/******************************************************************************
 * Copyright (c) 2008-2012 Transmission authors and contributors
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 *****************************************************************************/

#import "BlocklistDownloader.h"
#import "BlocklistDownloaderViewController.h"
#import "BlocklistScheduler.h"
#import "Controller.h"

@interface BlocklistDownloader (Private)

- (void) startDownload;
- (void) decompressBlocklist;

@end

@implementation BlocklistDownloader

BlocklistDownloader * fBLDownloader = nil;
+ (BlocklistDownloader *) downloader
{
    if (!fBLDownloader)
    {
        fBLDownloader = [[BlocklistDownloader alloc] init];
        [fBLDownloader startDownload];
    }

    return fBLDownloader;
}

+ (BOOL) isRunning
{
    return fBLDownloader != nil;
}

- (void) setViewController: (BlocklistDownloaderViewController *) viewController
{
    fViewController = viewController;
    if (fViewController)
    {
        switch (fState)
        {
            case BLOCKLIST_DL_START:
                [fViewController setStatusStarting];
                break;
            case BLOCKLIST_DL_DOWNLOADING:
                [fViewController setStatusProgressForCurrentSize: fCurrentSize expectedSize: fExpectedSize];
                break;
            case BLOCKLIST_DL_PROCESSING:
                [fViewController setStatusProcessing];
                break;
        }
    }
}


- (void) cancelDownload
{
    [fViewController setFinished];

    [fDownload cancel];

    [[BlocklistScheduler scheduler] updateSchedule];

    fBLDownloader = nil;
}

//using the actual filename is the best bet
- (void) download: (NSURLDownload *) download decideDestinationWithSuggestedFilename: (NSString *) filename
{
    [fDownload setDestination: [NSTemporaryDirectory() stringByAppendingPathComponent: filename] allowOverwrite: NO];
}

- (void) download: (NSURLDownload *) download didCreateDestination: (NSString *) path
{
    fDestination = path;
}

- (void) download: (NSURLDownload *) download didReceiveResponse: (NSURLResponse *) response
{
    fState = BLOCKLIST_DL_DOWNLOADING;

    fCurrentSize = 0;
    fExpectedSize = [response expectedContentLength];

    [fViewController setStatusProgressForCurrentSize: fCurrentSize expectedSize: fExpectedSize];
}

- (void) download: (NSURLDownload *) download didReceiveDataOfLength: (NSUInteger) length
{
    fCurrentSize += length;
    [fViewController setStatusProgressForCurrentSize: fCurrentSize expectedSize: fExpectedSize];
}

- (void) download: (NSURLDownload *) download didFailWithError: (NSError *) error
{
    [fViewController setFailed: [error localizedDescription]];

    [[NSUserDefaults standardUserDefaults] setObject: [NSDate date] forKey: @"BlocklistNewLastUpdate"];
    [[BlocklistScheduler scheduler] updateSchedule];

    fBLDownloader = nil;
}

- (void) downloadDidFinish: (NSURLDownload *) download
{
    fState = BLOCKLIST_DL_PROCESSING;

    [fViewController setStatusProcessing];

    NSAssert(fDestination != nil, @"the blocklist file destination has not been specified");

    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
        [self decompressBlocklist];

        dispatch_async(dispatch_get_main_queue(), ^{
            const int count = tr_blocklistSetContent([(Controller *)[NSApp delegate] sessionHandle], [fDestination UTF8String]);

            //delete downloaded file
            [[NSFileManager defaultManager] removeItemAtPath: fDestination error: NULL];

            if (count > 0)
                [fViewController setFinished];
            else
                [fViewController setFailed: NSLocalizedString(@"The specified blocklist file did not contain any valid rules.",
                                                              "blocklist fail message")];

            //update last updated date for schedule
            NSDate * date = [NSDate date];
            [[NSUserDefaults standardUserDefaults] setObject: date forKey: @"BlocklistNewLastUpdate"];
            [[NSUserDefaults standardUserDefaults] setObject: date forKey: @"BlocklistNewLastUpdateSuccess"];
            [[BlocklistScheduler scheduler] updateSchedule];

            [[NSNotificationCenter defaultCenter] postNotificationName: @"BlocklistUpdated" object: nil];

            fBLDownloader = nil;
        });
    });
}

- (BOOL) download: (NSURLDownload *) download shouldDecodeSourceDataOfMIMEType: (NSString *) encodingType
{
    return YES;
}

@end

@implementation BlocklistDownloader (Private)

- (void) startDownload
{
    fState = BLOCKLIST_DL_START;

    [[BlocklistScheduler scheduler] cancelSchedule];

    NSString * urlString = [[NSUserDefaults standardUserDefaults] stringForKey: @"BlocklistURL"];
    if (!urlString)
        urlString = @"";
    else if (![urlString isEqualToString: @""] && [urlString rangeOfString: @"://"].location == NSNotFound)
        urlString = [@"http://" stringByAppendingString: urlString];

    NSURLRequest * request = [NSURLRequest requestWithURL: [NSURL URLWithString: urlString]];

    fDownload = [[NSURLDownload alloc] initWithRequest: request delegate: self];
}

//.gz, .tar.gz, .tgz, and .bgz will be decompressed by NSURLDownload for us. However, we have to do .zip files manually.
- (void) decompressBlocklist
{
    if ([[[fDestination pathExtension] lowercaseString] isEqualToString: @"zip"]) {
        BOOL success = NO;

        NSString * workingDirectory = [fDestination stringByDeletingLastPathComponent];

        //First, perform the actual unzipping
        NSTask  * unzip = [[NSTask alloc] init];
        [unzip setLaunchPath: @"/usr/bin/unzip"];
        [unzip setCurrentDirectoryPath: workingDirectory];
        [unzip setArguments: @[
                                @"-o",  /* overwrite */
                                @"-q", /* quiet! */
                                fDestination, /* source zip file */
                                @"-d", workingDirectory /*destination*/
                                ]];

        @try
        {
            [unzip launch];
            [unzip waitUntilExit];

            if ([unzip terminationStatus] == 0)
                success = YES;
        }
        @catch(id exc)
        {
            success = NO;
        }

        if (success) {
            //Now find out what file we actually extracted; don't just assume it matches the zipfile's name
            NSTask *zipinfo;

            zipinfo = [[NSTask alloc] init];
            [zipinfo setLaunchPath: @"/usr/bin/zipinfo"];
            [zipinfo setArguments: @[
                                    @"-1",  /* just the filename */
                                    fDestination /* source zip file */
                                    ]];
            [zipinfo setStandardOutput: [NSPipe pipe]];

            @try
            {
                NSFileHandle * zipinfoOutput = [[zipinfo standardOutput] fileHandleForReading];

                [zipinfo launch];
                [zipinfo waitUntilExit];

                NSString * actualFilename = [[NSString alloc] initWithData: [zipinfoOutput readDataToEndOfFile]
                                                encoding: NSUTF8StringEncoding];
                actualFilename = [actualFilename stringByTrimmingCharactersInSet: [NSCharacterSet whitespaceAndNewlineCharacterSet]];
                NSString * newBlocklistPath = [workingDirectory stringByAppendingPathComponent: actualFilename];

                //Finally, delete the ZIP file; we're done with it, and we'll return the unzipped blocklist
                [[NSFileManager defaultManager] removeItemAtPath: fDestination error: NULL];

                fDestination = newBlocklistPath;
            }
            @catch(id exc) {}
        }
    }
}

@end