require 'readline'
require 'tsort'

class Hash
  include TSort
  alias tsort_each_node each_key
  def tsort_each_child(node, &block)
    fetch(node).each(&block)
  end
end

$deps = {}
$variants = {}

def analyse_deps(name, history=[])
  return if history.include? name
  lines = `port deps #{name} #{$variants[name]}`
  return unless $? == 0
  $stderr.puts "analyses dependencies of #{name}..."
  deps = lines.inject([]) {|acc, line|
    case line
    when /\A#{name} has/
      # TODO: dependency category handling
    else
      acc.push line.strip
    end
    next acc
  }
  $deps[name] = deps
  history.push name
  deps.map {|dname| analyse_deps dname, history }
end

def add_deps(name)
  deps = analyse_deps(name)
end

def add_port(name, variants)
  $variants[name] = variants
  add_deps name
end

while line = Readline.readline('> ', true)
  case line
  when /\A(?:add port|ap)\s+(\S+)(?:\s+(\+\S+))?\b/
    name = $1
    variants = $2
    add_port name, variants || ''
  when /\A(?:show deps|sd)\s+(\S+)(?:\s+(\+\S+))?\b/
    name = $1
    variants = $2
    if variants
      system('port', 'deps', name, variants)
    else
      system('port', 'deps', name)
    end
  when /\A(?:show variants|sv)\s+(\S+)\b/
    name = $1
    system('port', 'variants', name)
  when /\As(?:earch)?\s+(\S+)\b/
    pattern = $1
    system('port', 'search', pattern)
  when /\Ar(?:esult)?\b/
    $deps.tsort.map {|name|
      puts "#{name} #{$variants[name]}"
    }
  when /\Ac(?:lear)?\b/
    $deps = {}
    $variants = {}
  when /\Ah(?:elp)?\b/
    print <<HELP
ap,add port NAME [VARIANTS]
sd,show deps NAME [VARIANTS]
sv,show variants NAME
s,search PATTERN
r,result
c,clear
h,help
q,quit,exit
HELP
  when /\Aq(?:uit)?\b/, /\Aexit\b/
    break
  else
    $stderr.puts "unknown command: #{line}"
  end
end