module StaticCms
  require 'fileutils'
  require 'ruby_patch'

  require 'static_cms/version'
  require 'static_cms/patch'

  SITE_TEMPLATE_DIR = File.join(__DIR__, '../data/site_template')

  module Command
    def self.init(dir = '.')
      FileUtils.mkdir_p(dir)
      success = false
      FileUtils.cd(dir){|dir|
        success = system <<-EOS
git init > #{File::NULL}
git commit --allow-empty -m 'Empty commit.' > #{File::NULL}
cp -r #{File.join(SITE_TEMPLATE_DIR, '*')} . > #{File::NULL}
git add . > #{File::NULL}
git commit -m 'Copied from site template.' > #{File::NULL}
        EOS
      }

      success
    end

    def self.update
      site_template_dir = File.join(__DIR__, '../data/site_template')
      FileUtils.cp_r(File.join(site_template_dir, 'templates'), '.')
      FileUtils.cp_r(File.join(site_template_dir, 'sources'), '.')
      FileUtils.cp_r(File.join(site_template_dir, 'statics'), '.')
      FileUtils.cp(File.join(site_template_dir, 'rakefile'), '.')
    end
  end

  class Site
    require 'yaml'

    CONFIG_DEFAULT = {
      'lang' => 'en',
      'www' => nil,
      'dir' => File.join(__DIR__, 'root'),
      'author' => '',
      'robots' => 'noarchive',
      'favicon' => 'images/favicon.png',
      'charset' => 'utf-8',
    }

    attr_accessor :page_alist
    attr_accessor *(CONFIG_DEFAULT.keys)

    def initialize
      config = CONFIG_DEFAULT.merge(YAML.load_file('config.yaml'))
      @www = config.delete('www')
      @www += '/' unless @www[-1] == '/'
      config.each{|k, v| instance_variable_set("@#{k}", v)}
      @page_alist = Hash.new{|h, k| raise KeyError, k}
      YAML.load_file('pages.yaml')\
        .sort\
        .each{|name, params|
        @page_alist[name] = ::StaticCms::Page.new(self, name, params)
      }
    end
  end

  class Page
    require 'fileutils'
    require 'haml'

    PARAMS_DEFAULT ={
      'visible' => true,
      'title' => '',
      'template' => 'default',
      'articles' => [],
      'statics' => [],
      'sources' => [],
      'base' => nil,
    }

    attr_accessor :site, :name, :dir, :template_file
    attr_accessor *(PARAMS_DEFAULT.keys)

    def initialize(site, name, params = {})
      @site = site
      @name = name
      @dir = File.join("root", @name)
      params = PARAMS_DEFAULT.merge(params)
      @template = params.delete('template')
      @template_file = File.join('templates', @template) + '.html.haml'
      @articles = params.delete('articles').map{|name| ::StaticCms::Article.use(self, name)}
      @statics = params.delete('statics').map{|file| File.join('statics', file)}
      @sources = params.delete('sources').map{|file| File.join('sources', file)}
      @base = params.delete('base') || @site.www
      params.each{|k, v|
        instance_variable_set("@#{k}", v)
      }
    end

    def generate
      FileUtils.mkdir_p(@dir)

      if @visible
        @statics.each{|file| cp_if_new(file)}
        @sources.each{|file| compile(file)}
        template_file = @template_file
      else
        @statics.each{|file| FileUtils.rm_rf(static_target(file))}
        @sources.each{|file| FileUtils.rm_rf(compile_target(file))}
        template_file = 'templates/moved.html.haml'
      end

      html = ::Haml::Engine.new(File.read(template_file)).render(self)
      target = File.join(@dir, 'index.html')
      open(target, 'w'){|io|
        io.write(html)
        io.flush
        io.fsync
      }
    end

    private

    def haml(text)
      ::Haml::Engine.new(text).render(self)
    end

    def nth_page_from_self(n)
      index = (@site.page_alist.to_a.index{|name, page| name == @name} + n)%@site.page_alist.size
      @site.page_alist.to_a[index][1]
    end

    def link_to_article(name)
      article = ::StaticCms::Article.alist[name]
      page = article.pages.first
      url = File.join(@site.www, page.name, "index.html\##{name}")

      "<a href='#{url}'>#{article.title}</a>"
    end

    def cp_if_new(source)
      target = static_target(source)
      if !File.file?(target) || File.mtime(source) > File.mtime(target)
        FileUtils.cp(source, target)
        FileUtils.chmod(0644, target)
      end
    end

    def compile(source)
      ext = File.extname(source)
      target = compile_target(source)

      case ext
      when /\A\.sass\z/
        system "sass #{source} > #{target}"
      else
        raise NotImplementedError, file
      end
    end

    def static_target(source)
      File.join(@dir, File.basename(source))
    end

    def compile_target(source)
      ext = File.extname(source)
      File.join(@dir, File.basename(source, ext))
    end
  end

  module Helpers
    require 'haml'

    EXT_TO_LANG = Hash.new(:general)\
      .merge({
               '.f90' => :fortran,
               '.f95' => :fortran,
               '.f03' => :fortran,
               '.f08' => :fortran,
               '.f' => :fortran,
               '.f77' => :fortran,
               '.rb' => :ruby,
             })

    module_function

    def to_plain(text)
      escaped_text = ::Haml::Helpers.html_escape(text)
      ::Haml::Helpers.preserve(escaped_text)
    end

    def to_code(text, lang = :general)
      pre_text = to_plain(text)
      "<pre class='code'><code class='#{lang}'>#{pre_text}</code></pre>"
    end
  end

  class Article
    @alist = Hash.new{|h, k| raise KeyError, k.to_s}

    def self.alist
      @alist
    end

    PARAMS_DEFAULT = {
      'title' => '',
    }

    attr_accessor :pages, :name, :file, :data
    attr_accessor *(PARAMS_DEFAULT.keys)

    def initialize(name)
      @pages = []
      @name = name
      @file = File.join('articles', name) + '.html.yhaml'
      yaml, @data = File.read(@file).split(/^\.\.\.$/, 2)
      params = PARAMS_DEFAULT.merge(YAML.load(yaml))
      params.each{|k, v| instance_variable_set("@#{k}", v)}
      self.class.alist[@name] = self
    end

    def self.load
      `git ls-files articles`.split\
        .select{|f| f =~ /\.html\.yhaml\z/}\
        .map{|f| f.sub(/\Aarticles\//, '')}\
        .map{|f| File.basename(f, '.html.yhaml')}\
        .each{|name| self.new(name)}
    end

    def self.use(page, name)
      self.load unless self.alist.has_key?(name)
      raise ArgumentError, name unless self.alist.has_key?(name)

      article = self.alist[name]
      article.pages << page
      article
    end
  end

  require 'thor'
  class Runner < Thor
    desc "init [DIR]", "Initialize DIR directory for StaticCms [default: .]."
    def init(dir = '.')
      ::StaticCms::Command.init(dir)
    end

    desc "update", "Update templates, sources, statics (and more)."
    def update
      ::StaticCms::Command.update
    end
  end
end