Markdown to Anki

example.md

Chapter 01

• AB
• Problem 01
  • Answer A
  • Answer B
  • Answer C
  • Answer D
• Problem 02
  • Answer A
  • Answer B
  • Answer C
  • Answer D

Chapter 02

• AB
• Problem 01
  • Answer A
  • Answer B
  • Answer C
  • Answer D
• Problem 02
  • Answer A
  • Answer B
  • Answer C
  • Answer D

parse.js

const fs = require('fs')
const file = fs.readFileSync('example.md', 'utf8').trim()

const res = file.split("#")
    .map(a => a.trim())
    .filter(a => a)
    .map(a => {
        let list = a.split("\r\n")
        const chapter = list.shift().trim()
        const answers = list.shift().replace("- ", "").trim()
        const raw_questions = list.map(a => a)

        let temp_list = [];
        raw_questions.forEach(a => {
            if (a.startsWith("- ")) {
                temp_list.push({
                    question: a.replace("- ", "").trim(),
                    choices: []
                })
            } else if (a.startsWith("  - ")) {
                temp_list[temp_list.length - 1].choices.push(a.replace("  - ", "").trim())
            } else {
                throw new Error(a)
            }
        })
        return [chapter, answers, temp_list]
    })
    .map(a => {
        const answer_map = "ABCD";
        [chapter, answers, temp_list] = a

        temp_list.map((a, i) => {
            a.answer = answer_map.indexOf(answers[i])
            a.answer_text = a.choices[a.answer]
            return a
        })

        return {
            chapter,
            questions: temp_list
        }
    });

console.log(res)
console.log(res.map(a => a.questions.length))

const anki_format = res.map(a => {
    const { chapter, questions } = a
    let list = questions.map(q => 
        [
            q.question,
            chapter,
            2,
            q.choices.join("\t"),
            "",
            q.choices.map((_, i) => i == q.answer ? 1 : 0).join(" ")
        ].join("\t"))
    
    list.unshift("#separator:tab")
    list.unshift("#html:false")
    list.unshift("#tags column:12")
    return list.join("\r\n")
});
console.log(anki_format)

// save files
anki_format.forEach((a, i) => {
    fs.writeFileSync(`${i + 1}.txt`, a)
})