (!strongSelf) return;
        if (strongSelf.isCancelled) return;
        [self.appDelegate.feedsViewController showSyncingNotifier:progress hoursBack:hours];
    });
}

- (void)storeAllUnreadStories:(NSDictionary *)results withHashes:(NSArray *)hashes {
    NSMutableArray *storyHashes = [hashes mutableCopy];
    __weak __typeof(&*self)weakSelf = self;

    [self.appDelegate.database inDatabase:^(FMDatabase *db) {
        __strong __typeof(&*weakSelf)strongSelf = weakSelf;
        if (!strongSelf) return;
        BOOL anyInserted = NO;
        for (NSDictionary *story in [results objectForKey:@"stories"]) {
            id storyFeedId = [story objectForKey:@"story_feed_id"];
            id storyHash = [story objectForKey:@"story_hash"];
            NSString *storyTimestamp = [story objectForKey:@"story_timestamp"];
            id imageUrls = [story objectForKey:@"image_urls"];
            BOOL inserted = [db executeUpdate:@"INSERT into stories "
                             "(story_feed_id, story_hash, story_timestamp, story_json) VALUES "
                             "(?, ?, ?, ?)",
                             storyFeedId,
                             storyHash,
                             storyTimestamp,
                             [story JSONRepresentation]
                             ];
            if ([self.appDelegate isFeedInTextView:storyFeedId]) {
                [db executeUpdate:@"INSERT INTO cached_text "
                 "(story_feed_id, story_hash, story_timestamp) VALUES "
                 "(?, ?, ?)",
                 storyFeedId,
                 storyHash,
                 storyTimestamp
                 ];
            }
            if ([imageUrls class] != [NSNull class] &&
                [imageUrls count]) {
                for (NSString *imageUrl in imageUrls) {
                    [db executeUpdate:@"INSERT INTO cached_images "
                     "(story_feed_id, story_hash, image_url) VALUES "
                     "(?, ?, ?)",
                     storyFeedId,
                     storyHash,
                     imageUrl
                     ];
                }
            }
            if (inserted) {
                anyInserted = YES;
                [storyHashes removeObject:storyHash];
            }
            if ([[[NSUserDefaults standardUserDefaults] objectForKey:@"default_order"] isEqualToString:@"oldest"]) {
                if ([storyTimestamp intValue] > self.appDelegate.latestFetchedStoryDate) {
                    self.appDelegate.latestFetchedStoryDate = [storyTimestamp intValue];
                }
            } else {
                if (!self.appDelegate.latestFetchedStoryDate ||
                    [storyTimestamp intValue] < self.appDelegate.latestFetchedStoryDate) {
                    self.appDelegate.latestFetchedStoryDate = [storyTimestamp intValue];
                }
            }
            self.appDelegate.remainingUnfetchedStoryCount--;
            if (self.appDelegate.remainingUnfetchedStoryCount % 10 == 0) {
                [strongSelf updateProgress];
            }

        }
        if (anyInserted) {
            NSDictionary *lastStory;
            if ([[[NSUserDefaults standardUserDefaults] objectForKey:@"default_order"]
                 isEqualToString:@"oldest"]) {
                lastStory = [[results objectForKey:@"stories"] firstObject];
            } else {
                lastStory = [[results objectForKey:@"stories"] lastObject];
            }
            self.appDelegate.latestFetchedStoryDate = [[lastStory
                                                   objectForKey:@"story_timestamp"]
                                                  intValue];
        }
        if ([storyHashes count]) {
            NSLog(@"Failed to fetch stories: %@", storyHashes);
            [db executeUpdate:[NSString stringWithFormat:@"DELETE FROM unread_hashes WHERE story_hash IN (\"%@\")",
                               [storyHashes componentsJoinedByString:@"\",\" "]]];
        }
    }];
    
    [self.appDelegate storeUserProfiles:[results objectForKey:@"user_profiles"]];
}


@end