import {
  Controller,
  Get,
  Post,
  Patch,
  Delete,
  Body,
  Param,
  Query,
  UseGuards,
  Request,
  UseInterceptors,
  UploadedFile,
  Logger,
  Inject,
  forwardRef,
  BadRequestException,
} from '@nestjs/common';
import { AuthGuard } from '@nestjs/passport';
import { FileInterceptor } from '@nestjs/platform-express';
import { ApiTags, ApiOperation, ApiBearerAuth, ApiConsumes } from '@nestjs/swagger';
import { ApplicationsService } from './applications.service';
import { CreateApplicationDto, UpdateApplicationDto, ScaleResourcesDto } from './dto/application.dto';
import { RolesGuard } from '../common/guards/roles.guard';
import { Roles } from '../common/decorators/roles.decorator';
import { UserRole, DatabaseType } from '../common/enums';
import { KubernetesService } from '../kubernetes/kubernetes.service';
import { DeploymentsService } from '../deployments/deployments.service';

@ApiTags('Applications')
@ApiBearerAuth()
@Controller('applications')
@UseGuards(AuthGuard('jwt'), RolesGuard)
export class ApplicationsController {
  private readonly logger = new Logger(ApplicationsController.name);

  constructor(
    private readonly applicationsService: ApplicationsService,
    private readonly kubernetesService: KubernetesService,
    @Inject(forwardRef(() => DeploymentsService))
    private readonly deploymentsService: DeploymentsService,
  ) {}

  @Post()
  @ApiOperation({ summary: 'Create a new application' })
  async create(@Request() req: any, @Body() dto: CreateApplicationDto) {
    return this.applicationsService.create(req.user.id, dto, req.user.role);
  }

  @Post(':id/upload')
  @ApiOperation({ summary: 'Upload application code (zip file)' })
  @ApiConsumes('multipart/form-data')
  @UseInterceptors(FileInterceptor('file', {
    limits: { fileSize: 200 * 1024 * 1024 }, // 200MB (WordPress sites can be large)
  }))
  async uploadCode(
    @Param('id') id: string,
    @Request() req: any,
    @UploadedFile() file: Express.Multer.File,
  ) {
    return this.applicationsService.uploadCode(id, req.user.id, file);
  }

  @Post(':id/db-upload')
  @ApiOperation({ summary: 'Upload and restore a SQL dump into the application database' })
  @ApiConsumes('multipart/form-data')
  @UseInterceptors(FileInterceptor('file', {
    limits: { fileSize: 500 * 1024 * 1024 }, // 500MB for DB dumps
  }))
  async uploadDbDump(
    @Param('id') id: string,
    @Request() req: any,
    @UploadedFile() file: Express.Multer.File,
  ) {
    if (!file) {
      throw new BadRequestException('No file uploaded');
    }

    const isStaff = req.user.role === UserRole.ADMIN || req.user.role === UserRole.TECHNICAL;
    const app = await this.applicationsService.findOne(id, isStaff ? undefined : req.user.id);

    if (app.databaseType === DatabaseType.NONE) {
      throw new BadRequestException('This application does not have a database configured');
    }

    this.logger.log(`DB dump upload for ${app.name} — ${(file.size / 1024).toFixed(1)} KB`);
    const result = await this.kubernetesService.restoreDatabaseDump(app, file.buffer);

    return {
      success: result.success,
      message: result.success ? 'Database restored successfully' : 'Database restore failed',
      logs: result.logs,
    };
  }

  @Get(':id/db-storage')
  @ApiOperation({ summary: 'Get current database PVC storage size' })
  async getDbStorage(@Param('id') id: string, @Request() req: any) {
    const isStaff = req.user.role === UserRole.ADMIN || req.user.role === UserRole.TECHNICAL;
    const app = await this.applicationsService.findOne(id, isStaff ? undefined : req.user.id);

    if (app.databaseType === DatabaseType.NONE) {
      throw new BadRequestException('This application does not have a database configured');
    }

    const currentSize = await this.kubernetesService.getDatabasePvcSize(app);
    return { currentSize, savedSize: app.dbStorageSize || '1Gi' };
  }

  @Patch(':id/db-storage')
  @ApiOperation({ summary: 'Resize (expand) database PVC storage' })
  async resizeDbStorage(
    @Param('id') id: string,
    @Request() req: any,
    @Body() body: { size: string },
  ) {
    const isStaff = req.user.role === UserRole.ADMIN || req.user.role === UserRole.TECHNICAL;
    const app = await this.applicationsService.findOne(id, isStaff ? undefined : req.user.id);

    if (app.databaseType === DatabaseType.NONE) {
      throw new BadRequestException('This application does not have a database configured');
    }

    if (!body.size || !/^\d+Gi$/.test(body.size)) {
      throw new BadRequestException('Size must be in format like "1Gi", "5Gi", "10Gi"');
    }

    const result = await this.kubernetesService.resizeDatabasePvc(app, body.size);

    if (result.success) {
      // Update the saved size in the DB
      await this.applicationsService.update(id, app.userId, { dbStorageSize: body.size } as any);
    }

    return result;
  }

  @Get()
  @ApiOperation({ summary: 'List my applications' })
  async findAll(@Request() req: any) {
    return this.applicationsService.findAllByUser(req.user.id);
  }

  @Get('all')
  @Roles(UserRole.ADMIN, UserRole.TECHNICAL)
  @ApiOperation({ summary: 'List all applications (admin/technical)' })
  async findAllAdmin(@Request() req: any, @Query('search') search?: string) {
    return this.applicationsService.findAll(search);
  }

  @Get(':id')
  @ApiOperation({ summary: 'Get application details' })
  async findOne(@Param('id') id: string, @Request() req: any) {
    if (req.user.role === UserRole.ADMIN || req.user.role === UserRole.TECHNICAL) {
      return this.applicationsService.findOne(id);
    }
    return this.applicationsService.findOne(id, req.user.id);
  }

  @Patch(':id')
  @ApiOperation({ summary: 'Update application configuration' })
  async update(
    @Param('id') id: string,
    @Request() req: any,
    @Body() dto: UpdateApplicationDto,
  ) {
    const isStaff = req.user.role === UserRole.ADMIN || req.user.role === UserRole.TECHNICAL;
    if (isStaff) {
      const app = await this.applicationsService.findOne(id);
      return this.applicationsService.update(id, app.userId, dto);
    }
    return this.applicationsService.update(id, req.user.id, dto);
  }

  @Get(':id/resources')
  @ApiOperation({ summary: 'Get real-time resource usage for an application' })
  async getResources(@Param('id') id: string, @Request() req: any) {
    const app = await this.applicationsService.findOne(
      id,
      (req.user.role === UserRole.ADMIN || req.user.role === UserRole.TECHNICAL) ? undefined : req.user.id,
    );
    return this.kubernetesService.getResourceUsage(app);
  }

  @Patch(':id/resources')
  @ApiOperation({ summary: 'Update application resources (CPU/Memory/Replicas)' })
  async updateResources(
    @Param('id') id: string,
    @Request() req: any,
    @Body() dto: ScaleResourcesDto,
  ) {
    const isStaff = req.user.role === UserRole.ADMIN || req.user.role === UserRole.TECHNICAL;
    const app = await this.applicationsService.findOne(id, isStaff ? undefined : req.user.id);

    // Update in K8s (live)
    await this.kubernetesService.updateResources(app, dto);

    // Update in DB
    const updateFields: any = {};
    if (dto.cpuRequest) updateFields.cpuRequest = dto.cpuRequest;
    if (dto.cpuLimit) updateFields.cpuLimit = dto.cpuLimit;
    if (dto.memoryRequest) updateFields.memoryRequest = dto.memoryRequest;
    if (dto.memoryLimit) updateFields.memoryLimit = dto.memoryLimit;
    if (dto.replicas !== undefined) updateFields.replicas = dto.replicas;

    const updated = await this.applicationsService.update(id, app.userId, updateFields);
    this.logger.log(`Updated resources for ${app.name}: ${JSON.stringify(dto)}`);
    return updated;
  }

  @Get(':id/preview')
  @ApiOperation({ summary: 'Get preview URL for the deployed application' })
  async getPreview(@Param('id') id: string, @Request() req: any) {
    const app = await this.applicationsService.findOne(
      id,
      (req.user.role === UserRole.ADMIN || req.user.role === UserRole.TECHNICAL) ? undefined : req.user.id,
    );
    return this.kubernetesService.getPreviewInfo(app);
  }

  @Delete(':id')
  @ApiOperation({ summary: 'Delete an application and all its resources' })
  async delete(@Param('id') id: string, @Request() req: any) {
    const isStaff = req.user.role === UserRole.ADMIN || req.user.role === UserRole.TECHNICAL;
    // 1. Get the app first
    const app = await this.applicationsService.findOne(id, isStaff ? undefined : req.user.id);

    // 2. Delete K8s resources (deployment, service, ingress, db, secrets)
    try {
      if (app.clusterId && app.latestImageTag) {
        await this.kubernetesService.deleteApplication(app);
        this.logger.log(`Deleted K8s resources for ${app.name}`);
      }
    } catch (e: any) {
      this.logger.warn(`K8s cleanup failed for ${app.name}: ${e.message}`);
    }

    // 3. Delete deployment records from DB
    try {
      await this.deploymentsService.deleteAllForApplication(app.id);
    } catch (e: any) {
      this.logger.warn(`Deployment records cleanup failed for ${app.name}: ${e.message}`);
    }

    // 4. Delete app (also deletes uploaded files)
    await this.applicationsService.delete(id, isStaff ? app.userId : req.user.id);

    return { message: `Application "${app.name}" and all resources deleted` };
  }
}