#!/usr/bin/env ruby

require 'yaml'
require 'slop'
require 'gitdis'

opts = Slop.parse { |o|
  o.banner = "USAGE: gitdis path/to/config.yaml [options]"
  o.separator '  Environment selection'
  o.string '-e', '--environment', 'select within YAML[environments]'
  o.separator '  Redis overrides'
  o.string  '-H', '--redis-host', 'string'
  o.integer '-p', '--redis-port', 'number'
  o.integer '-d', '--redis-db',   'number'
  o.separator '  Git repo overrides'
  o.string '-r', '--git-repo',   'path/to/repo_dir'
  o.string '-b', '--git-branch', 'e.g. master'
  o.separator '  Other options'
  o.bool '-D', '--dump', 'Just dump Redis contents per YAML keymap'
  o.on   '-h', '--help' do
    puts o
    exit
  end
}

unless(yaml_file = opts.arguments.shift)
  puts opts
  puts "path/to/config.yaml is required"
  exit 1
end

# load the default (required) config
yaml = YAML.load_file(yaml_file)
config = yaml.fetch('default')

# apply any env-specific settings
if opts[:environment]
  env = opts[:environment].downcase
  unless yaml.key?(env)
    warn "no environment #{env} found in #{yaml_file}"
    exit 1
  end
  config.merge!(yaml[env])
end

# make sure we have a keymap
keymap = config.fetch('keymap')
raise "keymap should be a hash/map" unless keymap.is_a?(Hash)

# update config with any settings from opts
# create redis_options
redis_options = {}
%w[git-repo git-branch redis-host redis-port redis-db].each { |item|
  opt_value = opts[item.to_sym]
  config[item] = opt_value if opt_value

  if item.match /^redis-/      # set :host, :port, :db
    cfg_value = config[item]
    if cfg_value
      # "redis-foo-bar" => :foo_bar
      ropt = item.split('-').drop(1).join('_').to_sym
      redis_options[ropt] = cfg_value
    end
  end
  puts [item, config[item]].join(': ') if config[item]
}
puts "Redis options: #{redis_options}"

# do things'n'stuff
if opts.dump?
  GitDis.dump(keymap.keys, redis_options)
else
  gd = GitDis.new config.fetch('git-repo')
  gd.git_pull config.fetch('git-branch')
  keymap.each { |key, fileglob|
    result = gd.update(key, fileglob)
    case result
    when nil
      puts "#{fileglob} not found"
    when false
      puts "#{fileglob} unchanged"
    else
      ver, md5 = *result
      puts "#{fileglob} updated:"
      puts "\tVersion: #{ver} (#{md5})"
    end
  }
end