#!/usr/bin/env ruby

require "pp"
require "rubasteme"

def version
  "Rubasteme version: #{Rubasteme::VERSION} (#{Rubasteme::RELEASE})"
end

def usage
  puts <<HELP
usage:
    rubasteme [option] [FILE]

Reads the given files as a sequence of tokens, then print AST nodes.
If no FILE is specified, then tries to read from the standard input.

option:
    -o, --output-file OUTPUT_FILE : specify the output file
    -t, --format-type TYPE : specify the output format
    -d, --debug   : specify to run verbosely
    -v, --version : print version
    -h, --help    : show this message

input format:
    Specify one of the following names:
        ast, array
HELP
end

def opt_parse(args, opts = {})
  files = []
  while args.size > 0
    arg = args.shift
    case arg
    when "-o", "--output-file"
      opts[:output_file] = args.shift
    when "-t", "--format-type"
      format_type = args.shift
      raise ArgumentError, "not specified as format type" if format_type.nil?
      opts[:format_type] = format_type.intern
    when "-d", "--debug"
      opts[:verbose] = true
    when "-v", "--version"
      puts version
      exit 0
    when "-h", "--help"
      puts usage
      exit 0
    else                        # must be a filename
      files << arg if arg
    end
  end
  args.concat(files)
  opts
end

opts = opt_parse(ARGV)
if opts[:verbose]
  puts version
  format = opts[:format_type] || "default (token)"
  puts "Input format: #{format}"
  ofname = opts[:output_file] || "STDOUT"
  puts "Output file: #{ofname}"
end

lines = []
if ARGV.size > 0
  lines = ARGF.entries.map{|s| s.delete_suffix("\n")}
else
  lines = STDIN.readlines(chomp: true)
end

tokens = lines.map{|e| Kernel.eval(e)}
lexer = Rubasteme.lexer(tokens)
parser = Rubasteme.parser(lexer)
ast = parser.parse

output = ""
PP.pp(ast.to_a, output)

form = opts[:format_type] || :token
of = STDOUT
of = File.open(opts[:output_file], "w") if opts[:output_file]

of.puts(output)

of.close