#!/usr/bin/env ruby
require 'coderay'

$options, args = ARGV.partition { |arg| arg[/^-[hv]$|--\w+/] }
subcommand = args.detect { |arg| arg[/^\w/] }
subcommand = nil if subcommand && File.exist?(subcommand)
args.delete subcommand

def option? *options
  !($options & options).empty?
end

def tty?
  $stdout.tty? || option?('--tty')
end

def version
  puts <<-USAGE
CodeRay #{CodeRay::VERSION}
  USAGE
end

def help
  puts <<-HELP
This is CodeRay #{CodeRay::VERSION}, a syntax highlighting tool for selected languages.

usage:
  coderay [-language] [input] [-format] [output]
  
defaults:
  language   detect from input file name or shebang; fall back to plain text
  input      STDIN
  format     detect from output file name or use terminal; fall back to HTML page
  output     STDOUT

common:
  coderay file.rb                      # highlight file to terminal
  coderay file.rb > file.html          # highlight file to HTML page
  coderay file.rb -div > file.html     # highlight file to HTML snippet

configure output:
  coderay file.py output.json          # output tokens as JSON
  coderay file.py -loc                 # count lines of code in Python file

configure input:
  coderay -python file                 # specify the input language
  coderay -ruby                        # take input from STDIN

more:
  coderay stylesheet [style]           # print CSS stylesheet
  HELP
end

def commands
  puts <<-COMMANDS
  general:
    highlight   code highlighting (default command)
    stylesheet  print the CSS stylesheet with the given name
  
  about:
    list [of]   list all available plugins (or just the scanners|encoders)
    commands    print this list
    help        show some help
    version     print CodeRay version
  COMMANDS
end

if option? '-v', '--version'
  version
end

if option? '-h', '--help'
  help
end

case subcommand
when 'highlight', nil
  if ARGV.empty?
    version
    help
  else
    signature = args.map { |arg| arg[/^-/] ? '-' : 'f' }.join
    names     = args.map { |arg| arg.sub(/^-/, '') }
    case signature
    when /^$/
      exit
    when /^ff?$/
      input_file, output_file, = *names
    when /^f-f?$/
      input_file, output_filetype, output_file, = *names
    when /^-ff?$/
      input_filetype, input_file, output_file, = *names
    when /^-f-f?$/
      input_filetype, input_file, output_filetype, output_file, = *names
    when /^--?f?$/
      input_filetype, output_filetype, output_file, = *names
    else
      raise signature
    end
    
    if input_file
      input_filetype ||= CodeRay::FileType.fetch input_file, :text, true
    end
    
    if output_file
      output_filetype ||= CodeRay::FileType[output_file]
    else
      output_filetype ||= tty? ? :term : :page
    end
    
    if input_file
      input = File.read input_file
    else
      input = $stdin.read
    end
    
    output = CodeRay.scan(input, input_filetype).encode(output_filetype)
    
    if output_file
      File.open output_file, 'w' do |file|
        file.puts output
      end
    else
      puts output
    end
  end
when 'list'
  arg = args.first && args.first.downcase
  if [nil, 's', 'sc', 'scanner', 'scanners'].include? arg
    puts 'input languages (Scanners):'
    scanners = CodeRay::Scanners.all_plugins.map do |plugin|
      aliases = (plugin.aliases - [nil]).map { |key| "-#{key}" }.sort_by { |key| key.size }
      "  #{plugin.lang}: #{plugin.title}#{" (.#{plugin.file_extension}; #{aliases.join(', ')})" unless aliases.empty?}"
    end
    puts scanners.sort
    puts
  end
  
  if [nil, 'e', 'en', 'enc', 'encoder', 'encoders'].include? arg
    puts 'output formats (Encoders):'
    encoders = CodeRay::Encoders.all_plugins.map do |plugin|
      aliases = (plugin.aliases - [nil]).map { |key| "-#{key}" }.sort_by { |key| key.size }
      "  #{plugin.plugin_id}: #{plugin.title}#{" (.#{plugin.file_extension}; #{aliases.join(', ')})" unless aliases.empty?}"
    end
    puts encoders.sort
  end
when 'stylesheet'
  puts CodeRay::Encoders[:html]::CSS.new(args.first).stylesheet
when 'commands'
  commands
when 'help'
  help
else
  puts "Unknown command: #{subcommand}"
  help
end