// src/controllers/DicomStudyController.ts

import { Request, Response, NextFunction } from 'express';
import { DicomStudyService, CommonService} from '../services';
import logger from '../utils/logger';
import { Pool } from 'mysql2/promise';

export class DicomStudyController {
  private service: DicomStudyService;
  private commonService: CommonService;

  constructor(pool:Pool) {
    this.service = new DicomStudyService(pool);
    this.commonService = new CommonService();
  }

  getAllStudies = async (req: Request, res: Response, next: NextFunction) => {
    try {
      const studies = await this.service.getAllStudies();
      res.json(studies);
    } catch (error) {
      const apiError = this.commonService.handleError(error, 'Failed to fetch studies');
      res.status(500).json({ error: apiError });
    }
  };

  getStudyById = async (req: Request, res: Response, next: NextFunction) => {
    try {
      const id = parseInt(req.params.id);
      if (isNaN(id)) {
        return res.status(400).json({ error: 'Invalid study ID' });
      }

      const study = await this.service.getStudyById(id);
      if (!study) {
        return res.status(404).json({ error: 'Study not found' });
      }
      
      res.json(study);
    } catch (error) {
      const apiError = this.commonService.handleError(error, `Failed to fetch study ${req.params.id}`);
      res.status(500).json({ error: apiError });
    }
  };

  getStudiesByRouterId = async (req: Request, res: Response, next: NextFunction) => {
    try {
      const routerId = req.params.routerId;
      if (!routerId || typeof routerId !== 'string') {
        return res.status(400).json({ error: 'Invalid router ID' });
      }

      const studies = await this.service.getStudiesByRouterId(routerId);
      res.json(studies);
    } catch (error) {
      const apiError = this.commonService.handleError(error, `Failed to fetch studies for router ${req.params.routerId}`);
      // If router not found, return 404
      if (error instanceof Error && error.message.includes('Invalid router_id')) {
        return res.status(404).json({ error: 'Router not found' });
      }
      res.status(500).json({ error: apiError });
    }
  };

  createStudy = async (req: Request, res: Response, next: NextFunction) => {
    try {
      const requiredFields = [
        'router_id',
        'study_instance_uid',
        'patient_id',
        'patient_name',
        'accession_number',
        'study_date',
        'modality',
        'series_instance_uid',
        'study_status_code',
        'association_id'
      ];

      const missingFields = requiredFields.filter(field => !req.body[field]);
      if (missingFields.length > 0) {
        return res.status(400).json({
          error: 'Missing required fields',
          missingFields
        });
      }

      // Validate router_id format if needed
      if (typeof req.body.router_id !== 'string') {
        return res.status(400).json({
          error: 'Invalid router_id format',
          details: 'router_id must be a string'
        });
      }

      const study = await this.service.createStudy(req.body);
      res.status(201).json(study);
    } catch (error) {
      const apiError = this.commonService.handleError(error, 'Failed to create study');
      
      // Handle specific error cases
      if (error instanceof Error) {
        if (error.message.includes('Missing required field')) {
          return res.status(400).json({ error: apiError });
        }
        if (error.message.includes('Invalid router_id')) {
          return res.status(404).json({ error: 'Router not found' });
        }
        if (error.message.includes('Invalid study status code')) {
          return res.status(400).json({ error: apiError });
        }
        if (error.message.includes('Invalid study date format')) {
          return res.status(400).json({ error: apiError });
        }
      }
      
      res.status(500).json({ error: apiError });
    }
  };

  updateStudy = async (req: Request, res: Response, next: NextFunction) => {
    try {
      const id = parseInt(req.params.id);
      if (isNaN(id)) {
        return res.status(400).json({ error: 'Invalid study ID' });
      }

      const study = await this.service.updateStudy(id, req.body);
      if (!study) {
        return res.status(404).json({ error: 'Study not found' });
      }
      
      res.json(study);
    } catch (error) {
      const apiError = this.commonService.handleError(error, `Failed to update study ${req.params.id}`);
      res.status(500).json({ error: apiError });
    }
  };

  deleteStudy = async (req: Request, res: Response, next: NextFunction) => {
    try {
      const id = parseInt(req.params.id);
      if (isNaN(id)) {
        return res.status(400).json({ error: 'Invalid study ID' });
      }

      const success = await this.service.deleteStudy(id);
      if (!success) {
        return res.status(404).json({ error: 'Study not found' });
      }
      
      res.status(204).send();
    } catch (error) {
      const apiError = this.commonService.handleError(error, `Failed to delete study ${req.params.id}`);
      res.status(500).json({ error: apiError });
    }
  };

  searchStudies = async (req: Request, res: Response, next: NextFunction) => {
    try {
      const { startDate, endDate, modality, patientName } = req.query;

      if (startDate && typeof startDate !== 'string') {
        return res.status(400).json({ 
          error: 'Invalid startDate format',
          expected: 'YYYY-MM-DD'
        });
      }
      if (endDate && typeof endDate !== 'string') {
        return res.status(400).json({ 
          error: 'Invalid endDate format',
          expected: 'YYYY-MM-DD'
        });
      }

      const studies = await this.service.searchStudies({
        startDate: startDate as string,
        endDate: endDate as string,
        modality: modality as string,
        patientName: patientName as string
      });

      res.json(studies);
    } catch (error) {
      const apiError = this.commonService.handleError(error, 'Failed to search studies');
      res.status(500).json({ error: apiError });
    }
  };
}