import { Injectable, NotFoundException } from '@nestjs/common';
import { PrismaService } from '../prisma/prisma.service';
import { DbClient } from '../prisma/db-client';
import { lockRowForUpdate } from '../prisma/row-lock';
import { AuditLogService } from '../audit/audit-log.service';
import { DomainEventsService } from '../domain-events/domain-events.service';
import { TasksService } from '../tasks/tasks.service';
import { Inspection, Task } from '../../generated/prisma';
import { CreateInspectionDto } from './dto/create-inspection.dto';
import { CreateTaskFromInspectionDto } from './dto/create-task-from-inspection.dto';
import { UpdateInspectionDto } from './dto/update-inspection.dto';
import { optionalDate } from '../common/patch-values';

/**
 * Inspections are written together with their audit entry and domain event
 * in one transaction: InspectionRecorded, InspectionCorrected. Automation
 * rules (automation.inspection-rules, on InspectionRecorded only), calendar
 * entry (calendar-sync.inspection) and the inspection.created webhook
 * (webhooks.forward) follow from the event, never from a direct call - so
 * none of them can fail the request or run twice on a retried one.
 */
@Injectable()
export class InspectionsService {
  constructor(
    private readonly prisma: PrismaService,
    private readonly auditLog: AuditLogService,
    private readonly events: DomainEventsService,
    private readonly tasks: TasksService,
  ) {}

  async findAll(): Promise<Inspection[]> {
    return this.prisma.inspection.findMany({ orderBy: { date: 'desc' } });
  }

  async findById(id: string): Promise<Inspection> {
    return this.findIn(this.prisma, id);
  }

  async findByColony(colonyId: string): Promise<Inspection[]> {
    return this.prisma.inspection.findMany({
      where: { colonyId },
      orderBy: { date: 'desc' },
    });
  }

  async create(
    dto: CreateInspectionDto,
    actingUserId: string,
  ): Promise<Inspection> {
    return this.prisma.$transaction(async (tx) => {
      const inspection = await tx.inspection.create({
        data: { ...dto, date: new Date(dto.date), userId: actingUserId },
      });
      await this.auditLog.record(
        {
          entityType: 'Inspection',
          entityId: inspection.id,
          action: 'CREATE',
          userId: actingUserId,
          afterData: inspection,
        },
        tx,
      );
      await this.events.record(tx, {
        type: 'InspectionRecorded',
        aggregateType: 'Inspection',
        aggregateId: inspection.id,
        payload: { colonyId: inspection.colonyId },
        actorUserId: actingUserId,
      });
      return inspection;
    });
  }

  /**
   * A correction evaluates no automation rule, as before the event
   * backbone. InspectionCorrected moves the calendar entry when the date or
   * colony changed instead of leaving the old one behind.
   */
  async update(
    id: string,
    dto: UpdateInspectionDto,
    actingUserId: string,
  ): Promise<Inspection> {
    return this.prisma.$transaction(async (tx) => {
      // "before" is read under the row lock: a concurrent correction can
      // neither slip in between nor be mislabelled in the audit entry.
      await lockRowForUpdate(tx, 'Inspection', id);
      const before = await this.findIn(tx, id);
      const inspection = await tx.inspection.update({
        where: { id },
        data: { ...dto, date: dto.date ? new Date(dto.date) : undefined },
      });
      await this.auditLog.record(
        {
          entityType: 'Inspection',
          entityId: id,
          action: 'UPDATE',
          userId: actingUserId,
          beforeData: before,
          afterData: inspection,
        },
        tx,
      );
      await this.events.record(tx, {
        type: 'InspectionCorrected',
        aggregateType: 'Inspection',
        aggregateId: id,
        payload: { colonyId: inspection.colonyId },
        actorUserId: actingUserId,
      });
      return inspection;
    });
  }

  // Through TasksService like a task from the task page: audit entry,
  // TaskCreated and with it calendar entry and webhook do not depend on
  // where the task was started.
  async createTaskFromInspection(
    id: string,
    dto: CreateTaskFromInspectionDto,
    actingUserId: string,
  ): Promise<Task> {
    const inspection = await this.findById(id);
    return this.prisma.$transaction((tx) =>
      this.tasks.createInTx(
        tx,
        {
          title: dto.title,
          description: dto.description,
          priority: dto.priority,
          dueDate: optionalDate(dto.dueDate),
          assignedUserId: dto.assignedUserId,
          relatedType: 'COLONY',
          relatedId: inspection.colonyId,
          sourceInspectionId: inspection.id,
        },
        actingUserId,
      ),
    );
  }

  private async findIn(db: DbClient, id: string): Promise<Inspection> {
    const inspection = await db.inspection.findUnique({ where: { id } });
    if (!inspection) {
      throw new NotFoundException('Inspection not found');
    }
    return inspection;
  }
}