#!/usr/bin/env ruby
# encoding: UTF-8

$VERBOSE = true                         # -w
$KCODE   = "U" if RUBY_VERSION < "1.9"  # -KU

require 'optparse'
require 'socket'
require 'tempfile'
require 'yaml'
require 'fileutils'

module Rmate
  DATE           = "2021-04-26"
  VERSION        = "1.5.10"
  VERSION_STRING = "rmate version #{Rmate::VERSION} (#{Rmate::DATE})"

  class Settings
    attr_accessor :host, :port, :unixsocket, :wait, :force, :verbose, :lines, :names, :types, :reactivate

    def initialize
      @host, @port, @unixsocket = 'localhost', 52698, '~/.rmate.socket'

      @wait       = false
      @force      = false
      @verbose    = false
      @reactivate = true
      @lines      = []
      @names      = []
      @types      = []

      read_disk_settings

      @host       = ENV['RMATE_HOST'].to_s       if ENV.has_key? 'RMATE_HOST'
      @port       = ENV['RMATE_PORT'].to_i       if ENV.has_key? 'RMATE_PORT'
      @unixsocket = ENV['RMATE_UNIXSOCKET'].to_s if ENV.has_key? 'RMATE_UNIXSOCKET'

      parse_cli_options

      @host = parse_ssh_connection if @host == 'auto'
    end

    def read_disk_settings
      [ "/etc/rmate.rc", "/usr/local/etc/rmate.rc", "~/.rmate.rc"].each do |current_file|
        file = File.expand_path current_file
        if File.exist? file
          params = YAML::load(File.open(file))
          @host       = params["host"] unless params["host"].nil?
          @port       = params["port"] unless params["port"].nil?
          @unixsocket = params["unixsocket"] unless params["unixsocket"].nil?
        end
      end
    end

    def parse_cli_options
      OptionParser.new do |o|
        o.on(           '--host=name',       "Connect to host.", "Use 'auto' to detect the host from SSH.", "Defaults to #{@host}.") { |v| @host       = v       }
        o.on('-s',      '--unixsocket=name', "UNIX socket path.", "Takes precedence over host/port if the file exists", \
                                                                  "Default #{@unixsocket}")                                          { |v| @unixsocket = v       }
        o.on('-p',      '--port=#', Integer, "Port number to use for connection.", "Defaults to #{@port}.")                          { |v| @port       = v       }
        o.on('-w',      '--[no-]wait',       'Wait for file to be closed by TextMate.')                                              { |v| @wait       = v       }
        o.on('-l',      '--line [NUMBER]',   'Place caret on line [NUMBER] after loading file.')                                     { |v| @lines      <<= v     }
        o.on('-m',      '--name [NAME]',     'The display name shown in TextMate.')                                                  { |v| @names      <<= v     }
        o.on('-t',      '--type [TYPE]',     'Treat file as having [TYPE].')                                                         { |v| @types      <<= v     }
        o.on('-f',      '--force',           'Open even if the file is not writable.')                                               { |v| @force      = v       }
        o.on('-k',      '--[no-]keep-focus', 'Have TextMate retain window focus after file is closed.')                              { |v| @reactivate = !v      }
        o.on('-v',      '--verbose',         'Verbose logging messages.')                                                            { |v| @verbose    = v       }
        o.on_tail('-h', '--help',            'Show this message.')                                                                   { puts o; exit              }
        o.on_tail(      '--version',         'Show version.')                                                                        { puts VERSION_STRING; exit }
        o.parse!
      end
    end

    def parse_ssh_connection
      ENV['SSH_CONNECTION'].nil? ? 'localhost' : ENV['SSH_CONNECTION'].split(' ').first
    end
  end

  class Command
     def initialize(name)
       @command   = name
       @variables = {}
       @data      = nil
       @size      = nil
     end

     def []=(name, value)
       @variables[name] = value
     end

     def read_file(path)
       @size = File.size(path)
       @data = File.open(path, "rb") { |io| io.read(@size) }
     end

     def read_stdin
       @data = $stdin.read
       @size = @data.bytesize
     end

     def send(socket)
       socket.puts @command
       @variables.each_pair do |name, value|
         value = 'yes' if value === true
         socket.puts "#{name}: #{value}"
       end
       if @data
         socket.puts "data: #{@size}"
         socket.puts @data
       end
       socket.puts
     end
  end

  module_function

  def handle_save(socket, variables, data)
    path = variables["token"]
    if File.writable?(path) || !File.exist?(path)
      $stderr.puts "Saving #{path}" if $settings.verbose
      begin
        backup_path = "#{path}~"
        backup_path = "#{backup_path}~" while File.exist? backup_path
        FileUtils.cp(path, backup_path, :preserve => true) if File.exist?(path)
        open(path, 'wb') { |file| file << data }
        File.unlink(backup_path) if File.exist? backup_path
      rescue
        # TODO We probably want some way to notify the server app that the save failed
        $stderr.puts "Save failed! #{$!}" if $settings.verbose
      end
    else
      $stderr.puts "Skipping save, file not writable." if $settings.verbose
    end
  end

  def handle_close(socket, variables, data)
    path = variables["token"]
    $stderr.puts "Closed #{path}" if $settings.verbose
  end

  def handle_cmd(socket)
    cmd = socket.readline.chomp

    variables = {}
    data = ""

    while line = socket.readline.chomp
      break if line.empty?
      name, value     = line.split(': ', 2)
      variables[name] = value
      data << socket.read(value.to_i) if name == "data"
    end
    variables.delete("data")

    case cmd
    when "save"   then handle_save(socket, variables, data)
    when "close"  then handle_close(socket, variables, data)
    else          abort "Received unknown command “#{cmd}”, exiting."
    end
  end

  def connect_and_handle_cmds(host, port, unixsocketpath, cmds)
    socket = nil
    unixsocketpath = File.expand_path(unixsocketpath) unless unixsocketpath.nil?
    if unixsocketpath.nil? || !File.exist?(unixsocketpath)
      $stderr.puts "Using TCP socket to connect: ‘#{host}:#{port}’" if $settings.verbose
      begin
        socket = TCPSocket.new(host, port)
      rescue Exception => e
        abort "Error connecting to ‘#{host}:#{port}’: #{e.message}"
      end
    else
      $stderr.puts "Using UNIX socket to connect: ‘#{unixsocketpath}’" if $settings.verbose
      socket = UNIXSocket.new(unixsocketpath)
    end
    server_info = socket.readline.chomp
    $stderr.puts "Connect: ‘#{server_info}’" if $settings.verbose

    cmds.each { |cmd| cmd.send(socket) }

    socket.puts "."
    handle_cmd(socket) while !socket.eof?
    socket.close
    $stderr.puts "Done" if $settings.verbose
  end
end

## MAIN

$settings = Rmate::Settings.new

## Parse arguments.
cmds = []

ARGV << '-' if ARGV.empty? and (!$stdin.tty? or $settings.wait)

ARGV.each_index do |idx|
  path = ARGV[idx]
  if path == '-'
    $stderr.puts "Reading from stdin, press ^D to stop" if $stdin.tty?
  else
    abort "'#{path}' is a directory! Aborting." if File.directory? path
    abort "File #{path} is not writable! Use -f/--force to open anyway." unless $settings.force or File.writable? path or not File.exist? path
    $stderr.puts "File #{path} is not writable. Opening anyway." if not File.writable? path and File.exist? path and $settings.verbose
  end
  cmd                 = Rmate::Command.new("open")
  cmd['display-name'] = "#{Socket.gethostname}:untitled (stdin)" if path == '-'
  cmd['display-name'] = "#{Socket.gethostname}:#{path}" unless path == '-'
  cmd['display-name'] = $settings.names[idx] if $settings.names.length > idx
  cmd['real-path']    = File.expand_path(path) unless path == '-'
  cmd['data-on-save'] = true
  cmd['re-activate']  = $settings.reactivate
  cmd['token']        = path
  cmd['selection']    = $settings.lines[idx] if $settings.lines.length > idx
  cmd['file-type']    = 'txt'                if path == '-'
  cmd['file-type']    = $settings.types[idx] if $settings.types.length > idx
  cmd.read_stdin                    if path == '-'
  cmd.read_file(path)               if path != '-' and File.exist? path
  cmd['data']         = "0"     unless path == '-' or  File.exist? path
  cmds << cmd
end

unless $settings.wait
  pid = fork do
    Rmate::connect_and_handle_cmds($settings.host, $settings.port, $settings.unixsocket, cmds)
  end
  Process.detach(pid)
else
  Rmate::connect_and_handle_cmds($settings.host, $settings.port, $settings.unixsocket, cmds)
end