import { Injectable, NotFoundException } from '@nestjs/common';
import { InjectRepository } from '@nestjs/typeorm';
import { Repository } from 'typeorm';
import { Parents } from 'src/entities/parents.entity';
import { AssistanteMaternelle } from 'src/entities/assistantes_maternelles.entity';
import { StatutUtilisateurType, Users } from 'src/entities/users.entity';
import { ParentsService } from '../parents/parents.service';
import { SuppressionService } from '../suppressions/suppression.service';
import { DossierUnifieDto } from './dto/dossier-unifie.dto';
import { DossierAmCompletDto, DossierAmUserDto } from './dto/dossier-am-complet.dto';
import { DossierListItemDto } from './dto/dossier-list-item.dto';

/**
 * Dossiers unifiés — détail (#119) + liste (#153) + sans_enfant (#159).
 */
@Injectable()
export class DossiersService {
  constructor(
    @InjectRepository(Parents)
    private readonly parentsRepository: Repository<Parents>,
    @InjectRepository(AssistanteMaternelle)
    private readonly amRepository: Repository<AssistanteMaternelle>,
    private readonly parentsService: ParentsService,
    private readonly suppressionService: SuppressionService,
  ) {}

  /**
   * Liste unifiée tous dossiers (familles + AM) ayant un numero_dossier.
   * Ticket #153 — optionnel `q` filtre n° / nom / prénom / email (côté serveur).
   */
  async listDossiers(q?: string): Promise<DossierListItemDto[]> {
    const items: DossierListItemDto[] = [
      ...(await this.listFamilleItems()),
      ...(await this.listAmItems()),
    ];

    const needle = (q ?? '').trim().toLowerCase();
    const filtered = needle
      ? items.filter((item) => this.matchesQuery(item, needle))
      : items;

    filtered.sort((a, b) => {
      // À valider d'abord, puis n° dossier décroissant
      if (a.a_valider !== b.a_valider) return a.a_valider ? -1 : 1;
      return b.numero_dossier.localeCompare(a.numero_dossier, 'fr');
    });

    for (const item of filtered) {
      if (item.type === 'famille') {
        const n = await this.suppressionService.countEnfantsForNumero(
          item.numero_dossier,
        );
        item.sans_enfant = n === 0;
      } else {
        item.sans_enfant = false;
      }
    }

    return filtered;
  }

  private async listFamilleItems(): Promise<DossierListItemDto[]> {
    const parents = await this.parentsRepository
      .createQueryBuilder('p')
      .innerJoinAndSelect('p.user', 'u')
      .leftJoinAndSelect('p.co_parent', 'cp')
      .where('p.numero_dossier IS NOT NULL')
      .andWhere("TRIM(p.numero_dossier) <> ''")
      .getMany();

    const byNum = new Map<string, Parents[]>();
    for (const p of parents) {
      const num = (p.numero_dossier ?? '').trim();
      if (!num) continue;
      const group = byNum.get(num) ?? [];
      group.push(p);
      byNum.set(num, group);
    }

    const items: DossierListItemDto[] = [];
    for (const [numero_dossier, group] of byNum) {
      const usersMap = new Map<string, Users>();
      for (const p of group) {
        if (p.user) usersMap.set(p.user.id, p.user);
        if (p.co_parent) usersMap.set(p.co_parent.id, p.co_parent);
      }
      const users = [...usersMap.values()].sort((a, b) => {
        const an = `${a.nom ?? ''} ${a.prenom ?? ''}`.toLowerCase();
        const bn = `${b.nom ?? ''} ${b.prenom ?? ''}`.toLowerCase();
        return an.localeCompare(bn, 'fr') || a.id.localeCompare(b.id);
      });
      if (users.length === 0) continue;

      const names = users.map((u) => this.formatPersonName(u)).filter(Boolean);
      const libelle =
        names.length === 0
          ? `Dossier ${numero_dossier}`
          : names.length === 1
            ? names[0]
            : names.join(' & ');

      const emails = users.map((u) => u.email).filter(Boolean);
      const user_ids = users.map((u) => u.id);
      const a_valider = users.some((u) => u.statut === StatutUtilisateurType.EN_ATTENTE);
      const statut = a_valider
        ? StatutUtilisateurType.EN_ATTENTE
        : (users[0].statut ?? StatutUtilisateurType.ACTIF);
      const date_reference = this.minCreeLeIso(users);

      items.push({
        type: 'famille',
        numero_dossier,
        libelle,
        emails,
        user_ids,
        statut,
        a_valider,
        date_reference,
      });
    }
    return items;
  }

  private async listAmItems(): Promise<DossierListItemDto[]> {
    const ams = await this.amRepository
      .createQueryBuilder('am')
      .innerJoinAndSelect('am.user', 'u')
      .where('am.numero_dossier IS NOT NULL')
      .andWhere("TRIM(am.numero_dossier) <> ''")
      .getMany();

    const byNum = new Map<string, AssistanteMaternelle>();
    for (const am of ams) {
      const num = (am.numero_dossier ?? '').trim();
      if (!num || !am.user) continue;
      // Un n° = une AM ; garder le premier
      if (!byNum.has(num)) byNum.set(num, am);
    }

    const items: DossierListItemDto[] = [];
    for (const [numero_dossier, am] of byNum) {
      const u = am.user!;
      const libelle = this.formatPersonName(u) || `AM ${numero_dossier}`;
      const a_valider = u.statut === StatutUtilisateurType.EN_ATTENTE;
      items.push({
        type: 'assistante_maternelle',
        numero_dossier,
        libelle,
        emails: u.email ? [u.email] : [],
        user_ids: [u.id],
        statut: u.statut ?? StatutUtilisateurType.ACTIF,
        a_valider,
        date_reference: this.minCreeLeIso([u]),
      });
    }
    return items;
  }

  private matchesQuery(item: DossierListItemDto, needle: string): boolean {
    const hay = [
      item.numero_dossier,
      item.libelle,
      ...item.emails,
      item.statut,
      item.type,
    ]
      .join(' ')
      .toLowerCase();
    return hay.includes(needle);
  }

  private formatPersonName(u: Users): string {
    const prenom = (u.prenom ?? '').trim();
    const nom = (u.nom ?? '').trim();
    const nomFmt = nom ? nom.toUpperCase() : '';
    return [prenom, nomFmt].filter(Boolean).join(' ');
  }

  private minCreeLeIso(users: Users[]): string | null {
    let min: Date | null = null;
    for (const u of users) {
      const d = u.cree_le;
      if (!d) continue;
      const date = d instanceof Date ? d : new Date(d);
      if (Number.isNaN(date.getTime())) continue;
      if (!min || date < min) min = date;
    }
    return min ? min.toISOString() : null;
  }

  async getDossierByNumero(numeroDossier: string): Promise<DossierUnifieDto> {
    const num = numeroDossier?.trim();
    if (!num) {
      throw new NotFoundException('Numéro de dossier requis.');
    }

    // 1) Famille : un parent a ce numéro ?
    const parentWithNum = await this.parentsRepository.findOne({
      where: { numero_dossier: num },
      select: ['user_id'],
    });
    if (parentWithNum) {
      const dossier = await this.parentsService.getDossierFamilleByNumero(num);
      return { type: 'family', dossier };
    }

    // 2) AM : une assistante maternelle a ce numéro ?
    const am = await this.amRepository.findOne({
      where: { numero_dossier: num },
      relations: ['user'],
    });
    if (am?.user) {
      const dossier: DossierAmCompletDto = {
        numero_dossier: num,
        user: this.toDossierAmUserDto(am.user),
        numero_agrement: am.approval_number,
        nir: am.nir,
        biographie: am.biography,
        disponible: am.available,
        ville_residence: am.residence_city,
        date_agrement: am.agreement_date,
        annees_experience: am.years_experience,
        specialite: am.specialty,
        nb_max_enfants: am.max_children,
        place_disponible: am.places_available,
      };
      return { type: 'am', dossier };
    }

    throw new NotFoundException('Aucun dossier trouvé pour ce numéro.');
  }

  private toDossierAmUserDto(user: {
    id: string;
    email: string;
    prenom?: string;
    nom?: string;
    telephone?: string;
    adresse?: string;
    ville?: string;
    code_postal?: string;
    profession?: string;
    date_naissance?: Date;
    lieu_naissance_ville?: string;
    lieu_naissance_pays?: string;
    photo_url?: string;
    consentement_photo?: boolean;
    statut: any;
  }): DossierAmUserDto {
    return {
      id: user.id,
      email: user.email,
      prenom: user.prenom,
      nom: user.nom,
      telephone: user.telephone,
      adresse: user.adresse,
      ville: user.ville,
      code_postal: user.code_postal,
      profession: user.profession,
      date_naissance: user.date_naissance,
      lieu_naissance_ville: user.lieu_naissance_ville,
      lieu_naissance_pays: user.lieu_naissance_pays,
      photo_url: user.photo_url,
      consentement_photo: user.consentement_photo,
      statut: user.statut,
    };
  }
}