module Padrino::Rendering::InstanceMethods

def content_type(type=nil, params={})
  unless type.nil?
    super(type, params)
    @_content_type = type
  end
  @_content_type
end

def locale
  I18n.locale if defined?(I18n)
end

def render(engine, data=nil, options={}, locals={}, &block)
  # If engine is a hash then render data converted to json
  content_type(:json, :charset => 'utf-8') and return engine.to_json if engine.is_a?(Hash)
  # If engine is nil, ignore engine parameter and shift up all arguments
  # render nil, "index", { :layout => true }, { :localvar => "foo" }
  engine, data, options = data, options, locals if engine.nil? && data
  # Data is a hash of options when no engine isn't explicit
  # render "index", { :layout => true }, { :localvar => "foo" }
  # Data is options, and options is locals in this case
  data, options, locals = nil, data, options if data.is_a?(Hash)
  # If data is unassigned then this is a likely a template to be resolved
  # This means that no engine was explicitly defined
  data, engine = *resolve_template(engine, options.dup) if data.nil?
  # Setup root
  root = settings.respond_to?(:root) ? settings.root : ""
  # Use @layout if it exists
  options[:layout] = @layout if options[:layout].nil?
  # Resolve layouts similar to in Rails
  if (options[:layout].nil? || options[:layout] == true) && !settings.templates.has_key?(:layout)
    layout_path, layout_engine = *resolved_layout
    options[:layout] = layout_path || false # We need to force layout false so sinatra don't try to render it
    options[:layout] = false unless layout_engine == engine # TODO allow different layout engine
    options[:layout_engine] = layout_engine || engine if options[:layout]
  elsif options[:layout].present?
    options[:layout] = settings.fetch_layout_path(options[:layout] || @layout)
  end
  # Cleanup the template
  @current_engine, engine_was = engine, @current_engine
  @_out_buf,  _buf_was = "", @_out_buf
  # Pass arguments to Sinatra render method
  super(engine, data, options.dup, locals, &block)
ensure
  @current_engine = engine_was
  @_out_buf = _buf_was
end

def resolve_template(template_path, options={})
  began_at = Time.now
  # Fetch cached template for rendering options
  template_path = template_path.to_s[0] == ?/ ? template_path.to_s : "/#{template_path}"
  rendering_options = [template_path, content_type, locale]
  cached_template = settings.fetch_template_file(rendering_options)
  if cached_template
    logger.debug :cached, began_at, cached_template[0] if settings.logging? && defined?(logger)
    return cached_template
  end
  # Resolve view path and options
  options.reverse_merge!(DEFAULT_RENDERING_OPTIONS)
  view_path = options.delete(:views) || settings.views || "./views"
  target_extension = File.extname(template_path)[1..-1] || "none" # explicit template extension
  template_path = template_path.chomp(".#{target_extension}")
  # Generate potential template candidates
  templates = Dir[File.join(view_path, template_path) + ".*"].map do |file|
    template_engine = File.extname(file)[1..-1].to_sym # retrieves engine extension
    template_file   = file.sub(view_path, '').chomp(".#{template_engine}").to_sym # retrieves template filename
    [template_file, template_engine] unless IGNORE_FILE_PATTERN.any? { |pattern| template_engine.to_s =~ pattern }
  end
  # Check if we have a simple content type
  simple_content_type = [:html, :plain].include?(content_type)
  # Resolve final template to render
  located_template =
    templates.find { |file, e| file.to_s == "#{template_path}.#{locale}.#{content_type}" } ||
    templates.find { |file, e| file.to_s == "#{template_path}.#{locale}" && simple_content_type } ||
    templates.find { |file, e| File.extname(file.to_s) == ".#{target_extension}" or e.to_s == target_extension.to_s } ||
    templates.find { |file, e| file.to_s == "#{template_path}.#{content_type}" } ||
    templates.find { |file, e| file.to_s == "#{template_path}" && simple_content_type } ||
    (!options[:strict_format] && templates.first) # If not strict, fall back to the first located template
  raise TemplateNotFound, "Template '#{template_path}' not found in '#{view_path}'!"  if !located_template && options[:raise_exceptions]
  settings.cache_template_file!(located_template, rendering_options) unless settings.reload_templates?
  logger.debug :template, began_at, located_template[0] if located_template && settings.logging? && defined?(logger)
  located_template
end

def resolved_layout
  located_layout = resolve_template(settings.fetch_layout_path, :raise_exceptions => false, :strict_format => true)
  located_layout ? located_layout : [nil, nil]
end