module Sinatra::Templates

def builder(template=nil, options={}, locals={}, &block)
  options[:default_content_type] = :xml
  render_ruby(:builder, template, options, locals, &block)
end

def coffee(template, options={}, locals={})
  options.merge! :layout => false, :default_content_type => :js
  render :coffee, template, options, locals
end

def compile_template(engine, data, options, views)
  eat_errors = options.delete :eat_errors
  template_cache.fetch engine, data, options do
    template = Tilt[engine]
    raise "Template engine not found: #{engine}" if template.nil?
    case
    when data.is_a?(Symbol)
      body, path, line = settings.templates[data]
      if body
        body = body.call if body.respond_to?(:call)
        template.new(path, line.to_i, options) { body }
      else
        found = false
        @preferred_extension = engine.to_s
        find_template(views, data, template) do |file|
          path ||= file # keep the initial path rather than the last one
          if found = File.exists?(file)
            path = file
            break
          end
        end
        throw :layout_missing if eat_errors and not found
        template.new(path, 1, options)
      end
    when data.is_a?(Proc) || data.is_a?(String)
      body = data.is_a?(String) ? Proc.new { data } : data
      path, line = settings.caller_locations.first
      template.new(path, line.to_i, options, &body)
    else
      raise ArgumentError
    end
  end
end

def erb(template, options={}, locals={})
  render :erb, template, options, locals
end

def erubis(template, options={}, locals={})
  render :erubis, template, options, locals
end

def find_template(views, name, engine)
  yield ::File.join(views, "#{name}.#{@preferred_extension}")
  Tilt.mappings.each do |ext, engines|
    next unless ext != @preferred_extension and Array(engines).include? engine
    yield ::File.join(views, "#{name}.#{ext}")
  end
end

def haml(template, options={}, locals={})
  render :haml, template, options, locals
end

def less(template, options={}, locals={})
  options.merge! :layout => false, :default_content_type => :css
  render :less, template, options, locals
end

def liquid(template, options={}, locals={})
  render :liquid, template, options, locals
end

def markaby(template=nil, options={}, locals={}, &block)
  render_ruby(:mab, template, options, locals, &block)
end

def markdown(template, options={}, locals={})
  render :markdown, template, options, locals
end

def nokogiri(template=nil, options={}, locals={}, &block)
  options[:default_content_type] = :xml
  render_ruby(:nokogiri, template, options, locals, &block)
end

def radius(template, options={}, locals={})
  render :radius, template, options, locals
end

def rdoc(template, options={}, locals={})
  render :rdoc, template, options, locals
end

def render(engine, data, options={}, locals={}, &block)
  # merge app-level options
  options = settings.send(engine).merge(options) if settings.respond_to?(engine)
  options[:outvar]           ||= '@_out_buf'
  options[:default_encoding] ||= settings.default_encoding
  # extract generic options
  locals          = options.delete(:locals) || locals         || {}
  views           = options.delete(:views)  || settings.views || "./views"
  @default_layout = :layout if @default_layout.nil?
  layout          = options.delete(:layout)
  eat_errors      = layout.nil?
  layout          = @default_layout if layout.nil? or layout == true
  content_type    = options.delete(:content_type)  || options.delete(:default_content_type)
  layout_engine   = options.delete(:layout_engine) || engine
  scope           = options.delete(:scope)         || self
  # compile and render template
  layout_was      = @default_layout
  @default_layout = false
  template        = compile_template(engine, data, options, views)
  output          = template.render(scope, locals, &block)
  @default_layout = layout_was
  # render layout
  if layout
    options = options.merge(:views => views, :layout => false, :eat_errors => eat_errors, :scope => scope)
    catch(:layout_missing) { return render(layout_engine, layout, options, locals) { output } }
  end
  output.extend(ContentTyped).content_type = content_type if content_type
  output
end

def render_ruby(engine, template, options={}, locals={}, &block)
  options, template = template, nil if template.is_a?(Hash)
  template = Proc.new { block } if template.nil?
  render engine, template, options, locals
end

def sass(template, options={}, locals={})
  options.merge! :layout => false, :default_content_type => :css
  render :sass, template, options, locals
end

def scss(template, options={}, locals={})
  options.merge! :layout => false, :default_content_type => :css
  render :scss, template, options, locals
end

def slim(template, options={}, locals={})
  render :slim, template, options, locals
end

def textile(template, options={}, locals={})
  render :textile, template, options, locals
end