# Copyright (c) 2005 Martin Ankerl
# This application is free software; you can redistribute it and/or
# modify it under the terms of the Ruby license defined in the
# COPYING file.
#
class Search_Engine
	def initialize(gui, data)
		@gui = gui
		@data = data
		@search_thread = nil
	end	
	
	# Executed whenever a search criteria changes to update the packet list.
	def on_search
		# restart current search
		@end_time = Time.now + $cfg.search_delay
		@restart_search = true
		@gui.search_label.enabled = false
		return if @search_thread && @search_thread.status
			
		@search_thread = Thread.new(@search_thread) do
			begin
				@gui.search_label.enabled = false
				# wait untill deadline
				while (t = (@end_time - Time.now)) > 0
					sleep(t)
				end
				
				@data.gui_mutex.synchronize do
					# the thread has to use the gui mutex inside
					@restart_search = false
					
					match_data = get_match_data
				
					# remove all items
					@gui.packet_list.dirty_clear
					
					# add all items that match the search criteria
					status_text_deadline = Time.now + $cfg.status_line_update_interval
					@data.items.each do |item|
						#item.parent = @gui.packet_list if match?(item, match_data)
						if match?(item, match_data)
							item.show
							now = Time.now
							if now > status_text_deadline
								update_search_status_text
								status_text_deadline = now + $cfg.status_line_update_interval
							end
						end
						break if @restart_search
					end
					update_search_status_text
					
					if (@gui.packet_list.numItems > 0)
						@gui.packet_list.setCurrentItem(0) 
						@gui.packet_list.selectItem(0)
						@gui.main.show_info(@gui.packet_list.getItem(0).packet_item.data)
					end
					@gui.search_label.enabled = true
					
				end # synchronize
			end while @restart_search# || match_data != @gui.search_field.text.downcase.split
		end #thread.new
	end
	
	def get_match_data
		str_to_match_data(@gui.search_field.text)
	end

	# Converts a string into a match_data representation.
	def str_to_match_data(str, index=0)
		words = [ ]
		exclude = [ ]
		is_exclude = false
		
		while str[index]
			case str[index]
			when ?", ?'
				word, index = get_word(str, index+1, str[index])
				unless word.empty?
					if is_exclude
						exclude.push word
						is_exclude = false
					else
						words.push word
					end
				end
			
			when 32 # space
				is_exclude = false

=begin
			when ?>
				min, index = get_word(str, index+1)
				min = @gui.logic.size_to_nr(min)
				
			when ?<
				max, index = get_word(str, index+1)
				max = @gui.logic.size_to_nr(max)
=end
			when ?-
				is_exclude = true
			
			else
				word, index = get_word(str, index)
				if is_exclude
					exclude.push word
					is_exclude = false
				else
					words.push word
				end				
			end
			
			index += 1
		end
		
		# check if word has upcase letters
		words.collect! do |w| 
			[w, /[A-Z]/.match(w)!=nil]
		end
		exclude.collect! do |w| 
			[w, /[A-Z]/.match(w)!=nil]
		end
		[words, exclude]
	end
	
	def get_word(str, index, delim=32) # 32==space
		word = ""
		c = str[index]
		while (c && c != delim)
			word += c.chr
			index += 1
			c = str[index]
		end
		[word, index]
	end

	# Update the text for the number of displayed packs.
	def update_search_status_text
		@gui.search_label.text = sprintf($cfg.text.search, @gui.packet_list.numItems, @data.items.size)
	end

	# Find out if item is matched by current search criteria.
	def match?(item, match_data)
		words, exclude, min, max = match_data
		
		# check text that has to be there
		searchable, sortable_downcase, sortable_normal = item.sortable(0)
		words.each do |match_str, is_sensitive|
			if is_sensitive
				return false unless sortable_normal.include?(match_str)
			else
				return false unless sortable_downcase.include?(match_str)
			end
		end
		
		# check text not allowed to be there
		exclude.each do |match_str, is_sensitive|
			if is_sensitive
				return false if sortable_normal.include?(match_str)
			else
				return false if sortable_downcase.include?(match_str)
			end		
		end
		
		# each check ok
		true
	end
end