#!/usr/bin/env node
const spinner = require('char-spinner')
const {gray, green, yellow, red, bold} = require('colorette')
const {SiteChecker} = require('broken-link-checker')

const yargs = require('yargs')
  .option('filter-level', {type: Number, alias: 'L', default: 3})
  .option('verbose', {type: Boolean, alias: 'v', default: false})

const options = Object.assign(
  {
    excludedKeywords: [
      // exclude dash-feed:// URLs (in meta)
      'dash-feed',
      // exclude github org repos, which are (mostly) private
      'https://github.com/github/*'
    ]
  },
  yargs.argv
)

const args = options._

const pages = []
const seen = new Set()

const VERBOSE = options.v === true
const OK = ' ✓ '
const NOT_OK = ' ✘ '
const TAG_LENGTH = 3

const URL = args[0]
if (URL) {
  log(green('go!'), bold(URL))
} else {
  log('err', 'you must provide a URL')
  process.exit(1)
}

let page = {url: URL, links: []}

const checker = new SiteChecker(options, {
  page(error, url) {
    if (error) {
      log(red('ERR'), `${url} (${error.code})`)
    } else if (page) {
      const {url, response, links = []} = page
      const num = String(links.length).padEnd(TAG_LENGTH)
      let message = `${bold(num)} unique links`
      if (!VERBOSE) message = `${message} on ${yellow(url)}`
      log(OK, message)
      if (links.length) {
        pages.push(page)
      }
    }
  },

  html(tree, robots, response, url) {
    if (VERBOSE) log(yellow('get'), url)
    page = {url, links: []}
  },

  junk(result) {
    const url = result.url.resolved || result.url.original
    if (!url || seen.has(url)) {
      return
    } else if (VERBOSE) {
      log(' '.repeat(TAG_LENGTH), gray(`skip ${shorten(url)}`))
    } else if (result.excluded && url.indexOf(URL) !== 0) {
      log(yellow('???'), gray(`skip ${url}`))
    }
    seen.add(url)
  },

  link(result) {
    const url = result.url.resolved || result.url.original
    if (VERBOSE && !seen.has(url)) log(' + ', gray('link'), shorten(url))
    if (!seen.has(url)) page.links.push(result)
    seen.add(url)
  },

  end() {
    let brokenTotal = 0
    for (const page of pages) {
      const broken = page.links.filter(link => link.broken)
      brokenTotal += broken.length

      if (!broken.length && !VERBOSE) {
        continue
      } else {
        const num = broken.length ? red(` ${broken.length}`.padEnd(TAG_LENGTH)) : green(' 0').padEnd(TAG_LENGTH)
        log(bold(num), `broken links on ${bold(page.url)}`)
      }

      for (const link of page.links) {
        if (!link.broken && !VERBOSE) continue
        const tag = link.broken ? red(NOT_OK) : green(OK)
        const reason = link.broken ? yellow(link.brokenReason) : ''
        const url = link.url.resolved || link.url.original
        log(tag, shorten(url), reason)
      }
      log('')
    }

    if (brokenTotal) {
      log(red(String(brokenTotal).padEnd(TAG_LENGTH)), 'broken links!')
      process.exitCode = 1
    } else {
      log('')
      log(green(OK), bold('0'.padEnd(TAG_LENGTH)), 'broken links; nice work!')
    }

    log('')
  }
})

spinner()
checker.enqueue(URL)
checker.resume()

function log(tag, ...args) {
  spinner.clear()
  console.log(tag ? gray(`[${tag}]`) : '', ...args)
}

function shorten(url) {
  return String(url).indexOf(URL) === 0 ? url.substr(URL.length) || '/' : url
}