const AppError = require("../utils/appError");

const handleCastErrorDB = (err) => {
  const message = `Invalid ${err.path}: ${err.value}`;
  return new AppError(message, 400);
};

const handleDuplicateFieldsDB = (err) => {
  const message = `Duplicate field value: "${err.keyValue.name}". Please use another value!`;
  return new AppError(message, 400);
};

const handleValidationErrorDB = (err) => {
  const errors = Object.values(err.errors).map((val) => val.message);

  const message = `Invalid input data. ${errors.join(". ")}`;
  return new AppError(message, 400);
};

const handleJWTError = () =>
  new AppError("Invalid token. Please log in again!", 401);

const handleJWTExpiredError = () =>
  new AppError("Your token has expired. Please log in again!", 401);

const sendErrorDev = (err, req, res) => {
  res.status(err.statusCode).json({
    status: err.status,
    error: err,
    message: err.message,
    stack: err.stack,
  });
};

const sendErrorProd = (err, req, res) => {
  // a) APIs
  if (err.isOperational) {
    // Operational, trusted error: send message to client
    return res.status(err.statusCode).json({
      status: err.status,
      message: err.message,
    });

    // Programming or other unknown error: Don't leak error details
  }
  // 1) Log error
  console.error("ERROR 💥", err);

  // 2) Send generic message
  return res.status(500).json({
    status: "error",
    message: "Something went very wrong",
  });
};

module.exports = (err, req, res, next) => {
  // console.log(err.stack);

  err.statusCode = err.statusCode || 500;
  err.status = err.status || "error";

  if (process.env.NODE_ENV === "developement") {
    sendErrorDev(err, req, res);
  } else if (process.env.NODE_ENV === "production") {
    let error = JSON.parse(JSON.stringify(err));
    error.message = err.message;

    if (error.name === "CastError") error = handleCastErrorDB(error);
    if (error.code === 11000) error = handleDuplicateFieldsDB(error);
    if (error.name === "ValidationError")
      error = handleValidationErrorDB(error);
    if (error.name === "JsonWebTokenError") error = handleJWTError();
    if (error.name === "TokenExpiredError") error = handleJWTExpiredError();

    sendErrorProd(error, req, res);
  }
};