#! /usr/bin/env ruby
# -*- mode:ruby; coding:utf-8 -*-
#
# habatu.rb -
#
# Copyright(C) 2007 by mzp
# Author: MIZUNO Hiroki / mzpppp at gmail dot com
# http://howdyworld.org
#
# Timestamp: 2007/12/13 13:39:48
#
# This program is free software; you can redistribute it and/or
# modify it under MIT Lincence.
#
require 'yaml'
require 'webrick/cgi'
require 'jcode'

$KCODE='u'
class Array
  # treat Array as tree
  def value
    self.first
  end

  def children
    self[1]
  end
end

class Habastu < WEBrick::CGI
#  ChildJoinFirst = '┬─'
  ChildJoinFirst   = '├─'
  ChildJoinMid   = '├─'
  ChildJoinLast  = '└─'
  ChildSpan = '│　'
  ChildSpanLast  = '　　'


  RootJoin = ''
  RootSpanJP  = '　'
  RootSpanEN  = ' '

  def add_prefix(top,rest,lines)
    x,*xs = lines
    [top+x] + xs.map{|y| rest + y }
  end

  def take_block(lines,marker)
    buf = []
    until lines.empty? do
      break unless lines.first =~ marker
      buf.push lines.shift.sub(marker,'')
    end
    buf
  end

  def parse_tree(lines)
    buf = []
    until lines.empty? do
      value = lines.shift.strip
      child = parse_tree take_block(lines,/\A-/)

      if child.empty? then
        buf.push value.to_s
      else
        buf.push [value,child]
      end
    end
    buf
  end

  def habastu(tree)
    if tree.class == String then
      [tree]
    else
      children = tree.children.map{|c| habastu c }
      if children.size >= 2 then
        first_child = add_prefix ChildJoinFirst,ChildSpan,children.first

        mid_child = children[1...-1].map{|x|
          add_prefix ChildJoinMid,ChildSpan,x
        }

        last_child = add_prefix ChildJoinLast,ChildSpanLast,children.last

        child = ([first_child]+mid_child+[last_child]).flatten
      else
        child = add_prefix(ChildJoinLast,ChildSpanLast,children[0]).flatten
      end

      root = "#{tree.value}#{RootJoin}"
      span = RootSpanJP*2
      add_prefix root,span,[""]+child
    end
  end

  def make_span(str)
    span = ''
    str.each_char{|c|
      if c.size == 1 then
        span += RootSpanEN
      else
        span += RootSpanJP
      end
    }
    span
  end

  def do_GET(req,res)
    res['content-type'] = 'text/plain;charset=UTF-8'
    forrest = parse_tree req.query['input'].split("\n")
    res.body = forrest.map{|tree| habastu tree }.join("\n")
  end

  def do_POST(req,res)
    do_GET req,res
  end

end

Habastu.new.start