#!/usr/bin/env ruby
# -*- ruby -*-

require 'optparse'
require 'pione'
require 'pp'

include Pione

#
# options
#
$readline_mode = true
$verbose = false
$expr = []
option_parser = OptionParser.new do |opt|
  opt.on('-e', '--expr=expr') {|e| $expr << e; $readline_mode = false }
  opt.on('-v', '--verbose') { $verbose = true }
  opt.on('--version') { puts "Pione version: %s" % [Pione.version]; exit }
end

begin
  option_parser.parse!(ARGV)
rescue OptionParser::InvalidOption => e
  e.args.each {|arg| $stderr.puts "Unknown option: #{arg}" }
  abort
end

#
# print parsing result of the string
#
def print_result(str)
  begin
    puts DocumentTransformer.new.apply(DocumentParser.new.parse(str))[0].eval($vtable).textize
  rescue Pione::Parser::ParserError, Parslet::UnconsumedInput, Parslet::ParseFailed => e
    error("Pione syntax error", e)
  rescue Pione::Model::PioneModelTypeError,
    Pione::Model::VariableBindingError => e
    error("Pione model error", e)
  rescue Pione::Model::MethodNotFound, NoMethodError => e
    error("Pione method error", e)
  end
end

def error(msg, e)
  msg = "%s: %s (%s)" % [msg, e.message, e.class.name]
  msg << "\n" << e.backtrace.join("\n") if $verbose
  $readline_mode ? puts(msg) : abort(msg)
end

#
# variable table
#
$vtable = VariableTable.new

#
# History
#
$history = File.join(ENV["HOME"], ".pione", "pione-history")
# make pione directory if it is absent
unless Dir.exist?(File.join(ENV["HOME"], ".pione"))
  Dir.mkdir(File.join(ENV["HOME"], ".pione"))
end

#
# Ctr+C
#
trap("INT") do
  # save history
  i = 0
  File.open($history, "w+") do |file|
    Readline::HISTORY.to_a.reverse.each do |line|
      break if i >= 100
      file.puts(line) if /\S/.match(line)
    end
  end
  # quit
  exit
end

#
# readline loop
#
if $readline_mode
  require 'readline'

  # restore history
  if File.exist?($history)
    File.readlines($history).reverse.each do |line|
      Readline::HISTORY.push line.chomp
    end
  end

  # start loop
  while buf = Readline.readline(Terminal.red("> "), true)
    if /[^\s]/.match(buf)
      # don't record if previous line is the same
      if Readline::HISTORY.size > 1 && Readline::HISTORY[-2] == buf
        Readline::HISTORY.pop
      end
      # print parsing result
      print_result(buf)
    else
      # don't record if it is an empty line
      Readline::HISTORY.pop
    end
  end
else
  # print parsing result
  $expr.each {|e| print_result(e) }
end