require 'tempfile'

class Thor
  module Shell
    class Basic
      attr_accessor :base, :padding

      # Initialize base and padding to nil.
      #
      def initialize #:nodoc:
        @base, @padding = nil, 0
      end

      # Sets the output padding, not allowing less than zero values.
      #
      def padding=(value)
        @padding = [0, value].max
      end

      # Ask something to the user and receives a response.
      #
      # ==== Example
      # ask("What is your name?")
      #
      def ask(statement, color=nil)
        say("#{statement} ", color)
        $stdin.gets.strip
      end

      # Say (print) something to the user. If the sentence ends with a whitespace
      # or tab character, a new line is not appended (print + flush). Otherwise
      # are passed straight to puts (behavior got from Highline).
      #
      # ==== Example
      # say("I know you knew that.")
      #
      def say(message="", color=nil, force_new_line=(message.to_s !~ /( |\t)$/))
        message  = message.to_s
        message  = set_color(message, color) if color

        spaces = "  " * padding

        if force_new_line
          $stdout.puts(spaces + message)
        else
          $stdout.print(spaces + message)
        end
        $stdout.flush
      end

      # Say a status with the given color and appends the message. Since this
      # method is used frequently by actions, it allows nil or false to be given
      # in log_status, avoiding the message from being shown. If a Symbol is
      # given in log_status, it's used as the color.
      #
      def say_status(status, message, log_status=true)
        return if quiet? || log_status == false
        spaces = "  " * (padding + 1)
        color  = log_status.is_a?(Symbol) ? log_status : :green

        status = status.to_s.rjust(12)
        status = set_color status, color, true if color
        say "#{status}#{spaces}#{message}", nil, true
      end

      # Make a question the to user and returns true if the user replies "y" or
      # "yes".
      #
      def yes?(statement, color=nil)
        ask(statement, color) =~ is?(:yes)
      end

      # Make a question the to user and returns true if the user replies "n" or
      # "no".
      #
      def no?(statement, color=nil)
        !yes?(statement, color)
      end

      # Prints a table.
      #
      # ==== Parameters
      # Array[Array[String, String, ...]]
      #
      # ==== Options
      # ident<Integer>:: Indent the first column by ident value.
      # colwidth<Integer>:: Force the first column to colwidth spaces wide.
      #
      def print_table(table, options={})
        return if table.empty?

        formats, ident, colwidth = [], options[:ident].to_i, options[:colwidth]
        options[:truncate] = terminal_width if options[:truncate] == true

        formats << "%-#{colwidth + 2}s" if colwidth
        start = colwidth ? 1 : 0

        start.upto(table.first.length - 2) do |i|
          maxima ||= table.max{|a,b| a[i].size <=> b[i].size }[i].size
          formats << "%-#{maxima + 2}s"
        end

        formats[0] = formats[0].insert(0, " " * ident)
        formats << "%s"

        table.each do |row|
          sentence = ""

          row.each_with_index do |column, i|
            sentence << formats[i] % column.to_s
          end

          sentence = truncate(sentence, options[:truncate]) if options[:truncate]
          $stdout.puts sentence
        end
      end

      # Prints a long string, word-wrapping the text to the current width of the
      # terminal display. Ideal for printing heredocs.
      #
      # ==== Parameters
      # String
      #
      # ==== Options
      # ident<Integer>:: Indent each line of the printed paragraph by ident value.
      #
      def print_wrapped(message, options={})
        ident = options[:ident] || 0
        width = terminal_width - ident
        paras = message.split("\n\n")

        paras.map! do |unwrapped|
          unwrapped.strip.gsub(/\n/, " ").squeeze(" ").
          gsub(/.{1,#{width}}(?:\s|\Z)/){($& + 5.chr).
          gsub(/\n\005/,"\n").gsub(/\005/,"\n")}
        end

        paras.each do |para|
          para.split("\n").each do |line|
            $stdout.puts line.insert(0, " " * ident)
          end
          $stdout.puts unless para == paras.last
        end
      end

      # Deals with file collision and returns true if the file should be
      # overwriten and false otherwise. If a block is given, it uses the block
      # response as the content for the diff.
      #
      # ==== Parameters
      # destination<String>:: the destination file to solve conflicts
      # block<Proc>:: an optional block that returns the value to be used in diff
      #
      def file_collision(destination)
        return true if @always_force
        options = block_given? ? "[Ynaqdh]" : "[Ynaqh]"

        while true
          answer = ask %[Overwrite #{destination}? (enter "h" for help) #{options}]

          case answer
            when is?(:yes), is?(:force), ""
              return true
            when is?(:no), is?(:skip)
              return false
            when is?(:always)
              return @always_force = true
            when is?(:quit)
              say 'Aborting...'
              raise SystemExit
            when is?(:diff)
              show_diff(destination, yield) if block_given?
              say 'Retrying...'
            else
              say file_collision_help
          end
        end
      end

      # Called if something goes wrong during the execution. This is used by Thor
      # internally and should not be used inside your scripts. If someone went
      # wrong, you can always raise an exception. If you raise a Thor::Error, it
      # will be rescued and wrapped in the method below.
      #
      def error(statement)
        $stderr.puts statement
      end

      # Apply color to the given string with optional bold. Disabled in the
      # Thor::Shell::Basic class.
      #
      def set_color(string, color, bold=false) #:nodoc:
        string
      end

      protected

        def is?(value) #:nodoc:
          value = value.to_s

          if value.size == 1
            /\A#{value}\z/i
          else
            /\A(#{value}|#{value[0,1]})\z/i
          end
        end

        def file_collision_help #:nodoc:
<<HELP
Y - yes, overwrite
n - no, do not overwrite
a - all, overwrite this and all others
q - quit, abort
d - diff, show the differences between the old and the new
h - help, show this help
HELP
        end

        def show_diff(destination, content) #:nodoc:
          diff_cmd = ENV['THOR_DIFF'] || ENV['RAILS_DIFF'] || 'diff -u'

          Tempfile.open(File.basename(destination), File.dirname(destination)) do |temp|
            temp.write content
            temp.rewind
            system %(#{diff_cmd} "#{destination}" "#{temp.path}")
          end
        end

        def quiet? #:nodoc:
          base && base.options[:quiet]
        end

        # This code was copied from Rake, available under MIT-LICENSE
        # Copyright (c) 2003, 2004 Jim Weirich
        def terminal_width
          if ENV['THOR_COLUMNS']
            result = ENV['THOR_COLUMNS'].to_i
          else
            result = unix? ? dynamic_width : 80
          end
          (result < 10) ? 80 : result
        rescue
          80
        end

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

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

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

        def unix?
          RUBY_PLATFORM =~ /(aix|darwin|linux|(net|free|open)bsd|cygwin|solaris|irix|hpux)/i
        end

        def truncate(string, width)
          if string.length <= width
            string
          else
            ( string[0, width-3] || "" ) + "..."
          end
        end

    end
  end
end