import { Service, Inject } from 'typedi';
import { Router, Request, Response, NextFunction } from 'express';
import { param, query } from 'express-validator';
import asyncMiddleware from 'api/middleware/asyncMiddleware';
import BaseController from './BaseController';
import { ServiceError } from 'exceptions';
import ResourceService from 'services/Resource/ResourceService';

@Service()
export default class ResourceController extends BaseController {
  @Inject()
  resourcesService: ResourceService;

  /**
   * Router constructor.
   */
  router() {
    const router = Router();

    router.get(
      '/:resource_model/meta',
      [...this.resourceModelParamSchema],
      this.asyncMiddleware(this.resourceMeta.bind(this)),
      this.handleServiceErrors
    );

    router.get(
      '/:resource_model/fields',
      [...this.resourceModelParamSchema],
      this.validationResult,
      asyncMiddleware(this.resourceFields.bind(this)),
      this.handleServiceErrors
    );
    router.get(
      '/:resource_model/data',
      [...this.resourceModelParamSchema],
      this.validationResult,
      asyncMiddleware(this.resourceData.bind(this)),
      this.handleServiceErrors
    );
    return router;
  }

  get resourceModelParamSchema() {
    return [param('resource_model').exists().trim().escape()];
  }

  /**
   * Retrieve resource model meta.
   * @param {Request} req -
   * @param {Response} res -
   * @param {NextFunction} next -
   * @returns {Response}
   */
  private resourceMeta = (
    req: Request,
    res: Response,
    next: NextFunction
  ): Response => {
    const { tenantId } = req;
    const { resource_model: resourceModel } = req.params;

    try {
      const resourceMeta = this.resourcesService.getResourceMeta(
        tenantId,
        resourceModel
      );
      return res
        .status(200)
        .send({ resource_meta: this.transfromToResponse(resourceMeta) });
    } catch (error) {
      next(error);
    }
  };

  /**
   * Retrieve resource fields of the given resource.
   * @param {Request} req
   * @param {Response} res
   * @param {NextFunction} next
   */
  resourceFields(req: Request, res: Response, next: NextFunction) {
    const { tenantId } = req;
    const { resource_model: resourceModel } = req.params;

    try {
      // const resourceFields = this.resourcesService.getResourceFields(
      //   tenantId,
      //   resourceModel
      // );

      return res.status(200).send({
        resource_fields: [],
      });
    } catch (error) {
      next(error);
    }
  }

  /**
   * Retrieve resource data of the give resource based on the given query.
   * @param {Request} req
   * @param {Response} res
   * @param {NextFunction} next
   */
  async resourceData(req: Request, res: Response, next: NextFunction) {
    const { tenantId } = req;
    const { resource_model: resourceModel } = req.params;
    const filter = req.query;

    try {
      const resourceData = await this.resourcesService.getResourceData(
        tenantId,
        resourceModel,
        filter
      );

      return res.status(200).send({
        resource_data: this.transfromToResponse(resourceData),
      });
    } catch (error) {
      next(error);
    }
  }

  /**
   * Handles service errors.
   * @param {Error} error
   * @param {Request} req
   * @param {Response} res
   * @param {NextFunction} next
   */
  private handleServiceErrors(
    error: Error,
    req: Request,
    res: Response,
    next: NextFunction
  ) {
    if (error instanceof ServiceError) {
      if (error.errorType === 'RESOURCE_MODEL_NOT_FOUND') {
        return res.status(400).send({
          errors: [{ type: 'RESOURCE.MODEL.NOT.FOUND', code: 100 }],
        });
      }
    }
    next(error);
  }
}