//Imports
  import fs from "fs/promises"
  import fss from "fs"
  import os from "os"
  import paths from "path"
  import url from "url"
  import util from "util"
  import processes from "child_process"
  import axios from "axios"
  import _puppeteer from "puppeteer"
  import git from "simple-git"
  import twemojis from "twemoji-parser"
  import jimp from "jimp"
  import opengraph from "open-graph-scraper"
  import rss from "rss-parser"
  import nodechartist from "node-chartist"
  import GIFEncoder from "gifencoder"
  import PNG from "png-js"

//Exports
  export {fs, os, paths, url, util, processes, axios, git, opengraph, jimp, rss}

/**Returns module __dirname */
  export function __module(module) {
    return paths.join(paths.dirname(url.fileURLToPath(module)))
  }

/**Puppeteer instantier */
  export const puppeteer = {
    async launch() {
      return _puppeteer.launch({
        headless:this.headless,
        executablePath:process.env.PUPPETEER_BROWSER_PATH,
        args:this.headless ? ["--no-sandbox", "--disable-extensions", "--disable-setuid-sandbox", "--disable-dev-shm-usage"] : [],
        ignoreDefaultArgs:["--disable-extensions"],
      })
    },
    headless:true,
  }

/**Plural formatter */
  export function s(value, end = "") {
    return value !== 1 ? {y:"ies", "":"s"}[end] : end
  }

/**Formatter */
  export function format(n, {sign = false, unit = true, fixed} = {}) {
    if (unit) {
      for (const {u, v} of [{u:"b", v:10**9}, {u:"m", v:10**6}, {u:"k", v:10**3}]) {
        if (n/v >= 1)
          return `${(sign)&&(n > 0) ? "+" : ""}${(n/v).toFixed(fixed ?? 2).substr(0, 4).replace(/[.]0*$/, "")}${u}`
      }
    }
    return `${(sign)&&(n > 0) ? "+" : ""}${fixed ? n.toFixed(fixed) : n}`
  }

/**Bytes formatter */
  export function bytes(n) {
    for (const {u, v} of [{u:"E", v:10**18}, {u:"P", v:10**15}, {u:"T", v:10**12}, {u:"G", v:10**9}, {u:"M", v:10**6}, {u:"k", v:10**3}]) {
      if (n/v >= 1)
        return `${(n/v).toFixed(2).substr(0, 4).replace(/[.]0*$/, "")} ${u}B`
    }
    return `${n} byte${n > 1 ? "s" : ""}`
  }
  format.bytes = bytes

/**Percentage formatter */
  export function percentage(n, {rescale = true} = {}) {
    return `${(n*(rescale ? 100 : 1)).toFixed(2)
      .replace(/(?<=[.])(?<decimal>[1-9]*)0+$/, "$<decimal>")
      .replace(/[.]$/, "")}%`
  }
  format.percentage = percentage

/**Text ellipsis formatter */
  export function ellipsis(text, {length = 20} = {}) {
    text = `${text}`
    if (text.length < length)
      return text
    return `${text.substring(0, length)}…`
  }
  format.ellipsis = ellipsis

/**Date formatter */
  export function date(string, options) {
    return new Intl.DateTimeFormat("en-GB", options).format(new Date(string))
  }
  format.date = date

/**Array shuffler */
  export function shuffle(array) {
    for (let i = array.length-1; i > 0; i--) {
      const j = Math.floor(Math.random()*(i+1))
      ;[array[i], array[j]] = [array[j], array[i]]
    }
    return array
  }

/**Escape html */
  export function htmlescape(string, u = {"&":true, "<":true, ">":true, '"':true, "'":true}) {
    return string
      .replace(/&(?!(?:amp|lt|gt|quot|apos);)/g, u["&"] ? "&amp;" : "&")
      .replace(/</g, u["<"] ? "&lt;" : "<")
      .replace(/>/g, u[">"] ? "&gt;" : ">")
      .replace(/"/g, u['"'] ? "&quot;" : '"')
      .replace(/'/g, u["'"] ? "&apos;" : "'")
  }

/**Unescape html */
  export function htmlunescape(string, u = {"&":true, "<":true, ">":true, '"':true, "'":true}) {
    return string
      .replace(/&lt;/g, u["<"] ? "<" : "&lt;")
      .replace(/&gt;/g, u[">"] ? ">" : "&gt;")
      .replace(/&quot;/g, u['"'] ? '"' : "&quot;")
      .replace(/&(?:apos|#39);/g, u["'"] ? "'" : "&apos;")
      .replace(/&amp;/g, u["&"] ? "&" : "&amp;")
  }

/**Chartist */
  export async function chartist() {
    const css = `<style>${await fs.readFile(paths.join(__module(import.meta.url), "../../../node_modules", "node-chartist/dist/main.css")).catch(_ => "")}</style>`
    return (await nodechartist(...arguments))
      .replace(/class="ct-chart-line">/, `class="ct-chart-line">${css}`)
  }

/**Run command */
  export async function run(command, options, {prefixed = true} = {}) {
    const prefix = {win32:"wsl"}[process.platform] ?? ""
    command = `${prefixed ? prefix : ""} ${command}`.trim()
    return new Promise((solve, reject) => {
      console.debug(`metrics/command > ${command}`)
      const child = processes.exec(command, options)
      let [stdout, stderr] = ["", ""]
      child.stdout.on("data", data => stdout += data)
      child.stderr.on("data", data => stderr += data)
      child.on("close", code => {
        console.debug(`metrics/command > ${command} > exited with code ${code}`)
        console.debug(stdout)
        console.debug(stderr)
        return code === 0 ? solve(stdout) : reject(stderr)
      })
    })
  }

/**Check command existance */
  export async function which(command) {
    try {
      console.debug(`metrics/command > checking existence of ${command}`)
      await run(`which ${command}`)
      return true
    }
    catch {
      console.debug(`metrics/command > checking existence of ${command} > failed`)
    }
    return false
  }

/**Image to base64 */
  export async function imgb64(image, {width, height, fallback = true} = {}) {
    //Undefined image
      if (!image)
        return fallback ? "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mOcOnfpfwAGfgLYttYINwAAAABJRU5ErkJggg==" : null
    //Load image
      image = await jimp.read(image)
    //Resize image
      if ((width)&&(height))
        image = image.resize(width, height)
    return image.getBase64Async(jimp.AUTO)
  }

/**SVG utils */
  export const svg = {
    /**Render and resize svg */
      async resize(rendered, {paddings, convert}) {
        //Instantiate browser if needed
          if (!svg.resize.browser) {
            svg.resize.browser = await puppeteer.launch()
            console.debug(`metrics/svg/resize > started ${await svg.resize.browser.version()}`)
          }
        //Format padding
          const [pw = 1, ph] = (Array.isArray(paddings) ? paddings : `${paddings}`.split(",").map(x => x.trim())).map(padding => `${padding}`.substring(0, padding.length-1)).map(value => 1+Number(value)/100)
          const padding = {width:pw, height:ph ?? pw}
          console.debug(`metrics/svg/resize > padding width*${padding.width}, height*${padding.height}`)
        //Render through browser and resize height
          console.debug("metrics/svg/resize > loading svg")
          const page = await svg.resize.browser.newPage()
          page.on("console", ({_text:text}) => console.debug(`metrics/svg/resize > puppeteer > ${text}`))
          await page.setContent(rendered, {waitUntil:["load", "domcontentloaded", "networkidle2"]})
          console.debug("metrics/svg/resize > loaded svg successfully")
          await page.addStyleTag({content:"body { margin: 0; padding: 0; }"})
          let mime = "image/svg+xml"
          console.debug("metrics/svg/resize > resizing svg")
          let height, resized, width
          try {
            ({resized, width, height} = await page.evaluate(async padding => {
              //Disable animations
                const animated = !document.querySelector("svg").classList.contains("no-animations")
                if (animated)
                  document.querySelector("svg").classList.add("no-animations")
                console.debug(`animations are ${animated ? "enabled" : "disabled"}`)
                await new Promise(solve => setTimeout(solve, 2400))
              //Get bounds and resize
                let {y:height, width} = document.querySelector("svg #metrics-end").getBoundingClientRect()
                console.debug(`bounds width=${width}, height=${height}`)
                height = Math.ceil(height*padding.height)
                width = Math.ceil(width*padding.width)
                console.debug(`bounds after applying padding width=${width} (*${padding.width}), height=${height} (*${padding.height})`)
              //Resize svg
                document.querySelector("svg").setAttribute("height", height)
              //Enable animations
                if (animated)
                  document.querySelector("svg").classList.remove("no-animations")
              //Result
                return {resized:new XMLSerializer().serializeToString(document.querySelector("svg")), height, width}
            }, padding))
          }
          catch (error) {
            console.error(error)
            console.debug(`metrics/svg/resize > an error occured: ${error}`)
            throw error
          }
        //Convert if required
          if (convert) {
            console.debug(`metrics/svg/resize > convert to ${convert}`)
            resized = await page.screenshot({type:convert, clip:{x:0, y:0, width, height}, omitBackground:true})
            mime = `image/${convert}`
          }
        //Result
          await page.close()
          console.debug("metrics/svg/resize > rendering complete")
          return {resized, mime}
      },
    /**Render twemojis */
      async twemojis(rendered) {
        //Load emojis
          console.debug("metrics/svg/twemojis > rendering twemojis")
          const emojis = new Map()
          for (const {text:emoji, url} of twemojis.parse(rendered)) {
            if (!emojis.has(emoji))
              emojis.set(emoji, (await axios.get(url)).data.replace(/^<svg /, '<svg class="twemoji" '))
          }
        //Apply replacements
          for (const [emoji, twemoji] of emojis) {
            rendered = rendered.replace(new RegExp(`<metrics[ ]*(?<attributes>[^>]*)>${emoji}</metrics>`, "g"), twemoji.replace(/(<svg class="twemoji" [\s\S]+?)(>)/, "$1 $<attributes> $2")) //eslint-disable-line prefer-named-capture-group
            rendered = rendered.replace(new RegExp(emoji, "g"), twemoji)
          }
        return rendered
      },
    /**Render github emojis */
      async gemojis(rendered, {rest}) {
        //Load gemojis
          console.debug("metrics/svg/gemojis > rendering gemojis")
          const emojis = new Map()
          try {
            for (const [emoji, url] of Object.entries((await rest.emojis.get()).data).map(([key, value]) => [`:${key}:`, value])) {
              if (((!emojis.has(emoji)))&&(new RegExp(emoji, "g").test(rendered)))
                emojis.set(emoji, `<img class="gemoji" src="${await imgb64(url)}" height="16" width="16" alt="">`)
            }
          }
          catch (error) {
            console.debug("metrics/svg/gemojis > could not load gemojis")
            console.debug(error)
          }
        //Apply replacements
          for (const [emoji, gemoji] of emojis)
            rendered = rendered.replace(new RegExp(emoji, "g"), gemoji)
        return rendered
      },
  }

/**Wait */
  export async function wait(seconds) {
    await new Promise(solve => setTimeout(solve, seconds*1000))
  }

/**Create record from puppeteer browser */
  export async function record({page, width, height, frames, scale = 1, quality = 80, x = 0, y = 0, delay = 150, background = true}) {
    //Register images frames
      const images = []
      for (let i = 0; i < frames; i++) {
        images.push(await page.screenshot({type:"png", clip:{width, height, x, y}, omitBackground:background}))
        await wait(delay/1000)
        if (i%10 === 0)
          console.debug(`metrics/record > processed ${i}/${frames} frames`)
      }
      console.debug(`metrics/record > processed ${frames}/${frames} frames`)
    //Post-processing
      console.debug("metrics/record > applying post-processing")
      return Promise.all(images.map(async buffer => (await jimp.read(buffer)).scale(scale).quality(quality).getBase64Async("image/png")))
  }

/**Create gif from puppeteer browser*/
  export async function gif({page, width, height, frames, x = 0, y = 0, repeat = true, delay = 150, quality = 10}) {
    //Create temporary stream
      const path = paths.join(os.tmpdir(), `${Math.round(Math.random()*1000000000)}.gif`)
      console.debug(`metrics/puppeteergif > set write stream to "${path}"`)
      if (fss.existsSync(path))
        await fs.unlink(path)
    //Create encoder
      const encoder = new GIFEncoder(width, height)
      encoder.createWriteStream().pipe(fss.createWriteStream(path))
      encoder.start()
      encoder.setRepeat(repeat ? 0 : -1)
      encoder.setDelay(delay)
      encoder.setQuality(quality)
    //Register frames
      for (let i = 0; i < frames; i++) {
        const buffer = new PNG(await page.screenshot({clip:{width, height, x, y}}))
        encoder.addFrame(await new Promise(solve => buffer.decode(pixels => solve(pixels))))
        if (frames%10 === 0)
          console.debug(`metrics/puppeteergif > processed ${i}/${frames} frames`)
      }
      console.debug(`metrics/puppeteergif > processed ${frames}/${frames} frames`)
    //Close encoder and convert to base64
      encoder.finish()
      const result = await fs.readFile(path, "base64")
      await fs.unlink(path)
      return `data:image/gif;base64,${result}`
  }