git-wiki.rb

#!/usr/bin/env ruby

require 'sinatra'
require 'haml'
require 'grit'
require 'rdiscount'
require 'time'

module GitWiki
  class << self
    attr_accessor :wiki_path, :root_page, :extension, :link_pattern
    attr_reader :wiki_name, :repo
    def wiki_path=(path)
      @wiki_name = File.basename(path)
      @repo = Grit::Repo.new(path)
    end
    def all_page_blobs
      @repo.head.commit.tree.contents.select do |obj|
        obj.kind_of?(Grit::Blob) && obj.name.end_with?(@extension)
      end
    end
    def create_blob(path)
      Grit::Blob.create(@repo, :name => path)
    end
    def file_path(name)
      (name.empty? ? @root_page : name) + @extension
    end
    def url(page=nil, params=nil)
      '/' + (page && page.name != @root_page ? page.name : '') + (params ? "?#{Rack::Utils.build_query(params)}" : '')
    end
    def expand_links(html)
      html.gsub(@link_pattern) do
        link_text = $1
        page = Page.find_or_create(link_text.gsub(/[^\w\s]/, '').split.join('-').downcase)
        "<a class='page #{'new' unless page.exists?}' href='#{url(page)}'>#{link_text}</a>"
      end
    end
  end
end

class Page
  def self.find_all
    GitWiki.all_page_blobs.map {|blob| new(blob) }
  end

  def self.find_or_create(name, rev=nil)
    path = GitWiki.file_path(name)
    commit = rev ? GitWiki.repo.commit(rev) : GitWiki.repo.head.commit
    blob = commit.tree/path
    new(blob || GitWiki.create_blob(path))
  end

  def initialize(blob)
    @blob = blob
  end

  def name
    @blob.name.sub(/#{GitWiki.extension}$/, '')
  end

  def exists?
    !!@blob.id
  end

  def content
    @blob.data
  end

  def to_html
    GitWiki.expand_links(RDiscount.new(content).to_html)
  end

  def log
    head = GitWiki.repo.head.name
    GitWiki.repo.log(head, @blob.name).map {|commit| commit.to_hash }
  end

  def save!(data, msg)
    msg = "web commit: #{name}" if msg.empty?
    Dir.chdir(GitWiki.repo.working_dir) do
      File.open(@blob.name, 'w') {|f| f.puts(data.gsub("\r\n", "\n")) }
      GitWiki.repo.add(@blob.name)
      GitWiki.repo.commit_index(msg)
    end
  end
end

set :haml, :format => :html5, :attr_wrapper => '"'

get '/*' do
  if params[:view] == 'tree'
    @pages = Page.find_all
    haml :list
  else
    @page = Page.find_or_create(*params[:splat], params[:rev])
    case params[:view]
    when 'log'; haml :log
    when 'edit'; haml :edit
    else haml @page.exists? ? :show : :edit
    end
  end
end

post '/*' do
  @page = Page.find_or_create(*params[:splat])
  @page.save!(params[:content], params[:msg])
  redirect GitWiki.url(@page), 303
end

configure do
  GitWiki.wiki_path = Dir.pwd
  GitWiki.root_page = 'index'
  GitWiki.extension = '.md'
  GitWiki.link_pattern = /\[\[(.*?)\]\]/
end