# frozen_string_literal: true

# Convertible provides methods for converting a pagelike item
# from a certain type of markup into actual content
#
# Requires
#   self.site -> Bridgetown::Site
#   self.content
#   self.content=
#   self.data=
#   self.ext=
#   self.output=
#   self.name
#   self.path
#   self.type -> :page or :post

module Bridgetown
  module Convertible
    # Returns the contents as a String.
    def to_s
      content || ""
    end

    # Whether the file is published or not, as indicated in YAML front-matter
    def published?
      !(data.key?("published") && data["published"] == false)
    end

    # Read the YAML frontmatter.
    #
    # base - The String path to the dir containing the file.
    # name - The String filename of the file.
    # opts - optional parameter to File.read, default at site configs
    #
    # Returns nothing.
    # rubocop:disable Metrics/AbcSize
    def read_yaml(base, name, opts = {})
      filename = File.join(base, name)

      begin
        self.content = File.read(@path || site.in_source_dir(base, name),
                                 **Utils.merged_file_read_opts(site, opts))
        if content =~ Document::YAML_FRONT_MATTER_REGEXP
          self.content = $POSTMATCH
          self.data = SafeYAML.load(Regexp.last_match(1))
        end
      rescue Psych::SyntaxError => e
        Bridgetown.logger.warn "YAML Exception reading #{filename}: #{e.message}"
        raise e if site.config["strict_front_matter"]
      rescue StandardError => e
        Bridgetown.logger.warn "Error reading file #{filename}: #{e.message}"
        raise e if site.config["strict_front_matter"]
      end

      self.data ||= {}

      validate_data! filename
      validate_permalink! filename

      self.data
    end
    # rubocop:enable Metrics/AbcSize

    def validate_data!(filename)
      unless self.data.is_a?(Hash)
        raise Errors::InvalidYAMLFrontMatterError,
              "Invalid YAML front matter in #{filename}"
      end
    end

    def validate_permalink!(filename)
      if self.data["permalink"]&.to_s&.empty?
        raise Errors::InvalidPermalinkError, "Invalid permalink in #{filename}"
      end
    end

    # TODO: this method never seems to get called...why's it here?
    # Transform the contents based on the content type.
    #
    # Returns the transformed contents.
    def transform
      _renderer.convert(content)
    end

    # Determine the extension depending on content_type.
    #
    # Returns the String extension for the output file.
    #   e.g. ".html" for an HTML output file.
    def output_ext
      _renderer.output_ext
    end

    # Determine which converter to use based on this convertible's
    # extension.
    #
    # Returns the Converter instance.
    def converters
      _renderer.converters
    end

    # Render Liquid in the content
    #
    # content - the raw Liquid content to render
    # payload - the payload for Liquid
    # info    - the info for Liquid
    #
    # Returns the converted content
    def render_liquid(content, payload, info, path)
      _renderer.render_liquid(content, payload, info, path)
    end

    # Convert this Convertible's data to a Hash suitable for use by Liquid.
    #
    # Returns the Hash representation of this Convertible.
    def to_liquid(attrs = nil)
      further_data = \
        (attrs || self.class::ATTRIBUTES_FOR_LIQUID).each_with_object({}) do |attribute, hsh|
          hsh[attribute] = send(attribute)
        end

      defaults = site.frontmatter_defaults.all(relative_path, type)
      Utils.deep_merge_hashes defaults, Utils.deep_merge_hashes(data, further_data)
    end

    # The type of a document,
    #   i.e., its classname downcase'd and to_sym'd.
    #
    # Returns the type of self.
    def type
      :pages if is_a?(Page)
    end

    # returns the owner symbol for hook triggering
    def hook_owner
      :pages if is_a?(Page)
    end

    # TODO: Depricated
    # Used to determine CoffeeScript and Sass/SCSS files.
    def asset_file?
      false
    end

    # Determine whether the file should be rendered with Liquid.
    #
    # Returns true if the file has Liquid Tags or Variables, false otherwise.
    def render_with_liquid?
      return false if data["render_with_liquid"] == false

      Bridgetown::Utils.has_liquid_construct?(content)
    end

    # Determine whether the file should be placed into layouts.
    #
    # Returns false if the document is an asset file or if the front matter
    #   specifies `layout: none`
    def place_in_layout?
      !(asset_file? || no_layout?)
    end

    # Checks if the layout specified in the document actually exists
    #
    # layout - the layout to check
    #
    # Returns true if the layout is invalid, false if otherwise
    def invalid_layout?(layout)
      !data["layout"].nil? && layout.nil? && !(is_a? Bridgetown::Excerpt)
    end

    # Recursively render layouts
    #
    # layouts - a list of the layouts
    # payload - the payload for Liquid
    # info    - the info for Liquid
    #
    # Returns nothing
    def render_all_layouts(layouts, payload, info)
      _renderer.layouts = layouts
      self.output = _renderer.place_in_layouts(output, payload, info)
    ensure
      @_renderer = nil # this will allow the modifications above to disappear
    end

    # Add any necessary layouts to this convertible document.
    #
    # payload - The site payload Drop or Hash.
    # layouts - A Hash of {"name" => "layout"}.
    #
    # Returns nothing.
    def do_layout(payload, layouts)
      self.output = _renderer.tap do |renderer|
        renderer.layouts = layouts
        renderer.payload = payload
      end.run

      Bridgetown.logger.debug "Post-Render Hooks:", relative_path
      Bridgetown::Hooks.trigger hook_owner, :post_render, self
    ensure
      @_renderer = nil # this will allow the modifications above to disappear
    end

    # Write the generated page file to the destination directory.
    #
    # dest - The String path to the destination dir.
    #
    # Returns nothing.
    def write(dest)
      path = destination(dest)
      FileUtils.mkdir_p(File.dirname(path))
      Bridgetown.logger.debug "Writing:", path
      File.write(path, output, mode: "wb")
      Bridgetown::Hooks.trigger hook_owner, :post_write, self
    end

    # Accessor for data properties by Liquid.
    #
    # property - The String name of the property to retrieve.
    #
    # Returns the String value or nil if the property isn't included.
    def [](property)
      if self.class::ATTRIBUTES_FOR_LIQUID.include?(property)
        send(property)
      else
        data[property]
      end
    end

    private

    def _renderer
      @_renderer ||= Bridgetown::Renderer.new(site, self)
    end

    def no_layout?
      data["layout"] == "none"
    end
  end
end