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

$options, args = ARGV.partition { |arg| arg[/^-[hv]$|--\w+/] }
subcommand = args.first if /^\w/ === args.first
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
  output     STDOUT

common:
  coderay file.rb                      # highlight file to terminal
  coderay file.rb -page > 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, optional)
    stylesheet  print the CSS stylesheet with the given name (aliases: style, css)
  
  about:
    list [of]   list all available plugins (or just the scanners|encoders|styles|filetypes)
    commands    print this list
    help        show some help
    version     print CodeRay version
  COMMANDS
end

def print_list_of plugin_host
  plugins = plugin_host.all_plugins.map do |plugin|
    info = "  #{plugin.plugin_id}: #{plugin.title}"
    
    aliases = (plugin.aliases - [:default]).map { |key| "-#{key}" }.sort_by { |key| key.size }
    if plugin.respond_to?(:file_extension) || !aliases.empty?
      additional_info = []
      additional_info << aliases.join(', ') unless aliases.empty?
      info << " (#{additional_info.join('; ')})"
    end
    
    info << '  <-- default' if plugin.aliases.include? :default
    
    info
  end
  puts plugins.sort
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?$/
      input_file, output_format, output_file, = *names
    when /^-ff?$/
      input_lang, input_file, output_file, = *names
    when /^-f-f?$/
      input_lang, input_file, output_format, output_file, = *names
    when /^--?f?$/
      input_lang, output_format, output_file, = *names
    else
      $stdout = $stderr
      help
      puts
      puts "Unknown parameter order: #{args.join ' '}, expected: [-language] [input] [-format] [output]"
      exit 1
    end
    
    if input_file
      input_lang ||= CodeRay::FileType.fetch input_file, :text, true
    end
    
    if output_file
      output_format ||= CodeRay::FileType[output_file] || :plain
    else
      output_format ||= :terminal_256
    end
    
    output_format = :page if output_format.to_s == 'html'
    
    if input_file
      input = File.read input_file
    else
      input = $stdin.read
    end
    
    begin
      file =
        if output_file
          File.open output_file, 'w'
        else
          $stdout
        end
      CodeRay.encode(input, input_lang, output_format, :out => file)
      file.puts
    rescue CodeRay::PluginHost::PluginNotFound => boom
      $stdout = $stderr
      if boom.message[/CodeRay::(\w+)s could not load plugin :?(.*?): /]
        puts "I don't know the #$1 \"#$2\"."
      else
        puts boom.message
      end
      # puts "I don't know this plugin: #{boom.message[/Could not load plugin (.*?): /, 1]}."
    rescue CodeRay::Scanners::Scanner::ScanError
      # this is sometimes raised by pagers; ignore
    # FIXME: rescue Errno::EPIPE
    ensure
      file.close if output_file
    end
  end
when 'li', 'list'
  arg = args.first && args.first.downcase
  if [nil, 's', 'sc', 'scanner', 'scanners'].include? arg
    puts 'input languages (Scanners):'
    print_list_of CodeRay::Scanners
  end
  
  if [nil, 'e', 'en', 'enc', 'encoder', 'encoders'].include? arg
    puts 'output formats (Encoders):'
    print_list_of CodeRay::Encoders
  end
  
  if [nil, 'st', 'style', 'styles'].include? arg
    puts 'CSS themes for HTML output (Styles):'
    print_list_of CodeRay::Styles
  end
  
  if [nil, 'f', 'ft', 'file', 'filetype', 'filetypes'].include? arg
    puts 'recognized file types:'
    
    filetypes = Hash.new { |h, k| h[k] = [] }
    CodeRay::FileType::TypeFromExt.inject filetypes do |types, (ext, type)|
      types[type.to_s] << ".#{ext}"
      types
    end
    CodeRay::FileType::TypeFromName.inject filetypes do |types, (name, type)|
      types[type.to_s] << name
      types
    end
    
    filetypes.sort.each do |type, exts|
      puts "  #{type}: #{exts.sort_by { |ext| ext.size }.join(', ')}"
    end
  end
when 'stylesheet', 'style', 'css'
  puts CodeRay::Encoders[:html]::CSS.new(args.first || :default).stylesheet
when 'commands'
  commands
when 'help'
  help
else
  $stdout = $stderr
  help
  puts
  if subcommand[/\A\w+\z/]
    puts "Unknown command: #{subcommand}"
  else
    puts "File not found: #{subcommand}"
  end
  exit 1
end