# module    : exa/logger
# copyright : PRAGMA Publishing On Demand
# version   : 1.01 - 2002/2003
# author    : Hans Hagen
#
# project   : eXaMpLe
# concept   : Hans Hagen
# info      : j.hagen@xs4all.nl
# www       : www.pragma-pod.com / www.pragma-ade.com

require 'thread'

module EXA

    # The next calls are valid:
    #
    # @log.report('a','b','c', 'd')
    # @log.report('a','b',"c #{d}")
    # @log.report("a b c #{d}")
    #
    # Keep in mind that "whatever #{something}" is two times faster than
    # 'whatever ' + something or ['whatever',something].join and that
    # when verbosity is not needed the following is much faster too:
    #
    # @log.report('a','b','c', 'd') if @log.verbose?
    # @log.report('a','b',"c #{d}") if @log.verbose?
    # @log.report("a b c #{d}")     if @log.verbose?
    #
    # The last three cases are equally fast when verbosity is turned off.

    # Under consideration: verbose per instance

    class ExaLogger

        @@length  = 0
        @@verbose = false

        def initialize(tag=nil,length=0,verbose=false)
            @tag = tag || ''
            @@verbose = @@verbose || verbose
            @@length = @tag.length if @tag.length > @@length
            @@length =      length if      length > @@length
        end

        def report(*str)
            begin
                case str.length
                    when 0
                        print("\n")
                        return true
                    when 1
                        message = str.first
                    else
                        message = [str].flatten.collect{|s| s.to_s}.join(' ').chomp
                end
                if @tag.empty? then
                    print("#{message}\n")
                else
                    # try to avoid too many adjustments
                    @tag = @tag.ljust(@@length) unless @tag.length == @@length
                    print("#{@tag} | #{message}\n")
                end
            rescue
            end
            return true
        end

        def reportlines(*str)
            unless @tag.empty? then
                @tag = @tag.ljust(@@length) unless @tag.length == @@length
            end
            report([str].flatten.collect{|s| s.gsub(/\n/,"\n#{@tag} | ")}.join(' '))
        end

        def debug(*str)
            report(str) if @@verbose
        end

        def error(*str)
            if ! $! || $!.to_s.empty? then
                report(str)
            else
                report(str,$!)
            end
        end

        def verbose
            @@verbose = true
        end

        def silent
            @@verbose = false
        end

        def verbose?
            @@verbose
        end

        # attr_reader :tag

        # alias fatal  error
        # alias info   debug
        # alias warn   debug
        # alias debug? :verbose?

    end

end