import {
    Schema,
    SchemaFieldsByName,
    SchemaFieldNames,
    SchemaError,
} from '@sprucelabs/schema'
import chalk from 'chalk'
import { shuffle } from 'lodash'
import { GraphicsInterface } from '../types/cli.types'
import FormComponent, {
    FormOptions,
    FormPresentationOptions,
} from './FormComponent'

interface QuizMultipleChoiceQuestion {
    type: 'select'
    question: string
    answers: string[]
}

interface QuizTextQuestion {
    type: 'text'
    question: string
    answer: string
}

type QuizQuestions = Record<
    string,
    QuizMultipleChoiceQuestion | QuizTextQuestion
>

enum AnswerValidity {
    Correct = 'correct',
    Incorrect = 'incorrect',
}

interface QuizPresentationOptions<
    T extends Schema,
    Q extends QuizQuestions,
> extends Omit<FormPresentationOptions<T>, 'fields'> {
    questions?: QuizAnswerFieldNames<Q>[]
    randomizeQuestions?: boolean
}

type QuizAnswerFieldNames<Q extends QuizQuestions> = Extract<keyof Q, string>

type QuizAnswers<Q extends QuizQuestions> = Record<
    QuizAnswerFieldNames<Q>,
    string
>

type QuizAnswerValidities<Q extends QuizQuestions> = Record<
    QuizAnswerFieldNames<Q>,
    AnswerValidity
>

interface QuizPresentationResults<Q extends QuizQuestions> {
    /** The answers that were given */
    answers: QuizAnswers<Q>

    /** The answers right or wrong */
    answerValidities: QuizAnswerValidities<Q>

    /** The percent of correct answers given  */
    percentCorrect: number

    /** How long it took them to take the quiz in ms */
    time: {
        startTimeMs: number
        endTimeMs: number
        totalTimeSec: number
    }

    /** How many were correct */
    totalCorrect: number

    /** How many were wrong */
    totalWrong: number

    /** How many questions we ended up taking */
    totalQuestions: number
}

interface QuizOptions<T extends Schema, Q extends QuizQuestions> extends Omit<
    FormOptions<T>,
    'schema'
> {
    /** Should we randomize the questions */
    randomizeQuestions?: boolean
    /** The questions we are asking */
    questions: Q
}

export default class QuizComponent<T extends Schema, Q extends QuizQuestions> {
    public formBuilder: FormComponent<T>
    public term: GraphicsInterface
    public randomizeQuestions = true
    public originalQuestions: QuizQuestions
    public lastResults?: QuizPresentationResults<Q>

    public constructor(options: QuizOptions<T, Q>) {
        // We're going to build a schema from the questions and pass that to the form builder
        const definition = this.buildSchemaFromQuestions(options.questions)

        // Track questions for later reference
        this.originalQuestions = options.questions

        // Construct new form builder
        this.formBuilder = new FormComponent<T>({
            ...options,
            schema: definition,
        })

        // Set state locally
        this.term = options.ui
        this.randomizeQuestions = options.randomizeQuestions ?? true
    }

    /** Present the quiz */
    public async present(
        options: QuizPresentationOptions<T, Q> = {}
    ): Promise<QuizPresentationResults<Q>> {
        const {
            questions = this.formBuilder
                .getNamedFields()
                .map((nf) => nf.name) as QuizAnswerFieldNames<Q>[],
            randomizeQuestions = this.randomizeQuestions,
        } = options

        const startTime = new Date().getTime()

        // Pull out answers
        const fields = randomizeQuestions ? shuffle(questions) : questions

        // Ask for the answers
        const results = await this.formBuilder.present({
            ...options,
            fields: fields as SchemaFieldNames<T>[],
        })

        // Generate stats
        const answers: Partial<QuizAnswers<Q>> = {}
        const answerValidities: Partial<QuizAnswerValidities<Q>> = {}

        const totalQuestions = questions.length
        let totalCorrect = 0

        const questionNames = Object.keys(results) as QuizAnswerFieldNames<Q>[]

        questionNames.forEach((questionName) => {
            const fieldName = questionName as SchemaFieldNames<T>
            const answer = (results[fieldName] as string) || ''
            const [validity, idx] = answer.split('-')

            // Get the field to tell type
            const { field } =
                this.formBuilder
                    .getNamedFields()
                    .find((namedField) => namedField.name === fieldName) || {}

            if (!field) {
                throw new Error('Field issue in QuizComponent')
            }

            const fieldDefinition = field.definition

            switch (fieldDefinition.type) {
                case 'select':
                    // Pull the original multiple choice, we can cast it as multiple choice
                    // question with confidence
                    answers[questionName] = (
                        this.originalQuestions[
                            questionName
                        ] as QuizMultipleChoiceQuestion
                    ).answers[parseInt(idx)]
                    break
                default:
                    // @ts-ignore TODO proper questions to schema should fix this because we only support a few fields
                    answers[questionName] = results[fieldName]
            }

            // Track validity
            if (validity === AnswerValidity.Correct) {
                totalCorrect = totalCorrect + 1
                answerValidities[questionName] = AnswerValidity.Correct
            } else {
                answerValidities[questionName] = AnswerValidity.Incorrect
            }
        }, 0)

        const totalWrong = totalQuestions - totalCorrect

        // Track time
        const endTime = new Date().getTime()

        this.lastResults = {
            percentCorrect: totalCorrect / totalQuestions,
            totalCorrect,
            totalWrong,
            answerValidities: answerValidities as QuizAnswerValidities<Q>,
            answers: answers as QuizAnswers<Q>,
            totalQuestions,
            time: {
                startTimeMs: startTime,
                endTimeMs: endTime,
                totalTimeSec: +((endTime - startTime) / 1000).toFixed(1),
            },
        }

        return this.lastResults
    }

    public async scorecard(
        options: {
            results?: QuizPresentationResults<Q>
            headline?: string
        } = {}
    ) {
        const { headline, results = this.lastResults } = options
        const { term } = this

        if (!results) {
            throw new SchemaError({
                code: 'INVALID_PARAMETERS',
                parameters: [],
            })
        }

        term.clear()
        term.renderHero(headline ?? 'Quiz results!')

        const testResults: Record<string, string> = {}

        this.formBuilder.getNamedFields().forEach((namedField) => {
            const { name, field } = namedField
            const questionFieldName = name as QuizAnswerFieldNames<Q>

            // Get results
            const isCorrect =
                results.answerValidities[questionFieldName] ===
                AnswerValidity.Correct
            const guessedAnswer = `${results.answers[questionFieldName]}`

            // Build the real answer
            let correctAnswer = ''

            const originalQuestion = this.originalQuestions[questionFieldName]

            switch (originalQuestion.type) {
                case 'select':
                    correctAnswer = originalQuestion.answers[0]
                    break
                default:
                    // All options just pass through the answer tied to the question during instantiation
                    correctAnswer = originalQuestion.answer
            }

            const objectKey = field.label || '**missing'

            if (isCorrect) {
                testResults[objectKey] = `${chalk.bgGreenBright.black(
                    'Correct!'
                )} ${guessedAnswer} `
            } else {
                testResults[objectKey] = `${chalk.bgRedBright.black(
                    'Wrong!'
                )}  ${chalk.strikethrough(guessedAnswer)} -> ${correctAnswer}`
            }
        })

        term.renderObject(testResults)

        term.renderLine(`# questions: ${results.totalQuestions}`)
        term.renderLine(`# correct: ${results.totalCorrect}`)

        term.renderHeadline(
            `Your score: ${(results.percentCorrect * 100).toFixed(1)}%`
        )

        await term.waitForEnter()
    }

    /** Takes questions and builds a schema */
    private buildSchemaFromQuestions(questions: QuizQuestions): T {
        // TODO change SchemaFields to something based on schema generated from questions
        const fields: SchemaFieldsByName = {}

        Object.keys(questions).forEach((fieldName) => {
            const question = questions[fieldName]

            switch (question.type) {
                case 'select':
                    fields[fieldName] = {
                        type: question.type,
                        label: question.question,
                        options: {
                            choices: shuffle(
                                question.answers.map((question, idx) => ({
                                    value:
                                        idx === 0
                                            ? `${AnswerValidity.Correct}-${idx}`
                                            : `${AnswerValidity.Incorrect}-${idx}`,
                                    label: question,
                                }))
                            ),
                        },
                    }
                    break
                default:
                    fields[fieldName] = {
                        type: question.type,
                        label: question.question,
                    }
            }
        })

        //@ts-ignore TODO better mapping of questions to schema definition
        const definition: T = {
            id: 'quizGenerated',
            name: 'Generated quiz',
            fields,
        }

        return definition
    }
}