#!/usr/bin/env ruby
require 'find'
require 'net/http'
require 'uri'
require 'digest/sha1'
require 'json'
require 'fileutils'

@command = ARGV[0]
@pkgName = ARGV[1]

CREW_PREFIX = '/usr/local'
CREW_LIB_PATH = CREW_PREFIX + '/lib/crew/'
CREW_CONFIG_PATH = CREW_PREFIX + '/etc/crew/'
CREW_BREW_DIR = CREW_PREFIX + '/tmp/crew/'
CREW_DEST_DIR = CREW_BREW_DIR + '/dest'

$LOAD_PATH.push CREW_LIB_PATH

USER = `whoami`.chomp

@device = JSON.parse(File.read(CREW_CONFIG_PATH + 'device.json'), symbolize_names: true)
#symbolize also values
@device.each do |key, elem|
  @device[key] = @device[key].to_sym rescue @device[key]
end

def setPkg (pkgName, silent = false)
  require CREW_LIB_PATH + 'packages/' + pkgName
  @pkg = Object.const_get(pkgName.capitalize)
  @pkg.name = pkgName
  puts "Found #{pkgName}, version #{@pkg.version}" unless silent
end

def search (pkgName, silent = false)
  Find.find (CREW_LIB_PATH + 'packages') do |filename|
    return setPkg(pkgName, silent) if filename == CREW_LIB_PATH + 'packages/' + pkgName + '.rb'
  end
  abort "package #{pkgName} not found :("
end

def download
  if @pkg.binary_url && @pkg.binary_url.has_key?(@device[:architecture])
    url = @pkg.binary_url[@device[:architecture]]
    source = false
    puts "Precompiled binary available, downloading..."
  else
    url = @pkg.source_url
    source = true
    puts "No precompiled binary available for your platform, downloading source..."
  end
  uri = URI.parse url
  filename = File.basename(uri.path)
  if source
    sha1sum = @pkg.source_sha1
  else
    sha1sum = @pkg.binary_sha1[@device[:architecture]]
  end
  Dir.chdir CREW_BREW_DIR do
    system('wget', '--content-disposition', '--no-check-certificate', '-N', url)
    abort 'Checksum mismatch :/ try again' unless Digest::SHA1.hexdigest( File.read("./#{filename}") ) == sha1sum
  end
  puts "Archive downloaded"
  return {source: source, filename: filename}
end

def resolveDependenciesAndInstall
  origin = @pkgName

  resolveDependencies
  
  search origin
  install

  #cleanup
  unless ARGV[2] == 'keep'
    Dir.chdir CREW_BREW_DIR do
      system "rm -rf *"
      system "mkdir dest" #this is a little ugly, feel free to find a better way
    end
  end
end

def resolveDependencies
  @dependencies = []

  def pushDeps
    if @pkg.dependencies
      @dependencies << @pkg.dependencies
      
      @pkg.dependencies.each do |dep|
        search dep, true
        pushDeps
      end
    end
  end
  
  pushDeps
  
  return if @dependencies.empty?

  puts "Following packages also need to be installed: "
  @dependencies.flatten!.each do |dep|
    print dep + " "
  end
  puts ""
  puts "Do you agree? [Y/n]"
  response = STDIN.getc
  case response
  when "n"
    abort "No changes made."
  when "\n", "y", "Y"
    puts "Proceeding..."
    proceed = true
  else
    puts "I don't understand '#{response}' :("
    abort "No changes made."
  end

  if proceed
    @dependencies.each do |dep|
      search dep
      install
    end
  end
end

def install
  if @device[:installed_packages].any? { |pkg| pkg[:name] == @pkg.name }
    puts "Package #{@pkg.name} already installed, skipping..."
    return
  end

  unless @pkg.is_fake?
    meta = download
    Dir.chdir CREW_BREW_DIR do
      puts "Unpacking archive, this may take a while..."
      system "tar", "xf", meta[:filename]
      if meta[:source] == true
        abort "You don't have a working C compiler. Run 'crew install buildessential' to get one and try again." unless system("gcc", "--version")
        topdir = `tar -tf #{meta[:filename]} | sed -e 's@/.*@@' | uniq`.chomp!
        Dir.chdir CREW_BREW_DIR + topdir do
          puts "Building from source, this may take a while..."
          @pkg.build
          system "rm -rf", CREW_DEST_DIR + "/*" #wipe crew destdir
          puts "Preconfiguring package..."
          @pkg.install
        end

        Dir.chdir CREW_DEST_DIR do
          #create directory list
          system "find . -type f > ../filelist"
          system "find . -type l >> ../filelist"
          system "cut -c2- ../filelist > filelist"
          #create file list
          system "find . -type d > ../dlist"
          system "cut -c2- ../dlist > dlistcut"
          system "tail -n +2 dlistcut > dlist"
          #remove temporary files
          system "rm dlistcut ../dlist ../filelist"
          
          #create resulting folders list
          directories = []
          Dir.glob('*').select do |fn|
            if File.directory?(fn)
              directories.push(fn)
            end
          end

          #wipe directories with the same name in brew dir to avoid conflicts
          directories.each do |dir|
            system "rm -rf ../" + dir.chomp
          end

          #move result files and directories to brew dir
          system "mv * ../"
        end
      end

      puts "Installing..."

      FileUtils.mv 'dlist', CREW_CONFIG_PATH + "meta/#{@pkg.name}.directorylist"
      FileUtils.mv 'filelist', CREW_CONFIG_PATH + "meta/#{@pkg.name}.filelist"
 
      File.open(CREW_CONFIG_PATH + "meta/#{@pkg.name}.directorylist").each_line do |line|
        system "sudo", "mkdir", "-p", line.chomp
      end

      File.open(CREW_CONFIG_PATH + "meta/#{@pkg.name}.filelist").each_line do |line|
        system "sudo", "mv", CREW_BREW_DIR + line.chomp, line.chomp
      end
    end
  end
  
  #add to installed packages
  @device[:installed_packages].push(name: @pkg.name, version: @pkg.version)
  File.open(CREW_CONFIG_PATH + 'device.json', 'w') do |file|
    output = JSON.parse @device.to_json
    file.write JSON.pretty_generate(output)
  end
  puts "#{@pkg.name.capitalize} installed!"
end

def remove
  unless @device[:installed_packages].any? { |pkg| pkg[:name] == @pkg.name }
    puts "Package #{@pkg.name} isn't installed."
    return
  end
  
  unless @pkg.is_fake?
    Dir.chdir CREW_CONFIG_PATH do
      File.open("meta/#{@pkg.name}.filelist").each_line do |line|
        begin
          File.unlink line.chomp
        rescue => exception #swallow exception
        end
      end
  
      File.readlines("meta/#{@pkg.name}.directorylist").reverse.each do |line|
        begin
          Dir.rmdir line.chomp
        rescue => exception #swallow exception
        end
      end

      File.unlink "meta/#{@pkg.name}.filelist"
      File.unlink "meta/#{@pkg.name}.directorylist"
    end
  end

  #remove from installed packages
  @device[:installed_packages].each do |elem|
    @device[:installed_packages].delete elem if elem[:name] == @pkg.name
  end
  File.open(CREW_CONFIG_PATH + 'device.json', 'w') do |file|
    out = JSON.parse @device.to_json
    file.write JSON.pretty_generate(out)
  end
  puts "#{@pkgName.capitalize} removed!"
end

case @command
when "search"
  search @pkgName
when "download"
  search @pkgName
  download
when "update"
  unless @pkgName == 'crew'
    Dir.chdir CREW_LIB_PATH do
      system "git fetch origin master"
      system "git reset --hard origin/master"
    end
    puts "Package lists updated."
  else
    abort 'Updating crew itself must be done as root.' unless USER == 'root'
    #update crew binary
    Dir.chdir CREW_PREFIX + '/bin' do
      system "wget", "-N", "https://raw.github.com/skycocker/chromebrew/master/crew"
      system "sudo", "chmod", "+x", "crew"
    end
    #update crew library
    Dir.chdir CREW_LIB_PATH do
      system "wget", "-N", "https://raw.github.com/skycocker/chromebrew/master/lib/package.rb"
      system "wget", "-N", "https://raw.github.com/skycocker/chromebrew/master/lib/package_helpers.rb"
    end
  end
when "install"
  search @pkgName
  resolveDependenciesAndInstall
when "remove"
  abort 'Removing actions must be ran with sudo.' unless USER == 'root'
  search @pkgName
  remove
when nil
  puts "Chromebrew, version 0.1"
  puts "Usage: crew [command] [package]"
  puts "Available commands: search, download, install, remove"
else
  puts "I have no idea how to do #{@command} :("
  puts "Available commands: search, download, install, remove"
end