const reviewRoot = '../../target'
const settingsRoot = '../../tools/legal-review'

const express = require('express')
const app = express()
const open = require('open')
const fs = require('fs')
const path = require('path')

// The home page that lists available reports.
app.get('/', function (req, res) {
  let html = '<h1>Report review</h1>'
  const files = fs.readdirSync(reviewRoot)
  const reports = files
    .map(f => f.match(/^(.*)-report.html$/))
    .filter(m => m != null)
    .map(m => m[1])
  if (reports.length == 0) {
    html +=
      'No reports found. ' + 'Run <pre style="display:inline">enso / gatherLicenses</pre> first.'
  } else {
    html += 'Select report:'
    html += '<ul>'
    reports.forEach(report => {
      html += '<li><a href="/report/' + report + '">' + report + '</a></li>'
    })
    html += '</ul>'
  }
  res.send(html)
})

// Serves the injection script.
app.use('/static', express.static('static'))

// Serves contents of the given report, injecting the review-mode script.
app.get('/report/:report', function (req, res) {
  const report = req.params['report']
  console.log('Opening report for ', report)
  fs.readFile(path.join(reviewRoot, report + '-report.html'), 'utf-8', (err, data) => {
    const injection =
      '<script src="/static/inject.js"></script>' +
      '<script>var reportName = "' +
      report +
      '";</script>'
    if (err) {
      res.status(400).send(err)
    } else {
      const injected = data.replace('</head>', injection + '</head>')
      res.send(injected)
    }
  })
})

// Appends a line to the setting file.
function addLine(report, package, file, line) {
  const dir = path.join(settingsRoot, report, package)
  const location = path.join(dir, file)
  console.log('Adding ' + line + ' to ' + location)
  fs.mkdirSync(dir, {
    recursive: true,
  })
  fs.appendFileSync(location, line + '\n')
}

// Removes a line from the setting file.
function removeLine(report, package, file, line) {
  const location = path.join(settingsRoot, report, package, file)
  console.log('Removing ' + line + ' from ' + location)
  const lines = fs
    .readFileSync(location, 'utf-8')
    .split(/\r?\n/)
    .filter(x => x.length > 0)
  const toRemove = lines.filter(x => x == line)
  const others = lines.filter(x => x != line)
  if (toRemove.length == 0) {
    throw (
      'Line ' + line + ' was not present in the file. ' + 'Are you sure the report is up to date?'
    )
  } else {
    var newContent = others.join('\n') + '\n'
    if (others.length == 0) {
      newContent = ''
    }
    fs.writeFileSync(location, newContent)
  }
}

// Handles the requests to add or remove lines.
app.use(express.urlencoded({ extended: true }))
app.post('/modify/:report', function (req, res) {
  const report = req.params['report']
  const package = req.body['package']
  const action = req.body['action']
  const file = req.body['file']
  let line = req.body['line']
  const encodedLine = req.body['encoded_line']
  if (encodedLine !== undefined) {
    line = Buffer.from(encodedLine, 'base64').toString()
  }

  try {
    if (action == 'add') {
      addLine(report, package, file, line)
    } else if (action == 'remove') {
      removeLine(report, package, file, line)
    } else {
      throw 'Unknown action'
    }
    res.send('OK')
  } catch (error) {
    console.error(error)
    res.status(500).send(error)
  }
})

// Handles the request to rename a package directory.
app.post('/rename-package/:report', function (req, res) {
  const report = req.params['report']
  const from = req.body['from']
  const to = req.body['to']

  try {
    const fromPath = path.join(settingsRoot, report, from)
    const toPath = path.join(settingsRoot, report, to)

    if (!fs.existsSync(fromPath)) {
      throw 'The source directory ' + fromPath + ' does not exist...'
    }

    if (fs.existsSync(toPath)) {
      const isTargetEmpty = fs.readdirSync(toPath).length == 0
      if (!isTargetEmpty) {
        throw (
          'The target directory ' +
          toPath +
          ' already exists. Please merge the directories manually using your preferred file explorer.'
        )
      }

      fs.rmdirSync(toPath)
    }

    fs.renameSync(fromPath, toPath)
    res.send('OK')
  } catch (error) {
    console.error(error)
    res.status(500).send(error)
  }
})

app.post('/override-custom-license/:report', function (req, res) {
  const report = req.params['report']
  const package = req.body['package']
  const file = req.body['file']

  try {
    const dir = path.join(settingsRoot, report, package)

    const defaultAndCustom = path.join(dir, 'default-and-custom-license')
    if (fs.existsSync(defaultAndCustom)) {
      fs.unlinkSync(defaultAndCustom)
    }

    const fileName = file.split('/').pop()

    const custom = path.join(dir, 'custom-license')
    fs.writeFileSync(custom, fileName + '\n')
    res.send('OK')
  } catch (error) {
    console.error(error)
    res.status(500).send(error)
  }
})

app.get('/get-known-license-texts', function (req, res) {
  const knownLicenses = fs.readdirSync(path.join(settingsRoot, 'license-texts'))
  res.send(JSON.stringify(knownLicenses))
})

app.post('/mark-license-as-reviewed/:report', function (req, res) {
  const report = req.params['report']
  const licenseName = req.body['licenseName']
  const licenseTextPath = 'tools/legal-review/license-texts/' + req.body['licenseTextPath']
  const location = path.join(settingsRoot, report, 'reviewed-licenses', licenseName)

  console.log(licenseTextPath + ' -> ' + location)

  if (fs.existsSync(location)) {
    res.status(400).send('License already marked as reviewed')
    return
  }

  fs.writeFileSync(location, licenseTextPath)
  res.send('Marked ' + licenseName + ' as reviewed: ' + licenseTextPath)
})

/*
 * Listens on a random free port, opens a browser with the home page and waits
 * for a newline to terminate.
 */
const server = app.listen(0, () => {
  const port = server.address().port
  console.log('Listening on at ', 'http://localhost:' + port + '/')
  open('http://localhost:' + port + '/')

  console.log('Press ENTER to stop the server.')
  process.stdin.on('data', function (chunk) {
    if (chunk.indexOf('\n') >= 0) {
      console.log('Good bye')
      process.exit(0)
    }
  })
})