# frozen_string_literal: true
# -*- mode: ruby; ruby-indent-level: 2; tab-width: 2 -*-

require 'erb'
require 'fileutils'
require 'pathname'
require_relative 'markup'

##
# Darkfish RDoc HTML Generator
#
# $Id: darkfish.rb 52 2009-01-07 02:08:11Z deveiant $
#
# == Author/s
# * Michael Granger (ged@FaerieMUD.org)
#
# == Contributors
# * Mahlon E. Smith (mahlon@martini.nu)
# * Eric Hodel (drbrain@segment7.net)
#
# == License
#
# Copyright (c) 2007, 2008, Michael Granger. All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# * Redistributions of source code must retain the above copyright notice,
#   this list of conditions and the following disclaimer.
#
# * Redistributions in binary form must reproduce the above copyright notice,
#   this list of conditions and the following disclaimer in the documentation
#   and/or other materials provided with the distribution.
#
# * Neither the name of the author/s, nor the names of the project's
#   contributors may be used to endorse or promote products derived from this
#   software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
# SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#
# == Attributions
#
# Darkfish uses the {Silk Icons}[http://www.famfamfam.com/lab/icons/silk/] set
# by Mark James.

class RDoc::Generator::Darkfish

  RDoc::RDoc.add_generator self

  include ERB::Util

  ##
  # Stylesheets, fonts, etc. that are included in RDoc.

  BUILTIN_STYLE_ITEMS = # :nodoc:
    %w[
      css/fonts.css
      fonts/Lato-Light.ttf
      fonts/Lato-LightItalic.ttf
      fonts/Lato-Regular.ttf
      fonts/Lato-RegularItalic.ttf
      fonts/SourceCodePro-Bold.ttf
      fonts/SourceCodePro-Regular.ttf
      css/rdoc.css
  ]

  ##
  # Release Version

  VERSION = '3'

  ##
  # Description of this generator

  DESCRIPTION = 'HTML generator, written by Michael Granger'

  ##
  # The relative path to style sheets and javascript.  By default this is set
  # the same as the rel_prefix.

  attr_accessor :asset_rel_path

  ##
  # The path to generate files into, combined with <tt>--op</tt> from the
  # options for a full path.

  attr_reader :base_dir

  ##
  # Classes and modules to be used by this generator, not necessarily
  # displayed.  See also #modsort

  attr_reader :classes

  ##
  # No files will be written when dry_run is true.

  attr_accessor :dry_run

  ##
  # When false the generate methods return a String instead of writing to a
  # file.  The default is true.

  attr_accessor :file_output

  ##
  # Files to be displayed by this generator

  attr_reader :files

  ##
  # The JSON index generator for this Darkfish generator

  attr_reader :json_index

  ##
  # Methods to be displayed by this generator

  attr_reader :methods

  ##
  # Sorted list of classes and modules to be displayed by this generator

  attr_reader :modsort

  ##
  # The RDoc::Store that is the source of the generated content

  attr_reader :store

  ##
  # The directory where the template files live

  attr_reader :template_dir # :nodoc:

  ##
  # The output directory

  attr_reader :outputdir

  ##
  # Initialize a few instance variables before we start

  def initialize(store, options)
    @store   = store
    @options = options

    @asset_rel_path = ''
    @base_dir       = Pathname.pwd.expand_path
    @dry_run        = @options.dry_run
    @file_output    = true
    @template_dir   = Pathname.new options.template_dir
    @template_cache = {}

    @classes = nil
    @context = nil
    @files   = nil
    @methods = nil
    @modsort = nil

    @json_index = RDoc::Generator::JsonIndex.new self, options
  end

  ##
  # Output progress information if debugging is enabled

  def debug_msg(*msg)
    return unless $DEBUG_RDOC
    $stderr.puts(*msg)
  end

  ##
  # Create the directories the generated docs will live in if they don't
  # already exist.

  def gen_sub_directories
    @outputdir.mkpath
  end

  ##
  # Copy over the stylesheet into the appropriate place in the output
  # directory.

  def write_style_sheet
    debug_msg "Copying static files"
    options = { :verbose => $DEBUG_RDOC, :noop => @dry_run }

    BUILTIN_STYLE_ITEMS.each do |item|
      install_rdoc_static_file @template_dir + item, "./#{item}", options
    end

    unless @options.template_stylesheets.empty?
      FileUtils.cp @options.template_stylesheets, '.', **options
    end

    Dir[(@template_dir + "{js,images}/**/*").to_s].each do |path|
      next if File.directory? path
      next if File.basename(path) =~ /^\./

      dst = Pathname.new(path).relative_path_from @template_dir

      install_rdoc_static_file @template_dir + path, dst, options
    end
  end

  ##
  # Build the initial indices and output objects based on an array of TopLevel
  # objects containing the extracted information.

  def generate
    setup

    write_style_sheet
    generate_index
    generate_class_files
    generate_file_files
    generate_table_of_contents
    @json_index.generate
    @json_index.generate_gzipped

    copy_static

  rescue => e
    debug_msg "%s: %s\n  %s" % [
      e.class.name, e.message, e.backtrace.join("\n  ")
    ]

    raise
  end

  ##
  # Copies static files from the static_path into the output directory

  def copy_static
    return if @options.static_path.empty?

    fu_options = { :verbose => $DEBUG_RDOC, :noop => @dry_run }

    @options.static_path.each do |path|
      unless File.directory? path then
        FileUtils.install path, @outputdir, **fu_options.merge(:mode => 0644)
        next
      end

      Dir.chdir path do
        Dir[File.join('**', '*')].each do |entry|
          dest_file = @outputdir + entry

          if File.directory? entry then
            FileUtils.mkdir_p entry, **fu_options
          else
            FileUtils.install entry, dest_file, **fu_options.merge(:mode => 0644)
          end
        end
      end
    end
  end

  ##
  # Return a list of the documented modules sorted by salience first, then
  # by name.

  def get_sorted_module_list(classes)
    classes.select do |klass|
      klass.display?
    end.sort
  end

  ##
  # Generate an index page which lists all the classes which are documented.

  def generate_index
    template_file = @template_dir + 'index.rhtml'
    return unless template_file.exist?

    debug_msg "Rendering the index page..."

    out_file = @base_dir + @options.op_dir + 'index.html'
    rel_prefix = @outputdir.relative_path_from out_file.dirname
    search_index_rel_prefix = rel_prefix
    search_index_rel_prefix += @asset_rel_path if @file_output

    asset_rel_prefix = rel_prefix + @asset_rel_path

    @title = @options.title
    @main_page = @files.find { |f| f.full_name == @options.main_page }

    render_template template_file, out_file do |io|
      here = binding
      # suppress 1.9.3 warning
      here.local_variable_set(:asset_rel_prefix, asset_rel_prefix)
      # some partials rely on the presence of current variable to render
      here.local_variable_set(:current, @main_page) if @main_page
      here
    end
  rescue => e
    error = RDoc::Error.new \
      "error generating index.html: #{e.message} (#{e.class})"
    error.set_backtrace e.backtrace

    raise error
  end

  ##
  # Generates a class file for +klass+

  def generate_class(klass, template_file = nil)
    # This is used to auto-collapse Pages section on class/module pages
    @inside_class_file = true
    current = klass

    template_file ||= @template_dir + 'class.rhtml'

    debug_msg "  working on %s (%s)" % [klass.full_name, klass.path]
    out_file   = @outputdir + klass.path
    rel_prefix = @outputdir.relative_path_from out_file.dirname
    search_index_rel_prefix = rel_prefix
    search_index_rel_prefix += @asset_rel_path if @file_output

    asset_rel_prefix = rel_prefix + @asset_rel_path

    breadcrumb = # used in templates
    breadcrumb = generate_nesting_namespaces_breadcrumb(current, rel_prefix)

    @title = "#{klass.type} #{klass.full_name} - #{@options.title}"

    debug_msg "  rendering #{out_file}"
    render_template template_file, out_file do |io|
      here = binding
      # suppress 1.9.3 warning
      here.local_variable_set(:asset_rel_prefix, asset_rel_prefix)
      here
    end
  ensure
    @inside_class_file = false
  end

  ##
  # Generate a documentation file for each class and module

  def generate_class_files
    template_file = @template_dir + 'class.rhtml'
    template_file = @template_dir + 'classpage.rhtml' unless
      template_file.exist?
    return unless template_file.exist?
    debug_msg "Generating class documentation in #{@outputdir}"

    current = nil

    # Document files are generated only for non-alias classes/modules
    @classes.reject(&:is_alias_for).each do |klass|

      current = klass

      generate_class klass, template_file
    end
  rescue => e
    error = RDoc::Error.new \
      "error generating #{current.path}: #{e.message} (#{e.class})"
    error.set_backtrace e.backtrace

    raise error
  end

  ##
  # Generate a documentation file for each file

  def generate_file_files
    page_file     = @template_dir + 'page.rhtml'
    fileinfo_file = @template_dir + 'fileinfo.rhtml'

    # for legacy templates
    filepage_file = @template_dir + 'filepage.rhtml' unless
      page_file.exist? or fileinfo_file.exist?

    return unless
      page_file.exist? or fileinfo_file.exist? or filepage_file.exist?

    debug_msg "Generating file documentation in #{@outputdir}"

    out_file = nil
    current = nil

    @files.each do |file|
      current = file

      if file.text? and page_file.exist? then
        generate_page file
        next
      end

      template_file = nil
      out_file = @outputdir + file.path
      debug_msg "  working on %s (%s)" % [file.full_name, out_file]
      rel_prefix = @outputdir.relative_path_from out_file.dirname
      search_index_rel_prefix = rel_prefix
      search_index_rel_prefix += @asset_rel_path if @file_output

      asset_rel_prefix = rel_prefix + @asset_rel_path

      unless filepage_file then
        if file.text? then
          next unless page_file.exist?
          template_file = page_file
          @title = file.page_name
        else
          next unless fileinfo_file.exist?
          template_file = fileinfo_file
          @title = "File: #{file.base_name}"
        end
      end

      @title += " - #{@options.title}"
      template_file ||= filepage_file

      render_template template_file, out_file do |io|
        here = binding
        # suppress 1.9.3 warning
        here.local_variable_set(:asset_rel_prefix, asset_rel_prefix)
        here.local_variable_set(:current, current)
        here
      end
    end
  rescue => e
    error =
      RDoc::Error.new "error generating #{out_file}: #{e.message} (#{e.class})"
    error.set_backtrace e.backtrace

    raise error
  end

  ##
  # Generate a page file for +file+

  def generate_page(file)
    template_file = @template_dir + 'page.rhtml'

    out_file = @outputdir + file.path
    debug_msg "  working on %s (%s)" % [file.full_name, out_file]
    rel_prefix = @outputdir.relative_path_from out_file.dirname
    search_index_rel_prefix = rel_prefix
    search_index_rel_prefix += @asset_rel_path if @file_output

    current          = file
    asset_rel_prefix = rel_prefix + @asset_rel_path

    @title = "#{file.page_name} - #{@options.title}"

    debug_msg "  rendering #{out_file}"
    render_template template_file, out_file do |io|
      here = binding
      # suppress 1.9.3 warning
      here.local_variable_set(:current, current)
      here.local_variable_set(:asset_rel_prefix, asset_rel_prefix)
      here
    end
  end

  ##
  # Generates the 404 page for the RDoc servlet

  def generate_servlet_not_found(message)
    template_file = @template_dir + 'servlet_not_found.rhtml'
    return unless template_file.exist?

    debug_msg "Rendering the servlet 404 Not Found page..."

    rel_prefix = rel_prefix = ''
    search_index_rel_prefix = rel_prefix
    search_index_rel_prefix += @asset_rel_path if @file_output

    asset_rel_prefix = ''

    @title = 'Not Found'

    render_template template_file do |io|
      here = binding
      # suppress 1.9.3 warning
      here.local_variable_set(:asset_rel_prefix, asset_rel_prefix)
      here
    end
  rescue => e
    error = RDoc::Error.new \
      "error generating servlet_not_found: #{e.message} (#{e.class})"
    error.set_backtrace e.backtrace

    raise error
  end

  ##
  # Generates the servlet root page for the RDoc servlet

  def generate_servlet_root(installed)
    template_file = @template_dir + 'servlet_root.rhtml'
    return unless template_file.exist?

    debug_msg 'Rendering the servlet root page...'

    rel_prefix = '.'
    asset_rel_prefix = rel_prefix
    search_index_rel_prefix = asset_rel_prefix
    search_index_rel_prefix += @asset_rel_path if @file_output

    @title = 'Local RDoc Documentation'

    render_template template_file do |io| binding end
  rescue => e
    error = RDoc::Error.new \
      "error generating servlet_root: #{e.message} (#{e.class})"
    error.set_backtrace e.backtrace

    raise error
  end

  ##
  # Generate an index page which lists all the classes which are documented.

  def generate_table_of_contents
    template_file = @template_dir + 'table_of_contents.rhtml'
    return unless template_file.exist?

    debug_msg "Rendering the Table of Contents..."

    out_file = @outputdir + 'table_of_contents.html'
    rel_prefix = @outputdir.relative_path_from out_file.dirname
    search_index_rel_prefix = rel_prefix
    search_index_rel_prefix += @asset_rel_path if @file_output

    asset_rel_prefix = rel_prefix + @asset_rel_path

    @title = "Table of Contents - #{@options.title}"

    render_template template_file, out_file do |io|
      here = binding
      # suppress 1.9.3 warning
      here.local_variable_set(:asset_rel_prefix, asset_rel_prefix)
      here
    end
  rescue => e
    error = RDoc::Error.new \
      "error generating table_of_contents.html: #{e.message} (#{e.class})"
    error.set_backtrace e.backtrace

    raise error
  end

  def install_rdoc_static_file(source, destination, options) # :nodoc:
    return unless source.exist?

    begin
      FileUtils.mkdir_p File.dirname(destination), **options

      begin
        FileUtils.ln source, destination, **options
      rescue Errno::EEXIST
        FileUtils.rm destination
        retry
      end
    rescue
      FileUtils.cp source, destination, **options
    end
  end

  ##
  # Prepares for generation of output from the current directory

  def setup
    return if instance_variable_defined? :@outputdir

    @outputdir = Pathname.new(@options.op_dir).expand_path @base_dir

    return unless @store

    @classes = @store.all_classes_and_modules.sort
    @files   = @store.all_files.sort
    @methods = @classes.flat_map { |m| m.method_list }.sort
    @modsort = get_sorted_module_list @classes
  end

  ##
  # Creates a template from its components and the +body_file+.
  #
  # For backwards compatibility, if +body_file+ contains "<html" the body is
  # used directly.

  def assemble_template(body_file)
    body = body_file.read
    return body if body =~ /<html/

    head_file = @template_dir + '_head.rhtml'

    <<-TEMPLATE
<!DOCTYPE html>

<html lang="#{@options.locale&.name || 'en'}">
<head>
#{head_file.read}

#{body}
    TEMPLATE
  end

  ##
  # Renders the ERb contained in +file_name+ relative to the template
  # directory and returns the result based on the current context.

  def render(file_name)
    template_file = @template_dir + file_name

    template = template_for template_file, false, RDoc::ERBPartial

    template.filename = template_file.to_s

    template.result @context
  end

  ##
  # Load and render the erb template in the given +template_file+ and write
  # it out to +out_file+.
  #
  # Both +template_file+ and +out_file+ should be Pathname-like objects.
  #
  # An io will be yielded which must be captured by binding in the caller.

  def render_template(template_file, out_file = nil) # :yield: io
    io_output = out_file && !@dry_run && @file_output
    erb_klass = io_output ? RDoc::ERBIO : ERB

    template = template_for template_file, true, erb_klass

    if io_output then
      debug_msg "Outputting to %s" % [out_file.expand_path]

      out_file.dirname.mkpath
      out_file.open 'w', 0644 do |io|
        io.set_encoding @options.encoding

        @context = yield io

        template_result template, @context, template_file
      end
    else
      @context = yield nil

      output = template_result template, @context, template_file

      debug_msg "  would have written %d characters to %s" % [
        output.length, out_file.expand_path
      ] if @dry_run

      output
    end
  end

  ##
  # Creates the result for +template+ with +context+.  If an error is raised a
  # Pathname +template_file+ will indicate the file where the error occurred.

  def template_result(template, context, template_file)
    template.filename = template_file.to_s
    template.result context
  rescue NoMethodError => e
    raise RDoc::Error, "Error while evaluating %s: %s" % [
      template_file.expand_path,
      e.message,
    ], e.backtrace
  end

  ##
  # Retrieves a cache template for +file+, if present, or fills the cache.

  def template_for(file, page = true, klass = ERB)
    template = @template_cache[file]

    return template if template

    if page then
      template = assemble_template file
      erbout = 'io'
    else
      template = file.read
      template = template.encode @options.encoding

      file_var = File.basename(file).sub(/\..*/, '')

      erbout = "_erbout_#{file_var}"
    end

    template = klass.new template, trim_mode: '-', eoutvar: erbout
    @template_cache[file] = template
    template
  end

  # :stopdoc:
  ParagraphExcerptRegexpOther = %r[\b\w[^./:]++\.]
  # use \p/\P{letter} instead of \w/\W in Unicode
  ParagraphExcerptRegexpUnicode = %r[\b\p{letter}[^./:]++\.]
  # :startdoc:

  # Returns an excerpt of the comment for usage in meta description tags
  def excerpt(comment)
    text = case comment
    when RDoc::Comment
      comment.text
    else
      comment
    end

    # Match from a capital letter to the first period, discarding any links, so
    # that we don't end up matching badges in the README
    pattern = ParagraphExcerptRegexpUnicode
    begin
      first_paragraph_match = text.match(pattern)
    rescue Encoding::CompatibilityError
      # The doc is non-ASCII text and encoded in other than Unicode base encodings.
      raise if pattern == ParagraphExcerptRegexpOther
      pattern = ParagraphExcerptRegexpOther
      retry
    end
    return text[0...150].tr_s("\n", " ").squeeze(" ") unless first_paragraph_match

    extracted_text = first_paragraph_match[0]
    second_paragraph = text.match(pattern, first_paragraph_match.end(0))
    extracted_text << " " << second_paragraph[0] if second_paragraph

    extracted_text[0...150].tr_s("\n", " ").squeeze(" ")
  end

  def generate_ancestor_list(ancestors, klass)
    return '' if ancestors.empty?

    ancestor = ancestors.shift
    content = +'<ul><li>'

    if ancestor.is_a?(RDoc::NormalClass)
      content << "<a href=\"#{klass.aref_to ancestor.path}\">#{ancestor.full_name}</a>"
    else
      content << ancestor.to_s
    end

    # Recursively call the method for the remaining ancestors
    content << generate_ancestor_list(ancestors, klass)

    content << '</li></ul>'
  end

  def generate_class_link(klass, rel_prefix)
    if klass.display?
      %(<code><a href="#{rel_prefix}/#{klass.path}">#{klass.name}</a></code>)
    else
      %(<code>#{klass.name}</code>)
    end
  end

  def generate_class_index_content(classes, rel_prefix)
    grouped_classes = group_classes_by_namespace_for_sidebar(classes)
    return '' unless top = grouped_classes[nil]

    solo = top.one? { |klass| klass.display? }
    traverse_classes(top, grouped_classes, rel_prefix, solo)
  end

  def traverse_classes(klasses, grouped_classes, rel_prefix, solo = false)
    content = +'<ul class="link-list nav-list">'

    klasses.each do |index_klass|
      if children = grouped_classes[index_klass.full_name]
        content << %(<li><details#{solo ? ' open' : ''}><summary>#{generate_class_link(index_klass, rel_prefix)}</summary>)
        content << traverse_classes(children, grouped_classes, rel_prefix)
        content << '</details></li>'
        solo = false
      elsif index_klass.display?
        content << %(<li>#{generate_class_link(index_klass, rel_prefix)}</li>)
      end
    end

    "#{content}</ul>"
  end

  def group_classes_by_namespace_for_sidebar(classes)
    grouped_classes = classes.group_by do |klass|
      klass.full_name[/\A[^:]++(?:::[^:]++(?=::))*+(?=::[^:]*+\z)/]
    end.select do |_, klasses|
      klasses.any?(&:display?)
    end

    grouped_classes.values.each(&:uniq!)
    grouped_classes
  end

  private

  def nesting_namespaces_to_class_modules(klass)
    tree = {}

    klass.nesting_namespaces.zip(klass.fully_qualified_nesting_namespaces) do |ns, fqns|
      tree[ns] = @store.classes_hash[fqns] || @store.modules_hash[fqns]
    end

    tree
  end

  def generate_nesting_namespaces_breadcrumb(klass, rel_prefix)
    nesting_namespaces_to_class_modules(klass).map do |namespace, class_module|
      path = class_module ? (rel_prefix + class_module.path).to_s : ""
      { name: namespace, path: path, self: klass.full_name == class_module&.full_name }
    end
  end
end
