import { IsNull } from "typeorm";
import follow from "@/services/following/create.js";

import * as Acct from "@/misc/acct.js";
import { resolveUser } from "@/remote/resolve-user.js";
import { downloadTextFile } from "@/misc/download-text-file.js";
import { isSelfHost, toPuny } from "@/misc/convert-host.js";
import { Users, DriveFiles } from "@/models/index.js";
import type { DbUserImportJobData } from "@/queue/types.js";
import { queueLogger } from "../../logger.js";
import { cache as heuristic } from "@/server/api/common/generate-following-query.js";
import { Job } from "bullmq";

const logger = queueLogger.createSubLogger("import-following");

export async function importFollowing(
	job: Job<DbUserImportJobData>,
): Promise<string> {
	logger.info(`Importing following of ${job.data.user.id} ...`);

	const user = await Users.findOneBy({ id: job.data.user.id });
	if (user == null) {
		return "skip: User not found";
	}

	const file = await DriveFiles.findOneBy({
		id: job.data.fileId,
	});
	if (file == null) {
		return "skip: File not found";
	}

	const csv = await downloadTextFile(file.url);

	let linenum = 0;

	if (file.type.endsWith("json")) {
		for (const acct of JSON.parse(csv)) {
			try {
				const { username, host } = Acct.parse(acct);

				let target = isSelfHost(host!)
					? await Users.findOneBy({
							host: IsNull(),
							usernameLower: username.toLowerCase(),
					  })
					: await Users.findOneBy({
							host: toPuny(host!),
							usernameLower: username.toLowerCase(),
					  });

				if (host == null && target == null) continue;

				if (target == null) {
					target = await resolveUser(username, host);
				}

				if (target == null) {
					throw new Error(`cannot resolve user: @${username}@${host}`);
				}

				// skip myself
				if (target.id === job.data.user.id) continue;

				logger.info(`Follow[${linenum}] ${target.id} ...`);

				follow(user, target);
			} catch (e) {
				logger.warn(`Error in line:${linenum} ${e}`);
			}
		}
	} else {
		for (const line of csv.trim().split("\n")) {
			linenum++;

			try {
				const acct = line.split(",")[0].trim();
				const { username, host } = Acct.parse(acct);

				let target = isSelfHost(host!)
					? await Users.findOneBy({
							host: IsNull(),
							usernameLower: username.toLowerCase(),
					  })
					: await Users.findOneBy({
							host: toPuny(host!),
							usernameLower: username.toLowerCase(),
					  });

				if (host == null && target == null) continue;

				if (target == null) {
					target = await resolveUser(username, host);
				}

				if (target == null) {
					throw new Error(`cannot resolve user: @${username}@${host}`);
				}

				// skip myself
				if (target.id === job.data.user.id) continue;

				logger.info(`Follow[${linenum}] ${target.id} ...`);

				follow(user, target);
			} catch (e) {
				logger.warn(`Error in line:${linenum} ${e}`);
			}
		}
	}

	await heuristic.delete(user.id);
	logger.succ("Imported");
	return "Success";
}
