/* @flow */

import {
	compose,
	defaultTo,
	identity,
	isNil,
	lensPath,
	omit,
	over,
	set,
	uniq,
	without
} from 'ramda'
import reduceReducers from 'reduce-reducers'
import { combineReducers } from 'redux'
// $FlowFixMe
import { reducer as formReducer } from 'redux-form'
import i18n from '../i18n'
import inFranceAppReducer from './inFranceAppReducer'
import storageReducer from './storageReducer'
import type { Action } from 'Types/ActionsTypes'

function explainedVariable(state = null, { type, variableName = null }) {
	switch (type) {
		case 'EXPLAIN_VARIABLE':
			return variableName
		case 'STEP_ACTION':
			return null
		default:
			return state
	}
}

function currentExample(state = null, { type, situation, name, dottedName }) {
	switch (type) {
		case 'SET_EXAMPLE':
			return name != null ? { name, situation, dottedName } : null
		default:
			return state
	}
}

function situationBranch(state = null, { type, id }) {
	switch (type) {
		case 'SET_SITUATION_BRANCH':
			return id
		default:
			return state
	}
}

function activeTargetInput(state = null, { type, name }) {
	switch (type) {
		case 'SET_ACTIVE_TARGET_INPUT':
			return name
		case 'RESET_SIMULATION':
			return null
		default:
			return state
	}
}

function lang(state = i18n.language, { type, lang }) {
	switch (type) {
		case 'SWITCH_LANG':
			return lang
		default:
			return state
	}
}

type ConversationSteps = {|
	+foldedSteps: Array<string>,
	+unfoldedStep: ?string
|}

function conversationSteps(
	state: ConversationSteps = {
		foldedSteps: [],
		unfoldedStep: null
	},
	action: Action
): ConversationSteps {
	if (action.type === 'RESET_SIMULATION')
		return { foldedSteps: [], unfoldedStep: null }

	if (action.type !== 'STEP_ACTION') return state
	const { name, step } = action
	if (name === 'fold')
		return {
			foldedSteps: [...state.foldedSteps, step],
			unfoldedStep: null
		}
	if (name === 'unfold') {
		return {
			foldedSteps: without([step], state.foldedSteps),
			unfoldedStep: step
		}
	}
	return state
}

function updatePeriod(situation, { toPeriod, needConvertion }) {
	const currentPeriod = situation['période'] || 'mois'
	if (currentPeriod === toPeriod) {
		return situation
	}
	if (!['mois', 'année'].includes(toPeriod)) {
		throw new Error('Oups, changement de période invalide')
	}

	const updatedSituation = Object.entries(situation)
		.filter(([fieldName]) => needConvertion.includes(fieldName))
		.map(([fieldName, value]) => [
			fieldName,
			currentPeriod === 'mois' && toPeriod === 'année' ? value * 12 : value / 12
		])

	return {
		...situation,
		...Object.fromEntries(updatedSituation),
		période: toPeriod
	}
}

function simulation(
	state = null,
	{ type, config, url, id, fieldName, value, toPeriod, needConvertion }
) {
	if (type === 'SET_SIMULATION') {
		return { config, url, hiddenControls: [], situation: {} }
	}
	if (state === null) {
		return state
	}
	switch (type) {
		case 'HIDE_CONTROL':
			return { ...state, hiddenControls: [...state.hiddenControls, id] }
		case 'RESET_SIMULATION':
			return { ...state, hiddenControls: [], situation: {} }
		case 'UPDATE_SITUATION':
			const { config, situation } = state
			const removePreviousTarget = config.objectifs.includes(fieldName)
				? omit(config.objectifs)
				: identity
			return {
				...state,
				situation: { ...removePreviousTarget(situation), [fieldName]: value }
			}
		case 'UPDATE_PERIOD':
			return {
				...state,
				situation: updatePeriod(state.situation, { toPeriod, needConvertion })
			}
	}
	return state
}

const addAnswerToSituation = (dottedName, value, state) => {
	const dottedPath = dottedName.split(' . ')
	return compose(
		set(lensPath(['form', 'conversation', 'values', ...dottedPath]), value),
		over(lensPath(['conversationSteps', 'foldedSteps']), (steps = []) =>
			uniq([...steps, dottedName])
		)
	)(state)
}

const existingCompanyReducer = (state, action) => {
	if (action.type !== 'SAVE_EXISTING_COMPANY_DETAILS') {
		return state
	}
	const details = action.details
	let newState = state
	if (details.localisation) {
		newState = addAnswerToSituation(
			'établissement . localisation',
			JSON.stringify(details.localisation),
			newState
		)
	}
	if (!isNil(details.effectif)) {
		newState = addAnswerToSituation(
			'entreprise . effectif',
			details.effectif,
			newState
		)
	}
	return newState
}
export default reduceReducers(
	existingCompanyReducer,
	storageReducer,
	combineReducers({
		sessionId: defaultTo(Math.floor(Math.random() * 1000000000000) + ''),
		//  this is handled by redux-form, pas touche !
		form: formReducer,
		conversationSteps,
		lang,
		simulation,
		explainedVariable,
		previousSimulation: defaultTo(null),
		currentExample,
		situationBranch,
		activeTargetInput,
		inFranceApp: inFranceAppReducer
	})
)