module ReactOnRails::Helper

def build_react_component_result_for_server_rendered_hash(
  server_rendered_html: required("server_rendered_html"),
  component_specification_tag: required("component_specification_tag"),
  console_script: required("console_script"),
  render_options: required("render_options")
)
  content_tag_options = render_options.html_options
  content_tag_options[:id] = render_options.dom_id
  unless server_rendered_html[COMPONENT_HTML_KEY]
    raise ReactOnRails::Error, "server_rendered_html hash expected to contain \"#{COMPONENT_HTML_KEY}\" key."
  end
  rendered_output = content_tag(:div,
                                server_rendered_html[COMPONENT_HTML_KEY].html_safe,
                                content_tag_options)
  result_console_script = render_options.replay_console ? console_script : ""
  result = compose_react_component_html_with_spec_and_console(
    component_specification_tag, rendered_output, result_console_script
  )
  # Other HTML strings need to be marked as html_safe too:
  server_rendered_hash_except_component = server_rendered_html.except(COMPONENT_HTML_KEY)
  server_rendered_hash_except_component.each do |key, html_string|
    server_rendered_hash_except_component[key] = html_string.html_safe
  end
  result_with_rails_context = prepend_render_rails_context(result)
  { COMPONENT_HTML_KEY => result_with_rails_context }.merge(
    server_rendered_hash_except_component
  )
end

def build_react_component_result_for_server_rendered_string(
  server_rendered_html: required("server_rendered_html"),
  component_specification_tag: required("component_specification_tag"),
  console_script: required("console_script"),
  render_options: required("render_options")
)
  content_tag_options = render_options.html_options
  if content_tag_options.key?(:tag)
    content_tag_options_html_tag = content_tag_options[:tag]
    content_tag_options.delete(:tag)
  else
    content_tag_options_html_tag = "div"
  end
  content_tag_options[:id] = render_options.dom_id
  rendered_output = content_tag(content_tag_options_html_tag.to_sym,
                                server_rendered_html.html_safe,
                                content_tag_options)
  result_console_script = render_options.replay_console ? console_script : ""
  result = compose_react_component_html_with_spec_and_console(
    component_specification_tag, rendered_output, result_console_script
  )
  prepend_render_rails_context(result)
end

def compose_react_component_html_with_spec_and_console(component_specification_tag, rendered_output,
                                                       console_script)
  # IMPORTANT: Ensure that we mark string as html_safe to avoid escaping.
  added_html = "#{component_specification_tag}\n#{console_script}".strip
  added_html = added_html.present? ? "\n#{added_html}" : ""
  "#{rendered_output}#{added_html}".html_safe
end

def create_render_options(react_component_name, options)
  # If no store dependencies are passed, default to all registered stores up till now
  unless options.key?(:store_dependencies)
    store_dependencies = registered_stores_including_deferred.map { |store| store[:store_name] }
    options = options.merge(store_dependencies: store_dependencies.presence)
  end
  ReactOnRails::ReactComponent::RenderOptions.new(react_component_name: react_component_name,
                                                  options: options)
end

def generated_components_pack_path(component_name)
  "#{ReactOnRails::PackerUtils.packer_source_entry_path}/generated/#{component_name}.js"
end

def in_mailer?
  return false unless defined?(controller)
  return false unless defined?(ActionMailer::Base)
  controller.is_a?(ActionMailer::Base)
end

def initialize_redux_stores(render_options)
  result = +<<-JS
  ReactOnRails.clearHydratedStores();
  JS
  store_dependencies = render_options.store_dependencies
  return result unless store_dependencies.present?
  declarations = +"var reduxProps, store, storeGenerator;\n"
  store_objects = registered_stores_including_deferred.select do |store|
    store_dependencies.include?(store[:store_name])
  end
  result << store_objects.each_with_object(declarations) do |redux_store_data, memo|
    store_name = redux_store_data[:store_name]
    props = props_string(redux_store_data[:props])
    memo << <<-JS.strip_heredoc
    reduxProps = #{props};
    storeGenerator = ReactOnRails.getStoreGenerator('#{store_name}');
    store = storeGenerator(reduxProps, railsContext);
    ReactOnRails.setStore('#{store_name}', store);
    JS
  end
  result
end

def internal_react_component(react_component_name, options = {})
  # Create the JavaScript and HTML to allow either client or server rendering of the
  # react_component.
  #
  # Create the JavaScript setup of the global to initialize the client rendering
  # (re-hydrate the data). This enables react rendered on the client to see that the
  # server has already rendered the HTML.
  render_options = create_render_options(react_component_name, options)
  # Setup the page_loaded_js, which is the same regardless of prerendering or not!
  # The reason is that React is smart about not doing extra work if the server rendering did its job.
  component_specification_tag = generate_component_script(render_options)
  load_pack_for_generated_component(react_component_name, render_options)
  # Create the HTML rendering part
  result = server_rendered_react_component(render_options)
  {
    render_options: render_options,
    tag: component_specification_tag,
    result: result
  }
end

def json_safe_and_pretty(hash_or_string)
  return "{}" if hash_or_string.nil?
  unless hash_or_string.is_a?(String) || hash_or_string.is_a?(Hash)
    raise ReactOnRails::Error, "#{__method__} only accepts String or Hash as argument " \
                               "(#{hash_or_string.class} given)."
  end
  json_value = hash_or_string.is_a?(String) ? hash_or_string : hash_or_string.to_json
  ReactOnRails::JsonOutput.escape(json_value)
end

def load_pack_for_generated_component(react_component_name, render_options)
  return unless render_options.auto_load_bundle
  ReactOnRails::PackerUtils.raise_nested_entries_disabled unless ReactOnRails::PackerUtils.nested_entries?
  if Rails.env.development?
    is_component_pack_present = File.exist?(generated_components_pack_path(react_component_name))
    raise_missing_autoloaded_bundle(react_component_name) unless is_component_pack_present
  end
  options = { defer: ReactOnRails.configuration.generated_component_packs_loading_strategy == :defer }
  # Old versions of Shakapacker don't support async script tags.
  # ReactOnRails.configure already validates if async loading is supported by the installed Shakapacker version.
  # Therefore, we only need to pass the async option if the loading strategy is explicitly set to :async
  options[:async] = true if ReactOnRails.configuration.generated_component_packs_loading_strategy == :async
  append_javascript_pack_tag("generated/#{react_component_name}", **options)
  append_stylesheet_pack_tag("generated/#{react_component_name}")
end

def prepend_render_rails_context(render_value)
  rails_context_content = rails_context_if_not_already_rendered
  rails_context_content = rails_context_content.present? ? "#{rails_context_content}\n" : ""
  "#{rails_context_content}#{render_value}".html_safe
end

def props_string(props)
  props.is_a?(String) ? props : props.to_json
end

def rails_context(server_side: true)
  # ALERT: Keep in sync with packages/react-on-rails/src/types/index.ts for the properties of RailsContext
  @rails_context ||= begin
    result = {
      componentRegistryTimeout: ReactOnRails.configuration.component_registry_timeout,
      railsEnv: Rails.env,
      inMailer: in_mailer?,
      # Locale settings
      i18nLocale: I18n.locale,
      i18nDefaultLocale: I18n.default_locale,
      rorVersion: ReactOnRails::VERSION,
      # TODO: v13 just use the version if existing
      rorPro: ReactOnRails::Utils.react_on_rails_pro?
    }
    if ReactOnRails::Utils.react_on_rails_pro?
      result[:rorProVersion] = ReactOnRails::Utils.react_on_rails_pro_version
      if ReactOnRails::Utils.rsc_support_enabled?
        rsc_payload_url = ReactOnRailsPro.configuration.rsc_payload_generation_url_path
        result[:rscPayloadGenerationUrlPath] = rsc_payload_url
      end
    end
    if defined?(request) && request.present?
      # Check for encoding of the request's original_url and try to force-encoding the
      # URLs as UTF-8. This situation can occur in browsers that do not encode the
      # entire URL as UTF-8 already, mostly on the Windows platform (IE11 and lower).
      original_url_normalized = request.original_url
      if original_url_normalized.encoding == Encoding::BINARY
        original_url_normalized = original_url_normalized.force_encoding(Encoding::ISO_8859_1)
                                                         .encode(Encoding::UTF_8)
      end
      # Using Addressable instead of standard URI to better deal with
      # non-ASCII characters (see https://github.com/shakacode/react_on_rails/pull/405)
      uri = Addressable::URI.parse(original_url_normalized)
      # uri = Addressable::URI.parse("http://foo.com:3000/posts?id=30&limit=5#time=1305298413")
      result.merge!(
        # URL settings
        href: uri.to_s,
        location: "#{uri.path}#{"?#{uri.query}" if uri.query.present?}",
        scheme: uri.scheme, # http
        host: uri.host, # foo.com
        port: uri.port,
        pathname: uri.path, # /posts
        search: uri.query, # id=30&limit=5
        httpAcceptLanguage: request.env["HTTP_ACCEPT_LANGUAGE"]
      )
    end
    if ReactOnRails.configuration.rendering_extension
      custom_context = ReactOnRails.configuration.rendering_extension.custom_context(self)
      result.merge!(custom_context) if custom_context
    end
    result
  end
  @rails_context.merge(serverSide: server_side)
end

def rails_context_if_not_already_rendered
  return "" if @rendered_rails_context
  data = rails_context(server_side: false)
  @rendered_rails_context = true
  attribution_comment = react_on_rails_attribution_comment
  script_tag = content_tag(:script,
                           json_safe_and_pretty(data).html_safe,
                           type: "application/json",
                           id: "js-react-on-rails-context")
  "#{attribution_comment}\n#{script_tag}".html_safe
end

def raise_missing_autoloaded_bundle(react_component_name)
  raise ReactOnRails::SmartError.new(
    error_type: :missing_auto_loaded_bundle,
    component_name: react_component_name,
    expected_path: generated_components_pack_path(react_component_name)
  )
end

def raise_prerender_error(json_result, react_component_name, props, js_code)
  raise ReactOnRails::PrerenderError.new(
    component_name: react_component_name,
    props: sanitized_props_string(props),
    err: nil,
    js_code: js_code,
    console_messages: json_result["consoleReplayScript"]
  )
end

def react_component(component_name, options = {})
  internal_result = internal_react_component(component_name, options)
  server_rendered_html = internal_result[:result]["html"]
  console_script = internal_result[:result]["consoleReplayScript"]
  render_options = internal_result[:render_options]
  case server_rendered_html
  when String
    html = build_react_component_result_for_server_rendered_string(
      server_rendered_html: server_rendered_html,
      component_specification_tag: internal_result[:tag],
      console_script: console_script,
      render_options: render_options
    )
    html.html_safe
  when Hash
    msg = <<~MSG
      Use react_component_hash (not react_component) to return a Hash to your ruby view code. See
      https://github.com/shakacode/react_on_rails/blob/master/spec/dummy/client/app/startup/ReactHelmetServerApp.jsx
      for an example of the necessary javascript configuration.
    MSG
    raise ReactOnRails::Error, msg
  else
    class_name = server_rendered_html.class.name
    msg = <<~MSG
      ReactOnRails: server_rendered_html is expected to be a String or Hash for #{component_name}.
      Type is #{class_name}
      Value:
      #{server_rendered_html}
      If you're trying to use a Render-Function to return a Hash to your ruby view code, then use
      react_component_hash instead of react_component and see
      https://github.com/shakacode/react_on_rails/blob/master/spec/dummy/client/app/startup/ReactHelmetServerApp.jsx
      for an example of the JavaScript code.
    MSG
    raise ReactOnRails::Error, msg
  end
end

def react_component_hash(component_name, options = {})
  options[:prerender] = true
  internal_result = internal_react_component(component_name, options)
  server_rendered_html = internal_result[:result]["html"]
  console_script = internal_result[:result]["consoleReplayScript"]
  render_options = internal_result[:render_options]
  if server_rendered_html.is_a?(String) && internal_result[:result]["hasErrors"]
    server_rendered_html = { COMPONENT_HTML_KEY => internal_result[:result]["html"] }
  end
  if server_rendered_html.is_a?(Hash)
    build_react_component_result_for_server_rendered_hash(
      server_rendered_html: server_rendered_html,
      component_specification_tag: internal_result[:tag],
      console_script: console_script,
      render_options: render_options
    )
  else
    msg = <<~MSG
      Render-Function used by react_component_hash for #{component_name} is expected to return
      an Object. See https://github.com/shakacode/react_on_rails/blob/master/spec/dummy/client/app/startup/ReactHelmetServerApp.jsx
      for an example of the JavaScript code.
      Note, your Render-Function must either take 2 params or have the property
      `.renderFunction = true` added to it to distinguish it from a React Function Component.
    MSG
    raise ReactOnRails::Error, msg
  end
end

def react_on_rails_attribution_comment
  if ReactOnRails::Utils.react_on_rails_pro?
    ReactOnRailsPro::Utils.pro_attribution_comment
  else
    "<!-- Powered by React on Rails (c) ShakaCode | Open Source -->"
  end
end

def redux_store(store_name, props: {}, defer: false, immediate_hydration: nil)
  immediate_hydration = ReactOnRails::Utils.normalize_immediate_hydration(immediate_hydration, store_name, "Store")
  redux_store_data = { store_name: store_name,
                       props: props,
                       immediate_hydration: immediate_hydration }
  if defer
    registered_stores_defer_render << redux_store_data
    "YOU SHOULD NOT SEE THIS ON YOUR VIEW -- Uses as a code block, like <% redux_store %> " \
      "and not <%= redux store %>"
  else
    registered_stores << redux_store_data
    result = render_redux_store_data(redux_store_data)
    prepend_render_rails_context(result).html_safe
  end
end

def redux_store_hydration_data
  return if registered_stores_defer_render.blank?
  registered_stores_defer_render.reduce(+"") do |accum, redux_store_data|
    accum << render_redux_store_data(redux_store_data)
  end.html_safe
end

def registered_stores
  @registered_stores ||= []
end

def registered_stores_defer_render
  @registered_stores_defer_render ||= []
end

def registered_stores_including_deferred
  registered_stores + registered_stores_defer_render
end

def render_redux_store_data(redux_store_data)
  store_hydration_data = generate_store_script(redux_store_data)
  prepend_render_rails_context(store_hydration_data)
end

def replay_console_option(val)
  val.nil? ? ReactOnRails.configuration.replay_console : val
end

def sanitized_props_string(props)
  ReactOnRails::JsonOutput.escape(props.is_a?(String) ? props : props.to_json)
end

def server_render_js(js_expression, options = {})
  render_options = ReactOnRails::ReactComponent::RenderOptions
                   .new(react_component_name: "generic-js", options: options)
  js_code = <<-JS.strip_heredoc
  (function() {
    var htmlResult = '';
    var consoleReplayScript = '';
    var hasErrors = false;
    var renderingError = null;
    var renderingErrorObject = {};
    try {
      htmlResult =
        (function() {
          return #{js_expression};
        })();
    } catch(e) {
      renderingError = e;
      if (#{render_options.throw_js_errors}) {
        throw e;
      }
      htmlResult = ReactOnRails.handleError({e: e, name: null,
        jsCode: '#{escape_javascript(js_expression)}', serverSide: true});
      hasErrors = true;
      renderingErrorObject = {
        message: renderingError.message,
        stack: renderingError.stack,
      }
    }
    consoleReplayScript = ReactOnRails.buildConsoleReplay();
    return JSON.stringify({
        html: htmlResult,
        consoleReplayScript: consoleReplayScript,
        hasErrors: hasErrors,
        renderingError: renderingErrorObject
    });
  })()
  JS
  result = ReactOnRails::ServerRenderingPool
           .server_render_js_with_console_logging(js_code, render_options)
  html = result["html"]
  console_log_script = result["consoleLogScript"]
  raw("#{html}#{console_log_script if render_options.replay_console}")
rescue ExecJS::ProgramError => err
  raise ReactOnRails::PrerenderError.new(component_name: "N/A (server_render_js called)",
                                         err: err,
                                         js_code: js_code)
end

def server_rendered_react_component(render_options)
  return { "html" => "", "consoleReplayScript" => "" } unless render_options.prerender
  react_component_name = render_options.react_component_name
  props = render_options.props
  # On server `location` option is added (`location = request.fullpath`)
  # React Router needs this to match the current route
  # Make sure that we use up-to-date bundle file used for server rendering, which is defined
  # by config file value for config.server_bundle_js_file
  ReactOnRails::ServerRenderingPool.reset_pool_if_server_bundle_was_modified
  # Since this code is not inserted on a web page, we don't need to escape props
  #
  # However, as JSON (returned from `props_string(props)`) isn't JavaScript,
  # but we want treat it as such, we need to compensate for the difference.
  #
  # \u2028 and \u2029 are valid characters in strings in JSON, but are treated
  # as newline separators in JavaScript. As no newlines are allowed in
  # strings in JavaScript, this causes an exception.
  #
  # We fix this by replacing these unicode characters with their escaped versions.
  # This should be safe, as the only place they can appear is in strings anyway.
  #
  # Read more here: http://timelessrepo.com/json-isnt-a-javascript-subset
  js_code = ReactOnRails::ServerRenderingJsCode.server_rendering_component_js_code(
    props_string: props_string(props).gsub("\u2028", '\u2028').gsub("\u2029", '\u2029'),
    rails_context: rails_context(server_side: true).to_json,
    redux_stores: initialize_redux_stores(render_options),
    react_component_name: react_component_name,
    render_options: render_options
  )
  begin
    result = ReactOnRails::ServerRenderingPool.server_render_js_with_console_logging(js_code, render_options)
  rescue StandardError => err
    # This error came from the renderer
    raise ReactOnRails::PrerenderError.new(component_name: react_component_name,
                                           # Sanitize as this might be browser logged
                                           props: sanitized_props_string(props),
                                           err: err,
                                           js_code: js_code)
  end
  if render_options.streaming?
    result.transform do |chunk_json_result|
      if should_raise_streaming_prerender_error?(chunk_json_result, render_options)
        raise_prerender_error(chunk_json_result, react_component_name, props, js_code)
      end
      # It doesn't make any transformation, it listens and raises error if a chunk has errors
      chunk_json_result
    end
    result.rescue do |err|
      # This error came from the renderer
      raise ReactOnRails::PrerenderError.new(component_name: react_component_name,
                                             # Sanitize as this might be browser logged
                                             props: sanitized_props_string(props),
                                             err: err,
                                             js_code: js_code)
    end
  elsif result["hasErrors"] && render_options.raise_on_prerender_error
    raise_prerender_error(result, react_component_name, props, js_code)
  end
  result
end

def should_raise_streaming_prerender_error?(chunk_json_result, render_options)
  chunk_json_result["hasErrors"] &&
    (if chunk_json_result["isShellReady"]
       render_options.raise_non_shell_server_rendering_errors
     else
       render_options.raise_on_prerender_error
     end)
end