install

#!/usr/bin/env node
var fs = require('fs')
  , path = require('path')
  , exec = require('child_process').exec
  , sh

// Normalize HOME environment variable.
process.env.HOME = process.env.HOME || process.env.HOMEDRIVE + process.env.HOMEPATH
if (!process.env.HOME) {
  console.error(
    'No HOME environment variables available. Dotfiles cannot be installed.'
  )
  process.exit(1)
}

// Handle ~ as Bash does.
function aTarget(file) {
  return path.normalize(file.replace(/~/g, process.env.HOME))
}

// Absolute source file paths.
function aSource(file) {
  return path.resolve(__dirname, file)
}

// HOME-relative source file paths
function rSource(file) {
  return path.relative(process.env.HOME, aSource(file))
}

// CWD-relative source file paths
function lSource(file) {
  return path.relative(process.cwd(), aSource(file))
}

// Detects the complete list of file paths that should be included or linked.
function detectSources(file) {
  var sources = []

  if (sh.test('-f', aSource(file))) {
    sources.push(file)
  }

  if (sh.test('-f', aSource(file + '_' + process.platform))) {
    sources.push(file + '_' + process.platform)
  }

  return sources
}

// Call each function in the given array in order. Each function is given
// a function that, when called, calls the next function in the list.
function step(arr) {
  if (!arr.length) {
    return
  }

  arr[0](function () {
    step(arr.slice(1))
  })
}

step([
  // Install our dependencies if necessary, calling `callback` upon successful
  // completion.
  function bootstrap(callback) {
    try {
      sh = require('shelljs')
      return callback()
    } catch (e) {}

    exec('npm install --no-bin-links', {
      cwd: __dirname
    }, function (err) {
      if (err) {
        console.error('Failed to install shelljs.')
        console.error('Error:', err.message)
        process.exit(1)
      }

      sh = require('shelljs')
      return callback()
    })
  },
  // Link all the dotfiles, and install all the things.
  function install() {
    // Bash
    sh.rm('-f', aTarget('~/.bashrc'))
    detectSources('bash/.bashrc')
      .reduce(function (str, file) {
        return str + 'source ~/' + rSource(file) + '\n'
      }, '')
      .to(aTarget('~/.bashrc'))

    // Git
    sh.rm('-f', aTarget('~/.gitconfig'))
    detectSources('git/.gitconfig')
      .reduce(function (str, file) {
        return str + '[include]\n  path = ' + rSource(file) + '\n'
      }, '')
      .to(aTarget('~/.gitconfig'))
    sh.ln('-sf', lSource('git/.gitignore_global'), aTarget('~/.gitignore_global'))

    // SSH
    sh.mkdir('-p', aTarget('~/.ssh'))
    sh.ln('-sf', lSource('ssh/config'), aTarget('~/.ssh/config'))

    // Vim
    sh.rm('-f', aTarget('~/.vimrc'))
    detectSources('vim/.vimrc')
      .reduce(function (str, file) {
        return str + 'source ~/' + rSource(file) + '\n'
      }, '')
      .to(aTarget('~/.vimrc'))

    // iTerm
    if (process.platform === 'darwin') {
      sh.rm('-f', aTarget('~/.iterm/com.googlecode.iterm2.plist'))
      sh.ln('-sf', lSource('iterm/config.plist'), aTarget('~/.iterm/com.googlecode.iterm2.plist'))
    }
  }
])