'use strict'

var util = require('util')

/**
 * Make custom error types that pass `instanceof` checks, have stack traces,
 * support custom messages and properties, and support wrapping errors (causes).
 *
 * @module
 */

//
// For ES6+ Classes
//

/**
 * A base class for custom errors that handles:
 *
 * 1. Wrapping an optional 'cause'.
 * 2. Storing an 'info' object with additional data.
 * 3. Setting the name to the subclass name.
 *
 * @extends Error
 */
class ErrorTypeError extends Error {
  /**
   * @param {string} message as for built-in Error
   * @param {?object} info extra data to attach to the error
   */
  constructor ({ message, info }) {
    super(message)
    this.name = this.constructor.name
    if (info) {
      this.info = info
    }
  }

  /**
   * Wrap the given error, which caused this error.
   *
   * @param {Error} cause
   * @return {this}
   */
  withCause (cause) {
    this.cause = cause
    if (this.message && cause.message) {
      this.message += ': ' + cause.message
    }
    return this
  }
}

/**
 * Base class for errors with a corresponding HTTP status code.
 *
 * @extends ErrorTypeError
 */
class ErrorWithStatusCode extends ErrorTypeError {
  /**
   * @param {?number} statusCode an HTTP status code
   * @param {object} options as for ErrorTypeError
   */
  constructor ({ statusCode, ...options }) {
    super(options)
    this.statusCode = statusCode || 500
  }
}
exports.ErrorWithStatusCode = ErrorWithStatusCode

/**
 * Return the `info` property from `error` and recursively merge the `info`
 * properties from the error's causes, if any.
 *
 * If a property is repeated, the first one in the cause chain wins.
 *
 * @param {?Error} error assumed not to have circular causes
 * @return {Object}
 */
function getFullInfo (error) {
  if (!error) return {}
  const info = getFullInfo(error.cause)
  if (typeof error.info === 'object') Object.assign(info, error.info)
  return info
}

/**
 * Return the `stack` property from `error` and recursively append the `stack`
 * properties from the error's causes, if any.
 *
 * @param {?Error} error assumed not to have circular causes
 * @return {string}
 */
function getFullStack (error) {
  if (!error) return ''
  const causeStack = getFullStack(error.cause)
  if (causeStack) return (error.stack + '\ncaused by: ' + causeStack)
  return error.stack
}

/**
 * Is `error` or one of its causes an instance of `klass`?
 *
 * @param  {?Error} error assumed not to have circular causes
 * @param  {function} klass
 * @return {Boolean}
 */
function hasCauseInstanceOf (error, klass) {
  if (!error) return false
  return error instanceof klass || hasCauseInstanceOf(error.cause, klass)
}

exports.Error = ErrorTypeError
exports.getFullInfo = getFullInfo
exports.getFullStack = getFullStack
exports.hasCauseInstanceOf = hasCauseInstanceOf

//
// For ES5
//

function extendErrorType (base, name, builder) {
  var errorConstructor = function () {
    Error.captureStackTrace && Error.captureStackTrace(this, this.constructor)
    if (builder) builder.apply(this, arguments)
    this.name = name
  }

  util.inherits(errorConstructor, base)

  errorConstructor.prototype.withCause = function (cause) {
    this.cause = cause
    if (this.message && cause.message) {
      this.message += ': ' + cause.message
    }
    return this
  }

  return errorConstructor
}

function defineErrorType (name, builder) {
  return extendErrorType(Error, name, builder)
}

function extendErrorTypeIn (container, base, name, builder) {
  container[name] = extendErrorType(base, name, builder)
}

function defineErrorTypeIn (container, name, builder) {
  extendErrorTypeIn(container, Error, name, builder)
}

exports.extend = extendErrorType
exports.define = defineErrorType
exports.extendIn = extendErrorTypeIn
exports.defineIn = defineErrorTypeIn