const logger = require('../logger');

class Controller {
  static sendResponse(response, payload) {
    /**
     * The default response-code is 200. We want to allow to change that. in That case,
     * payload will be an object consisting of a code and a payload. If not customized
     * send 200 and the payload as received in this method.
     */
    response.status(payload.code || 200);
    const responsePayload = payload.payload !== undefined ? payload.payload : payload;
    if (responsePayload instanceof Object) {
      response.json(responsePayload);
    } else {
      response.end(responsePayload);
    }
  }

  static sendError(response, error) {
    response.status(error.code || 500);
    if (error.error instanceof Object) {
      response.json(error.error);
    } else {
      response.end(error.error || error.message);
    }
  }

  static collectFiles(request) {
    logger.info('Checking if files are expected in schema');
    if (request.openapi.schema.requestBody !== undefined) {
      const [contentType] = request.headers['content-type'].split(';');
      if (contentType === 'multipart/form-data') {
        const contentSchema = request.openapi.schema.requestBody.content[contentType].schema;
        Object.entries(contentSchema.properties).forEach(([name, property]) => {
          if (property.type === 'string' && ['binary', 'base64'].indexOf(property.format) > -1) {
            request.body[name] = request.files.find(file => file.fieldname === name);
          }
        });
      } else if (request.openapi.schema.requestBody.content[contentType] !== undefined
          && request.files !== undefined) {
        [request.body] = request.files;
      }
    }
  }

  static collectRequestParams(request) {
    this.collectFiles(request);
    const requestParams = {};
    if (request.openapi.schema.requestBody !== undefined) {
      requestParams.body = request.body;
    }
    request.openapi.schema.parameters.forEach((param) => {
      if (param.in === 'path') {
        requestParams[param.name] = request.openapi.pathParams[param.name];
      } else if (param.in === 'query') {
        requestParams[param.name] = request.query[param.name];
      }
    });
    return requestParams;
  }

  static async handleRequest(request, response, serviceOperation) {
    try {
      const serviceResponse = await serviceOperation(this.collectRequestParams(request));
      Controller.sendResponse(response, serviceResponse);
    } catch (error) {
      Controller.sendError(response, error);
    }
  }
}

module.exports = Controller;