import {
  ConflictException,
  Injectable,
  NotFoundException,
} from '@nestjs/common';
import { PrismaService } from '../prisma/prisma.service';
import { AuditLogService } from '../audit/audit-log.service';
import { WebhooksService } from '../webhooks/webhooks.service';
import { Colony, ColonyStatus } from '../../generated/prisma';
import { CreateColonyDto } from './dto/create-colony.dto';
import { UpdateColonyDto } from './dto/update-colony.dto';
import { MoveColonyDto } from './dto/move-colony.dto';
import { SplitColonyDto } from './dto/split-colony.dto';
import { MergeColonyDto } from './dto/merge-colony.dto';

export interface ColonyFilter {
  status?: ColonyStatus;
  apiaryId?: string;
}

@Injectable()
export class ColoniesService {
  constructor(
    private readonly prisma: PrismaService,
    private readonly auditLog: AuditLogService,
    private readonly webhooks: WebhooksService,
  ) {}

  async findAll(filter: ColonyFilter = {}): Promise<Colony[]> {
    return this.prisma.colony.findMany({
      where: { status: filter.status, apiaryId: filter.apiaryId },
      orderBy: { code: 'asc' },
    });
  }

  async findById(id: string): Promise<Colony> {
    const colony = await this.prisma.colony.findUnique({ where: { id } });
    if (!colony) {
      throw new NotFoundException('Colony not found');
    }
    return colony;
  }

  private assertActive(colony: Colony): void {
    if (colony.status !== 'ACTIVE') {
      throw new ConflictException(
        `Colony ${colony.id} is not active (status: ${colony.status})`,
      );
    }
  }

  async create(dto: CreateColonyDto, actingUserId: string): Promise<Colony> {
    const colony = await this.prisma.colony.create({ data: { ...dto } });
    await this.auditLog.record({
      entityType: 'Colony',
      entityId: colony.id,
      action: 'CREATE',
      userId: actingUserId,
      afterData: colony,
    });
    await this.webhooks.dispatch('colony.created', colony);
    return colony;
  }

  async update(
    id: string,
    dto: UpdateColonyDto,
    actingUserId: string,
  ): Promise<Colony> {
    const before = await this.findById(id);
    const colony = await this.prisma.colony.update({
      where: { id },
      data: { ...dto },
    });
    await this.auditLog.record({
      entityType: 'Colony',
      entityId: id,
      action: 'UPDATE',
      userId: actingUserId,
      beforeData: before,
      afterData: colony,
    });
    return colony;
  }

  async move(
    id: string,
    dto: MoveColonyDto,
    actingUserId: string,
  ): Promise<Colony> {
    const before = await this.findById(id);
    this.assertActive(before);
    const colony = await this.prisma.$transaction(async (tx) => {
      const updated = await tx.colony.update({
        where: { id },
        data: { apiaryId: dto.apiaryId },
      });
      await tx.colonyApiaryHistory.create({
        data: {
          colonyId: id,
          apiaryId: dto.apiaryId,
          movedByUserId: actingUserId,
          notes: dto.notes,
        },
      });
      return updated;
    });
    await this.auditLog.record({
      entityType: 'Colony',
      entityId: id,
      action: 'UPDATE',
      userId: actingUserId,
      beforeData: before,
      afterData: colony,
    });
    return colony;
  }

  async split(
    id: string,
    dto: SplitColonyDto,
    actingUserId: string,
  ): Promise<Colony> {
    const parent = await this.findById(id);
    this.assertActive(parent);
    const child = await this.prisma.$transaction(async (tx) => {
      const created = await tx.colony.create({
        data: {
          code: dto.code,
          apiaryId: parent.apiaryId,
          colonyType: dto.colonyType,
          notes: dto.notes,
        },
      });
      await tx.colonyLineage.create({
        data: {
          type: 'SPLIT',
          fromColonyId: parent.id,
          toColonyId: created.id,
          date: new Date(),
          notes: dto.notes,
        },
      });
      return created;
    });
    await this.auditLog.record({
      entityType: 'Colony',
      entityId: child.id,
      action: 'CREATE',
      userId: actingUserId,
      afterData: { ...child, splitFromColonyId: parent.id },
    });
    return child;
  }

  async merge(
    id: string,
    dto: MergeColonyDto,
    actingUserId: string,
  ): Promise<Colony> {
    const survivor = await this.findById(id);
    this.assertActive(survivor);
    await this.prisma.$transaction(async (tx) => {
      for (const mergedColonyId of dto.mergedColonyIds) {
        const merged = await tx.colony.findUnique({
          where: { id: mergedColonyId },
        });
        if (!merged) {
          throw new NotFoundException(`Colony ${mergedColonyId} not found`);
        }
        this.assertActive(merged);
        await tx.colony.update({
          where: { id: mergedColonyId },
          data: { status: 'MERGED', deactivatedAt: new Date() },
        });
        await tx.colonyLineage.create({
          data: {
            type: 'MERGE',
            fromColonyId: mergedColonyId,
            toColonyId: survivor.id,
            date: new Date(),
            notes: dto.notes,
          },
        });
      }
    });
    await this.auditLog.record({
      entityType: 'Colony',
      entityId: survivor.id,
      action: 'UPDATE',
      userId: actingUserId,
      beforeData: survivor,
      afterData: { ...survivor, mergedColonyIds: dto.mergedColonyIds },
    });
    return this.findById(survivor.id);
  }

  async dissolve(id: string, actingUserId: string): Promise<Colony> {
    const before = await this.findById(id);
    const colony = await this.prisma.colony.update({
      where: { id },
      data: { status: 'DISSOLVED', deactivatedAt: new Date() },
    });
    await this.auditLog.record({
      entityType: 'Colony',
      entityId: id,
      action: 'DEACTIVATE',
      userId: actingUserId,
      beforeData: before,
      afterData: colony,
    });
    return colony;
  }

  async reactivate(id: string, actingUserId: string): Promise<Colony> {
    const before = await this.findById(id);
    if (before.status === 'ACTIVE') {
      throw new ConflictException('Colony is already active');
    }
    const colony = await this.prisma.colony.update({
      where: { id },
      data: { status: 'ACTIVE', deactivatedAt: null },
    });
    await this.auditLog.record({
      entityType: 'Colony',
      entityId: id,
      action: 'UPDATE',
      userId: actingUserId,
      beforeData: before,
      afterData: colony,
    });
    return colony;
  }

  async getHistory(id: string) {
    await this.findById(id);
    const [apiaryHistory, queenHistory, lineageAsSource, lineageAsResult] =
      await Promise.all([
        this.prisma.colonyApiaryHistory.findMany({
          where: { colonyId: id },
          orderBy: { movedAt: 'desc' },
        }),
        this.prisma.queenColonyHistory.findMany({
          where: { colonyId: id },
          orderBy: { startDate: 'desc' },
        }),
        this.prisma.colonyLineage.findMany({ where: { fromColonyId: id } }),
        this.prisma.colonyLineage.findMany({ where: { toColonyId: id } }),
      ]);
    return { apiaryHistory, queenHistory, lineageAsSource, lineageAsResult };
  }
}