#! /usr/bin/ruby

if RUBY_VERSION < "2.1.0"
    STDERR.puts "autoproj requires Ruby >= 2.1.0"
    exit 1
elsif ENV['AUTOPROJ_CURRENT_ROOT'] && (ENV['AUTOPROJ_CURRENT_ROOT'] != Dir.pwd)
    STDERR.puts "it seems that you've already loaded an env.sh script in this console, open a new console and try again"
    exit 1
end

require 'pathname'
require 'optparse'
require 'fileutils'
require 'yaml'

module Autoproj
    module Ops
        # This class contains the functionality necessary to install autoproj in a
        # clean root
        #
        # It can be required standalone (i.e. does not depend on anything else than
        # ruby and the ruby standard library)
        class Install
            class UnexpectedBinstub < RuntimeError; end

            # The created workspace's root directory
            attr_reader :root_dir
            # Content of the Gemfile generated to install autoproj itself
            attr_accessor :gemfile
            # The environment that is passed to the bundler installs
            attr_reader :env
            # The configuration hash
            attr_reader :config
            # A set of options that should be passed to autoproj when calling it
            # in a subprocess
            attr_reader :autoproj_options
            # The Ruby interpreter we use for this install
            attr_reader :ruby_executable
            # The URL of the source to be used to get gems
            attr_accessor :gem_source

            def initialize(root_dir)
                @root_dir = root_dir
                @gem_source = "https://rubygems.org"
                @gemfile = nil
                @skip_stage2 = false

                @autoproj_options = Array.new

                @env = Hash.new
                env['RUBYOPT'] = []
                env['RUBYLIB'] = []
                env['PATH'] = self.class.sanitize_env(ENV['PATH'] || "")
                env['BUNDLE_GEMFILE'] = []

                load_config

                if config['ruby_executable'] != Gem.ruby
                    raise "this autoproj installation was already bootstrapped using "\
                        "#{config['ruby_executable']}, but you are currently running "\
                        "under #{Gem.ruby}. Changing the ruby interpreter in a given "\
                        "workspace is not supported, you need to do a clean bootstrap"
                end
                @ruby_executable = config['ruby_executable']
                @local = false

                unless @gems_install_path
                    install_gems_in_gem_user_dir
                end
                env['GEM_HOME'] = [gems_gem_home]
                env['GEM_PATH'] = [gems_gem_home]
            end

            def env_for_child(env = self.env)
                env.inject(Hash.new) do |h, (k, v)|
                    h[k] = if v && !v.empty? then v.join(File::PATH_SEPARATOR)
                           end
                    h
                end
            end

            def apply_env(env)
                env.each do |k, v|
                    if v
                        ENV[k] = v
                    else
                        ENV.delete(k)
                    end
                end
            end

            def self.sanitize_env(value)
                value.split(File::PATH_SEPARATOR).
                    find_all { |p| !in_workspace?(p) }
            end

            def self.in_workspace?(base_dir)
                path = Pathname.new(base_dir)
                while !path.root?
                    if (path + ".autoproj").exist? || (path + "autoproj").exist?
                        return true
                    end
                    path = path.parent
                end
                return false
            end

            # The path to the .autoproj configuration directory
            #
            # @return [String]
            def dot_autoproj; File.join(root_dir, '.autoproj') end

            # The path to the gemfile used to install autoproj
            #
            # @return [String]
            def autoproj_gemfile_path; File.join(dot_autoproj, 'Gemfile') end

            # The path to the autoproj configuration file
            #
            # @return [String]
            def autoproj_config_path; File.join(dot_autoproj, 'config.yml') end

            # Whether the stage2 install should be called or not
            def skip_stage2?; !!@skip_stage2 end
            # (see #skip_stage2?)
            def skip_stage2=(flag); @skip_stage2 = flag end

            # Whether we can access the network while installing
            def local?; !!@local end
            # (see #local?)
            def local=(flag); @local = flag end

            # The user-wide place where RubyGems installs gems
            def dot_gem_dir
                File.join(Gem.user_home, ".gem")
            end

            # The version and platform-specific suffix under {#dot_gem_dir}
            #
            # This is also the suffix used by bundler to install gems
            def gem_path_suffix
                @gem_path_suffix ||= Pathname.new(Gem.user_dir).
                    relative_path_from(Pathname.new(dot_gem_dir)).to_s
            end

            # The path into which the workspace's gems should be installed
            #
            # They are installed in a versioned subdirectory of this path, e.g.
            # {#gem_path_suffix}.
            #
            # @return [String]
            attr_reader :gems_install_path
            # The GEM_HOME under which the workspace's gems should be installed
            #
            # @return [String]
            def gems_gem_home
                File.join(gems_install_path, gem_path_suffix)
            end
            # Sets where the workspace's gems should be installed
            #
            # @param [String] path the absolute path that should be given to
            #   bundler. The gems themselves will be installed in the
            #   {#gem_path_suffix} subdirectory under this
            def gems_install_path=(path)
                @gems_install_path = path
            end

            private def xdg_var(varname, default)
                if (env = ENV[varname]) && !env.empty?
                    env
                else
                    default
                end
            end

            # Install autoproj in Gem's default user dir
            def install_gems_in_gem_user_dir
                xdg_default_gem_path = xdg_var('XDG_DATA_HOME',
                    File.join(Dir.home, '.local', 'share', 'autoproj', 'gems'))
                default_gem_path = File.join(
                    Dir.home, '.autoproj', 'gems')
                @gems_install_path =
                    if File.directory?(xdg_default_gem_path)
                        xdg_default_gem_path
                    elsif File.directory?(default_gem_path)
                        default_gem_path
                    else
                        xdg_default_gem_path
                    end
            end

            # Whether autoproj should prefer OS-independent packages over their
            # OS-packaged equivalents (e.g. the thor gem vs. the ruby-thor
            # Debian package)
            def prefer_indep_over_os_packages?
                @prefer_indep_over_os_packages
            end
            # (see #prefer_index_over_os_packages?)
            def prefer_indep_over_os_packages=(flag)
                @prefer_indep_over_os_packages = !!flag
            end

            def self.guess_gem_program
                ruby_bin = RbConfig::CONFIG['RUBY_INSTALL_NAME']
                ruby_bindir = RbConfig::CONFIG['bindir']

                candidates = ['gem']
                if ruby_bin =~ /^ruby(.+)$/
                    candidates.unshift "gem#{$1}"
                end

                candidates.each do |gem_name|
                    if File.file?(gem_full_path = File.join(ruby_bindir, gem_name))
                        return gem_full_path
                    end
                end
                raise ArgumentError, "cannot find a gem program "\
                    "(tried #{candidates.sort.join(", ")} in #{ruby_bindir})"
            end

            # The content of the default {#gemfile}
            #
            # @param [String] autoproj_version a constraint on the autoproj version
            #   that should be used
            # @return [String]
            def default_gemfile_contents(autoproj_version = ">= 2.0.0")
                ["source \"#{gem_source}\"",
                 "ruby \"#{RUBY_VERSION}\" if respond_to?(:ruby)",
                 "gem \"autoproj\", \"#{autoproj_version}\"",
                 "gem \"utilrb\", \">= 3.0.1\""].join("\n")
            end

            # Parse the provided command line options and returns the non-options
            def parse_options(args = ARGV)
                options = OptionParser.new do |opt|
                    opt.on '--local', 'do not access the network (may fail)' do
                        @local = true
                    end
                    opt.on '--skip-stage2', 'do not run the stage2 install' do
                        @skip_stage2 = true
                    end
                    opt.on '--gem-source=URL', String, "use this source for RubyGems "\
                        "instead of rubygems.org" do |url|
                        @gem_source = url
                    end
                    opt.on '--gems-path=PATH', "install gems under this path instead "\
                        "of ~/.autoproj/gems" do |path|
                        self.gems_install_path     = path
                    end
                    opt.on '--public-gems', "install gems in the default gem location" do
                        self.install_gems_in_gem_user_dir
                    end
                    opt.on '--version=VERSION_CONSTRAINT', String, 'use the provided "\
                        "string as a version constraint for autoproj' do |version|
                        if @gemfile
                            raise "cannot give both --version and --gemfile"
                        end
                        @gemfile = default_gemfile_contents(version)
                    end
                    opt.on '--gemfile=PATH', String, 'use the given Gemfile to install "\
                        "autoproj instead of the default' do |path|
                        if @gemfile
                            raise "cannot give both --version and --gemfile"
                        end
                        @gemfile = File.read(path)
                    end
                    opt.on '--seed-config=PATH', String, 'path to a seed file that "\
                        "should be used to initialize the configuration' do |path|
                        @config.merge!(YAML.load(File.read(path)))
                    end
                    opt.on '--prefer-os-independent-packages', 'prefer OS-independent "\
                        "packages (such as a RubyGem) over their OS-packaged equivalent "\
                        "(e.g. the thor gem vs. the ruby-thor debian package)' do
                        @prefer_indep_over_os_packages = true
                    end
                    opt.on '--[no-]color', 'do not use colored output (enabled by "\
                        "default if the terminal supports it)' do |color|
                        if color then autoproj_options << "--color"
                        else autoproj_options << '--no-color'
                        end
                    end
                    opt.on '--[no-]progress', 'do not use progress output (enabled by "\
                        "default if the terminal supports it)' do |color|
                        if color then autoproj_options << "--progress"
                        else autoproj_options << '--no-progress'
                        end
                    end
                end
                args = options.parse(ARGV)
                autoproj_options + args
            end

            def find_bundler(gem_program)
                setup_paths =
                    IO.popen([env_for_child, Gem.ruby, gem_program, 'which','-a', 'bundler/setup']) do |io|
                        io.read
                    end
                return unless $?.success?
                bundler_path = File.join(gems_gem_home, 'bin', 'bundle')
                setup_paths.each_line do |setup_path|
                    if File.exist?(bundler_path) && setup_path.start_with?(gems_gem_home)
                        return bundler_path
                    end
                end
                return
            end

            def install_bundler(gem_program, silent: false)
                local = ['--local'] if local?

                redirection = Hash.new
                if silent
                    redirection = Hash[out: :close]
                end

                # Shut up the bundler warning about 'bin' not being in PATH
                env = self.env
                env['PATH'] += [File.join(gems_gem_home, 'bin')]
                result = system(
                    env_for_child(env),
                    Gem.ruby, gem_program, 'install',
                        '--env-shebang', '--no-document', '--no-format-executable',
                        '--clear-sources', '--source', gem_source,
                        '--no-user-install', '--install-dir', gems_gem_home,
                        *local, "--bindir=#{File.join(gems_gem_home, 'bin')}",
                        'bundler', **redirection)

                if !result
                    STDERR.puts "FATAL: failed to install bundler in #{gems_gem_home}"
                    nil
                end

                if (bundler_path = find_bundler(gem_program))
                    bundler_path
                else
                    STDERR.puts "gem install bundler returned successfully, but still "\
                        "cannot find bundler in #{gems_gem_home}"
                    nil
                end
            end

            def install_autoproj(bundler)
                # Force bundler to update. If the user does not want this, let
                # him specify a Gemfile with tighter version constraints
                lockfile = File.join(dot_autoproj, 'Gemfile.lock')
                if File.exist?(lockfile)
                    FileUtils.rm lockfile
                end

                clean_env = env_for_child.dup

                opts = Array.new
                opts << '--local' if local?
                opts << "--path=#{gems_install_path}"
                shims_path = File.join(dot_autoproj, 'bin')

                result = system(clean_env,
                    Gem.ruby, bundler, 'install',
                        "--gemfile=#{autoproj_gemfile_path}",
                        "--shebang=#{Gem.ruby}",
                        "--binstubs=#{shims_path}",
                        *opts, chdir: dot_autoproj)

                if !result
                    STDERR.puts "FATAL: failed to install autoproj in #{dot_autoproj}"
                    exit 1
                end
            ensure
                self.class.rewrite_shims(shims_path, ruby_executable,
                    root_dir, autoproj_gemfile_path, gems_gem_home)
            end

            EXCLUDED_FROM_SHIMS = %w{rake thor}

            def self.rewrite_shims(shim_path, ruby_executable,
                root_dir, autoproj_gemfile_path, gems_gem_home)
                FileUtils.mkdir_p shim_path
                File.open(File.join(shim_path, 'ruby'), 'w') do |io|
                    io.puts "#! /bin/sh"
                    io.puts "exec #{ruby_executable} \"$@\""
                end
                FileUtils.chmod 0755, File.join(shim_path, 'ruby')

                Dir.glob(File.join(shim_path, '*')) do |bin_script|
                    next unless File.file?(bin_script)

                    bin_name = File.basename(bin_script)
                    if EXCLUDED_FROM_SHIMS.include?(bin_name)
                        FileUtils.rm_f bin_script
                        next
                    end
                    next if bin_name == 'ruby'

                    bin_shim = File.join(shim_path, bin_name)
                    bin_script_lines = File.readlines(bin_script)
                    next if has_autoproj_preamble?(bin_script_lines)

                    File.open(bin_shim, 'w') do |io|
                        if bin_name == 'bundler' || bin_name == 'bundle'
                            io.puts shim_bundler(bin_script_lines, ruby_executable,
                                autoproj_gemfile_path, gems_gem_home)
                        else
                            io.puts shim_script(bin_script_lines, ruby_executable, root_dir,
                                autoproj_gemfile_path, gems_gem_home)
                        end
                    end
                    FileUtils.chmod 0755, bin_shim
                end
            end

            def self.new_style_bundler_binstub?(script_lines)
                script_lines.any? { |l| l =~ /This file was generated by Bundler/ }
            end

            def self.has_autoproj_preamble?(script_lines)
                script_lines.any? { |l| l =~ /Autoproj generated preamble/ }
            end

            def self.shim_bundler(script_lines, ruby_executable, autoproj_gemfile_path, gems_gem_home)
                return shim_bundler_old(ruby_executable, autoproj_gemfile_path, gems_gem_home) \
                    unless new_style_bundler_binstub?(script_lines)

                script_lines.insert(1, <<-RESTART_BUNDLER)
#
# This file was generated by Bundler.
#

# Autoproj generated preamble
if defined?(Bundler)
    Bundler.with_clean_env do
        exec($0, *ARGV)
    end
end
ENV['BUNDLE_GEMFILE'] ||= '#{autoproj_gemfile_path}'
ENV['GEM_HOME'] = '#{gems_gem_home}'
ENV.delete('GEM_PATH')
Gem.paths = Hash['GEM_HOME' => '#{gems_gem_home}', 'GEM_PATH' => '']
                RESTART_BUNDLER
                script_lines.join
            end

            def self.shim_bundler_old(ruby_executable, autoproj_gemfile_path, gems_gem_home)
"#! #{ruby_executable}

if defined?(Bundler)
    Bundler.with_clean_env do
        exec($0, *ARGV)
    end
end

ENV['BUNDLE_GEMFILE'] ||= '#{autoproj_gemfile_path}'
ENV['GEM_HOME'] = '#{gems_gem_home}'
ENV.delete('GEM_PATH')
Gem.paths = Hash['GEM_HOME' => '#{gems_gem_home}', 'GEM_PATH' => '']

load Gem.bin_path('bundler', 'bundler')"
            end

            def self.shim_script(script_lines, ruby_executable, root_dir,
                    autoproj_gemfile_path, gems_gem_home)
                new_style = !script_lines.empty? && script_lines.any? do |l|
                    l =~ /This file was generated by Bundler/
                end
                load_line = script_lines.grep(/load Gem.bin_path/).first
                return shim_script_old(ruby_executable, root_dir,
                    autoproj_gemfile_path, gems_gem_home, load_line) \
                    unless new_style

                script_lines.insert(1, <<-AUTOPROJ_PREAMBLE)
#
# This file was generated by Bundler.
#

# Autoproj generated preamble, v1
if defined?(Bundler)
    Bundler.with_clean_env do
        exec(Hash['RUBYLIB' => nil], $0, *ARGV)
    end
elsif ENV['RUBYLIB']
    exec(Hash['RUBYLIB' => nil], $0, *ARGV)
end

ENV['BUNDLE_GEMFILE'] = '#{autoproj_gemfile_path}'
ENV['AUTOPROJ_CURRENT_ROOT'] = '#{root_dir}'
Gem.paths = Hash['GEM_HOME' => '#{gems_gem_home}', 'GEM_PATH' => '']
                AUTOPROJ_PREAMBLE
                return script_lines.join
            end

            def self.shim_script_old(ruby_executable, root_dir, autoproj_gemfile_path,
                gems_gem_home, load_line)
"#! #{ruby_executable}

if defined?(Bundler)
    Bundler.with_clean_env do
        exec(Hash['RUBYLIB' => nil], $0, *ARGV)
    end
elsif ENV['RUBYLIB']
    exec(Hash['RUBYLIB' => nil], $0, *ARGV)
end

ENV['BUNDLE_GEMFILE'] = '#{autoproj_gemfile_path}'
ENV['AUTOPROJ_CURRENT_ROOT'] = '#{root_dir}'
require 'rubygems'
Gem.paths = Hash['GEM_HOME' => '#{gems_gem_home}', 'GEM_PATH' => '']
require 'bundler/setup'
#{load_line}"
            end

            def save_env_sh(*vars)
                env = Autobuild::Environment.new
                env.prepare
                vars.each do |kv|
                    k, *v = kv.split("=")
                    v = v.join("=")

                    if v.empty?
                        env.unset k
                    else
                        env.set k, *v.split(File::PATH_SEPARATOR)
                    end
                end
                # Generate environment files right now, we can at least use bundler
                File.open(File.join(dot_autoproj, 'env.sh'), 'w') do |io|
                    env.export_env_sh(io)
                end

                # And now the root envsh
                env = Autobuild::Environment.new
                env.source_before File.join(dot_autoproj, 'env.sh')
                env.set('AUTOPROJ_CURRENT_ROOT', root_dir)
                File.open(File.join(root_dir, 'env.sh'), 'w') do |io|
                    env.export_env_sh(io)
                end
            end

            def save_gemfile
                gemfile =
                    if @gemfile
                        @gemfile
                    elsif File.file?(autoproj_gemfile_path)
                        File.read(autoproj_gemfile_path)
                    else
                        default_gemfile_contents
                    end

                gemfile += [
                    "",
                    "config_path = File.join(__dir__, 'config.yml')",
                    "if File.file?(config_path)",
                    "    require 'yaml'",
                    "    config = YAML.load(File.read(config_path)) || Hash.new",
                    "    (config['plugins'] || Hash.new).",
                    "        each do |plugin_name, (version, options)|",
                    "            gem plugin_name, version, **options",
                    "        end",
                    "end"
                ].join("\n")

                FileUtils.mkdir_p File.dirname(autoproj_gemfile_path)
                File.open(autoproj_gemfile_path, 'w') do |io|
                    io.write gemfile
                end
            end

            ENV_BUNDLE_GEMFILE_RX = /^(\s*ENV\[['"]BUNDLE_GEMFILE['"]\]\s*)(?:\|\|)?=/


            def find_in_clean_path(command, *additional_paths)
                clean_path = env_for_child['PATH'].split(File::PATH_SEPARATOR) +
                    additional_paths
                clean_path.each do |p|
                    full_path = File.join(p, command)
                    if File.file?(full_path)
                        return full_path
                    end
                end
                nil
            end

            # The path of the bin/ folder for installed gems
            def gem_bindir
                return @gem_bindir if @gem_bindir

                # Here, we're getting into the esotheric
                #
                # The problem is that e.g. Ubuntu and Debian install an
                # operating_system.rb file that sets proper OS defaults. Some
                # autoproj installs have it in their RUBYLIB but should not
                # because of limitations of autoproj 1.x. This leads to
                # Gem.bindir being *not* valid for subprocesses
                #
                # So, we're calling 'gem' as a subcommand to discovery the
                # actual bindir
                bindir = IO.popen(env_for_child,
                    [Gem.ruby, '-e', 'puts "#{Gem.user_dir}/bin"']).read
                if bindir
                    @gem_bindir = bindir.chomp
                else
                    raise "FATAL: cannot run #{Gem.ruby} -e 'puts Gem.bindir'"
                end
            end

            def install
                if ENV['BUNDLER_GEMFILE']
                    raise "cannot run autoproj_install or autoproj_bootstrap while "\
                        "under a 'bundler exec' subcommand or having loaded an env.sh. "\
                        "Open a new console and try again"
                end

                gem_program  = self.class.guess_gem_program
                puts "Detected 'gem' to be #{gem_program}"
                env['GEM_HOME'] = [gems_gem_home]
                env['GEM_PATH'] = [gems_gem_home]

                if bundler = find_bundler(gem_program)
                    puts "Detected bundler at #{bundler}"
                else
                    puts "Installing bundler in #{gems_gem_home}"
                    if !(bundler = install_bundler(gem_program))
                        exit 1
                    end
                end
                self.class.rewrite_shims(
                    File.join(dot_autoproj, 'bin'),
                    ruby_executable,
                    root_dir,
                    autoproj_gemfile_path,
                    gems_gem_home)
                env['PATH'].unshift File.join(dot_autoproj, 'bin')
                save_gemfile

                puts "Installing autoproj in #{gems_gem_home}"
                install_autoproj(bundler)
            end

            def load_config
                v1_config_path = File.join(root_dir, 'autoproj', 'config.yml')

                config = Hash.new
                if File.file?(v1_config_path)
                    config.merge!(YAML.load(File.read(v1_config_path)) || Hash.new)
                end
                if File.file?(autoproj_config_path)
                    config.merge!(YAML.load(File.read(autoproj_config_path)) || Hash.new)
                end

                ruby = RbConfig::CONFIG['RUBY_INSTALL_NAME']
                ruby_bindir = RbConfig::CONFIG['bindir']
                ruby_executable = File.join(ruby_bindir, ruby)
                if current = config['ruby_executable'] # When upgrading or reinstalling
                    if current != ruby_executable
                        raise "this workspace has already been initialized using "\
                        "#{current}, you cannot run autoproj install with "\
                        "#{ruby_executable}. If you know what you're doing, "\
                        "delete the ruby_executable line in config.yml and try again"
                    end
                else
                    config['ruby_executable'] = ruby_executable
                end

                @config = config
                %w{gems_install_path prefer_indep_over_os_packages}.each do |flag|
                    instance_variable_set "@#{flag}", config.fetch(flag, false)
                end
            end

            def save_config
                config['gems_install_path']     = gems_install_path
                config['prefer_indep_over_os_packages'] = prefer_indep_over_os_packages?
                File.open(autoproj_config_path, 'w') { |io| YAML.dump(config, io) }
            end

            def autoproj_path
                File.join(dot_autoproj, 'bin', 'autoproj')
            end

            def run_autoproj(*args)
                system env_for_child.merge('BUNDLE_GEMFILE' => autoproj_gemfile_path),
                    Gem.ruby, autoproj_path, *args, *autoproj_options
            end

            def v1_workspace?
                File.file?(File.join(root_dir, 'autoproj', 'config.yml')) &&
                    !File.directory?(File.join(root_dir, '.autoproj'))
            end

            def stage1
                if v1_workspace? && File.file?(v1_envsh = File.join(root_dir, 'env.sh'))
                    FileUtils.cp v1_envsh, 'env.sh-autoproj-v1'
                end
                FileUtils.mkdir_p dot_autoproj
                save_config
                install
            rescue Exception
                FileUtils.rm_rf dot_autoproj
                raise
            end

            def call_stage2
                clean_env = env_for_child
                stage2_vars = clean_env.map { |k, v| "#{k}=#{v}" }
                puts "starting the newly installed autoproj for stage2 install"
                if !run_autoproj('install-stage2', root_dir, *stage2_vars)
                    raise "failed to execute autoproj install-stage2"
                end
            end

            def stage2(*vars)
                require 'autobuild'
                puts "saving temporary env.sh and .autoproj/env.sh"
                save_env_sh(*vars)
                puts "running 'autoproj envsh' to generate a proper env.sh"
                if !system(Gem.ruby, autoproj_path, 'envsh', *autoproj_options)
                    STDERR.puts "failed to run autoproj envsh on the newly installed "\
                        "autoproj (#{autoproj_path})"
                    exit 1
                end
                # This is really needed on an existing install to install the
                # gems that were present in the v1 layout
                puts "running 'autoproj osdeps' to re-install missing gems"
                if !system(Gem.ruby, autoproj_path, 'osdeps')
                    STDERR.puts "failed to run autoproj osdeps on the newly installed "\
                        "autoproj (#{autoproj_path})"
                    exit 1
                end
            end
        end
    end
end


ENV.delete('BUNDLE_GEMFILE')
ENV.delete('RUBYLIB')
ops = Autoproj::Ops::Install.new(Dir.pwd)
ops.parse_options(ARGV)
ops.stage1
if !ops.skip_stage2?
    ops.call_stage2
end