#!/usr/bin/env node

// Generate a graphviz (graphviz.org) .dot file for the package relationships
// of the currently running N|Solid instances, using the N|Solid 1.3
// package_info command.

'use strict'

var fs = require('fs')
var path = require('path')
var child_process = require('child_process')

nsolidAgent('info', function (err, infos) {
  if (err) {
    console.log('error connecting to N|Solid agents:', err.message)
    return
  }

  if (infos.length == 0) {
    console.log('There are no N|Solid agents running at this time')
    return
  }

  console.log('To convert the generated graphviz .dot files to PDF, use the command:')
  console.log('')
  console.log('   dot -Tpdf -O <file name of .dot file>')
  console.log('')

  infos.forEach(function (info) {
    var appId = {
      app: info.app,
      id: info.id
    }

    getPackageInfo(appId)
  })
})

function getPackageInfo (appId) {
  var app = appId.app
  var id = appId.id

  nsolidAgent('package_info', app, id, function (err, packageInfo) {
    if (err) throw err

    processPackageInfo(app, id, packageInfo)
  })
}

function processPackageInfo (app, id, packageInfo) {
  if (!packageInfo.packages) throw new Error('expecting packages property')

  // get the package directories
  var pkgDirs = packageInfo.packages.map(function (pkg) { return pkg.path })

  // create a map of package dir : package, and name/version counts
  var pkgMap = {}
  var pkgCount = {}
  packageInfo.packages.forEach(function (pkg) {
    pkgMap[pkg.path] = pkg

    const nameVersion = pkg.name + '@' + pkg.version
    if (pkgCount[nameVersion] == null) {
      pkgCount[nameVersion] = 1
    } else {
      pkgCount[nameVersion]++
    }
  })

  // turn all the dependencies into refs to their packages
  packageInfo.packages.forEach(function (pkg) {
    pkg.dependencies = pkg.dependencies.map(function (dep) {
      var depPath = path.resolve(pkg.path, dep)
      return pkgMap[depPath]
    })
  })

  // console.log(app + ' - ' + id)
  // console.log('')

  var oName = app + '-' + id + '.dot'
  console.log('creating ' + oName)

  var oStream = fs.createWriteStream(oName)
  oStream.write('digraph packages {\n')
  oStream.write('node [style=filled];\n')

  pkgDirs.forEach(function (pkgDir) {
    var pkg = pkgMap[pkgDir]
    var pkgNode = pkg.name + '\\n' + pkg.version
    var count = pkgCount[pkg.name + '@' + pkg.version]

    if (count > 1) {
      oStream.write('"' + getNodeName(pkg) + '" [color="#FFA0A0"];\n')
    }

    pkg.dependencies.forEach(function (dep) {
      oStream.write('"' + getNodeName(pkg) + '" -> "' + getNodeName(dep) + '";\n')
    })
  })

  oStream.write('}\n')

  function getNodeName(pkg) {
    var name = pkg.name.replace(/-/g, '-\\n') + '\\n' + pkg.version
    var count = pkgCount[pkg.name + '@' + pkg.version]

    if (count === 1) return name
    return name + '\\n' + count + ' copies'
  }
}


function uniquePackageVersions (pkgs) {
  var result = []
  var found = {}

  pkgs.forEach(function (pkg) {
    var pkgVersion = pkg.name + '@' + pkg.version
    if (found[pkgVersion]) return

    found[pkgVersion] = true

    result.push({
      name: pkg.name,
      version: pkg.version
    })
  })

  return result
}

function nsolidAgent (command, app, id, cb) {
  if ((typeof app === 'function') && !id && !cb) {
    cb = app
    app = null
    id = null
  }

  if ((typeof id === 'function') && !cb) {
    cb = id
    id = null
  }

  var options = []

  if (app) options.push('--app ' + app)
  if (id) options.push('--id ' + id)

  options = options.join(' ')
  if (options !== '') options = ' ' + options + ' '

  command = 'nsolid-cli' + options + ' ' + command

  var execOpts = {
    maxBuffer: 20 * 1000 * 1000
  }

  child_process.exec(command, execOpts, done)

  debugLog('running: ' + command)

  function done (err, stdout, stderr) {
    debugLog('ran:     ' + command)
    if (stderr) debugLog('stderr: ' + stderr)

    if (err) {
      debugLog('err:    ' + err)
      return cb(err)
    }

    var result = []
    var lines = stdout.split('\n')
    for (var i = 0; i < lines.length; i++) {
      var line = lines[i]
      if (line === '') continue

      try {
        line = JSON.parse(line)
      } catch (err) {
        line = JSON.stringify({err: 'invalid JSON'})
      }

      if (app && id) {
        result.push(line)
      } else {
        result.push(line.reply)
      }
    }

    if (app && id) {
      cb(null, result[0])
    } else {
      cb(null, result)
    }
  }
}

function debugLog (message) {
  // console.error(message)
}