import ms from 'ms';
import { Inject, Injectable } from '@nestjs/common';
import { Endpoint } from '@/server/api/endpoint-base.js';
import type { UsersRepository, FollowingsRepository } from '@/models/index.js';
import { IdentifiableError } from '@/misc/identifiable-error.js';
import { UserEntityService } from '@/core/entities/UserEntityService.js';
import { UserFollowingService } from '@/core/UserFollowingService.js';
import { DI } from '@/di-symbols.js';
import { GetterService } from '@/server/api/GetterService.js';
import { ApiError } from '../../error.js';

export const meta = {
	tags: ['following', 'users'],

	limit: {
		duration: ms('1hour'),
		max: 50,
	},

	requireCredential: true,

	prohibitMoved: true,

	kind: 'write:following',

	errors: {
		noSuchUser: {
			message: 'No such user.',
			code: 'NO_SUCH_USER',
			id: 'fcd2eef9-a9b2-4c4f-8624-038099e90aa5',
		},

		followeeIsYourself: {
			message: 'Followee is yourself.',
			code: 'FOLLOWEE_IS_YOURSELF',
			id: '26fbe7bb-a331-4857-af17-205b426669a9',
		},

		alreadyFollowing: {
			message: 'You are already following that user.',
			code: 'ALREADY_FOLLOWING',
			id: '35387507-38c7-4cb9-9197-300b93783fa0',
		},

		blocking: {
			message: 'You are blocking that user.',
			code: 'BLOCKING',
			id: '4e2206ec-aa4f-4960-b865-6c23ac38e2d9',
		},

		blocked: {
			message: 'You are blocked by that user.',
			code: 'BLOCKED',
			id: 'c4ab57cc-4e41-45e9-bfd9-584f61e35ce0',
		},
	},

	res: {
		type: 'object',
		optional: false, nullable: false,
		ref: 'UserLite',
	},
} as const;

export const paramDef = {
	type: 'object',
	properties: {
		userId: { type: 'string', format: 'misskey:id' },
	},
	required: ['userId'],
} as const;

// eslint-disable-next-line import/no-default-export
@Injectable()
export default class extends Endpoint<typeof meta, typeof paramDef> {
	constructor(
		@Inject(DI.usersRepository)
		private usersRepository: UsersRepository,

		@Inject(DI.followingsRepository)
		private followingsRepository: FollowingsRepository,

		private userEntityService: UserEntityService,
		private getterService: GetterService,
		private userFollowingService: UserFollowingService,
	) {
		super(meta, paramDef, async (ps, me) => {
			const follower = me;

			// 自分自身
			if (me.id === ps.userId) {
				throw new ApiError(meta.errors.followeeIsYourself);
			}

			// Get followee
			const followee = await this.getterService.getUser(ps.userId).catch(err => {
				if (err.id === '15348ddd-432d-49c2-8a5a-8069753becff') throw new ApiError(meta.errors.noSuchUser);
				throw err;
			});

			// Check if already following
			const exist = await this.followingsRepository.exist({
				where: {
					followerId: follower.id,
					followeeId: followee.id,
				},
			});

			if (exist) {
				throw new ApiError(meta.errors.alreadyFollowing);
			}

			try {
				await this.userFollowingService.follow(follower, followee);
			} catch (e) {
				if (e instanceof IdentifiableError) {
					if (e.id === '710e8fb0-b8c3-4922-be49-d5d93d8e6a6e') throw new ApiError(meta.errors.blocking);
					if (e.id === '3338392a-f764-498d-8855-db939dcf8c48') throw new ApiError(meta.errors.blocked);
				}
				throw e;
			}

			return await this.userEntityService.pack(followee.id, me);
		});
	}
}