# = to_s Style
#
#--
# Ruby version 1.8
#
# == Authors
# * Yomei Komiya
# 
# == Copyright
# 2008 the original author or authors.
#
# == License
# Apache License 2.0
# 
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
# 
#  http://www.apache.org/licenses/LICENSE-2.0
# 
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#++
# == Version
# SVN: $Id: to_s_style.rb 75 2008-10-12 10:35:52Z whitestar $
#
# == Since
# File available since Release 0.8.0

require 'commons/lang/class_utils'
require 'commons/lang/object_utils'
require 'commons/lang/system_utils'

module Commons
  module Lang
    module Builder
      
      class ToSStyle

        attr_accessor \
          :use_class_name, :use_short_className, :use_identity_hash_code,
          :use_field_names, :default_full_detail, :array_content_detail,
          :array_start, :array_end, :array_separator, :content_start, :content_end,
          :field_name_value_separator, :field_separator, :field_separator_at_start,
          :field_separator_at_end, :nil_text, :size_start_text, :size_end_text,
          :summary_object_start_text, :summary_object_end_text
        
        attr_reader :registry
        
        protected \
          :registry, :use_class_name, :use_short_className, :use_identity_hash_code,
          :use_field_names, :default_full_detail, :array_content_detail,
          :array_start, :array_end, :array_separator, :content_start, :content_end,
          :field_name_value_separator, :field_separator, :field_separator_at_start,
          :field_separator_at_end, :nil_text, :size_start_text, :size_end_text,
          :summary_object_start_text, :summary_object_end_text
        
        
        def initialize
          super()
          
          @registry = Hash.new
          
          # Whether to use the field names, the default is true.
          @use_field_names = true
          
          # Whether to use the class name, the default is true.
          @use_class_name = true
          
          # Whether to use short class names, the default is false.
          @use_short_className = false
          
          #  Whether to use the identity hash code, the default is true.
          @use_identity_hash_code = true
          
          # The content start '{'.
          @content_start = '{'
          
          # The content end '}'.
          @content_end = '}'
          
          # The field name value separator '='.
          @field_name_value_separator = '='
          
          # Whether the field separator should be added before any other fields.
          @field_separator_at_start = false
          
          # Whether the field separator should be added after any other fields.
          @field_separator_at_end = false
          
          # The field separator ','.
          @field_separator = ','
          
          # The array start '['.
          @array_start = '['
          
          # The array separator ','.
          @array_separator = ','
          
          # The detail for array content.
          @array_content_detail = true
          
          # The array end ']'.
          @array_end = ']'
          
          # The value to use when fullDetail is nil,
          # the default value is true.
          @default_full_detail = true
          
          # The nil text '<nil>'.
          @nil_text = '<nil>'
          
          # The summary size text start '<size'.
          @size_start_text = '<size='
          
          # The summary size text start '&gt;'.
          @size_end_text = '>'
          
          # The summary object text start '&lt;'.
          @summary_object_start_text = '<'
          
          # The summary object text start '&gt;'.
          @summary_object_end_text = '>'
        end
        
        
        def registered?(value)
          return @registry.has_key?(value.__id__)
        end
        
        
        def register(value)
          if value != nil
            @registry[value.__id__] = value
          end
        end
        
        
        def unregister(value)
          @registry.delete(value.__id__);
        end


        def append_super(buffer, super_to_s)
          append_to_s(buffer, super_to_s)
        end
        
        
        def append_to_s(buffer, to_s)
          if to_s != nil
            pos1 = to_s.index(@content_start) + @content_start.length
            pos2 = to_s.rindex(@content_end)
            if pos1 != pos2 && pos1 >= 0 && pos2 >= 0
              data = to_s[pos1 ... pos2]
              if @field_separator_at_start
                remove_last_field_separator(buffer)
              end
              buffer.concat(data)
              append_field_separator(buffer)
            end
          end
        end
        
        
        def append_start(buffer, object)
          if object != nil
            append_class_name(buffer, object)
            append_identity_hash_code(buffer, object)
            append_content_start(buffer)
            if @field_separator_at_start
              append_field_separator(buffer)
            end
          end
        end
        
        
        def append_end(buffer, object)
          if @field_separator_at_end == false
            remove_last_field_separator(buffer)
          end
          append_content_end(buffer)
        end
        
        
        def remove_last_field_separator(buffer)
          len = buffer.length
          sep_len = @field_separator.length
          if len > 0 && sep_len > 0 && len >= sep_len
            match = true
            (0 ... sep_len).each {|i|
              if buffer[len - 1 - i] != @field_separator[sep_len - 1 - i]
                match = false
                break
              end
            }
            if match
              buffer[len - sep_len .. -1] = ''
            end
          end
        end
        protected :remove_last_field_separator
        
        #-- ------------------------------------------------------------------------------
        #++
        
        def append(buffer, field_name, value, full_detail)
          append_field_start(buffer, field_name)
          
          if value == nil
            append_nil_text(buffer, field_name)
          else
            append_internal(buffer, field_name, value, full_detail)
          end
          
          append_field_end(buffer, field_name)
        end
        
        
        def append_internal(buffer, field_name, value, detail)
          if registered?(value)
            append_cyclic_object(buffer, field_name, value)
            return
          end
          
          register(value)

          begin
            case value
              when Hash
                if detail
                  append_hash_detail(buffer, field_name, value)
                else
                  append_summary_size(buffer, field_name, value.size)
                end
              when Array
                if detail
                  # We do not use Array#to_s
                  append_array_detail(buffer, field_name, value)
                else
                  append_summary_size(buffer, field_name, value.size)
                end
              else
                if detail
                  append_detail(buffer, field_name, value)
                else
                  append_summary(buffer, field_name, value)
                end
            end
          ensure
            unregister(value)
          end
        end
        protected :append_internal
        
        
        def append_cyclic_object(buffer, field_name, value)
          ObjectUtils.append_identity_to_s(buffer, value)
          buffer.concat('...')
        end
        protected :append_cyclic_object
        
        
        def append_summary(buffer, field_name, value)
          buffer.concat(@summary_object_start_text)
          buffer.concat(get_short_class_name(value.class))
          buffer.concat(@summary_object_end_text)
        end
        protected :append_summary
        
        
        def append_detail(buffer, field_name, value)
          buffer.concat(value.to_s)
        end
        protected :append_detail

        #-- ------------------------------------------------------------------------------
        #++
        
        def append_hash_detail(buffer, field_name, hash)
          buffer.concat(@array_start)
          i = 0
          hash.each_pair {|key, value|
            if i > 0
              buffer.concat(@array_separator)
            end
            if value == nil
              append_nil_text(buffer, field_name)
            else
              buffer.concat(key.to_s + '=>')
              append_internal(buffer, field_name, value, @array_content_detail)
            end
            i += 1
          }
          buffer.concat(@array_end)
        end
        protected :append_hash_detail
        
        
        def append_array_detail(buffer, field_name, array)
          buffer.concat(@array_start)
          array.each_index {|i|
            item = array[i]
            if i > 0
              buffer.concat(@array_separator)
            end
            if item == nil
              append_nil_text(buffer, field_name)
            else
              append_internal(buffer, field_name, item, @array_content_detail)
            end
          }
          buffer.concat(@array_end)
        end
        protected :append_array_detail
        
        #-- ------------------------------------------------------------------------------
        #++
        
        def append_class_name(buffer, object)
          if @use_class_name && object != nil
            if @use_short_className
              buffer.concat(get_short_class_name(object.class))
            else
              buffer.concat(object.class.name)
            end
          end
        end
        protected :append_class_name
        
        
        def append_identity_hash_code(buffer, object)
          if @use_identity_hash_code && object != nil
            buffer.concat(':')
            buffer.concat('0x' + object.__id__.to_s(16))
          end
        end
        protected :append_identity_hash_code
        
        
        def append_content_start(buffer)
          buffer.concat(@content_start)
        end
        protected :append_content_start
        
        
        def append_content_end(buffer)
          buffer.concat(@content_end)
        end
        protected :append_content_end
        
        
        def append_nil_text(buffer, field_name)
          buffer.concat(@nil_text)
        end
        protected :append_nil_text

        
        def append_field_separator(buffer)
          buffer.concat(@field_separator)
        end
        protected :append_field_separator
        
        
        def append_field_start(buffer, field_name)
          if @use_field_names && field_name != nil
            buffer.concat(field_name)
            buffer.concat(@field_name_value_separator)
          end
        end
        protected :append_field_start
        
        
        def append_field_end(buffer, field_name)
          append_field_separator(buffer)
        end
        protected :append_field_end
        
        
        def append_summary_size(buffer, field_name, size)
          buffer.concat(@size_start_text)
          buffer.concat(size.to_s)
          buffer.concat(@size_end_text)
        end
        protected :append_summary_size
        
        
        def get_short_class_name(clazz)
          return ClassUtils.get_short_class_name(clazz)
        end
        protected :get_short_class_name

        #-- ------------------------------------------------------------------------------
        #++
        
        class DefaultToSStyle < ToSStyle
          def initialize
            super()
          end
          
          
          def read_resolve
            return ToSStyle::DEFAULT_STYLE
          end
          private :read_resolve
        end
        
        
        # ToSStyle that does not print out the field names.
        class NoFieldNameToSStyle < ToSStyle
          def initialize
            super()
            self.use_field_names = false
          end
          
          
          def read_resolve
            return ToSStyle::NO_FIELD_NAMES_STYLE
          end
          private :read_resolve
        end
        
        
        # ToSStyle that prints out the short
        # class name and no identity hashcode.
        class ShortPrefixToSStyle < ToSStyle
          def initialize
            super()
            self.use_short_className = true
            self.use_identity_hash_code = false
          end
          
          
          def read_resolve
            return ToSStyle::SHORT_PREFIX_STYLE
          end
          private :read_resolve
        end
        
        
        # ToSStyle that does not print out the
        # classname, identity hashcode, content start or field name.
        class SimpleToSStyle < ToSStyle
          def initialize
            super()
            self.use_class_name = false
            self.use_identity_hash_code = false
            self.use_field_names = false
            self.content_start = ''
            self.content_end = ''
          end
          
          
          def read_resolve
            return ToSStyle::SIMPLE_STYLE
          end
          private :read_resolve
        end
        
        
        # ToSStyle that outputs on multiple lines.
        class MultiLineToSStyle < ToSStyle
          def initialize
            super()
            self.content_start = '{'
            self.field_separator = SystemUtils.line_separator + '  '
            self.field_separator_at_start = true
            self.content_end = SystemUtils.line_separator + '}'
          end
          
          def read_resolve
            return ToSStyle::MULTI_LINE_STYLE
          end
          private :read_resolve
        end
        
        
        DEFAULT_STYLE = DefaultToSStyle.new
        
        MULTI_LINE_STYLE = MultiLineToSStyle.new
        
        NO_FIELD_NAMES_STYLE = NoFieldNameToSStyle.new
        
        SHORT_PREFIX_STYLE = ShortPrefixToSStyle.new
        
        SIMPLE_STYLE = SimpleToSStyle.new
      end

    end
  end
end