import {
  Body,
  Controller,
  Delete,
  ForbiddenException,
  Get,
  HttpCode,
  HttpStatus,
  Inject,
  NotFoundException,
  Param,
  Patch,
  Post,
  UseGuards,
} from '@nestjs/common';
import type { Brain } from '@mosaic/brain';
import { BRAIN } from '../brain/brain.tokens.js';
import { AuthGuard } from '../auth/auth.guard.js';
import { CurrentUser } from '../auth/current-user.decorator.js';
import { assertOwner } from '../auth/resource-ownership.js';
import { CreateMissionDto, UpdateMissionDto } from './missions.dto.js';

@Controller('api/missions')
@UseGuards(AuthGuard)
export class MissionsController {
  constructor(@Inject(BRAIN) private readonly brain: Brain) {}

  @Get()
  async list() {
    return this.brain.missions.findAll();
  }

  @Get(':id')
  async findOne(@Param('id') id: string, @CurrentUser() user: { id: string }) {
    return this.getOwnedMission(id, user.id);
  }

  @Post()
  async create(@Body() dto: CreateMissionDto) {
    return this.brain.missions.create({
      name: dto.name,
      description: dto.description,
      projectId: dto.projectId,
      status: dto.status,
    });
  }

  @Patch(':id')
  async update(
    @Param('id') id: string,
    @Body() dto: UpdateMissionDto,
    @CurrentUser() user: { id: string },
  ) {
    await this.getOwnedMission(id, user.id);
    if (dto.projectId) {
      await this.getOwnedProject(dto.projectId, user.id, 'Mission');
    }
    const mission = await this.brain.missions.update(id, dto);
    if (!mission) throw new NotFoundException('Mission not found');
    return mission;
  }

  @Delete(':id')
  @HttpCode(HttpStatus.NO_CONTENT)
  async remove(@Param('id') id: string, @CurrentUser() user: { id: string }) {
    await this.getOwnedMission(id, user.id);
    const deleted = await this.brain.missions.remove(id);
    if (!deleted) throw new NotFoundException('Mission not found');
  }

  private async getOwnedMission(id: string, userId: string) {
    const mission = await this.brain.missions.findById(id);
    if (!mission) throw new NotFoundException('Mission not found');
    await this.getOwnedProject(mission.projectId, userId, 'Mission');
    return mission;
  }

  private async getOwnedProject(
    projectId: string | null | undefined,
    userId: string,
    resourceName: string,
  ) {
    if (!projectId) {
      throw new ForbiddenException(`${resourceName} does not belong to the current user`);
    }

    const project = await this.brain.projects.findById(projectId);
    if (!project) {
      throw new ForbiddenException(`${resourceName} does not belong to the current user`);
    }

    assertOwner(project.ownerId, userId, resourceName);
    return project;
  }
}