# frozen_string_literal: true

require "jekyll/esm/version"
require "jekyll"
require "open3"
require 'tmpdir'
require 'nokogiri'
require 'json'

module Jekyll
  module Esm
    @@existing_esm_packages = []
    @@new_esm_packages = []
    @@esm_ids = []

    class Error < StandardError; end

    def self.process(page)
      doc = Nokogiri::HTML(page.output)

      import_maps = doc.search('script[type=importmap]')

      import_maps.each do |value|
        esm_id = value.attributes["data-esm-id"]&.value
        # declare a data-esm-id so that jekyll will only process an esm declaration once
        next if @@esm_ids.include?(esm_id)
        @@esm_ids << esm_id if esm_id

        importmap = JSON.parse(value.children[0].content)
        imports = importmap["imports"]
        imports.keys.each do |import_key|
          # ignore urls
          next if import_key =~ /https?:\/\/[\S]+/
          # ignore relative paths
          next if import_key =~ /(^\.+\/)+/
          # ignore absolute paths
          next if import_key =~ /^\/[\S]+/

          # ignore namespaces but only if it is not scoped
          if import_key =~ /^@[\S]+/
            import = import_key.split('/')[0..2].join('/')
          else
            import = import_key.split('/').first
          end

          pkg_path = File.join(page.site.source, 'node_modules', import)

          # don't repeatedly attempt to install a package
          next if Dir.exists?(pkg_path) && @@new_esm_packages.include?(import)

          @@new_esm_packages << import

          stdout, stderr, status = Open3.capture3(
            "yarn add #{import}",
            chdir: File.expand_path(page.site.source)
          )

          if page.site.config.dig('esm', 'strict')
            runtime_error = stdout =~ /ERROR in|SyntaxError/

            raise Error, stderr if stderr.size > 0
            raise Error, stdout if !runtime_error.nil?
          end
        end
      end
    end

    def self.apply(site)
      if @@existing_esm_packages.any?
        for_removal = @@existing_esm_packages - @@new_esm_packages.uniq

        # Remove any packages that are no longer referenced in an esm declaration
        if for_removal.any?
          stdout, stderr, status = Open3.capture3(
            "yarn remove #{for_removal.join(' ')}",
            chdir: File.expand_path(site.source)
          )

          if site.config.dig('esm', 'strict')
            runtime_error = stdout =~ /ERROR in|SyntaxError/

            raise Error, stderr if stderr.size > 0
            raise Error, stdout if !runtime_error.nil?
          end
        end
      end

      FileUtils.rm_rf(File.join(site.dest, 'node_modules'))
      FileUtils.cp_r(File.join(site.source, 'node_modules'), File.join(site.dest, 'node_modules'))
      @@existing_esm_packages = @@new_esm_packages
      @@new_esm_packages = []
      @@esm_ids = []
    end
  end
end


Jekyll::Hooks.register :pages, :post_render do |page|
  Jekyll::Esm.process(page)
end

Jekyll::Hooks.register :documents, :post_render do |page|
  Jekyll::Esm.process(page)
end

Jekyll::Hooks.register :posts, :post_render do |page|
  Jekyll::Esm.process(page)
end

Jekyll::Hooks.register :site, :post_write do |site|
  Jekyll::Esm.apply(site)
end