import {
  BadRequestException,
  ForbiddenException,
  Injectable,
  NotFoundException,
} from '@nestjs/common';
import { InjectRepository } from '@nestjs/typeorm';
import { IsNull, Repository } from 'typeorm';
import { AbsencesGardeService } from '../absences-garde/absences-garde.service';
import {
  StatutAbsenceGardeType,
  TypeAbsenceGardeType,
} from 'src/entities/absences_garde.entity';
import { AmChildren } from 'src/entities/am_children.entity';
import { ParentsChildren } from 'src/entities/parents_children.entity';
import { RoleType } from 'src/entities/users.entity';
import { CardType, CardResponseModeType } from 'src/entities/card_types.entity';
import {
  CardInstance,
  CardInstanceStatutType,
  CardOperationType,
} from 'src/entities/card_instances.entity';
import { CardAudienceMember } from 'src/entities/card_audience_members.entity';
import {
  CardResponse,
  CardResponseActionType,
} from 'src/entities/card_responses.entity';
import {
  CarteDto,
  CreerCarteDto,
  ListeCartesDto,
  MajCarteDto,
  RepondreCarteDto,
} from './dto/cards.dto';
import { CardsRealtimeService } from './cards-realtime.service';

@Injectable()
export class CardsService {
  constructor(
    @InjectRepository(CardType)
    private readonly typesRepo: Repository<CardType>,
    @InjectRepository(CardInstance)
    private readonly cardsRepo: Repository<CardInstance>,
    @InjectRepository(CardAudienceMember)
    private readonly audienceRepo: Repository<CardAudienceMember>,
    @InjectRepository(CardResponse)
    private readonly responsesRepo: Repository<CardResponse>,
    @InjectRepository(AmChildren)
    private readonly amChildrenRepo: Repository<AmChildren>,
    @InjectRepository(ParentsChildren)
    private readonly parentsChildrenRepo: Repository<ParentsChildren>,
    private readonly absencesService: AbsencesGardeService,
    private readonly realtime: CardsRealtimeService,
  ) {}

  async listerTypes(role: RoleType): Promise<CardType[]> {
    const all = await this.typesRepo.find({ where: { system: true } });
    return all.filter((t) => t.emitter_roles.includes(role));
  }

  async lister(
    userId: string,
    role: RoleType,
    placementId?: string,
  ): Promise<ListeCartesDto> {
    const qb = this.cardsRepo
      .createQueryBuilder('c')
      .innerJoin('c.audience', 'aud', 'aud.id_utilisateur = :userId', { userId })
      .leftJoinAndSelect('c.type', 'type')
      .leftJoinAndSelect('c.responses', 'responses')
      .where('c.purge_at > now()')
      .orderBy(
        `CASE c.statut WHEN 'refusee' THEN 0 WHEN 'ouverte' THEN 1 ELSE 2 END`,
        'ASC',
      )
      .addOrderBy('c.modifie_le', 'DESC');

    if (placementId) {
      await this.assertPlacementAccess(userId, role, placementId);
      qb.andWhere('c.id_placement = :placementId', { placementId });
    }

    const rows = await qb.getMany();
    return {
      items: rows.map((c) => this.toDto(c, userId)),
    };
  }

  async creer(
    userId: string,
    role: RoleType,
    dto: CreerCarteDto,
  ): Promise<CarteDto> {
    if (dto.date_fin < dto.date_debut) {
      throw new BadRequestException('date_fin < date_debut');
    }

    const type = await this.typesRepo.findOne({ where: { code: dto.type_code } });
    if (!type || !type.system) {
      throw new NotFoundException('Type de carte inconnu');
    }
    if (!type.emitter_roles.includes(role)) {
      throw new ForbiddenException('Vous ne pouvez pas émettre ce type de carte');
    }

    const placement = await this.assertPlacementAccess(
      userId,
      role,
      dto.id_placement,
    );
    const operation = dto.operation ?? CardOperationType.CREATE;

    let absenceId = dto.id_absence;
    const absenceType = this.mapAbsenceType(dto.type_code);

    if (operation === CardOperationType.CREATE) {
      const absence = await this.absencesService.creer(userId, role, {
        id_placement: dto.id_placement,
        type: absenceType,
        date_debut: dto.date_debut,
        date_fin: dto.date_fin,
        motif: dto.motif,
      });
      absenceId = absence.id;
    } else {
      if (!absenceId) {
        throw new BadRequestException('id_absence requis pour operation=update');
      }
      await this.absencesService.maj(userId, role, absenceId, {
        date_debut: dto.date_debut,
        date_fin: dto.date_fin,
        motif: dto.motif,
        // Congé accepté modifié → repasse en attente via cartes respond flow;
        // pour absence enfant update immédiat déjà fait.
        ...(dto.type_code === 'conge_am'
          ? { statut: StatutAbsenceGardeType.EN_ATTENTE }
          : {}),
      });
    }

    const statutInitial =
      type.response_mode === CardResponseModeType.NONE
        ? CardInstanceStatutType.TRAITEE
        : CardInstanceStatutType.OUVERTE;

    const card = this.cardsRepo.create({
      type_code: type.code,
      id_placement: dto.id_placement,
      id_absence: absenceId,
      cree_par: userId,
      operation,
      statut: statutInitial,
      payload: {
        date_debut: dto.date_debut,
        date_fin: dto.date_fin,
        motif: dto.motif ?? null,
      },
      purge_at: this.purgeAt(type.retention_days, statutInitial),
    });
    const saved = await this.cardsRepo.save(card);

    if (absenceId) {
      await this.linkAbsenceCard(absenceId, saved.id);
    }

    await this.buildAudience(saved, type, placement, userId, role);

    const full = await this.loadCard(saved.id);
    const dtoOut = this.toDto(full, userId);
    this.emitAudience(full, 'card.created', dtoOut);
    return dtoOut;
  }

  async repondre(
    userId: string,
    role: RoleType,
    cardId: string,
    dto: RepondreCarteDto,
  ): Promise<CarteDto> {
    const card = await this.loadCard(cardId);
    await this.assertInAudience(card, userId);
    if (card.statut !== CardInstanceStatutType.OUVERTE) {
      throw new BadRequestException('Cette carte n’est plus ouverte');
    }
    if (card.cree_par === userId) {
      throw new ForbiddenException('Le créateur ne répond pas à sa propre carte');
    }

    const mode = card.type.response_mode;
    if (mode === CardResponseModeType.NONE) {
      throw new BadRequestException('Ce type de carte ne demande pas de réponse');
    }
    if (mode === CardResponseModeType.ACK && dto.action !== CardResponseActionType.ACK) {
      throw new BadRequestException('Action attendue : ack');
    }
    if (
      mode === CardResponseModeType.ACCEPT_REFUSE &&
      dto.action !== CardResponseActionType.ACCEPT &&
      dto.action !== CardResponseActionType.REFUSE
    ) {
      throw new BadRequestException('Action attendue : accept ou refuse');
    }
    if (dto.action === CardResponseActionType.REFUSE && !dto.comment?.trim()) {
      throw new BadRequestException('Motivation obligatoire en cas de refus');
    }

    await this.responsesRepo.save(
      this.responsesRepo.create({
        id_card: card.id,
        id_utilisateur: userId,
        action: dto.action,
        comment: dto.comment?.trim(),
      }),
    );

    if (card.id_absence) {
      if (dto.action === CardResponseActionType.ACCEPT || dto.action === CardResponseActionType.ACK) {
        await this.absencesService.maj(userId, role, card.id_absence, {
          statut: StatutAbsenceGardeType.ACCEPTE,
        });
        card.statut = CardInstanceStatutType.TRAITEE;
      } else if (dto.action === CardResponseActionType.REFUSE) {
        await this.absencesService.maj(userId, role, card.id_absence, {
          statut: StatutAbsenceGardeType.REFUSE,
          motif: dto.comment!.trim(),
        });
        card.statut = CardInstanceStatutType.REFUSEE;
      }
    } else if (dto.action === CardResponseActionType.ACK) {
      card.statut = CardInstanceStatutType.TRAITEE;
    }

    card.purge_at = this.purgeAt(card.type.retention_days, card.statut);
    await this.cardsRepo.save(card);
    const full = await this.loadCard(cardId);
    const dtoOut = this.toDto(full, userId);
    this.emitAudience(full, 'response.added', {
      action: dto.action,
      card: dtoOut,
    });
    this.emitAudience(full, 'card.updated', dtoOut);
    return dtoOut;
  }

  async majEnAttente(
    userId: string,
    role: RoleType,
    cardId: string,
    dto: MajCarteDto,
  ): Promise<CarteDto> {
    const card = await this.loadCard(cardId);
    if (card.cree_par !== userId) {
      throw new ForbiddenException('Seul le créateur peut modifier cette carte');
    }
    if (
      card.statut !== CardInstanceStatutType.OUVERTE &&
      card.statut !== CardInstanceStatutType.REFUSEE
    ) {
      throw new BadRequestException('Carte non modifiable dans cet état');
    }

    const debut =
      dto.date_debut ?? String(card.payload?.['date_debut'] ?? '');
    const fin = dto.date_fin ?? String(card.payload?.['date_fin'] ?? '');
    if (!debut || !fin || fin < debut) {
      throw new BadRequestException('Dates invalides');
    }

    if (card.id_absence) {
      await this.absencesService.maj(userId, role, card.id_absence, {
        date_debut: debut,
        date_fin: fin,
        motif: dto.motif,
        statut: StatutAbsenceGardeType.EN_ATTENTE,
      });
    }

    card.payload = {
      ...card.payload,
      date_debut: debut,
      date_fin: fin,
      motif: dto.motif ?? card.payload?.['motif'] ?? null,
    };
    card.statut = CardInstanceStatutType.OUVERTE;
    card.purge_at = this.purgeAt(card.type.retention_days, card.statut);
    await this.cardsRepo.save(card);
    const full = await this.loadCard(cardId);
    const dtoOut = this.toDto(full, userId);
    this.emitAudience(full, 'card.updated', dtoOut);
    return dtoOut;
  }

  async supprimer(
    userId: string,
    role: RoleType,
    cardId: string,
  ): Promise<void> {
    const card = await this.loadCard(cardId);
    if (card.cree_par !== userId) {
      throw new ForbiddenException('Seul le créateur peut supprimer cette carte');
    }
    const audienceIds = await this.audienceUserIds(card);
    if (card.id_absence) {
      const absStatut =
        card.statut === CardInstanceStatutType.TRAITEE
          ? null
          : card.id_absence;
      // Supprime l’absence liée si pas encore acceptée définitivement
      if (
        card.statut === CardInstanceStatutType.OUVERTE ||
        card.statut === CardInstanceStatutType.REFUSEE
      ) {
        await this.absencesService.supprimer(userId, role, card.id_absence);
      }
      void absStatut;
    }
    await this.cardsRepo.delete({ id: cardId });
    this.realtime.emitToUsers(audienceIds, 'card.deleted', cardId, {
      id: cardId,
    });
  }

  private emitAudience(
    card: CardInstance,
    event: 'card.created' | 'card.updated' | 'response.added',
    data: unknown,
  ): void {
    const ids = (card.audience ?? []).map((a) => a.id_utilisateur);
    if (ids.length === 0) return;
    this.realtime.emitToUsers(ids, event, card.id, data);
  }

  private async audienceUserIds(card: CardInstance): Promise<string[]> {
    if (card.audience?.length) {
      return card.audience.map((a) => a.id_utilisateur);
    }
    const rows = await this.audienceRepo.find({ where: { id_card: card.id } });
    return rows.map((r) => r.id_utilisateur);
  }

  private mapAbsenceType(typeCode: string): TypeAbsenceGardeType {
    if (typeCode === 'absence_enfant' || typeCode === 'absence_enfant_modif') {
      return TypeAbsenceGardeType.ABSENCE_ENFANT;
    }
    if (typeCode === 'conge_am') return TypeAbsenceGardeType.CONGE_AM;
    if (typeCode === 'arret_maladie_am') {
      return TypeAbsenceGardeType.ARRET_MALADIE_AM;
    }
    throw new BadRequestException(`Type non mappé à une absence: ${typeCode}`);
  }

  private async linkAbsenceCard(absenceId: string, cardId: string): Promise<void> {
    // Update direct pour éviter droits maj vides
    await this.cardsRepo.manager.query(
      `UPDATE absences_garde SET id_card_instance = $1, modifie_le = now() WHERE id = $2`,
      [cardId, absenceId],
    );
  }

  private async buildAudience(
    card: CardInstance,
    type: CardType,
    placement: AmChildren,
    creatorId: string,
    creatorRole: RoleType,
  ): Promise<void> {
    const members: Partial<CardAudienceMember>[] = [
      {
        id_card: card.id,
        id_utilisateur: creatorId,
        role_snapshot: creatorRole,
        is_creator: true,
      },
    ];

    if (type.audience_resolver === 'couple_am') {
      members.push({
        id_card: card.id,
        id_utilisateur: placement.amId,
        role_snapshot: RoleType.ASSISTANTE_MATERNELLE,
        is_creator: false,
      });
    } else if (type.audience_resolver === 'couple_parents') {
      const liens = await this.parentsChildrenRepo.find({
        where: { enfantId: placement.enfantId },
      });
      for (const l of liens) {
        if (l.parentId === creatorId) continue;
        members.push({
          id_card: card.id,
          id_utilisateur: l.parentId,
          role_snapshot: RoleType.PARENT,
          is_creator: false,
        });
      }
    }

    // dédup
    const seen = new Set<string>();
    const unique = members.filter((m) => {
      const k = m.id_utilisateur!;
      if (seen.has(k)) return false;
      seen.add(k);
      return true;
    });
    await this.audienceRepo.save(this.audienceRepo.create(unique));
  }

  private purgeAt(
    retentionDays: number,
    statut: CardInstanceStatutType,
  ): Date {
    const days =
      statut === CardInstanceStatutType.OUVERTE
        ? Math.max(retentionDays, 15)
        : retentionDays;
    return new Date(Date.now() + days * 24 * 60 * 60 * 1000);
  }

  private async loadCard(id: string): Promise<CardInstance> {
    const card = await this.cardsRepo.findOne({
      where: { id },
      relations: ['type', 'responses', 'audience'],
    });
    if (!card) throw new NotFoundException('Carte introuvable');
    return card;
  }

  private async assertInAudience(card: CardInstance, userId: string): Promise<void> {
    const ok = (card.audience ?? []).some((a) => a.id_utilisateur === userId);
    if (!ok) {
      const row = await this.audienceRepo.findOne({
        where: { id_card: card.id, id_utilisateur: userId },
      });
      if (!row) throw new ForbiddenException('Carte hors de votre audience');
    }
  }

  private async assertPlacementAccess(
    userId: string,
    role: RoleType,
    placementId: string,
  ): Promise<AmChildren> {
    const placement = await this.amChildrenRepo.findOne({
      where: { id: placementId, date_fin: IsNull() },
    });
    if (!placement) {
      throw new NotFoundException('Placement introuvable ou inactif');
    }
    if (role === RoleType.ASSISTANTE_MATERNELLE) {
      if (placement.amId !== userId) {
        throw new ForbiddenException('Placement non autorisé');
      }
      return placement;
    }
    if (role === RoleType.PARENT) {
      const lien = await this.parentsChildrenRepo.findOne({
        where: { parentId: userId, enfantId: placement.enfantId },
      });
      if (!lien) throw new ForbiddenException('Placement non autorisé');
      return placement;
    }
    throw new ForbiddenException('Rôle non autorisé');
  }

  private toDto(card: CardInstance, userId: string): CarteDto {
    const lastRefuse = [...(card.responses ?? [])]
      .reverse()
      .find((r) => r.action === CardResponseActionType.REFUSE);
    return {
      id: card.id,
      type_code: card.type_code,
      titre: card.type?.titre ?? card.type_code,
      couleur: card.type?.couleur ?? null,
      id_placement: card.id_placement,
      id_absence: card.id_absence ?? null,
      operation: card.operation,
      statut: card.statut,
      payload: card.payload ?? {},
      purge_at: card.purge_at?.toISOString?.() ?? String(card.purge_at),
      cree_par: card.cree_par ?? null,
      is_creator: card.cree_par === userId,
      response_mode: card.type?.response_mode,
      last_refuse_comment: lastRefuse?.comment ?? null,
      cree_le: card.cree_le?.toISOString?.() ?? String(card.cree_le),
      modifie_le: card.modifie_le?.toISOString?.() ?? String(card.modifie_le),
    };
  }
}