1begin
 2  require 'open3_detach'
 3rescue LoadError
 4  require 'open3'
 5end
 6
 7module GitHub
 8  module Markup
 9    extend self
10    @@markups = {}
11
12    def render(filename, content = nil)
13      content ||= File.read(filename)
14
15      if proc = renderer(filename)
16        proc[content]
17      else
18        content
19      end
20    end
21
22    def markup(file, pattern, &block)
23      require file.to_s
24      add_markup(pattern, &block)
25    rescue LoadError
26      nil
27    end
28
29    def command(command, regexp, &block)
30      command = command.to_s
31
32      if File.exists?(file = File.dirname(__FILE__) + "/commands/#{command}")
33        command = file
34      end
35
36      add_markup(regexp) do |content|
37        rendered = execute(command, content)
38        rendered = rendered.to_s.empty? ? content : rendered
39
40        if block && block.arity == 2
41          # If the block takes two arguments, pass new content and old
42          # content.
43          block.call(rendered, content)
44        elsif block
45          # One argument is just the new content.
46          block.call(rendered)
47        else
48          # No block? No problem!
49          rendered
50        end
51      end
52    end
53
54    def add_markup(regexp, &block)
55      @@markups[regexp] = block
56    end
57
58    def can_render?(filename)
59      !!renderer(filename)
60    end
61
62    def renderer(filename)
63      @@markups.each do |key, value|
64        if Regexp.compile("\\.(#{key})$") =~ filename
65          return value
66        end
67      end
68      nil
69    end
70
71    def execute(command, target)
72      out = ''
73      Open3.popen3(command) do |stdin, stdout, _|
74        stdin.puts target
75        stdin.close
76        out = stdout.read
77      end
78      out.gsub("\r", '')
79    rescue Errno::EPIPE
80      ""
81    end
82
83    # Define markups
84    instance_eval File.read(File.dirname(__FILE__) + '/markups.rb')
85  end
86end