const fs = require('fs')
const path = require('path')
const markdownit = require('markdown-it')
const md = markdownit({
    html: true,
    breaks: true,
    typographer: {
        whitespace: 'all'
    },
})
const logger = require('./logger')()

// Parse markdown
class Blog {
    constructor() {}

    async ReadBlogs() {return this.#LoadBlogs().then(output => {return output})}

    // ! Check if file is a markdown file
    async #LoadBlogs() {
        return new Promise((res, rej) => {
            if (fs.existsSync('./blog/')) {
                fs.readdir('./blog/', (err, files) => {
                    if (err) {
                        logger.Error(`${err.code}: Error reading directory`)
                        rej(`${err.code}: Error reading directory`)
                    } else {
                        this.blog = new Map()
                        files.forEach(file => {
                            this.blog.set(file.replace('.md', ''), fs.readFileSync(path.resolve(`./blog/${file}`), 'utf-8', (err, data) => {
                                if (err) {
                                    logger.Error(`${err.code}: Failed to read ${file}`)
                                    rej(`${err.code}: Failed to read ${file}`)
                                    return
                                }
                                return data
                            }))
                        })
                        this.blog.forEach((value, key) => {
                            const regex = /# (.*)\nDate: (.*)\n---(.*?)---/s
                            const match = value.match(regex)

                            if (match) {
                                const [, title, date, description] = match
                                this.blog.set(key, {
                                    title: title,
                                    date: new Date(date),
                                    short: description,
                                    body: md.render(value)
                                })
                            } else {
                                this.blog.set(key, {
                                    title: undefined,
                                    date: undefined,
                                    short: undefined,
                                    body: md.render(value)
                                })
                            }
                        })
                        res(this.#OrderByDate(this.blog))
                    }
                })
            } else {
                logger.Error('ERROR: blog directory does not exist')
                rej('ERROR: blog directory does not exist')
            }
        })
    }

    #OrderByDate(x) {
        const entries =[]
        x.forEach((value, key) => {entries.push([key, value])})
        entries.sort((a, b) => {
            const dateA = b[1].date
            const dateB = a[1].date
            return dateA - dateB
        })
        return new Map(entries)
    }
}

module.exports = () => {return new Blog()}