require 'fileutils'

module Pidgin2Adium
    # A holding object for the result of LogParser.parse.  It makes the
    # instance variable @chat_lines available, which is an array of Message
    # subclass instances (XMLMessage, Event, etc.)
    # Here is a list of the instance variables for each class in @chat_lines:
    # 
    # <b>All of these variables are read/write.</b>
    # All::		 sender, time, buddy_alias
    # XMLMessage::	 body
    # AutoReplyMessage:: body
    # Event::		 body, event_type
    # StatusMessage::	 status
    class LogFile
	include Pidgin2Adium
	def initialize(chat_lines, service, user_SN, partner_SN, adium_chat_time_start)
	    @chat_lines = chat_lines
	    @user_SN = user_SN
	    @partner_SN = partner_SN
	    @adium_chat_time_start = adium_chat_time_start

	    # @chat_str is generated when to_s is called
	    @chat_str = nil
	    
	    # key is for Pidgin, value is for Adium
	    # Just used for <service>.<screenname> in directory structure
	    service_name_map = {'aim' => 'AIM',
		'jabber' =>'Jabber',
		'gtalk'=> 'GTalk',
		'icq' => 'ICQ',
		'qq' => 'QQ',
		'msn' => 'MSN',
		'yahoo' => 'Yahoo!'}
	    
	    @service = service_name_map[service.downcase]
	end
	
	attr_reader :chat_lines, :service, :user_SN, :partner_SN, :adium_chat_time_start

	# Returns contents of log file
	def to_s
	    if @chat_str.nil?
		# Faster than inject() or each()
		@chat_str = @chat_lines.map{|l| l.to_s }.join
	    end
	    return @chat_str
	end
	
	def each(&blk)
	    @chat_lines.each{|l| yield l }
	end

	# Set overwrite=true to create a logfile even if logfile already exists.
	# Returns one of:
	# * false (if an error occurred),
	# * Pidgin2Adium::FILE_EXISTS if the file to be generated already exists and overwrite=false, or
	# * the path to the new Adium log file.
	def write_out(overwrite = false, output_dir_base = ADIUM_LOG_DIR)
	    # output_dir_base + "/buddyname (2009-08-04T18.38.50-0700).chatlog"
	    output_dir = File.join(output_dir_base, "#{@service}.#{@user_SN}", @partner_SN, "#{@partner_SN} (#{@adium_chat_time_start}).chatlog")
	    # output_dir + "/buddyname (2009-08-04T18.38.50-0700).chatlog/buddyname (2009-08-04T18.38.50-0700).xml"
	    output_path = output_dir + '/' + "#{@partner_SN} (#{@adium_chat_time_start}).xml"
	    begin
		FileUtils.mkdir_p(output_dir)
	    rescue => bang
		error "Could not create destination directory for log file. (Details: #{bang.class}: #{bang.message})"
		return false
	    end
	    if overwrite
		unless File.exist?(output_path) 
		    # File doesn't exist, but maybe it does with a different
		    # time zone. Check for a file that differs only in time
		    # zone and, if found, change @output_path to target it.
		    maybe_matches = Dir.glob(output_dir_base + '/' << File.basename(output_path).sub(/-\d{4}\)\.chatlog$/, '') << '/*')
		    unless maybe_matches.empty?
			output_path = maybe_matches[0]
		    end
		end
	    else
		if File.exist?(output_path)
		    return FILE_EXISTS
		end
	    end

	    begin
		outfile = File.new(output_path, 'w')
	    rescue => bang
		error "Could not open log file for writing. (Details: #{bang.class}: #{bang.message})"
		return false
	    end

	    # no \n before </chat> because @chat_str (from to_s) has it already
	    outfile.printf('<?xml version="1.0" encoding="UTF-8" ?>'<<"\n"+
			   '<chat xmlns="http://purl.org/net/ulf/ns/0.4-02" account="%s" service="%s">'<<"\n"<<'%s</chat>',
			   @user_SN, @service, self.to_s)
	    outfile.close

	    return output_path
	end
    end
end