import { ShowValuesConsumer } from 'Components/rule/ShowValuesContext'
import RuleLink from 'Components/RuleLink'
import { evolve, map } from 'ramda'
import React from 'react'
import { Trans } from 'react-i18next'
import { capitalise0, coerceArray } from '../utils'
import { warning } from './error'
import evaluate from './evaluateRule'
import { evaluateNode, makeJsx, mergeAllMissing } from './evaluation'
import { Node } from './mecanismViews/common'
import { parse } from './parse'
import {
	disambiguateRuleReference,
	findParentDependencies,
	nameLeaf
} from './ruleUtils'
import { ParsedRule, Rule, Rules } from './types'
import { parseUnit } from './units'

export default function<Names extends string>(
	rules: Rules<Names>,
	dottedName,
	parsedRules
): ParsedRule<Names> {
	if (parsedRules[dottedName]) return parsedRules[dottedName]

	parsedRules[dottedName] = 'being parsed'
	/*
		The parseRule function will traverse the tree of the `rule` and produce an
		AST, an object containing other objects containing other objects... Some of
		the attributes of the rule are dynamic, they need to be parsed. It is the
		case of  `non applicable si`, `applicable si`, `formule`. These attributes'
		values themselves may have  mechanism properties (e. g. `barème`) or inline
		expressions (e. g. `maVariable + 3`). These mechanisms or variables are in
		turn traversed by `parse()`. During this processing, 'evaluate' and'jsx'
		functions are attached to the objects of the AST. They will be evaluated
		during the evaluation phase, called "analyse".
	*/

	let parentDependencies = findParentDependencies(rules, dottedName)
	let rawRule = rules[dottedName]
	if (rawRule == null) {
		rawRule = {}
	}
	if (typeof rawRule === 'string') {
		rawRule = {
			formule: rawRule
		}
	}
	rawRule as Rule

	const name = nameLeaf(dottedName)
	let unit = rawRule.unité && parseUnit(rawRule.unité)
	let defaultUnit =
		rawRule['unité par défaut'] && parseUnit(rawRule['unité par défaut'])

	if (defaultUnit && unit) {
		warning(
			name,
			'Le paramètre `unité` est plus contraignant que `unité par défaut`.',
			'Si vous souhaitez que la valeur de votre variable soit toujours la même unité, gardez `unité`'
		)
	}

	const rule = {
		...rawRule,
		name,
		dottedName,
		type: rawRule.type,
		title: capitalise0(rawRule['titre'] || name),
		defaultValue: rawRule['par défaut'],
		examples: rawRule['exemples'],
		icons: rawRule['icônes'],
		summary: rawRule['résumé'],
		unit,
		defaultUnit,
		parentDependencies
	}

	let parsedRule = evolve({
		// Voilà les attributs d'une règle qui sont aujourd'hui dynamiques, donc à traiter
		// Les métadonnées d'une règle n'en font pas aujourd'hui partie

		// condition d'applicabilité de la règle
		parentDependencies: parents =>
			parents.map(parent => {
				let node = parse(rules, rule, parsedRules)(parent)

				let jsx = (nodeValue, explanation) => (
					<ShowValuesConsumer>
						{showValues =>
							!showValues ? (
								<div>Active seulement si {makeJsx(explanation)}</div>
							) : nodeValue === true ? (
								<div>Active car {makeJsx(explanation)}</div>
							) : nodeValue === false ? (
								<div>Non active car {makeJsx(explanation)}</div>
							) : null
						}
					</ShowValuesConsumer>
				)

				return {
					evaluate: (cache, situation, parsedRules) =>
						node.evaluate(cache, situation, parsedRules, node),
					jsx,
					category: 'ruleProp',
					rulePropType: 'cond',
					name: 'parentDependencies',
					type: 'numeric',
					explanation: node
				}
			}),
		'non applicable si': evolveCond(
			'non applicable si',
			rule,
			rules,
			parsedRules
		),
		'applicable si': evolveCond('applicable si', rule, rules, parsedRules),
		'rend non applicable': nonApplicableRules =>
			coerceArray(nonApplicableRules).map(referenceName => {
				return disambiguateRuleReference(rules, dottedName, referenceName)
			}),
		remplace: evolveReplacement(rules, rule, parsedRules),
		formule: value => {
			let evaluate = (cache, situationGate, parsedRules, node) => {
				let explanation = evaluateNode(
						cache,
						situationGate,
						parsedRules,
						node.explanation
					),
					{ nodeValue, unit, missingVariables, temporalValue } = explanation

				return {
					...node,
					nodeValue,
					unit,
					missingVariables,
					explanation,
					temporalValue
				}
			}

			let child = parse(rules, rule, parsedRules)(value)

			let jsx = (_nodeValue, explanation) => makeJsx(explanation)

			return {
				evaluate,
				jsx,
				category: 'ruleProp',
				rulePropType: 'formula',
				name: 'formule',
				unit: child.unit,
				explanation: child
			}
		},
		contrôles: map((control: any) => {
			let testExpression = parse(rules, rule, parsedRules)(control.si)
			if (
				!testExpression.explanation &&
				!(testExpression.category === 'reference')
			)
				throw new Error(
					'Ce contrôle ne semble pas être compris :' + control['si']
				)

			return {
				dottedName: dottedName,
				level: control['niveau'],
				test: control['si'],
				message: control['message'],
				testExpression,
				solution: control['solution']
			}
		})
	})(rule)

	parsedRules[dottedName] = {
		// Pas de propriété explanation et jsx ici car on est parti du (mauvais)
		// principe que 'non applicable si' et 'formule' sont particuliers, alors
		// qu'ils pourraient être rangé avec les autres mécanismes
		...parsedRule,
		evaluate,
		parsed: true,
		defaultUnit: parsedRule.defaultUnit || parsedRule.formule?.unit,
		isDisabledBy: [],
		replacedBy: []
	}
	parsedRules[dottedName]['rendu non applicable'] = {
		evaluate: (cache, situation, parsedRules, node) => {
			const isDisabledBy = node.explanation.isDisabledBy.map(disablerNode =>
				evaluateNode(cache, situation, parsedRules, disablerNode)
			)
			const nodeValue = isDisabledBy.some(x => !!x.nodeValue)
			const explanation = { ...node.explanation, isDisabledBy }
			return {
				...node,
				explanation,
				nodeValue,
				missingVariables: mergeAllMissing(isDisabledBy)
			}
		},

		jsx: (_nodeValue, { isDisabledBy }) => {
			return (
				isDisabledBy.length > 0 && (
					<>
						<h3>Exception{isDisabledBy.length > 1 && 's'}</h3>
						<p>
							<Trans>Cette règle ne s'applique pas pour</Trans> :{' '}
							{isDisabledBy.map((rule, i) => (
								<React.Fragment key={i}>
									{i > 0 && ', '}
									<RuleLink dottedName={dottedName} />
								</React.Fragment>
							))}
						</p>
					</>
				)
			)
		},
		category: 'ruleProp',
		rulePropType: 'cond',
		name: 'rendu non applicable',
		type: 'boolean',
		explanation: parsedRules[dottedName]
	}
	return parsedRules[dottedName]
}

let evolveCond = (dottedName, rule, rules, parsedRules) => value => {
	let evaluate = (cache, situationGate, parsedRules, node) => {
		let explanation = evaluateNode(
				cache,
				situationGate,
				parsedRules,
				node.explanation
			),
			nodeValue = explanation.nodeValue,
			missingVariables = explanation.missingVariables

		return { ...node, nodeValue, explanation, missingVariables }
	}

	let child = parse(rules, rule, parsedRules)(value)

	let jsx = (nodeValue, explanation) => (
		<Node
			classes="ruleProp mecanism cond"
			name={dottedName}
			value={nodeValue}
			unit={undefined}
		>
			{explanation.category === 'variable' ? (
				<div className="node">{makeJsx(explanation)}</div>
			) : (
				makeJsx(explanation)
			)}
		</Node>
	)

	return {
		evaluate,
		jsx,
		category: 'ruleProp',
		rulePropType: 'cond',
		dottedName,
		type: 'boolean',
		explanation: child
	}
}

let evolveReplacement = (rules, rule, parsedRules) => replacements =>
	coerceArray(replacements).map(reference => {
		const referenceName =
			typeof reference === 'string' ? reference : reference.règle
		let replacementNode = reference.par
		if (replacementNode != null) {
			replacementNode = parse(rules, rule, parsedRules)(replacementNode)
		}
		let [whiteListedNames, blackListedNames] = [
			reference.dans,
			reference['sauf dans']
		]
			.map(dottedName => dottedName && coerceArray(dottedName))
			.map(
				names =>
					names &&
					names.map(dottedName =>
						disambiguateRuleReference(rules, rule.dottedName, dottedName)
					)
			)

		return {
			referenceName: disambiguateRuleReference(
				rules,
				rule.dottedName,
				referenceName
			),
			replacementNode,
			whiteListedNames,
			blackListedNames
		}
	})