/*
Copyright 2024 New Vector Ltd.
Copyright 2017 Aram Sargsyan

SPDX-License-Identifier: AGPL-3.0-only
Please see LICENSE in the repository root for full details.
 */

@import MobileCoreServices;

#import <mach/mach.h>

#import "ShareManager.h"
#import "ShareViewController.h"
#import "ShareDataSource.h"
#import "ShareItemSenderProtocol.h"

#import "GeneratedInterface-Swift.h"

@interface ShareManager () <ShareViewControllerDelegate, ShareItemSenderDelegate>

@property (nonatomic, strong, readonly) id<ShareItemSenderProtocol> shareItemSender;

@property (nonatomic, strong, readonly) ShareViewController *shareViewController;

@property (nonatomic) BOOL useCustomSession;
@property (nonatomic, strong) MXSession* session;
@property (nonatomic, strong) MXKAccount *userAccount;
@property (nonatomic, strong) MXFileStore *fileStore;

/**
 An array of rooms that the item is being shared to. This is to maintain a strong ref
 to all necessary `MXRoom`s until sharing has completed.
 */
@property (nonatomic, strong) NSMutableArray<MXRoom *> *selectedRooms;

@end


@implementation ShareManager

/// A fake matrix session used to provide summaries with a REST client to handle room avatars.
/// The session is stored statically to prevent new ones from being created for each share.
static MXSession *fakeSession;

- (instancetype)initWithShareItemSender:(id<ShareItemSenderProtocol>)itemSender
                                   type:(ShareManagerType)type
                                session:(MXSession*)session
{
    if (self = [super init])
    {
        _shareItemSender = itemSender;
        _shareItemSender.delegate = self;
        _session = session;
        _useCustomSession = _session == nil;
        
        [NSNotificationCenter.defaultCenter addObserver:self selector:@selector(checkUserAccount) name:kMXKAccountManagerDidRemoveAccountNotification object:nil];
        [NSNotificationCenter.defaultCenter addObserver:self selector:@selector(checkUserAccount) name:NSExtensionHostWillEnterForegroundNotification object:nil];
        [NSNotificationCenter.defaultCenter addObserver:self selector:@selector(didReceiveMemoryWarning:) name:UIApplicationDidReceiveMemoryWarningNotification object:nil];
        
        _shareViewController = [[ShareViewController alloc] initWithType:(type == ShareManagerTypeForward ? ShareViewControllerTypeForward : ShareViewControllerTypeSend)
                                                            currentState:ShareViewControllerAccountStateNotConfigured];
        [_shareViewController setDelegate:self];
        
        // Set up runtime language on each context update.
        NSUserDefaults *sharedUserDefaults = [MXKAppSettings standardAppSettings].sharedUserDefaults;
        NSString *language = [sharedUserDefaults objectForKey:@"appLanguage"];
        [NSBundle mxk_setLanguage:language];
        [NSBundle mxk_setFallbackLanguage:@"en"];
        
        if (!_useCustomSession)
        {
            // If we don't use a custom session, we can initialize the shareViewController with our existing session
            self.userAccount = [MXKAccountManager sharedManager].activeAccounts.firstObject;
            ShareDataSource *roomDataSource = [[ShareDataSource alloc] initWithFileStore:_session.store
                                                                                 session:_session];
            
            [self.shareViewController configureWithState:ShareViewControllerAccountStateConfigured
                                          roomDataSource:roomDataSource];
        }
        else
        {
            [self checkUserAccount];
        }
    }
    
    return self;
}

#pragma mark - Public

- (UIViewController *)mainViewController
{
    return self.shareViewController;
}

#pragma mark - ShareViewControllerDelegate

- (void)shareViewController:(ShareViewController *)shareViewController didRequestShareForRoomIdentifiers:(NSSet<NSString *> *)roomIdentifiers
{
    MXWeakify(self);
    MXRestClient *restClient = [[MXRestClient alloc] initWithCredentials:self.userAccount.mxCredentials andOnUnrecognizedCertificateBlock:nil andPersistentTokenDataHandler:^(void (^handler)(NSArray<MXCredentials *> *credentials, void (^completion)(BOOL didUpdateCredentials))) {
        [[MXKAccountManager sharedManager] readAndWriteCredentials:handler];
    } andUnauthenticatedHandler:^(MXError *error, BOOL isSoftLogout, BOOL isRefreshTokenAuth, void (^completion)(void)) {
        MXStrongifyAndReturnIfNil(self);
        [self.userAccount handleUnauthenticatedWithError:error isSoftLogout:isSoftLogout isRefreshTokenAuth:isRefreshTokenAuth andCompletion:completion];
    }];
    if (self.useCustomSession || !self.session)
    {
        MXSession* session = [[MXSession alloc] initWithMatrixRestClient:restClient];
        [MXFileStore setPreloadOptions:0];
                
        MXWeakify(session);
        [session setStore:self.fileStore success:^{
            MXStrongifyAndReturnIfNil(session);
            [self shareForRoomIdentifiers:roomIdentifiers usingSession:session];
        } failure:^(NSError *error) {
            MXLogError(@"[ShareManager] Failed preparing matrix session");
        }];
    }
    else
    {
        [self shareForRoomIdentifiers:roomIdentifiers usingSession:self.session];
    }
}

- (void)shareViewControllerDidRequestDismissal:(ShareViewController *)shareViewController
{
    self.completionCallback(ShareManagerResultCancelled);
}

#pragma mark - ShareItemSenderDelegate

- (void)shareItemSenderDidStartSending:(id<ShareItemSenderProtocol>)shareItemSender
{
    [self.shareViewController showProgressIndicator];
}

- (void)shareItemSender:(id<ShareItemSenderProtocol>)shareItemSender didUpdateProgress:(CGFloat)progress
{
    [self.shareViewController setProgress:progress];
}

#pragma mark - Private

- (void)shareForRoomIdentifiers:(NSSet<NSString *> *)roomIdentifiers usingSession:(MXSession*)session
{
    self.selectedRooms = [NSMutableArray array];
    for (NSString *roomIdentifier in roomIdentifiers) {
        MXRoom *room = [MXRoom loadRoomFromStore:session.store withRoomId:roomIdentifier matrixSession:session];
        if (room) {
            [self.selectedRooms addObject:room];
        }
    }
    
    [self.shareItemSender sendItemsToRooms:self.selectedRooms success:^{
        self.selectedRooms = nil;
        self.completionCallback(ShareManagerResultFinished);
    } failure:^(NSArray<NSError *> *errors) {
        self.selectedRooms = nil;
        [self showFailureAlert:[VectorL10n roomEventFailedToSend]];
    }];
}

- (void)showFailureAlert:(NSString *)title
{
    UIAlertController *alertController = [UIAlertController alertControllerWithTitle:title message:nil preferredStyle:UIAlertControllerStyleAlert];
    
    MXWeakify(self);
    UIAlertAction *okAction = [UIAlertAction actionWithTitle:[VectorL10n ok] style:UIAlertActionStyleDefault handler:^(UIAlertAction *action) {
        MXStrongifyAndReturnIfNil(self);
        
        if (self.completionCallback)
        {
            self.completionCallback(ShareManagerResultFailed);
        }
    }];
    
    [alertController addAction:okAction];
    
    [self.mainViewController presentViewController:alertController animated:YES completion:nil];
}

- (void)checkUserAccount
{
    // Force account manager to reload account from the local storage.
    [MXKAccountManager sharedManagerWithReload:YES];
    
    if (self.userAccount)
    {
        // Check whether the used account is still the first active one
        MXKAccount *firstAccount = [MXKAccountManager sharedManager].activeAccounts.firstObject;
        
        // Compare the access token
        if (!firstAccount || ![self.userAccount.mxCredentials.accessToken isEqualToString:firstAccount.mxCredentials.accessToken])
        {
            // Remove this account
            self.userAccount = nil;
        }
    }
    
    if (!self.userAccount)
    {
        // We consider the first enabled account.
        // TODO: Handle multiple accounts
        self.userAccount = [MXKAccountManager sharedManager].activeAccounts.firstObject;
        [self checkFakeSession];
    }
    
    // Reset the file store to reload the room data.
    if (_fileStore)
    {
        [_fileStore close];
        _fileStore = nil;
    }
    
    if (self.userAccount && fakeSession)
    {
        _fileStore = [[MXFileStore alloc] initWithCredentials:self.userAccount.mxCredentials];
        
        ShareDataSource *roomDataSource = [[ShareDataSource alloc] initWithFileStore:_fileStore
                                                                             session:fakeSession];
        
        [self.shareViewController configureWithState:ShareViewControllerAccountStateConfigured
                                      roomDataSource:roomDataSource];
    } else {
        [self.shareViewController configureWithState:ShareViewControllerAccountStateNotConfigured
                                      roomDataSource:nil];
    }
}

- (void)checkFakeSession
{
    if (!self.userAccount)
    {
        return;
    }
    
    if (fakeSession && [fakeSession.credentials.userId isEqualToString:self.userAccount.mxCredentials.userId])
    {
        return;
    }
    
    MXRestClient *mxRestClient = [[MXRestClient alloc] initWithCredentials:self.userAccount.mxCredentials
                                         andOnUnrecognizedCertificateBlock:nil
                                             andPersistentTokenDataHandler:^(void (^handler)(NSArray<MXCredentials *> *credentials, void (^completion)(BOOL didUpdateCredentials))) {
        [[MXKAccountManager sharedManager] readAndWriteCredentials:handler];
    } andUnauthenticatedHandler:nil];
    
    fakeSession = [[MXSession alloc] initWithMatrixRestClient:mxRestClient];
}

- (void)didStartSending
{
    [self.shareViewController showProgressIndicator];
}

- (void)didReceiveMemoryWarning:(NSNotification*)notification
{
    MXLogDebug(@"[ShareManager] Did receive memory warning");
    [self logMemoryUsage];
}

// Log memory usage.
// NOTE: This result may not be reliable for all iOS versions (see https://forums.developer.apple.com/thread/64665 for more information).
- (void)logMemoryUsage
{
    struct task_basic_info basicInfo;
    mach_msg_type_number_t size = TASK_BASIC_INFO_COUNT;
    kern_return_t kerr = task_info(mach_task_self(),
                                   TASK_BASIC_INFO,
                                   (task_info_t)&basicInfo,
                                   &size);
    
    vm_size_t memoryUsedInBytes = basicInfo.resident_size;
    CGFloat memoryUsedInMegabytes = memoryUsedInBytes / (1024*1024);
    
    if (kerr == KERN_SUCCESS)
    {
        MXLogDebug(@"[ShareManager] Memory in use (in MB): %f", memoryUsedInMegabytes);
    }
    else
    {
        MXLogDebug(@"[ShareManager] Error with task_info(): %s", mach_error_string(kerr));
    }
}

@end