// # boot - error handler

var _ = require('underscore')
var util = require('util')

exports = module.exports = function(logger, settings) {

  return function() {

    var app = this

    app.use(function(err, req, res, next) {

      // set default error status code
      res.statusCode = (_.isNumber(err.status)) ? err.status : 500

      if (!_.isString(err.message))
        err.message = 'An unknown error has occured, please try again'

      if (_.isObject(err) && _.isNumber(err.code) && err.code === 11000) {
        // <https://github.com/LearnBoost/mongoose/issues/2129>
        var field = err.message.split('index: test.')[1].split('.$')[1]
        // now we have `email_1 dup key`
        field = field.split(' dup key')[0]
        field = field.substring(0, field.lastIndexOf('_'))
        err.message = util.format('Duplicate %s already exists in database, try making a more unique value', field)
        err.param = field
      }

      // if we pass an error object, then we want to simply return the message...
      // if we pass an object, then we want to do a stack trace, and then return the object + stack
      var error = {}

      // set error type
      error.type = _.isString(err.param) ? 'invalid_request_error' : 'api_error'

      if (error.type === 'invalid_request_error' && res.statusCode === 500)
        res.statusCode = 400

      // set error message and stack trace
      if (util.isError(err)) {
        error.message = err.message
      } else {
        _.extend(error, err)
      }

      // set status code for BadRequestError
      if (_.isString(error.name) && error.name === 'BadRequestError') {
        error.type = 'invalid_request_error'
        res.statusCode = 400
        delete error.name
      }

      if (settings.showStack)
        error.stack = _.isUndefined(err.stack) ? new Error(err.message).stack : err.stack

      // set error level
      var level = (res.statusCode < 500) ? 'warn' : 'error'
      logger[level](error)

      // set error back to warning if it was warn
      // logger level type = "warn"
      // req.flash messages type = "warning"
      if (level === 'warn')
        level = 'warning'

      // if we have a mongoose validation err
      // then we know to output all the errors
      if (_.isObject(error.errors) && !_.isEmpty(error.errors)) {
        var messages = []
        _.each(error.errors, function(errMsg) {
          if (_.isString(errMsg.message))
            messages.push(errMsg.message)
        })
        if (!_.isEmpty(messages))
          error.message = messages.join(' ')
      }

      res.format({
        text: function() {
          res.send(error.message)
        },
        html: function() {
          req.flash(level, error.message)
          res.redirect('back')
        },
        json: function() {
          res.json({ error: error })
        }
      })

    })

  }

}

exports['@singleton'] = true
exports['@require'] = [ 'igloo/logger', 'igloo/settings' ]