import { Injectable, NotFoundException, InternalServerErrorException } from '@nestjs/common';
import { InjectRepository } from '@nestjs/typeorm';
import { Repository } from 'typeorm';
import { Realm } from './entity/realm.entity';
import { CreateRealmDto } from './dto/create-realm.dto';
import { UpdateRealmDto } from './dto/update-realm.dto';
import { Participant } from '../participant/entity/participant.entity';
import axios from 'axios';
import { decode } from 'jsonwebtoken';
import { AuthRequest } from '../middleware/jwtMiddleware';

@Injectable()
export class RealmService {
  constructor(
    @InjectRepository(Realm)
    private readonly realmRepo: Repository<Realm>,
    @InjectRepository(Participant)
    private readonly participantRepo: Repository<Participant>,
  ) {}

  // service
  async create(data: CreateRealmDto, user: AuthRequest['user']): Promise<Realm> {
    const realm = this.realmRepo.create({
      ...data,
      ownerId: user.sub,    // we save userId as ownerId (not participantId)
    });
    return await this.realmRepo.save(realm);
  }


  async findAll(
    page = 1,
    limit = 10,
  ): Promise<{
    docs: Realm[];
    totalDocs: number;
    limit: number;
    page: number;
    totalPages: number;
    hasNextPage: boolean;
    hasPrevPage: boolean;
    nextPage: number | null;
    prevPage: number | null;
  }> {
    const [docs, totalDocs] = await this.realmRepo.findAndCount({
      skip: (page - 1) * limit,
      take: limit,
      relations: [
        'forms',
        'forms.pages',
        'forms.pages.formSections',
        'forms.pages.formSections.attachments',
        'forms.pages.formSections.questions',
        'forms.pages.formSections.questions.options',
        'forms.pages.formSections.questions.answers',
        'participants',
        'owner',
      ],
    });

    const totalPages = Math.ceil(totalDocs / limit);
    return {
      docs,
      totalDocs,
      limit,
      page,
      totalPages,
      hasNextPage: page < totalPages,
      hasPrevPage: page > 1,
      nextPage: page < totalPages ? page + 1 : null,
      prevPage: page > 1 ? page - 1 : null,
    };
  }

  async findById(id: string): Promise<Realm | null> {
    const realm = await this.realmRepo.findOne({
      where: { id },
      relations: [
        'forms',
        'forms.pages',
        'forms.pages.formSections',
        'forms.pages.formSections.attachments',
        'forms.pages.formSections.questions',
        'forms.pages.formSections.questions.options',
        'forms.pages.formSections.questions.answers',
        'participants',
        'owner',
      ],
    });
    if (!realm) {
      throw new NotFoundException(`Realm with ID "${id}" not found`);
    }
    return realm;
  }

  async update(id: string, data: UpdateRealmDto): Promise<Realm | null> {
    const result = await this.realmRepo.update(
      { id },
      { ...data, updatedAt: new Date() },
    );
    if (result.affected === 0) {
      throw new NotFoundException(`Realm with ID "${id}" not found`);
    }
    return await this.findById(id);
  }

  async remove(id: string): Promise<void> {
    const result = await this.realmRepo.delete({ id });
    if (result.affected === 0) {
      throw new NotFoundException(`Realm with ID "${id}" not found`);
    }
  }
}