/*
 * Reddit.m
 *
 * Copyright (c) 2013, Thomas Buck <xythobuz@xythobuz.de>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright notice,
 *   this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
#import "Reddit.h"
#import "AppDelegate.h"

@implementation Reddit

NSString *replaceTextForTitle = @"...";
NSString *subredditFormat = @" [r/%@]";
#define AUTHOR @"xythobuz"

@synthesize username, modhash, password, version, appName, author, length, subreddits, titleLength;

-(id)initWithUsername:(NSString *)name Modhash:(NSString *)hash Length:(NSInteger)leng TitleLength:(NSInteger)title {
    self = [super init];
    if (self) {
        username = name;
        modhash = hash;
        password = nil;
        length = leng;
        version = [[[NSBundle mainBundle] infoDictionary] objectForKey:@"CFBundleShortVersionString"];
        appName = [[[NSBundle mainBundle] infoDictionary] objectForKey:@"CFBundleName"];
        author = AUTHOR;
        titleLength = title;
    }
    return self;
}

-(id)initWithUsername:(NSString *)name Password:(NSString *)pass {
    self = [super init];
    if (self) {
        username = name;
        modhash = nil;
        password = pass;
        length = 0;
        version = [[[NSBundle mainBundle] infoDictionary] objectForKey:@"CFBundleShortVersionString"];
        appName = [[[NSBundle mainBundle] infoDictionary] objectForKey:@"CFBundleName"];
        author = AUTHOR;
        titleLength = 66;
    }
    return self;
}

-(NSString *)queryModhash {
    NSMutableString *stringData = [NSMutableString stringWithString:@"api_type=json"];
    [stringData appendFormat:@"&user=%@", [self urlencode: username]];
    [stringData appendFormat:@"&passwd=%@", [self urlencode: password]];
    [stringData appendString:@"&rem=True"];
    NSHTTPURLResponse *response;
    NSData *data = [self queryAPI:@"api/login" withData:stringData andResponse:&response];
    if (data == nil) {
        return nil;
    } else {
        long code = [response statusCode];
        if (code == 200) {
            NSError *error;
            id object = [NSJSONSerialization JSONObjectWithData:data options:0 error:&error];
            if (error)
                return nil;
            if([object isKindOfClass:[NSDictionary class]]) {
                NSDictionary *results = object;
                NSDictionary *json = [results valueForKey:@"json"];
                if (json == nil)
                    return nil;
                NSDictionary *data = [json valueForKey:@"data"];
                if (data == nil)
                    return nil;
                return [data valueForKey:@"modhash"];
            } else {
                return nil;
            }
        } else {
            return nil;
        }
    }
}

-(NSArray *)convertJSONToItemArray:(NSData *)data ShowSubs:(Boolean)showSubs {
    NSError *error;
    NSDictionary *json = [NSJSONSerialization JSONObjectWithData:data options:0 error:&error];
    NSDictionary *dat = [json valueForKey:@"data"];
    if (dat == nil)
        return nil;
    NSArray *children = [dat valueForKey:@"children"];
    if (children == nil)
        return nil;
    
    NSMutableArray *array = [NSMutableArray arrayWithCapacity:[children count]];
    for (NSUInteger i = 0; i < [children count]; i++) {
        NSDictionary *child = [children objectAtIndex:i];
        NSDictionary *current = [child valueForKey:@"data"];
        NSString *name = [current valueForKey:@"title"];
        NSString *link = [current valueForKey:@"url"];
        NSString *comments = nil;
        NSNumber *num = [current valueForKey:@"is_self"];
        BOOL isSelf = [num boolValue];
        if (!isSelf) {
            comments = [NSString stringWithFormat:@"http://www.reddit.com%@", [current valueForKey:@"permalink"]];
        }
        NSString *subreddit = [NSString stringWithFormat:subredditFormat, [current valueForKey:@"subreddit"]];
        NSInteger maxLen = titleLength;
        if ([subreddit length] >= titleLength)
            showSubs = FALSE;
        if (showSubs)
            maxLen -= [subreddit length];
        if ([name length] > maxLen)
            name = [NSString stringWithFormat:@"%@%@", [name substringToIndex:(maxLen - [replaceTextForTitle length])], replaceTextForTitle];
        if (showSubs)
            name = [NSString stringWithFormat:@"%@%@", name, subreddit];
        RedditItem *r = [RedditItem itemWithName:name Link:link Comments:comments Self:isSelf];
        NSString *fullName = [current valueForKey:@"title"];
        if (showSubs)
            fullName = [NSString stringWithFormat:@"%@%@", fullName, subreddit];
        [r setFullName:fullName];
        [array insertObject:r atIndex:i];
        
        if (i == ([children count] - 1)) {
            NSString *name = [NSString stringWithFormat:@"%@_%@", [child valueForKey:@"kind"], [current valueForKey:@"id"]];
            [array insertObject:name atIndex:i + 1];
        }
    }
    return array;
}

-(void)readFrontpage:(id)parent {
    NSHTTPURLResponse *response;
    
    NSString *after = ((AppDelegate *)parent).lastFullName;
    Boolean showSubreddits = ((AppDelegate *)parent).currentState.showSubreddit;
    NSString *url;
    if (after == nil)
        url = [NSString stringWithFormat:@"hot.json?limit=%ld", (long)length];
    else
        url = [NSString stringWithFormat:@"hot.json?limit=%ld&after=%@", (long)length, after];
        
    NSData *data = [self queryAPI:url withResponse:&response];
    if ((data == nil) || ([response statusCode] != 200)) {
        [parent performSelectorOnMainThread:@selector(reloadListHasFrontpageCallback:) withObject:nil waitUntilDone:false];
    } else {
        [parent performSelectorOnMainThread:@selector(reloadListHasFrontpageCallback:) withObject:[self convertJSONToItemArray:data ShowSubs:showSubreddits] waitUntilDone:false];
    }
}

-(void)readSubreddits:(id)parent {
    NSMutableString *subs = [NSMutableString stringWithString:@"r/"];
    for (NSUInteger i = 0; i < [subreddits count]; i++) {
        [subs appendString:[subreddits objectAtIndex:i]];
        if (i < ([subreddits count] - 1)) {
            [subs appendString:@"+"];
        }
    }
    
    NSString *after = ((AppDelegate *)parent).lastFullName;
    Boolean showSubreddits = ((AppDelegate *)parent).currentState.showSubreddit;
    NSString *url;
    if (after == nil)
        url = [NSString stringWithFormat:@"%@/hot.json?limit=%ld", subs, (long)length];
    else
        url = [NSString stringWithFormat:@"%@/hot.json?limit=%ld&after=%@", subs, (long)length, after];
    
    NSHTTPURLResponse *response;
    NSData *data = [self queryAPI:url withResponse:&response];
    if ((data == nil) || ([response statusCode] != 200)) {
        [parent performSelectorOnMainThread:@selector(reloadListHasSubredditsCallback:) withObject:nil waitUntilDone:false];
    } else {
        [parent performSelectorOnMainThread:@selector(reloadListHasSubredditsCallback:) withObject:[self convertJSONToItemArray:data ShowSubs:showSubreddits] waitUntilDone:false];
    }
}

-(void)isAuthenticatedNewModhash:(id)parent {
    NSHTTPURLResponse *response;
    NSData *dat = [self queryAPI:@"api/me.json" withResponse:&response];
    if ((dat != nil) && ([response statusCode] == 200)) {
        NSError *error;
        NSDictionary *json = [NSJSONSerialization JSONObjectWithData:dat options:0 error:&error];
        NSDictionary *data = [json valueForKey:@"data"];
        if (data == nil) {
            NSLog(@"Error loading me.json: not logged in!\n");
            [parent performSelectorOnMainThread:@selector(reloadListNotAuthenticatedCallback) withObject:nil waitUntilDone:false];
            return;
        }
        NSString *newHash = [data valueForKey:@"modhash"];
        if ((newHash == nil) || ([newHash isEqualToString:@""])) {
            NSLog(@"Error interpreting me.json: did not receive modhash!\n");
            [parent performSelectorOnMainThread:@selector(reloadListNotAuthenticatedCallback) withObject:nil waitUntilDone:false];
            return;
        }
        if (![newHash isEqualToString:modhash]) {
            modhash = newHash;
        }
        [parent performSelectorOnMainThread:@selector(reloadListIsAuthenticatedCallback) withObject:nil waitUntilDone:false];
        return;
        
    }
    [parent performSelectorOnMainThread:@selector(reloadListNotAuthenticatedCallback) withObject:nil waitUntilDone:false];
}

-(NSData *)queryAPI:(NSString *)api withResponse:(NSHTTPURLResponse **)res {
    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[self getAPIPoint:api]];
    [request setTimeoutInterval:5.0];
    [request setCachePolicy:NSURLRequestReloadIgnoringLocalCacheData];
    [request setValue:@"application/x-www-form-urlencoded; charset=UTF-8" forHTTPHeaderField:@"Content-Type"];
    [request setValue:[NSString stringWithFormat:@"%@/%@ by %@", appName, version, author] forHTTPHeaderField:@"User-Agent"];
    if ((modhash != nil) && (![modhash isEqualToString:@""]))
        [request addValue:modhash forHTTPHeaderField:@"X-Modhash"];
    [request setHTTPMethod:@"GET"];
    NSError *error = nil;
    NSData *data = [NSURLConnection sendSynchronousRequest:request returningResponse:res error:&error];
    if (error)
        return nil;
    return data;
}

-(NSData *)queryAPI:(NSString *)api withData:(NSString *)string andResponse:(NSHTTPURLResponse **)res {
    NSData *requestBodyData = [string dataUsingEncoding:NSUTF8StringEncoding];
    NSString *requestBodyLength = [NSString stringWithFormat:@"%lu", (unsigned long)[requestBodyData length]];
    NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[self getAPIPoint:api]];
    [request setTimeoutInterval:5.0];
    [request setCachePolicy:NSURLRequestReloadIgnoringLocalCacheData];
    [request setValue:@"application/x-www-form-urlencoded; charset=UTF-8" forHTTPHeaderField:@"Content-Type"];
    [request setValue:requestBodyLength forHTTPHeaderField:@"Content-Length"];
    [request setValue:[NSString stringWithFormat:@"%@/%@ by %@", appName, version, author] forHTTPHeaderField:@"User-Agent"];
    if ((modhash != nil) && (![modhash isEqualToString:@""]))
        [request addValue:modhash forHTTPHeaderField:@"X-Modhash"];
    
    [request setHTTPMethod:@"POST"];
    [request setHTTPBody:requestBodyData];
    NSError *error = nil;
    NSData *data = [NSURLConnection sendSynchronousRequest:request returningResponse:res error:&error];
    if (error)
        return nil;
    return data;
}

-(NSURL *)getAPIPoint:(NSString *)where {
    return [NSURL URLWithString:[NSString stringWithFormat:@"https://ssl.reddit.com/%@", where]];
}

-(NSString *)urlencode:(NSString *)string {
    NSMutableString *output = [NSMutableString string];
    const unsigned char *source = (const unsigned char *)[string UTF8String];
    long sourceLen = strlen((const char *)source);
    for (int i = 0; i < sourceLen; i++) {
        const unsigned char thisChar = source[i];
        if (thisChar == ' '){
            [output appendString:@"+"];
        } else if (thisChar == '.' || thisChar == '-' || thisChar == '_' || thisChar == '~' ||
                   (thisChar >= 'a' && thisChar <= 'z') ||
                   (thisChar >= 'A' && thisChar <= 'Z') ||
                   (thisChar >= '0' && thisChar <= '9')) {
            [output appendFormat:@"%c", thisChar];
        } else {
            [output appendFormat:@"%%%02X", thisChar];
        }
    }
    return output;
}

@end