require "optparse"

require "rake/task_manager"
require "rake/file_list"
require "rake/thread_pool"
require "rake/thread_history_display"
require "rake/trace_output"
require "rake/win32"

module Rake

  CommandLineOptionError = Class.new(StandardError)

  ##
  # Rake main application object.  When invoking +rake+ from the
  # command line, a Rake::Application object is created and run.

  class Application
    include TaskManager
    include TraceOutput

    # The name of the application (typically 'rake')
    attr_reader :name

    # The original directory where rake was invoked.
    attr_reader :original_dir

    # Name of the actual rakefile used.
    attr_reader :rakefile

    # Number of columns on the terminal
    attr_accessor :terminal_columns

    # List of the top level task names (task names from the command line).
    attr_reader :top_level_tasks

    # Override the detected TTY output state (mostly for testing)
    attr_writer :tty_output

    DEFAULT_RAKEFILES = [
      "rakefile",
      "Rakefile",
      "rakefile.rb",
      "Rakefile.rb"
    ].freeze

    # Initialize a Rake::Application object.
    def initialize
      super
      @name = "rake"
      @rakefiles = DEFAULT_RAKEFILES.dup
      @rakefile = nil
      @pending_imports = []
      @imported = []
      @loaders = {}
      @default_loader = Rake::DefaultLoader.new
      @original_dir = Dir.pwd
      @top_level_tasks = []
      add_loader("rb", DefaultLoader.new)
      add_loader("rf", DefaultLoader.new)
      add_loader("rake", DefaultLoader.new)
      @tty_output = STDOUT.tty?
      @terminal_columns = ENV["RAKE_COLUMNS"].to_i
    end

    # Run the Rake application.  The run method performs the following
    # three steps:
    #
    # * Initialize the command line options (+init+).
    # * Define the tasks (+load_rakefile+).
    # * Run the top level tasks (+top_level+).
    #
    # If you wish to build a custom rake command, you should call
    # +init+ on your application.  Then define any tasks.  Finally,
    # call +top_level+ to run your top level tasks.
    def run
      standard_exception_handling do
        init
        load_rakefile
        top_level
      end
    end

    # Initialize the command line parameters and app name.
    def init(app_name="rake")
      standard_exception_handling do
        @name = app_name
        args = handle_options
        collect_command_line_tasks(args)
      end
    end

    # Find the rakefile and then load it and any pending imports.
    def load_rakefile
      standard_exception_handling do
        raw_load_rakefile
      end
    end

    # Run the top level tasks of a Rake application.
    def top_level
      run_with_threads do
        if options.show_tasks
          display_tasks_and_comments
        elsif options.show_prereqs
          display_prerequisites
        else
          top_level_tasks.each { |task_name| invoke_task(task_name) }
        end
      end
    end

    # Run the given block with the thread startup and shutdown.
    def run_with_threads
      thread_pool.gather_history if options.job_stats == :history

      yield

      thread_pool.join
      if options.job_stats
        stats = thread_pool.statistics
        puts "Maximum active threads: #{stats[:max_active_threads]} + main"
        puts "Total threads in play:  #{stats[:total_threads_in_play]} + main"
      end
      ThreadHistoryDisplay.new(thread_pool.history).show if
        options.job_stats == :history
    end

    # Add a loader to handle imported files ending in the extension
    # +ext+.
    def add_loader(ext, loader)
      ext = ".#{ext}" unless ext =~ /^\./
      @loaders[ext] = loader
    end

    # Application options from the command line
    def options
      @options ||= OpenStruct.new
    end

    # Return the thread pool used for multithreaded processing.
    def thread_pool             # :nodoc:
      @thread_pool ||= ThreadPool.new(options.thread_pool_size || Rake.suggested_thread_count-1)
    end

    # internal ----------------------------------------------------------------

    # Invokes a task with arguments that are extracted from +task_string+
    def invoke_task(task_string) # :nodoc:
      name, args = parse_task_string(task_string)
      t = self[name]
      t.invoke(*args)
    end

    def parse_task_string(string) # :nodoc:
      /^([^\[]+)(?:\[(.*)\])$/ =~ string.to_s

      name           = $1
      remaining_args = $2

      return string, [] unless name
      return name,   [] if     remaining_args.empty?

      args = []

      begin
        /((?:[^\\,]|\\.)*?)\s*(?:,\s*(.*))?$/ =~ remaining_args

        remaining_args = $2
        args << $1.gsub(/\\(.)/, '\1')
      end while remaining_args

      return name, args
    end

    # Provide standard exception handling for the given block.
    def standard_exception_handling # :nodoc:
      yield
    rescue SystemExit
      # Exit silently with current status
      raise
    rescue OptionParser::InvalidOption => ex
      $stderr.puts ex.message
      exit(false)
    rescue Exception => ex
      # Exit with error message
      display_error_message(ex)
      exit_because_of_exception(ex)
    end

    # Exit the program because of an unhandled exception.
    # (may be overridden by subclasses)
    def exit_because_of_exception(ex) # :nodoc:
      exit(false)
    end

    # Display the error message that caused the exception.
    def display_error_message(ex) # :nodoc:
      trace "#{name} aborted!"
      display_exception_details(ex)
      trace "Tasks: #{ex.chain}" if has_chain?(ex)
      trace "(See full trace by running task with --trace)" unless
         options.backtrace
    end

    def display_exception_details(ex) # :nodoc:
      seen = Thread.current[:rake_display_exception_details_seen] ||= []
      return if seen.include? ex
      seen << ex

      display_exception_message_details(ex)
      display_exception_backtrace(ex)
      display_exception_details(ex.cause) if has_cause?(ex)
    end

    def has_cause?(ex) # :nodoc:
      ex.respond_to?(:cause) && ex.cause
    end

    def display_exception_message_details(ex) # :nodoc:
      if ex.instance_of?(RuntimeError)
        trace ex.message
      else
        trace "#{ex.class.name}: #{ex.message}"
      end
    end

    def display_exception_backtrace(ex) # :nodoc:
      if options.backtrace
        trace ex.backtrace.join("\n")
      else
        trace Backtrace.collapse(ex.backtrace).join("\n")
      end
    end

    # Warn about deprecated usage.
    #
    # Example:
    #    Rake.application.deprecate("import", "Rake.import", caller.first)
    #
    def deprecate(old_usage, new_usage, call_site) # :nodoc:
      unless options.ignore_deprecate
        $stderr.puts "WARNING: '#{old_usage}' is deprecated.  " +
          "Please use '#{new_usage}' instead.\n" +
          "    at #{call_site}"
      end
    end

    # Does the exception have a task invocation chain?
    def has_chain?(exception) # :nodoc:
      exception.respond_to?(:chain) && exception.chain
    end
    private :has_chain?

    # True if one of the files in RAKEFILES is in the current directory.
    # If a match is found, it is copied into @rakefile.
    def have_rakefile # :nodoc:
      @rakefiles.each do |fn|
        if File.exist?(fn)
          others = FileList.glob(fn, File::FNM_CASEFOLD)
          return others.size == 1 ? others.first : fn
        elsif fn == ""
          return fn
        end
      end
      return nil
    end

    # True if we are outputting to TTY, false otherwise
    def tty_output? # :nodoc:
      @tty_output
    end

    # We will truncate output if we are outputting to a TTY or if we've been
    # given an explicit column width to honor
    def truncate_output? # :nodoc:
      tty_output? || @terminal_columns.nonzero?
    end

    # Display the tasks and comments.
    def display_tasks_and_comments # :nodoc:
      displayable_tasks = tasks.select { |t|
        (options.show_all_tasks || t.comment) &&
          t.name =~ options.show_task_pattern
      }
      case options.show_tasks
      when :tasks
        width = displayable_tasks.map { |t| t.name_with_args.length }.max || 10
        if truncate_output?
          max_column = terminal_width - name.size - width - 7
        else
          max_column = nil
        end

        displayable_tasks.each do |t|
          printf("#{name} %-#{width}s  # %s\n",
            t.name_with_args,
            max_column ? truncate(t.comment, max_column) : t.comment)
        end
      when :describe
        displayable_tasks.each do |t|
          puts "#{name} #{t.name_with_args}"
          comment = t.full_comment || ""
          comment.split("\n").each do |line|
            puts "    #{line}"
          end
          puts
        end
      when :lines
        displayable_tasks.each do |t|
          t.locations.each do |loc|
            printf "#{name} %-30s %s\n", t.name_with_args, loc
          end
        end
      else
        fail "Unknown show task mode: '#{options.show_tasks}'"
      end
    end

    def terminal_width # :nodoc:
      if @terminal_columns.nonzero?
        result = @terminal_columns
      else
        result = unix? ? dynamic_width : 80
      end
      (result < 10) ? 80 : result
    rescue
      80
    end

    # Calculate the dynamic width of the
    def dynamic_width # :nodoc:
      @dynamic_width ||= (dynamic_width_stty.nonzero? || dynamic_width_tput)
    end

    def dynamic_width_stty # :nodoc:
      %x{stty size 2>/dev/null}.split[1].to_i
    end

    def dynamic_width_tput # :nodoc:
      %x{tput cols 2>/dev/null}.to_i
    end

    def unix? # :nodoc:
      RbConfig::CONFIG["host_os"] =~
        /(aix|darwin|linux|(net|free|open)bsd|cygwin|solaris|irix|hpux)/i
    end

    def windows? # :nodoc:
      Win32.windows?
    end

    def truncate(string, width) # :nodoc:
      if string.nil?
        ""
      elsif string.length <= width
        string
      else
        (string[0, width - 3] || "") + "..."
      end
    end

    # Display the tasks and prerequisites
    def display_prerequisites # :nodoc:
      tasks.each do |t|
        puts "#{name} #{t.name}"
        t.prerequisites.each { |pre| puts "    #{pre}" }
      end
    end

    def trace(*strings) # :nodoc:
      options.trace_output ||= $stderr
      trace_on(options.trace_output, *strings)
    end

    def sort_options(options) # :nodoc:
      options.sort_by { |opt|
        opt.select { |o| o =~ /^-/ }.map(&:downcase).sort.reverse
      }
    end
    private :sort_options

    # A list of all the standard options used in rake, suitable for
    # passing to OptionParser.
    def standard_rake_options # :nodoc:
      sort_options(
        [
          ["--all", "-A",
            "Show all tasks, even uncommented ones (in combination with -T or -D)",
            lambda { |value|
              options.show_all_tasks = value
            }
          ],
          ["--backtrace=[OUT]",
            "Enable full backtrace.  OUT can be stderr (default) or stdout.",
            lambda { |value|
              options.backtrace = true
              select_trace_output(options, "backtrace", value)
            }
          ],
          ["--build-all", "-B",
           "Build all prerequisites, including those which are up-to-date.",
           lambda { |value|
             options.build_all = true
           }
          ],
          ["--comments",
            "Show commented tasks only",
            lambda { |value|
              options.show_all_tasks = !value
            }
          ],
          ["--describe", "-D [PATTERN]",
            "Describe the tasks (matching optional PATTERN), then exit.",
            lambda { |value|
              select_tasks_to_show(options, :describe, value)
            }
          ],
          ["--dry-run", "-n",
            "Do a dry run without executing actions.",
            lambda { |value|
              Rake.verbose(true)
              Rake.nowrite(true)
              options.dryrun = true
              options.trace = true
            }
          ],
          ["--execute", "-e CODE",
            "Execute some Ruby code and exit.",
            lambda { |value|
              eval(value)
              exit
            }
          ],
          ["--execute-print", "-p CODE",
            "Execute some Ruby code, print the result, then exit.",
            lambda { |value|
              puts eval(value)
              exit
            }
          ],
          ["--execute-continue",  "-E CODE",
            "Execute some Ruby code, " +
            "then continue with normal task processing.",
            lambda { |value| eval(value) }
          ],
          ["--jobs",  "-j [NUMBER]",
            "Specifies the maximum number of tasks to execute in parallel. " +
            "(default is number of CPU cores + 4)",
            lambda { |value|
              if value.nil? || value == ""
                value = Float::INFINITY
              elsif value =~ /^\d+$/
                value = value.to_i
              else
                value = Rake.suggested_thread_count
              end
              value = 1 if value < 1
              options.thread_pool_size = value - 1
            }
          ],
          ["--job-stats [LEVEL]",
            "Display job statistics. " +
            "LEVEL=history displays a complete job list",
            lambda { |value|
              if value =~ /^history/i
                options.job_stats = :history
              else
                options.job_stats = true
              end
            }
          ],
          ["--libdir", "-I LIBDIR",
            "Include LIBDIR in the search path for required modules.",
            lambda { |value| $:.push(value) }
          ],
          ["--multitask", "-m",
            "Treat all tasks as multitasks.",
            lambda { |value| options.always_multitask = true }
          ],
          ["--no-search", "--nosearch",
            "-N", "Do not search parent directories for the Rakefile.",
            lambda { |value| options.nosearch = true }
          ],
          ["--prereqs", "-P",
            "Display the tasks and dependencies, then exit.",
            lambda { |value| options.show_prereqs = true }
          ],
          ["--quiet", "-q",
            "Do not log messages to standard output.",
            lambda { |value| Rake.verbose(false) }
          ],
          ["--rakefile", "-f [FILENAME]",
            "Use FILENAME as the rakefile to search for.",
            lambda { |value|
              value ||= ""
              @rakefiles.clear
              @rakefiles << value
            }
          ],
          ["--rakelibdir", "--rakelib", "-R RAKELIBDIR",
            "Auto-import any .rake files in RAKELIBDIR. " +
            "(default is 'rakelib')",
            lambda { |value|
              options.rakelib = value.split(File::PATH_SEPARATOR)
            }
          ],
          ["--require", "-r MODULE",
            "Require MODULE before executing rakefile.",
            lambda { |value|
              begin
                require value
              rescue LoadError => ex
                begin
                  rake_require value
                rescue LoadError
                  raise ex
                end
              end
            }
          ],
          ["--rules",
            "Trace the rules resolution.",
            lambda { |value| options.trace_rules = true }
          ],
          ["--silent", "-s",
            "Like --quiet, but also suppresses the " +
            "'in directory' announcement.",
            lambda { |value|
              Rake.verbose(false)
              options.silent = true
            }
          ],
          ["--suppress-backtrace PATTERN",
            "Suppress backtrace lines matching regexp PATTERN. " +
            "Ignored if --trace is on.",
            lambda { |value|
              options.suppress_backtrace_pattern = Regexp.new(value)
            }
          ],
          ["--system",  "-g",
            "Using system wide (global) rakefiles " +
            "(usually '~/.rake/*.rake').",
            lambda { |value| options.load_system = true }
          ],
          ["--no-system", "--nosystem", "-G",
            "Use standard project Rakefile search paths, " +
            "ignore system wide rakefiles.",
            lambda { |value| options.ignore_system = true }
          ],
          ["--tasks", "-T [PATTERN]",
            "Display the tasks (matching optional PATTERN) " +
            "with descriptions, then exit. " +
            "-AT combination displays all of tasks contained no description.",
            lambda { |value|
              select_tasks_to_show(options, :tasks, value)
            }
          ],
          ["--trace=[OUT]", "-t",
            "Turn on invoke/execute tracing, enable full backtrace. " +
            "OUT can be stderr (default) or stdout.",
            lambda { |value|
              options.trace = true
              options.backtrace = true
              select_trace_output(options, "trace", value)
              Rake.verbose(true)
            }
          ],
          ["--verbose", "-v",
            "Log message to standard output.",
            lambda { |value| Rake.verbose(true) }
          ],
          ["--version", "-V",
            "Display the program version.",
            lambda { |value|
              puts "rake, version #{Rake::VERSION}"
              exit
            }
          ],
          ["--where", "-W [PATTERN]",
            "Describe the tasks (matching optional PATTERN), then exit.",
            lambda { |value|
              select_tasks_to_show(options, :lines, value)
              options.show_all_tasks = true
            }
          ],
          ["--no-deprecation-warnings", "-X",
            "Disable the deprecation warnings.",
            lambda { |value|
              options.ignore_deprecate = true
            }
          ],
        ])
    end

    def select_tasks_to_show(options, show_tasks, value) # :nodoc:
      options.show_tasks = show_tasks
      options.show_task_pattern = Regexp.new(value || "")
      Rake::TaskManager.record_task_metadata = true
    end
    private :select_tasks_to_show

    def select_trace_output(options, trace_option, value) # :nodoc:
      value = value.strip unless value.nil?
      case value
      when "stdout"
        options.trace_output = $stdout
      when "stderr", nil
        options.trace_output = $stderr
      else
        fail CommandLineOptionError,
          "Unrecognized --#{trace_option} option '#{value}'"
      end
    end
    private :select_trace_output

    # Read and handle the command line options.  Returns the command line
    # arguments that we didn't understand, which should (in theory) be just
    # task names and env vars.
    def handle_options # :nodoc:
      options.rakelib = ["rakelib"]
      options.trace_output = $stderr

      OptionParser.new do |opts|
        opts.banner = "#{Rake.application.name} [-f rakefile] {options} targets..."
        opts.separator ""
        opts.separator "Options are ..."

        opts.on_tail("-h", "--help", "-H", "Display this help message.") do
          puts opts
          exit
        end

        standard_rake_options.each { |args| opts.on(*args) }
        opts.environment("RAKEOPT")
      end.parse(ARGV)
    end

    # Similar to the regular Ruby +require+ command, but will check
    # for *.rake files in addition to *.rb files.
    def rake_require(file_name, paths=$LOAD_PATH, loaded=$") # :nodoc:
      fn = file_name + ".rake"
      return false if loaded.include?(fn)
      paths.each do |path|
        full_path = File.join(path, fn)
        if File.exist?(full_path)
          Rake.load_rakefile(full_path)
          loaded << fn
          return true
        end
      end
      fail LoadError, "Can't find #{file_name}"
    end

    def find_rakefile_location # :nodoc:
      here = Dir.pwd
      until (fn = have_rakefile)
        Dir.chdir("..")
        return nil if Dir.pwd == here || options.nosearch
        here = Dir.pwd
      end
      [fn, here]
    ensure
      Dir.chdir(Rake.original_dir)
    end

    def print_rakefile_directory(location) # :nodoc:
      $stderr.puts "(in #{Dir.pwd})" unless
        options.silent or original_dir == location
    end

    def raw_load_rakefile # :nodoc:
      rakefile, location = find_rakefile_location
      if (! options.ignore_system) &&
          (options.load_system || rakefile.nil?) &&
          system_dir && File.directory?(system_dir)
        print_rakefile_directory(location)
        glob("#{system_dir}/*.rake") do |name|
          add_import name
        end
      else
        fail "No Rakefile found (looking for: #{@rakefiles.join(', ')})" if
          rakefile.nil?
        @rakefile = rakefile
        Dir.chdir(location)
        print_rakefile_directory(location)
        Rake.load_rakefile(File.expand_path(@rakefile)) if
          @rakefile && @rakefile != ""
        options.rakelib.each do |rlib|
          glob("#{rlib}/*.rake") do |name|
            add_import name
          end
        end
      end
      load_imports
    end

    def glob(path, &block) # :nodoc:
      FileList.glob(path.tr("\\", "/")).each(&block)
    end
    private :glob

    # The directory path containing the system wide rakefiles.
    def system_dir # :nodoc:
      @system_dir ||=
        begin
          if ENV["RAKE_SYSTEM"]
            ENV["RAKE_SYSTEM"]
          else
            standard_system_dir
          end
        end
    end

    # The standard directory containing system wide rake files.
    if Win32.windows?
      def standard_system_dir #:nodoc:
        Win32.win32_system_dir
      end
    else
      def standard_system_dir #:nodoc:
        File.join(File.expand_path("~"), ".rake")
      end
    end
    private :standard_system_dir

    # Collect the list of tasks on the command line.  If no tasks are
    # given, return a list containing only the default task.
    # Environmental assignments are processed at this time as well.
    #
    # `args` is the list of arguments to peruse to get the list of tasks.
    # It should be the command line that was given to rake, less any
    # recognised command-line options, which OptionParser.parse will
    # have taken care of already.
    def collect_command_line_tasks(args) # :nodoc:
      @top_level_tasks = []
      args.each do |arg|
        if arg =~ /^(\w+)=(.*)$/m
          ENV[$1] = $2
        else
          @top_level_tasks << arg unless arg =~ /^-/
        end
      end
      @top_level_tasks.push(default_task_name) if @top_level_tasks.empty?
    end

    # Default task name ("default").
    # (May be overridden by subclasses)
    def default_task_name # :nodoc:
      "default"
    end

    # Add a file to the list of files to be imported.
    def add_import(fn) # :nodoc:
      @pending_imports << fn
    end

    # Load the pending list of imported files.
    def load_imports # :nodoc:
      while fn = @pending_imports.shift
        next if @imported.member?(fn)
        fn_task = lookup(fn) and fn_task.invoke
        ext = File.extname(fn)
        loader = @loaders[ext] || @default_loader
        loader.load(fn)
        if fn_task = lookup(fn) and fn_task.needed?
          fn_task.reenable
          fn_task.invoke
          loader.load(fn)
        end
        @imported << fn
      end
    end

    def rakefile_location(backtrace=caller) # :nodoc:
      backtrace.map { |t| t[/([^:]+):/, 1] }

      re = /^#{@rakefile}$/
      re = /#{re.source}/i if windows?

      backtrace.find { |str| str =~ re } || ""
    end

  end
end
