#!/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'

# Set CREW_NPROC from environment variable or `nproc`
if ENV["CREW_NPROC"].to_s == ''
  CREW_NPROC = `nproc`.strip
else
  CREW_NPROC = ENV["CREW_NPROC"]
end

# Set XZ_OPT environment variable for build command.
# If CREW_XZ_OPT is defined, use it by default.  Use `-7e`, otherwise.
if ENV["CREW_XZ_OPT"].to_s == ''
  ENV["XZ_OPT"] = "-7e"
else
  ENV["XZ_OPT"] = ENV["CREW_XZ_OPT"]
end

ARCH = `uname -m`.strip

$LOAD_PATH.unshift "#{CREW_LIB_PATH}lib"

USER = `whoami`.chomp

#disallow sudo
abort "Chromebrew should not be run as root." if Process.uid == 0 && @command != "remove"

@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 set_package (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 list_packages
  Find.find (CREW_LIB_PATH + 'packages') do |filename|
    Find.find(CREW_CONFIG_PATH + 'meta/') do |packageList|
      packageName = File.basename filename, '.rb'
      print '(i) ' if packageList == CREW_CONFIG_PATH + 'meta/' + packageName + '.filelist'
    end
    puts File.basename filename, '.rb' if File.extname(filename) == '.rb'
  end
end

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

def help (pkgName)
  case pkgName
  when "build"
    puts "Build a package."
    puts "Usage: crew build [package]"
    puts "Build [package] from source and place the archive and checksum in the current working directory."
  when "download"
    puts "Download a package."
    puts "Usage: crew download [package]"
    puts "Download [package] to `CREW_BREW_DIR` (`/usr/local/tmp/crew` by default), but don't install it."
  when "install"
    puts "Install a package."
    puts "Usage: crew install [package]"
    puts "The [package] must be a valid name.  Use `crew search [package]` to search for a package to install."
  when "remove"
    puts "Remove a package."
    puts "Usage: crew remove [package]"
    puts "The [package] must be currently installed."
  when "search"
    puts "Look for a package."
    puts "Usage: crew search [package]"
    puts "If [package] is omitted, all packages will be returned.  (i) in front of the name means the package is installed."
    puts "Tips:"
    puts "  crew search | grep '(i)' will return all installed packages."
    puts "  crew search | grep -v '(i)' will return all available packages not already installed."
  when "update"
    puts "Update crew."
    puts "Usage: crew update"
    puts "This only updates crew itself.  Use 'crew upgrade' to update packages."
  when "upgrade"
    puts "Update package(s)."
    puts "Usage: crew upgrade [package]"
    puts "If [package] is omitted, all packages will be updated.  Otherwise, a specific package will be updated."
    puts "Use 'crew update' to update crew itself."
  when "whatprovides"
    puts "Determine which package(s) contains file(s)."
    puts "Usage: crew whatprovides [pattern]"
    puts "The [pattern] is a search string which can contain regular expressions."
  else
    puts "Available commands: build, download, install, remove, search, update, upgrade, whatprovides"
  end
end

def whatprovides (pkgName)
  fileArray = []
  Find.find (CREW_CONFIG_PATH + 'meta/') do |packageList|
    if File.file? packageList
      if packageList[/\.filelist$/]
        packageName = File.basename packageList, '.filelist'
        File.readlines(packageList).each do |line|
          found = line[/#{Regexp.new(pkgName)}/]
          if found
            fileLine = packageName + ': ' + line
            if not fileArray.include? fileLine
              fileArray.push(fileLine)
            end
          end
        end
      end
    end
  end
  if not fileArray.empty?
    fileArray.sort.each do |item|
      puts item
    end
    puts "\nTotal found: #{fileArray.length}"
  end
end

def update
  abort "'crew update' is used to update crew itself. Use 'crew upgrade <packageName> to upgrade a specific package." if @pkgName

  #update package lists
  Dir.chdir CREW_LIB_PATH do
    system "git fetch origin master"
    system "git reset --hard origin/master"
  end
  puts "Package lists, crew, and library updated."

  #check for outdated installed packages
  puts "Checking for package updates..."
  puts ""

  canBeUpdated = 0
  @device[:installed_packages].each do |package|
    search package[:name], true
    if package[:version] != @pkg.version
      canBeUpdated += 1
      puts @pkg.name + " could be updated from " + package[:version] + " to " + @pkg.version
    end
  end

  if canBeUpdated > 0
    puts ""
    puts "Run 'crew upgrade' to upgrade everything or 'crew upgrade <packageName>' to upgrade a specific package."
  else
    puts "Your software is up to date."
  end
end

def upgrade
  if @pkgName
    search @pkgName

    currentVersion = nil
    @device[:installed_packages].each do |package|
      if package[:name] == @pkg.name
        currentVersion = package[:version]
      end
    end

    if currentVersion != @pkg.version
      puts "Updating #{@pkg.name}..."
      @pkg.in_upgrade = true
      resolve_dependencies_and_install
      @pkg.in_upgrade = false
    else
      puts "#{@pkg.name} is already up to date."
    end
  else
    toBeUpdated = []
    @device[:installed_packages].each do |package|
      search package[:name], true
      if package[:version] != @pkg.version
        toBeUpdated.push(package[:name])
      end
    end

    if toBeUpdated.length > 0
      puts "Updating packages..."
      toBeUpdated.each do |package|
        search package
        @pkg.in_upgrade = true
        resolve_dependencies_and_install
        @pkg.in_upgrade = false
      end
      puts "Packages have been updated."
    else
      puts "Your software is already up to date."
    end
  end
end

def download
  url = @pkg.get_url(@device[:architecture])
  source = @pkg.is_source?(@device[:architecture])

  if !url
    abort "No precompiled binary for #{@device[:architecture]} nor source is available."
  elsif !source
    puts "Precompiled binary available, downloading..."
  elsif @pkg.build_from_source
    puts "Downloading source..."
  else
    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', '--continue', '--no-check-certificate', url, '-O', filename)
    abort 'Checksum mismatch :/ try again' unless Digest::SHA1.hexdigest( File.read("./#{filename}") ) == sha1sum
  end
  puts "Archive downloaded"
  return {source: source, filename: filename}
end

def unpack (meta)
  extract_dir = "#{meta[:filename]}.dir"
  target_dir = nil
  Dir.chdir CREW_BREW_DIR do
    puts "Unpacking archive, this may take a while..."
    Dir.mkdir("#{extract_dir}") unless Dir.exist?("#{extract_dir}")
    if meta[:filename][-4,4] == ".zip"
      system "unzip", "-qq", "-d", "#{extract_dir}", meta[:filename]
    else
      system "tar", "xf", meta[:filename], "-C", "#{extract_dir}"
    end
    if meta[:source] == true
      # Check the number of directories in the archive
      entries=Dir["#{extract_dir}/*"]
      if entries.length == 0
        abort "empty archive: #{meta[:filename]}"
      elsif entries.length == 1 && File.directory?(entries.first)
        # Use `extract_dir/dir_in_archive` if there is only one directory.
        target_dir = entries.first
      else
        # Use `extract_dir` otherwise
        target_dir = extract_dir
      end
    else
      # Use `extract_dir` for binary distribution
      target_dir = extract_dir
    end
  end
  return CREW_BREW_DIR + target_dir
end

def build_and_preconfigure (target_dir)
  Dir.chdir target_dir do
    puts "Building from source, this may take a while..."
    @pkg.in_build = true
    @pkg.build
    @pkg.in_build = false
    system "rm -rf #{CREW_DEST_DIR}/*" #wipe crew destdir
    puts "Preconfiguring package..."
    @pkg.install
  end
end

def prepare_package (destdir)
  Dir.chdir destdir 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"
  end
end

def install_package (pkgdir)
  Dir.chdir pkgdir do
    FileUtils.mv 'dlist', CREW_CONFIG_PATH + "meta/#{@pkg.name}.directorylist"
    FileUtils.mv 'filelist', CREW_CONFIG_PATH + "meta/#{@pkg.name}.filelist"

    system "tar cf - ./usr/* | (cd /; tar xp --keep-directory-symlink -f -)"
  end
end

def resolve_dependencies_and_install
  begin
    origin = @pkg.name

    resolveDependencies

    search origin, true
    install
  rescue InstallError => e
    abort "#{@pkg.name} failed to install: #{e.to_s}"
  ensure
    #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
end

def resolveDependencies
  @dependencies = []

  # check source packages existance
  @source_package = 0

  def push_dependencies
    if @pkg.is_binary?(@device[:architecture]) ||
       (!@pkg.in_upgrade && @device[:installed_packages].any? { |pkg| pkg[:name] == @pkg.name })
      # retrieve name of dependencies that doesn't contain :build tag
      @check_deps = @pkg.dependencies.select {|k, v| !v.include?(:build)}.map {|k, v| k}
    elsif @pkg.is_fake?
      # retrieve name of all dependencies
      @check_deps = @pkg.dependencies.map {|k, v| k}
    else
      # retrieve name of all dependencies
      @check_deps = @pkg.dependencies.map {|k, v| k}
      # count the number of source packages to add buildessential into dependencies later
      @source_package += 1
    end

    # remove a dependent package which is equal to the target
    @check_deps.select! {|name| @pkgName != name}

    # insert only not installed packages into dependencies
    @dependencies = @check_deps.select {|name| @device[:installed_packages].none? {|pkg| pkg[:name] == name}}.concat(@dependencies)

    # check all dependencies recursively
    @check_deps.each do |dep|
      search dep, true
      push_dependencies
    end
  end

  push_dependencies

  # Add buildessential and solve its dependencies if any of dependent
  # packages are made from source
  if @source_package > 0
    search 'buildessential', true
    push_dependencies
  end

  return if @dependencies.empty?

  puts "Following packages also need to be installed: "

  @dependencies.uniq!
  @dependencies.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 !@pkg.in_upgrade && @device[:installed_packages].any? { |pkg| pkg[:name] == @pkg.name }
    puts "Package #{@pkg.name} already installed, skipping..."
    return
  end

  unless @pkg.is_fake?
    meta = download
    target_dir = unpack meta
    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")

      # build from source and place binaries at CREW_DEST_DIR
      # CREW_DEST_DIR contains usr/local/... hierarchy
      build_and_preconfigure target_dir

      # prepare filelist and dlist at CREW_DEST_DIR
      prepare_package CREW_DEST_DIR

      # use CREW_DEST_DIR
      dest_dir = CREW_DEST_DIR
    else
      # use extracted binary directory
      dest_dir = target_dir
    end

    # remove it just before the file copy
    if @pkg.in_upgrade
      puts "Removing since upgrade..."
      remove @pkg.name
    end

    # install filelist, dlist and binary files
    puts "Installing..."
    install_package dest_dir
  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 resolve_dependencies_and_build
  begin
    origin = @pkg.name

    # mark current package as which is required to compile from source
    @pkg.build_from_source = true
    resolveDependencies

    search origin, true
    build_package Dir.pwd
  rescue InstallError => e
    abort "#{@pkg.name} failed to build: #{e.to_s}"
  ensure
    #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
end

def build_package (pwd)
  abort "It is not possible to build fake package" if @pkg.is_fake?
  abort "It is not possible to build without source" if !@pkg.is_source?(@device[:architecture])

  # download source codes and unpack it
  meta = download
  target_dir = unpack meta

  # build from source and place binaries at CREW_DEST_DIR
  build_and_preconfigure target_dir

  # call check method here.  this check method is called by this function only,
  # therefore it is possible place time consuming tests in the check method.
  if Dir.exist? target_dir
    Dir.chdir target_dir do
      puts "Checking..."
      @pkg.check
    end
  end

  # prepare filelist and dlist at CREW_DEST_DIR
  prepare_package CREW_DEST_DIR

  # build package from filelist, dlist and binary files in CREW_DEST_DIR
  puts "Archiving..."
  archive_package pwd
end

def archive_package (pwd)
  pkg_name = "#{@pkg.name}-#{@pkg.version}-chromeos-#{@device[:architecture]}.tar.xz"
  Dir.chdir CREW_DEST_DIR do
    system "tar cJf #{pwd}/#{pkg_name} *"
  end
  Dir.chdir pwd do
    system "sha1sum #{pkg_name} > #{pkg_name}.sha1"
  end
  puts "#{pkg_name} is built!"
end

def remove (pkgName)

  #make sure the package is actually installed
  unless @device[:installed_packages].any? { |pkg| pkg[:name] == pkgName }
    puts "Package #{pkgName} isn't installed."
    return
  end

  #if the filelist exists, remove the files and directories installed by the package
  if File.file?("#{CREW_CONFIG_PATH}meta/#{pkgName}.filelist")
    Dir.chdir CREW_CONFIG_PATH do

      #remove all files installed by the package
      File.open("meta/#{pkgName}.filelist").each_line do |line|
        begin
          File.unlink line.chomp
        rescue => exception #swallow exception
        end
      end

      #remove all directories installed by the package
      File.readlines("meta/#{pkgName}.directorylist").reverse.each do |line|
        begin
          Dir.rmdir line.chomp
        rescue => exception #swallow exception
        end
      end

      #remove the file and directory list
      File.unlink "meta/#{pkgName}.filelist"
      File.unlink "meta/#{pkgName}.directorylist"

    end
  end

  #remove from installed packages
  @device[:installed_packages].each do |elem|
    @device[:installed_packages].delete elem if elem[:name] == pkgName
  end

  #update the device manifest
  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 "help"
  if @pkgName
    help @pkgName
  else
    puts "Usage: crew help [command]"
    help nil
  end
when "search"
  if @pkgName
    search @pkgName
  else
    list_packages
  end
when "whatprovides"
  if @pkgName
    whatprovides @pkgName
  else
    help "whatprovides"
  end
when "download"
  if @pkgName
    search @pkgName
    download
  else
    help "download"
  end
when "update"
  update
when "upgrade"
  upgrade
when "install"
  if @pkgName
    search @pkgName
    resolve_dependencies_and_install
  else
    help "install"
  end
when "build"
  if @pkgName
    search @pkgName
    resolve_dependencies_and_build
  else
    help "build"
  end
when "remove"
  if @pkgName
    remove @pkgName
  else
    help "remove"
  end
when nil
  puts "Chromebrew, version 0.4.2"
  puts "Usage: crew [command] [package]"
  help nil
else
  puts "I have no idea how to do #{@command} :("
  help nil
end