//
//  MBIMSendMessageOperation.m
//  kordophoned
//
//  Created by James Magahern on 11/13/18.
//  Copyright © 2018 James Magahern. All rights reserved.
//

#import "MBIMSendMessageOperation.h"

#import "IMCore_ClassDump.h"
#import "IMMessageItem+Encoded.h"
#import "MBIMErrorResponse.h"

@implementation MBIMSendMessageOperation

+ (void)load { [super load]; }

+ (NSString *)endpointName
{
    return @"sendMessage";
}

- (nullable IMChat *)_existingSingleChatForHandle:(IMHandle *)handle registry:(IMChatRegistry *)registry
{
    if ([registry respondsToSelector:@selector(existingChatWithHandle:allowAlternativeService:)]) {
        MBIMLogInfo(@"Using IMChatRegistry existingChatWithHandle:allowAlternativeService:");
        return [registry existingChatWithHandle:handle allowAlternativeService:NO];
    }

    if ([registry respondsToSelector:@selector(existingChatWithHandle:)]) {
        MBIMLogInfo(@"Using IMChatRegistry existingChatWithHandle:");
        return [registry existingChatWithHandle:handle];
    }

    if ([registry respondsToSelector:@selector(existingChatForIMHandle:allowRetargeting:)]) {
        MBIMLogInfo(@"Using IMChatRegistry existingChatForIMHandle:allowRetargeting:");
        return [registry existingChatForIMHandle:handle allowRetargeting:NO];
    }

    if ([registry respondsToSelector:@selector(existingChatForIMHandle:)]) {
        MBIMLogInfo(@"Using IMChatRegistry existingChatForIMHandle:");
        return [registry existingChatForIMHandle:handle];
    }

    MBIMLogError(@"IMChatRegistry does not support any known single-handle existing chat lookup selector.");
    return nil;
}

- (nullable IMChat *)_createSingleChatForHandle:(IMHandle *)handle registry:(IMChatRegistry *)registry
{
    if ([registry respondsToSelector:@selector(chatWithHandle:)]) {
        MBIMLogInfo(@"Using IMChatRegistry chatWithHandle:");
        return [registry chatWithHandle:handle];
    }

    if ([registry respondsToSelector:@selector(chatForIMHandle:)]) {
        MBIMLogInfo(@"Using IMChatRegistry chatForIMHandle:");
        return [registry chatForIMHandle:handle];
    }

    MBIMLogError(@"IMChatRegistry does not support any known single-handle chat creation selector.");
    return nil;
}

- (nullable IMChat *)_existingGroupChatForHandles:(NSArray<IMHandle *> *)handles registry:(IMChatRegistry *)registry
{
    if ([registry respondsToSelector:@selector(existingChatWithHandles:allowAlternativeService:groupID:displayName:joinedChatsOnly:)]) {
        MBIMLogInfo(@"Using IMChatRegistry existingChatWithHandles:allowAlternativeService:groupID:displayName:joinedChatsOnly:");
        return [registry existingChatWithHandles:handles
                         allowAlternativeService:NO
                                         groupID:nil
                                     displayName:nil
                                 joinedChatsOnly:YES];
    }

    if ([registry respondsToSelector:@selector(existingChatWithHandles:allowAlternativeService:)]) {
        MBIMLogInfo(@"Using IMChatRegistry existingChatWithHandles:allowAlternativeService:");
        return [registry existingChatWithHandles:handles allowAlternativeService:NO];
    }

    if ([registry respondsToSelector:@selector(existingChatWithHandles:)]) {
        MBIMLogInfo(@"Using IMChatRegistry existingChatWithHandles:");
        return [registry existingChatWithHandles:handles];
    }

    if ([registry respondsToSelector:@selector(existingChatForIMHandles:allowRetargeting:groupID:displayName:joinedChatsOnly:)]) {
        MBIMLogInfo(@"Using IMChatRegistry existingChatForIMHandles:allowRetargeting:groupID:displayName:joinedChatsOnly:");
        return [registry existingChatForIMHandles:handles
                                 allowRetargeting:NO
                                           groupID:nil
                                       displayName:nil
                                   joinedChatsOnly:YES];
    }

    if ([registry respondsToSelector:@selector(existingChatForIMHandles:allowRetargeting:)]) {
        MBIMLogInfo(@"Using IMChatRegistry existingChatForIMHandles:allowRetargeting:");
        return [registry existingChatForIMHandles:handles allowRetargeting:NO];
    }

    if ([registry respondsToSelector:@selector(existingChatForIMHandles:)]) {
        MBIMLogInfo(@"Using IMChatRegistry existingChatForIMHandles:");
        return [registry existingChatForIMHandles:handles];
    }

    MBIMLogError(@"IMChatRegistry does not support any known multi-handle existing chat lookup selector.");
    return nil;
}

- (nullable IMChat *)_createGroupChatForHandles:(NSArray<IMHandle *> *)handles registry:(IMChatRegistry *)registry
{
    if ([registry respondsToSelector:@selector(chatWithHandles:displayName:joinedChatsOnly:)]) {
        MBIMLogInfo(@"Using IMChatRegistry chatWithHandles:displayName:joinedChatsOnly:");
        return [registry chatWithHandles:handles displayName:nil joinedChatsOnly:YES];
    }

    if ([registry respondsToSelector:@selector(chatWithHandles:)]) {
        MBIMLogInfo(@"Using IMChatRegistry chatWithHandles:");
        return [registry chatWithHandles:handles];
    }

    if ([registry respondsToSelector:@selector(chatForIMHandles:displayName:joinedChatsOnly:)]) {
        MBIMLogInfo(@"Using IMChatRegistry chatForIMHandles:displayName:joinedChatsOnly:");
        return [registry chatForIMHandles:handles displayName:nil joinedChatsOnly:YES];
    }

    if ([registry respondsToSelector:@selector(chatForIMHandles:)]) {
        MBIMLogInfo(@"Using IMChatRegistry chatForIMHandles:");
        return [registry chatForIMHandles:handles];
    }

    MBIMLogError(@"IMChatRegistry does not support any known multi-handle chat creation selector.");
    return nil;
}

- (nullable IMChat *)_chatForHandleIDs:(NSArray<NSString *> *)handleIDs registry:(IMChatRegistry *)registry
{
    MBIMLogInfo(@"Resolving send target for handles: %@", handleIDs);

    IMAccount *iMessageAccount = [[IMAccountController sharedInstance] bestAccountForService:[IMServiceImpl iMessageService]];
    if (!iMessageAccount) {
        MBIMLogError(@"Unable to find an iMessage account for message send.");
        return nil;
    }

    NSMutableArray<IMHandle *> *handles = [NSMutableArray arrayWithCapacity:[handleIDs count]];
    for (NSString *handleID in handleIDs) {
        IMHandle *handle = [iMessageAccount imHandleWithID:handleID];
        if (!handle) {
            MBIMLogError(@"Couldn't resolve IMHandle for id %@", handleID);
            return nil;
        }

        [handles addObject:handle];
    }

    if ([handles count] == 1) {
        IMHandle *handle = [handles firstObject];
        IMChat *chat = [self _existingSingleChatForHandle:handle registry:registry];
        if (!chat) {
            chat = [self _createSingleChatForHandle:handle registry:registry];
        }

        if (chat) {
            MBIMLogInfo(@"Resolved send target %@ to chat %@", [handle ID], [chat guid] ?: @"<unknown>");
        } else {
            MBIMLogError(@"Unable to locate or create chat for handle %@", [handle ID]);
        }

        return chat;
    }

    IMChat *chat = [self _existingGroupChatForHandles:handles registry:registry];
    if (!chat) {
        chat = [self _createGroupChatForHandles:handles registry:registry];
    }

    if (chat) {
        MBIMLogInfo(@"Resolved handles %@ to chat %@", handleIDs, [chat guid] ?: @"<unknown>");
    } else {
        MBIMLogError(@"Unable to locate or create chat for handles %@", handleIDs);
    }

    return chat;
}

- (nullable NSDictionary *)_sendMessage:(NSString *)messageBody toChat:(IMChat *)chat attachmentGUIDs:(NSArray<NSString *> *)guids includeConversationGUID:(BOOL)includeConversationGUID
{
    if (!chat) {
        return nil;
    }

    NSString *chatGUID = [chat guid];
    if (!chatGUID) {
        chatGUID = [[[IMChatRegistry sharedInstance] allGUIDsForChat:chat] firstObject];
    }

    MBIMLogInfo(@"Preparing sendMessage for chat %@ (bodyLength=%lu attachmentCount=%lu)", chatGUID ?: @"<unknown>", (unsigned long)[messageBody length], (unsigned long)[guids count]);

    IMAccount *sendingAccount = [chat account];
    if (!sendingAccount) {
        sendingAccount = [[IMAccountController sharedInstance] bestAccountForService:[IMServiceImpl iMessageService]];
    }

    IMHandle *senderHandle = [sendingAccount loginIMHandle];
    if (!senderHandle) {
        MBIMLogError(@"Unable to determine sender handle for message send.");
        return nil;
    }

    NSAttributedString *replyAttrString = [[NSAttributedString alloc] initWithString:messageBody];
    NSAttributedString *attrStringWithFileTransfers = IMCreateSuperFormatStringWithAppendedFileTransfers(replyAttrString, guids);

    IMMessage *reply = [IMMessage fromMeIMHandle:senderHandle
                                        withText:attrStringWithFileTransfers
                               fileTransferGUIDs:guids
                                           flags:(kIMMessageFinished | kIMMessageIsFromMe)];

    for (NSString *guid in [reply fileTransferGUIDs]) {
        [[IMFileTransferCenter sharedInstance] assignTransfer:guid toMessage:reply account:sendingAccount];
    }

    NSDictionary *replyRepresentation = [reply mbim_dictionaryRepresentation];
    if (![replyRepresentation isKindOfClass:[NSDictionary class]]) {
        MBIMLogError(@"Unable to encode sent message for chat %@", chatGUID ?: @"<unknown>");
        return nil;
    }

    NSMutableDictionary *result = [replyRepresentation mutableCopy];
    if (includeConversationGUID) {
        NSString *conversationGUID = chatGUID;
        if (!conversationGUID) {
            conversationGUID = [[[IMChatRegistry sharedInstance] allGUIDsForChat:chat] firstObject];
        }

        if (conversationGUID) {
            result[@"conversationGUID"] = conversationGUID;
        }
    }

    MBIMLogInfo(@"Dispatching IMCore send for chat %@", chatGUID ?: @"<unknown>");
    dispatch_async(dispatch_get_main_queue(), ^{
        [chat sendMessage:reply];
    });

    return result;
}

#if 0
- (NSDictionary *)adjustMessageSummaryInfoForSending:(NSDictionary *)messageSummaryInfo
{
    NSMutableDictionary *adjustedInfo = [messageSummaryInfo mutableCopy];
    if (!adjustedInfo) {
        adjustedInfo = [NSMutableDictionary dictionary];
    }

    if ([fullText length] > 50) {
        summary = [[summary substringToIndex:[summary rangeOfComposedCharacterSequenceAtIndex:kMaxSummaryLength].location] stringByAppendingString:@"…"];
        adjustedInfo[IMMessageSummaryInfoSummary] = summary;
    }

    
    adjustedInfo[IMMessageSummaryInfoTapbackRepresentationKey] = @"Loved";

    return adjustedInfo;
}
#endif

- (void)main
{
    __block NSObject<HTTPResponse> *response = [[HTTPErrorResponse alloc] initWithErrorCode:500];
    
    NSError *error = nil;
    NSDictionary *args = [NSJSONSerialization JSONObjectWithData:self.requestBodyData options:0 error:&error];
    if (error || args.count == 0) {
        MBIMLogError(@"Unable to parse sendMessage request body: %@", error);
        self.serverCompletionBlock(response);
        return;
    }
    
    NSString *guid = [args objectForKey:@"guid"];
    NSString *messageBody = [args objectForKey:@"body"];
    NSArray *rawHandleIDs = [args objectForKey:@"handleIDs"];
    BOOL hasGUID = [guid isKindOfClass:[NSString class]] && [guid length] > 0;
    BOOL hasHandleIDs = [rawHandleIDs isKindOfClass:[NSArray class]] && [rawHandleIDs count] > 0;

    if (![messageBody isKindOfClass:[NSString class]] || (!hasGUID && !hasHandleIDs) || (hasGUID && hasHandleIDs)) {
        response = [[MBIMErrorResponse alloc] initWithErrorCode:500 message:@"sendMessage requires body and exactly one of guid or handleIDs."];
        self.serverCompletionBlock(response);
        return;
    }
    
    NSMutableArray<NSString *> *handleIDs = [NSMutableArray array];
    if (hasHandleIDs) {
        for (id handleID in rawHandleIDs) {
            if ([handleID isKindOfClass:[NSString class]] && [handleID length] > 0) {
                [handleIDs addObject:handleID];
            }
        }

        handleIDs = [[[NSOrderedSet orderedSetWithArray:handleIDs] array] mutableCopy];
        if ([handleIDs count] == 0) {
            response = [[MBIMErrorResponse alloc] initWithErrorCode:500 message:@"No valid handle IDs provided."];
            self.serverCompletionBlock(response);
            return;
        }
    }

    NSArray *rawTransferGUIDs = [args objectForKey:@"fileTransferGUIDs"];
    NSMutableArray<NSString *> *transferGUIDs = [NSMutableArray array];
    if ([rawTransferGUIDs isKindOfClass:[NSArray class]]) {
        for (id transferGUID in rawTransferGUIDs) {
            if ([transferGUID isKindOfClass:[NSString class]] && [transferGUID length] > 0) {
                [transferGUIDs addObject:transferGUID];
            }
        }
    }

    MBIMLogInfo(@"sendMessage request received. guid=%@ handleIDs=%@ bodyLength=%lu attachmentGUIDs=%@", hasGUID ? guid : @"<none>", handleIDs, (unsigned long)[messageBody length], transferGUIDs);

    @try {
        dispatch_sync([[self class] sharedIMAccessQueue], ^{
            IMChatRegistry *registry = [IMChatRegistry sharedInstance];
            IMChat *chat = nil;
            BOOL includeConversationGUID = NO;

            if (hasGUID) {
                MBIMLogInfo(@"sendMessage targeting existing conversation %@", guid);
                chat = [registry existingChatWithGUID:guid];
                if (!chat) {
                    MBIMLogError(@"Chat does not exist for guid %@", guid);
                    response = [[MBIMErrorResponse alloc] initWithErrorCode:500 message:@"Chat does not exist for the provided guid."];
                    return;
                }
            } else {
                MBIMLogInfo(@"sendMessage targeting handles %@", handleIDs);
                chat = [self _chatForHandleIDs:handleIDs registry:registry];
                includeConversationGUID = YES;
                if (!chat) {
                    response = [[MBIMErrorResponse alloc] initWithErrorCode:500 message:@"Unable to create or locate a chat for the provided handles."];
                    return;
                }
            }

            NSString *resolvedChatGUID = [chat guid];
            if (!resolvedChatGUID) {
                resolvedChatGUID = [[[IMChatRegistry sharedInstance] allGUIDsForChat:chat] firstObject];
            }
            MBIMLogInfo(@"sendMessage resolved target chat %@", resolvedChatGUID ?: @"<unknown>");

            NSDictionary *result = [self _sendMessage:messageBody
                                               toChat:chat
                                      attachmentGUIDs:transferGUIDs
                               includeConversationGUID:includeConversationGUID];
            if (!result) {
                MBIMLogError(@"sendMessage failed before a response payload could be encoded for chat %@", resolvedChatGUID ?: @"<unknown>");
                response = [[MBIMErrorResponse alloc] initWithErrorCode:500 message:@"Unable to construct sent message response."];
                return;
            }

            NSObject<HTTPResponse> *jsonResponse = [MBIMJSONDataResponse responseWithJSONObject:result];
            if (jsonResponse) {
                response = jsonResponse;
            } else {
                MBIMLogError(@"Unable to encode sendMessage JSON response for chat %@", resolvedChatGUID ?: @"<unknown>");
                response = [[MBIMErrorResponse alloc] initWithErrorCode:500 message:@"Unable to encode sendMessage response."];
            }
        });
    } @catch (NSException *exception) {
        MBIMLogError(@"Unhandled exception during sendMessage. name=%@ reason=%@ userInfo=%@", exception.name, exception.reason, exception.userInfo);
        response = [[MBIMErrorResponse alloc] initWithErrorCode:500 message:@"Unhandled exception while sending message. Check server logs."];
    }

    if (response == nil) {
        MBIMLogError(@"sendMessage completed without producing a response. guid=%@ handleIDs=%@", hasGUID ? guid : @"<none>", handleIDs);
        response = [[MBIMErrorResponse alloc] initWithErrorCode:500 message:@"sendMessage did not produce a response. Check server logs."];
    }
    
    self.serverCompletionBlock(response);
}

@end