#!/usr/bin/env ruby
#
# SSX - SSH over colorful terminal.
#       Uses consisten colors over the same host names to for better navigation
#       over multiple hosts/windows.
#
# modified to change a running roxterm instance via DBus

require 'zlib'

# Defaults
DEFAULT_FONT     = "9x15"
DEFAULT_GEOMETRY = "120x25"

# Base colors from which color combinations are created.
FG_BASE = %w[
              White
              Yellow
            ]

BG_BASE = %w[
                #000000
                #0f0f0f
                #1e1e1e
                #2d2d2d
                #3c3c3c
                #4b4b4b

                #1e0000
                #2d0000
                #3c0000
                #4b0000

                #001e00
                #002d00
                #003c00
                #004b00

                #00001e
                #00002d
                #00003c
                #00004b

                #001e1e
                #002d2d
                #003c3c
                #004b4b

                #1e1e00
                #2d2d00
                #3c3c00
                #4b4b00

                #1e001e
                #2d002d
                #3c003c
                #4b004b

            ]

# This method maps hostname to pair of colors
# Given a hostname (string), and two arrays containing color names
# it returns an array of two, with the first element be fg color
# and the second element the background color
def get_colors_by_hostname hostname, fg_array, bg_array
  n = [fg_array.size, bg_array.size].min
  idx = Zlib.crc32(hostname) % n
  [fg_array[idx], bg_array[idx]]
end


# Extract hostname from SSH args. Search for the first argument not without
# a '-' prefix, while skipping those options that have such argument before
# the hostname: i.e. in -l username, discard 'username'.
# Expects: input parameter args to be an array of strings
# Returns: hostname or nil if didn't find one
def extract_hostname_from_args args
  opts_with_arg = %w[b c D e F I i L l m O o p R S W w]
  a = args.dup
  while a.size > 0
    opt = a[0]
    return opt.gsub(/^\w+@/,"") unless opt.chars.first == "-"
    opt_char = opt.chars.to_a[1]
    a.shift
    if opts_with_arg.include? opt_char
      a.shift if a.size > 0
    end
  end
  nil
end



# Generate all possible combinations between fg_base and bg_base colors.
# Returns two arrays of the same size, first contains fg colors, second
# contains bg colors.
def generate_color_combinations fg_base, bg_base
  combinations = fg_base.product(bg_base)
  fg_colors = []
  bg_colors = []
  combinations.each do |c|
    fg_colors.push c[0]
    bg_colors.push c[1]
  end
  [fg_colors, bg_colors]
end



hostname = extract_hostname_from_args ARGV
fg_array, bg_array = generate_color_combinations FG_BASE, BG_BASE
fg_color, bg_color = get_colors_by_hostname hostname, fg_array, bg_array
args_str = ARGV.join ' '
ssh_cmd  = "ssh #{args_str}"
font     = DEFAULT_FONT
geometry = DEFAULT_GEOMETRY

roxtermid = ENV["ROXTERM_ID"]

rox_change_profile = "dbus-send --session /net/sf/roxterm/Options net.sf.roxterm.Options.SetColourScheme \
            string:#{roxtermid} string:#{bg_color}"
rox_change_color   = "dbus-send --session /net/sf/roxterm/Options net.sf.roxterm.Options.StringOption \
            string:Colours/#{bg_color} string:background 'string:#{bg_color}' "

system rox_change_profile
system rox_change_color

system ssh_cmd

rox_reset = "dbus-send --session /net/sf/roxterm/Options net.sf.roxterm.Options.SetColourScheme \
            string:#{roxtermid} string:Default"

system rox_reset