#! /usr/bin/env ruby
#
# gonzui-server - a web-based search engine of gonzui
#
# Copyright (C) 2004-2005 Satoru Takabayashi <satoru@namazu.org> 
#     All rights reserved.
#     This is free software with ABSOLUTELY NO WARRANTY.
#
# You can redistribute it and/or modify it under the terms of 
# the GNU General Public License version 2.
#

require 'webrick'
require 'gonzui'
require 'gonzui/cmdapp'
require 'gonzui/webapp'
require 'ftools'
require 'fileutils'

include WEBrick
include Gonzui
include FileUtils

class NullWriter
  def << (message)
  end
end

class GonzuiServer < CommandLineApplication
  include GetText

  def be_secure
    return unless Process.uid == 0
    uid = Etc::getpwnam(@config.user).uid 
    gid = Etc::getgrnam(@config.group).gid
    touch(@config.pid_file)
    touch(@config.gonzui_log_file)
    touch(@config.access_log_file)
    File.chown(uid, gid, @config.pid_file)
    File.chown(uid, gid, @config.gonzui_log_file)
    File.chown(uid, gid, @config.access_log_file)
    Process.uid  = uid
    Process.gid  = gid
    Process.euid = uid
  end

  def make_webrick_options
    log_proc = lambda {@logger.log("server started [%d]", Process.pid) }
    webrick_options = {}
    webrick_options[:Port] = @config.http_port
    if @config.daemon
      eprintf("daemon mode is not supported in Windows platform") if windows?
      webrick_options[:StartCallback] = lambda {
        log_proc.call
        start_daemon
      }
      webrick_options[:Logger] = Log.new(NullWriter.new) # be quiet
    else
      webrick_options[:StartCallback] = log_proc
      webrick_options[:Logger] = Log.new(STDOUT, Log::ERROR)
    end
    access_logger = File.open(@config.access_log_file, "a")
    access_logger.sync = true
    webrick_options[:AccessLog] = 
      [[ access_logger, AccessLog::COMBINED_LOG_FORMAT ]]
    return webrick_options
  end

  def read_pid_file
    File.read(@config.pid_file).chomp.to_i
  end

  def write_pid_file
    begin
      File.open(@config.pid_file, "w") {|f| f.puts Process.pid }
    rescue
      # FIXME: we need logging here.
    end
  end

  def remove_pid_file
    File.safe_unlink(@config.pid_file)
  end

  def start_daemon
    Daemon.start
    write_pid_file
    be_secure
  end

  def stop_daemon
    begin
      pid = read_pid_file
      Process.kill("TERM", pid) 
    rescue
      wprintf("no processe to kill" )
    end
    remove_pid_file
    exit
  end

  def do_show_usage
    puts "Usage: #{program_name} [OPTION]"
    puts "  -p, --port=PORT                listen on the specified PORT [#{@config.http_port}]"
    puts "      --daemon                   run as a daemon"
    puts "  -u, --user=USER                use USER's UID when daemonized [#{@config.user}]"
    puts "  -g, --group=GROUP              use GROUP's GID when daemonized [#{@config.group}]"
    puts "  -t, --title=TITLE              use TITLE for HTML contents [#{@config.site_title}]"
  end

  def do_get_option_table
    [
      ['--port',           '-p', GetoptLong::REQUIRED_ARGUMENT],
      ['--user',           '-u', GetoptLong::REQUIRED_ARGUMENT],
      ['--group',          '-g', GetoptLong::REQUIRED_ARGUMENT],
      ['--title',          '-t', GetoptLong::REQUIRED_ARGUMENT],
      ['--daemon',               GetoptLong::NO_ARGUMENT],
      ['--stop',                 GetoptLong::NO_ARGUMENT],
    ]
  end

  def do_process_options(options)
    @config.http_port = options["port"].to_i if options["port"]
    @config.user = options["user"] if options["user"]
    @config.group = options["group"] if options["group"]
    @config.site_title = options["title"] if options["title"]
    @config.daemon = true if options["daemon"]
    stop_daemon if options["stop"]
  end

  def start_server(dbm, catalog_repository)
    server = HTTPServer.new(make_webrick_options)
    trap("INT"){ server.shutdown }
    GonzuiServlet.servlets.each {|klass|
      absolute_mount_point = URI.path_join(@config.base_mount_point, 
                                           klass.mount_point)
      server.mount(absolute_mount_point, klass,
                   @config, @logger, dbm, catalog_repository)
    }
    server.start
  end

  def do_start
    parse_options()
    ensure_db_directory_available
    init_logger
    @logger.monitor = STDOUT unless @config.daemon

    catalog_repository = CatalogRepository.new(@config.catalog_directory)
    printf("http://%s:%d/\n", Socket.gethostname, @config.http_port)
    
    dbm = Gonzui::DBM.open(@config, true)
    begin
      start_server(dbm, catalog_repository)
    rescue => e
      eprintf("%s", e.message)
    ensure
      @logger.log("server stopped [%d]", Process.pid)
      dbm.close
      remove_pid_file
    end
  end
end

GonzuiServer.start