import { Injectable } from '@nestjs/common';
import { InjectModel } from '@nestjs/mongoose';
import { Types, Model } from 'mongoose';
import { User, UserDocument } from '@/models/user.model';
import { CreateUserInput } from './dto/create-user.input';

@Injectable()
export class UsersService {

    constructor(
        @InjectModel(User.name) private readonly userModel: Model<UserDocument>
    ) { }

    async findAll(projection?: any): Promise<UserDocument[]> {
        return this.userModel.find({}, projection, { lean: false }).populate({ path: 'person', select: projection?.person }).exec();
    }

    async findById(id: Types.ObjectId, projection?: any): Promise<UserDocument | null> {
        return this.userModel.findById(id, projection, { lean: false }).populate({ path: 'person', select: projection?.person }).exec();
    }

    async create(input: CreateUserInput): Promise<UserDocument> {
        const user = new this.userModel(input);
        return user.save();
    }

    buildProjection(fields: Record<string, any>): any {
        const projection: any = {};
        for (const key in fields) {
            if (key === 'person' && typeof fields[key] === 'object') { for (const subField of Object.keys(fields[key])) { projection[`person.${subField}`] = 1 } }
            else { projection[key] = 1 }
        }
        return projection;
    }
}