import React from 'react'
import hoistNonReactStatics from 'hoist-non-react-statics'
import { assoc, assocPath, identity, is, map, prop } from 'ramda'
import isValid from './isValid'

// random helper function
// extract the needed information from the event
const getValueName = (e) => {
  const target = e.target
  const name = target.name
  const value = target.type === 'checkbox'
    ? target.checked
    : target.value

  return {name, value}
}

const revalidation = ({
  validateFn,
  mapPropsToState = identity,
  mapSetStateToProps = (updateState, actions) => ({
    onChange: e => {
      const { name, value } = getValueName(e)
      return updateState(actions.update(name, value))
    },
    validate: e => {
      const { name, value } = getValueName(e)
      return updateState(actions.validate(name, value))
    },
    onSubmit: (onsSubmitFn) => {
      return updateState(actions.validateAll(onsSubmitFn))
    }
  }),
  actions = {
    update: (name, value, state) => {
      return [ assocPath(['values', name], value, state) ]
    },
    validate: (name, value, state, validate) => {
      return [ assoc('errors', validate.input(name, value), state) ]
    },
    validateAll: (cbFn, state, validate) => {
      return [
        assoc('errors', validate.all(state.values), state),
        (state) => {
          if (isValid(state.errors)) {
            cbFn(state.values)
          }
        }
      ]
    }
  }
}) => Component => {
  class HigherOrderFormComponent extends React.Component {
    constructor(props) {
      super(props)
      this.state = { errors: {}, values: mapPropsToState(prop('values', props)) }
      this.actions = map(f => (...args) => f(...args, this.state, validateFn), actions)
      this.updateState = this.updateState.bind(this)
    }

    updateState(setState) {
      const [setStateFn, effects = () => {}] = setState
      this.setState(setStateFn, () => effects(this.state))
    }

    render() {
      const { values, errors } = this.state
      const dispatched = mapSetStateToProps(this.updateState, this.actions)
      return React.createElement(Component, {
        ...this.props,
        ...dispatched,
        form: values,
        errors
      })
    }
  }

  HigherOrderFormComponent.displayName = `Revalidation_(${Component.displayName || Component.name || 'Component'})`
  return hoistNonReactStatics(HigherOrderFormComponent, Component)
}

export default revalidation

export {
  isValid
}