# frozen_string_literal: false

module JekyllImport
  module Importers
    class WordPress < Importer
      def self.require_deps
        JekyllImport.require_with_fallback(%w(
          rubygems
          sequel
          fileutils
          safe_yaml
          unidecode
        ))
      end

      def self.specify_options(c)
        c.option "dbname",         "--dbname DB",           "Database name (default: '')"
        c.option "socket",         "--socket SOCKET",       "Database socket (default: '')"
        c.option "user",           "--user USER",           "Database user name (default: '')"
        c.option "password",       "--password PW",         "Database user's password (default: '')"
        c.option "host",           "--host HOST",           "Database host name (default: 'localhost')"
        c.option "port",           "--port PORT",           "Database port number (default: '')"
        c.option "table_prefix",   "--table_prefix PREFIX", "Table prefix name (default: 'wp_')"
        c.option "site_prefix",    "--site_prefix PREFIX",  "Site prefix name (default: '')"
        c.option "clean_entities", "--clean_entities",      "Whether to clean entities (default: true)"
        c.option "comments",       "--comments",            "Whether to import comments (default: true)"
        c.option "categories",     "--categories",          "Whether to import categories (default: true)"
        c.option "tags",           "--tags",                "Whether to import tags (default: true)"
        c.option "more_excerpt",   "--more_excerpt",        "Whether to use more excerpt (default: true)"
        c.option "more_anchor",    "--more_anchor",         "Whether to use more anchor (default: true)"

        c.option "status",         "--status STATUS,STATUS2", Array,
                 "Array of allowed statuses (default: ['publish'], other options: 'draft', 'private', 'revision')"
      end

      # Main migrator function. Call this to perform the migration.
      #
      # dbname::  The name of the database
      # user::    The database user name
      # pass::    The database user's password
      # host::    The address of the MySQL database host. Default: 'localhost'
      # port::    The port number of the MySQL database. Default: '3306'
      # socket::  The database socket's path
      # options:: A hash table of configuration options.
      #
      # Supported options are:
      #
      # :table_prefix::   Prefix of database tables used by WordPress.
      #                   Default: 'wp_'
      # :site_prefix::    Prefix of database tables used by WordPress
      #                   Multisite, eg: 2_.
      #                   Default: ''
      # :clean_entities:: If true, convert non-ASCII characters to HTML
      #                   entities in the posts, comments, titles, and
      #                   names. Requires the 'htmlentities' gem to
      #                   work. Default: true.
      # :comments::       If true, migrate post comments too. Comments
      #                   are saved in the post's YAML front matter.
      #                   Default: true.
      # :categories::     If true, save the post's categories in its
      #                   YAML front matter. Default: true.
      # :tags::           If true, save the post's tags in its
      #                   YAML front matter. Default: true.
      # :more_excerpt::   If true, when a post has no excerpt but
      #                   does have a <!-- more --> tag, use the
      #                   preceding post content as the excerpt.
      #                   Default: true.
      # :more_anchor::    If true, convert a <!-- more --> tag into
      #                   two HTML anchors with ids "more" and
      #                   "more-NNN" (where NNN is the post number).
      #                   Default: true.
      # :extension::      Set the post extension. Default: "html"
      # :status::         Array of allowed post statuses. Only
      #                   posts with matching status will be migrated.
      #                   Known statuses are :publish, :draft, :private,
      #                   and :revision. If this is nil or an empty
      #                   array, all posts are migrated regardless of
      #                   status. Default: [:publish].
      #
      def self.process(opts)
        options = {
          :user           => opts.fetch("user", ""),
          :pass           => opts.fetch("password", ""),
          :host           => opts.fetch("host", "localhost"),
          :port           => opts.fetch("port", "3306"),
          :socket         => opts.fetch("socket", nil),
          :dbname         => opts.fetch("dbname", ""),
          :table_prefix   => opts.fetch("table_prefix", "wp_"),
          :site_prefix    => opts.fetch("site_prefix", nil),
          :clean_entities => opts.fetch("clean_entities", true),
          :comments       => opts.fetch("comments", true),
          :categories     => opts.fetch("categories", true),
          :tags           => opts.fetch("tags", true),
          :more_excerpt   => opts.fetch("more_excerpt", true),
          :more_anchor    => opts.fetch("more_anchor", true),
          :extension      => opts.fetch("extension", "html"),
          :status         => opts.fetch("status", ["publish"]).map(&:to_sym), # :draft, :private, :revision
        }

        if options[:clean_entities]
          begin
            require "htmlentities"
          rescue LoadError
            warn "Could not require 'htmlentities', so the " \
                        ":clean_entities option is now disabled."
            options[:clean_entities] = false
          end
        end

        FileUtils.mkdir_p("_posts")
        FileUtils.mkdir_p("_drafts") if options[:status].include? :draft

        db = Sequel.mysql2(options[:dbname],
                           :user     => options[:user],
                           :password => options[:pass],
                           :socket   => options[:socket],
                           :host     => options[:host],
                           :port     => options[:port],
                           :encoding => "utf8")

        px = options[:table_prefix]
        sx = options[:site_prefix]

        page_name_list = {}

        page_name_query = "
           SELECT
             posts.ID            AS `id`,
             posts.post_title    AS `title`,
             posts.post_name     AS `slug`,
             posts.post_parent   AS `parent`
           FROM #{px}#{sx}posts AS `posts`
           WHERE posts.post_type = 'page'"

        db[page_name_query].each do |page|
          page[:slug] = sluggify(page[:title]) if page.fetch(:slug, "").empty?
          page_name_list[ page[:id] ] = {
            :slug   => page[:slug],
            :parent => page[:parent],
          }
        end

        posts_query = "
           SELECT
             posts.ID            AS `id`,
             posts.guid          AS `guid`,
             posts.post_type     AS `type`,
             posts.post_status   AS `status`,
             posts.post_title    AS `title`,
             posts.post_name     AS `slug`,
             posts.post_date     AS `date`,
             posts.post_date_gmt AS `date_gmt`,
             posts.post_content  AS `content`,
             posts.post_excerpt  AS `excerpt`,
             posts.comment_count AS `comment_count`,
             users.display_name  AS `author`,
             users.user_login    AS `author_login`,
             users.user_email    AS `author_email`,
             users.user_url      AS `author_url`
           FROM #{px}#{sx}posts AS `posts`
             LEFT JOIN #{px}#{sx}users AS `users`
               ON posts.post_author = users.ID"

        if options[:status] && !options[:status].empty?
          status = options[:status][0]
          posts_query << "
           WHERE posts.post_status = '#{status}'"
          options[:status][1..-1].each do |post_status|
            posts_query << " OR
             posts.post_status = '#{post_status}'"
          end
        end

        db[posts_query].each do |post|
          process_post(post, db, options, page_name_list)
        end
      end

      def self.process_post(post, db, options, page_name_list)
        px = options[:table_prefix]
        sx = options[:site_prefix]
        extension = options[:extension]

        title = post[:title]
        title = clean_entities(title) if options[:clean_entities]

        slug = post[:slug]
        slug = sluggify(title) if !slug || slug.empty?

        date = post[:date] || Time.now
        name = format("%02d-%02d-%02d-%s.%s", date.year, date.month, date.day, slug, extension)
        content = post[:content].to_s
        content = clean_entities(content) if options[:clean_entities]

        excerpt = post[:excerpt].to_s

        more_index = content.index(%r/<!-- *more* -->/)
        more_anchor = nil
        if more_index
          if options[:more_excerpt] &&
              (post[:excerpt].nil? || post[:excerpt].empty?)
            excerpt = content[0...more_index]
          end
          if options[:more_anchor]
            more_anchor = "more"
            content.sub!(%r/<!-- *more *-->/,
                         "<a id=\"more\"></a>" \
                         "<a id=\"more-#{post[:id]}\"></a>")
          end
        end

        categories = []
        tags = []

        if options[:categories] || options[:tags]

          cquery =
            "SELECT
               terms.name AS `name`,
               ttax.taxonomy AS `type`
             FROM
               #{px}#{sx}terms AS `terms`,
               #{px}#{sx}term_relationships AS `trels`,
               #{px}#{sx}term_taxonomy AS `ttax`
             WHERE
               trels.object_id = '#{post[:id]}' AND
               trels.term_taxonomy_id = ttax.term_taxonomy_id AND
               terms.term_id = ttax.term_id"

          db[cquery].each do |term|
            if options[:categories] && term[:type] == "category"
              categories << if options[:clean_entities]
                              clean_entities(term[:name])
                            else
                              term[:name]
                            end
            elsif options[:tags] && term[:type] == "post_tag"
              tags << if options[:clean_entities]
                        clean_entities(term[:name])
                      else
                        term[:name]
                      end
            end
          end
        end

        comments = []

        if options[:comments] && post[:comment_count].to_i.positive?
          cquery =
            "SELECT
               comment_ID           AS `id`,
               comment_author       AS `author`,
               comment_author_email AS `author_email`,
               comment_author_url   AS `author_url`,
               comment_date         AS `date`,
               comment_date_gmt     AS `date_gmt`,
               comment_content      AS `content`
             FROM #{px}#{sx}comments
             WHERE
               comment_post_ID = '#{post[:id]}' AND
               comment_approved != 'spam'"

          db[cquery].each do |comment|
            comcontent = comment[:content].to_s
            comcontent.force_encoding("UTF-8") if comcontent.respond_to?(:force_encoding)
            comcontent = clean_entities(comcontent) if options[:clean_entities]
            comauthor = comment[:author].to_s
            comauthor = clean_entities(comauthor) if options[:clean_entities]

            comments << {
              "id"           => comment[:id].to_i,
              "author"       => comauthor,
              "author_email" => comment[:author_email].to_s,
              "author_url"   => comment[:author_url].to_s,
              "date"         => comment[:date].to_s,
              "date_gmt"     => comment[:date_gmt].to_s,
              "content"      => comcontent,
            }
          end

          comments.sort! { |a, b| a["id"] <=> b["id"] }
        end

        # Get the relevant fields as a hash, delete empty fields and
        # convert to YAML for the header.
        data = {
          "layout"        => post[:type].to_s,
          "status"        => post[:status].to_s,
          "published"     => post[:status].to_s == "draft" ? nil : (post[:status].to_s == "publish"),
          "title"         => title.to_s,
          "author"        => {
            "display_name" => post[:author].to_s,
            "login"        => post[:author_login].to_s,
            "email"        => post[:author_email].to_s,
            "url"          => post[:author_url].to_s,
          },
          "author_login"  => post[:author_login].to_s,
          "author_email"  => post[:author_email].to_s,
          "author_url"    => post[:author_url].to_s,
          "excerpt"       => excerpt,
          "more_anchor"   => more_anchor,
          "wordpress_id"  => post[:id],
          "wordpress_url" => post[:guid].to_s,
          "date"          => date.to_s,
          "date_gmt"      => post[:date_gmt].to_s,
          "categories"    => options[:categories] ? categories : nil,
          "tags"          => options[:tags] ? tags : nil,
          "comments"      => options[:comments] ? comments : nil,
        }.delete_if { |_k, v| v.nil? || v == "" }.to_yaml

        if post[:type] == "page"
          filename = page_path(post[:id], page_name_list) + "index.#{extension}"
          FileUtils.mkdir_p(File.dirname(filename))
        elsif post[:status] == "draft"
          filename = "_drafts/#{slug}.md"
        else
          filename = "_posts/#{name}"
        end

        # Write out the data and content to file
        File.open(filename, "w") do |f|
          f.puts data
          f.puts "---"
          f.puts Util.wpautop(content)
        end
      end

      def self.clean_entities(text)
        text.force_encoding("UTF-8") if text.respond_to?(:force_encoding)
        text = HTMLEntities.new.encode(text, :named)
        # We don't want to convert these, it would break all
        # HTML tags in the post and comments.
        text.gsub!("&amp;", "&")
        text.gsub!("&lt;", "<")
        text.gsub!("&gt;", ">")
        text.gsub!("&quot;", '"')
        text.gsub!("&apos;", "'")
        text.gsub!("&#47;", "/")
        text
      end

      def self.sluggify(title)
        title.to_ascii.downcase.gsub(%r![^0-9A-Za-z]+!, " ").strip.tr(" ", "-")
      end

      def self.page_path(page_id, page_name_list)
        if page_name_list.key?(page_id)
          [
            page_path(page_name_list[page_id][:parent], page_name_list),
            page_name_list[page_id][:slug],
            "/",
          ].join("")
        else
          ""
        end
      end
    end
  end
end