import type { IMessage, IThreadMessage, MessageAttachment } from '@rocket.chat/core-typings';
import { createPredicateFromFilter } from '@rocket.chat/mongo-adapter';
import type { InfiniteData, QueryClient } from '@tanstack/react-query';
import type { Condition, Filter } from 'mongodb';

import { queryClient as defaultQueryClient } from '../queryClient';
import { roomsQueryKeys } from '../queryKeys';

export type NotifyRoomRidDeleteBulkEvent = {
	rid: IMessage['rid'];
	excludePinned: boolean;
	ignoreDiscussion: boolean;
	ts: Condition<Date>;
	users: string[];
	ids?: string[];
	showDeletedStatus?: boolean;
} & (
	| {
			filesOnly: true;
			replaceFileAttachmentsWith?: MessageAttachment;
	  }
	| {
			filesOnly?: false;
	  }
);

export const createDeleteCriteria = (params: NotifyRoomRidDeleteBulkEvent): ((message: IMessage) => boolean) => {
	const query: Filter<IMessage> = {};

	if (params.ids) {
		query._id = { $in: params.ids };
	} else {
		query.ts = params.ts;
	}

	if (params.excludePinned) {
		query.pinned = { $ne: true };
	}

	if (params.ignoreDiscussion) {
		query.drid = { $exists: false };
	}
	if (params.users?.length) {
		query['u.username'] = { $in: params.users };
	}

	return createPredicateFromFilter(query);
};

export type ThreadMessagesPage = {
	items: IThreadMessage[];
	itemCount: number;
};

export type ThreadMessagesInfiniteData = InfiniteData<ThreadMessagesPage, number>;

const dedupeThreadMessagesById = (messages: IThreadMessage[]): IThreadMessage[] => {
	const byId = new Map<string, IThreadMessage>();

	for (const message of messages) {
		const existing = byId.get(message._id);
		if (!existing) {
			byId.set(message._id, message);
			continue;
		}

		const messageTime = new Date(message._updatedAt ?? message.ts).getTime();
		const existingTime = new Date(existing._updatedAt ?? existing.ts).getTime();
		if (messageTime > existingTime) {
			byId.set(message._id, message);
		}
	}

	return Array.from(byId.values());
};

export const mutateThreadMessagesInfiniteData = (
	client: QueryClient,
	queryKey: readonly unknown[],
	mutation: (messages: IThreadMessage[]) => void,
): void => {
	client.setQueryData<ThreadMessagesInfiniteData>(queryKey, (old) => {
		if (!old?.pages.length) {
			return old;
		}

		const items = dedupeThreadMessagesById(old.pages.flatMap((page) => page.items));
		const originalPageLengths = old.pages.map((page) => page.items.length);
		const oldTotal = old.pages.at(-1)?.itemCount ?? 0;
		const oldIds = new Set(items.map((message) => message._id));
		const oldMaxTs = items.reduce((max, message) => Math.max(max, new Date(message.ts).getTime()), -Infinity);

		const beforeMutationItemsLength = items.length;
		mutation(items);
		const afterMutationItemsLength = items.length;

		const itemCountDelta = beforeMutationItemsLength - afterMutationItemsLength;
		const newTotal = Math.max(0, oldTotal - itemCountDelta);

		const newerInsertedCount = items.filter((message) => !oldIds.has(message._id) && new Date(message.ts).getTime() >= oldMaxTs).length;

		const pages: ThreadMessagesPage[] = [];
		let cursor = 0;
		for (let pageIndex = 0; pageIndex < old.pages.length; pageIndex++) {
			const isLastPage = pageIndex === old.pages.length - 1;
			const take = isLastPage ? items.length - cursor : Math.min(originalPageLengths[pageIndex], items.length - cursor);
			const slice = items.slice(cursor, cursor + Math.max(0, take));
			cursor += slice.length;
			pages.push({ items: slice, itemCount: newTotal });
		}

		return {
			pages,
			pageParams:
				newerInsertedCount > 0
					? old.pageParams.map((pageParam) => (pageParam > 0 ? pageParam + newerInsertedCount : pageParam))
					: old.pageParams,
		};
	});
};

export const upsertThreadMessageInCache = (
	message: IMessage,
	rid: IMessage['rid'],
	tmid: IMessage['_id'],
	client: QueryClient = defaultQueryClient,
): void => {
	const queryKey = roomsQueryKeys.threadMessages(rid, tmid);

	if (!client.getQueryData<ThreadMessagesInfiniteData>(queryKey)) {
		client.setQueryData<ThreadMessagesInfiniteData>(queryKey, {
			pages: [{ items: [message as IThreadMessage], itemCount: 1 }],
			pageParams: [0],
		});
		return;
	}

	mutateThreadMessagesInfiniteData(client, queryKey, (messages) => {
		let shouldReturn = false;
		for (let idx = 0; idx < messages.length; idx++) {
			if (messages[idx]._id === message._id) {
				messages[idx] = message as IThreadMessage;
				shouldReturn = true;
			}
		}
		if (shouldReturn) {
			return;
		}

		messages.push(message as IThreadMessage);
		messages.sort((a, b) => new Date(a.ts).getTime() - new Date(b.ts).getTime());
	});
};

export const markThreadMessagesAsRead = (messages: IThreadMessage[], until?: Date): IThreadMessage[] => {
	return messages.map((msg) => {
		if (!msg.unread) {
			return msg;
		}
		if (until && new Date(msg.ts) > until) {
			return msg;
		}
		const { unread: _, ...rest } = msg;
		return rest as IThreadMessage;
	});
};

export const mergeThreadMessages = (cachedMessages: IThreadMessage[], fetchedMessages: IThreadMessage[]): IThreadMessage[] => {
	const messageMap = new Map<string, IThreadMessage>();

	for (const msg of cachedMessages) {
		messageMap.set(msg._id, msg);
	}

	for (const msg of fetchedMessages) {
		const existing = messageMap.get(msg._id);
		if (!existing) {
			messageMap.set(msg._id, msg);
		} else {
			const msgTime = new Date(msg._updatedAt ?? msg.ts).getTime();
			const existingTime = new Date(existing._updatedAt ?? existing.ts).getTime();
			if (msgTime > existingTime) {
				messageMap.set(msg._id, msg);
			}
		}
	}

	return Array.from(messageMap.values()).sort((a, b) => new Date(a.ts).getTime() - new Date(b.ts).getTime());
};