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 { CreateAgentConfigDto, UpdateAgentConfigDto } from './agent-config.dto.js';

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

  @Get()
  async list(@CurrentUser() user: { id: string; role?: string }) {
    return this.brain.agents.findAccessible(user.id);
  }

  @Get(':id')
  async findOne(@Param('id') id: string, @CurrentUser() user: { id: string }) {
    const agent = await this.brain.agents.findById(id);
    if (!agent) throw new NotFoundException('Agent not found');
    if (!agent.isSystem && agent.ownerId !== user.id) {
      throw new ForbiddenException('Agent does not belong to the current user');
    }
    return agent;
  }

  @Post()
  async create(@Body() dto: CreateAgentConfigDto, @CurrentUser() user: { id: string }) {
    return this.brain.agents.create({
      ...dto,
      ownerId: user.id,
      isSystem: false,
    });
  }

  @Patch(':id')
  async update(
    @Param('id') id: string,
    @Body() dto: UpdateAgentConfigDto,
    @CurrentUser() user: { id: string; role?: string },
  ) {
    const agent = await this.brain.agents.findById(id);
    if (!agent) throw new NotFoundException('Agent not found');
    if (agent.isSystem && user.role !== 'admin') {
      throw new ForbiddenException('Only admins can update system agents');
    }
    if (!agent.isSystem && agent.ownerId !== user.id) {
      throw new ForbiddenException('Agent does not belong to the current user');
    }
    const updated = await this.brain.agents.update(id, dto);
    if (!updated) throw new NotFoundException('Agent not found');
    return updated;
  }

  @Delete(':id')
  @HttpCode(HttpStatus.NO_CONTENT)
  async remove(@Param('id') id: string, @CurrentUser() user: { id: string; role?: string }) {
    const agent = await this.brain.agents.findById(id);
    if (!agent) throw new NotFoundException('Agent not found');
    if (agent.isSystem) {
      throw new ForbiddenException('Cannot delete system agents');
    }
    if (agent.ownerId !== user.id) {
      throw new ForbiddenException('Agent does not belong to the current user');
    }
    const deleted = await this.brain.agents.remove(id);
    if (!deleted) throw new NotFoundException('Agent not found');
  }
}