orlowdev/gatsby-source-notion-api

const { pipeExtend } = require("or-pipets")

const pick = (key) => (obj) => obj[key]

const ifTrue = (predicate, transformer, orElse) => (data) =>
    predicate(data) ? transformer(data) : orElse(data)

const id = (x) => x

const annotateEquation = ifTrue(
    pick("equation"),
    ({ content }) => ({ content: `$${content}$` }),
    id,
)
const annotateBold = ifTrue(pick("bold"), ({ content }) => ({ content: `**${content}**` }), id)
const annotateItalic = ifTrue(pick("italic"), ({ content }) => ({ content: `_${content}_` }), id)
const annotateCode = ifTrue(pick("code"), ({ content }) => ({ content: `\`${content}\`` }), id)
const annotateStrikethrough = ifTrue(
    pick("strikethrough"),
    ({ content }) => ({ content: `~~${content}~~` }),
    id,
)
const annotateUnderline = ifTrue(
    pick("underline"),
    ({ content }) => ({ content: `<u>${content}</u>` }),
    id,
)
const annotateColor = ifTrue(
    ({ color }) => color != "default",
    ({ content, color }) => ({ content: `<span notion-color="${color}">${content}</span>` }),
    id,
)
const annotateLink = ifTrue(
    pick("link"),
    ({ content, link }) => ({ content: `[${content}](${link.url ? link.url : link})` }),
    id,
)

const stylize = pipeExtend(annotateBold)
    .pipeExtend(annotateItalic)
    .pipeExtend(annotateCode)
    .pipeExtend(annotateStrikethrough)
    .pipeExtend(annotateUnderline)
    .pipeExtend(annotateColor)
    .pipeExtend(annotateLink)
    .pipeExtend(annotateEquation)

exports.blockToString = (textBlocks) =>
    textBlocks.reduce((text, textBlock) => {
        const data = {
            ...textBlock.text,
            ...textBlock.annotations,
        }

        if (textBlock.type == "equation") {
            data.content = textBlock.equation.expression
            data.equation = true
        }

        if (textBlock.type == "mention") {
            if (textBlock.mention.type == "user") {
                data.content = textBlock.plain_text
            }

            if (textBlock.mention.type == "date") {
                if (textBlock.mention.date.end) {
                    data.content = `${textBlock.mention.date.start} → ${textBlock.mention.date.start}`
                } else {
                    data.content = textBlock.mention.date.start
                }

                data.content = `<time datetime="${data.content}">${data.content}</time>`
            }

            if (textBlock.mention.type == "page") {
                data.content = textBlock.plain_text
            }
        }

        return text.concat(stylize.process(data).content)
    }, "")