import {
  BlockNoteEditor,
  BlockSchema,
  InlineContentSchema,
  StyleSchema,
  mergeCSSClasses,
} from "@blocknote/core";
import React, {
  HTMLAttributes,
  ReactNode,
  Ref,
  useCallback,
  useEffect,
  useMemo,
  useState,
} from "react";
import { useBlockNoteEditor } from "../hooks/useBlockNoteEditor.js";
import { useEditorChange } from "../hooks/useEditorChange.js";
import { useEditorSelectionChange } from "../hooks/useEditorSelectionChange.js";
import { usePrefersColorScheme } from "../hooks/usePrefersColorScheme.js";
import {
  BlockNoteContext,
  BlockNoteContextValue,
  useBlockNoteContext,
} from "./BlockNoteContext.js";
import {
  BlockNoteDefaultUI,
  BlockNoteDefaultUIProps,
} from "./BlockNoteDefaultUI.js";
import { resolvePortalTarget } from "./portalElements.js";
import {
  BlockNoteViewContext,
  useBlockNoteViewContext,
} from "./BlockNoteViewContext.js";
import { useComponentsContext } from "./ComponentsContext.js";
import { Portals, getContentComponent } from "./EditorContent.js";
import { ElementRenderer } from "./ElementRenderer.js";

import "./styles.css";

const emptyFn = () => {
  // noop
};

export type BlockNoteViewProps<
  BSchema extends BlockSchema,
  ISchema extends InlineContentSchema,
  SSchema extends StyleSchema,
> = {
  /**
   * The {@link BlockNoteEditor} instance to render.
   * @remarks `BlockNoteEditor`
   */
  editor: BlockNoteEditor<BSchema, ISchema, SSchema>;

  /**
   * Forces the editor to use the light or dark theme. See [Themes](https://www.blocknotejs.org/docs/react/styling-theming/themes) for additional customization when using Mantine.
   */
  theme?: "light" | "dark";

  /**
   * Locks the editor from being editable by the user if set to `false`.
   *
   * @default true
   */
  editable?: boolean;
  /**
   * A callback function that runs whenever the text cursor position or selection changes.
   */
  onSelectionChange?: () => void;

  /**
   * A callback function that runs whenever the editor's contents change.
   * Same as {@link BlockNoteEditor.onChange}.
   * @remarks `(editor: BlockNoteEditor) => void`
   */
  onChange?: Parameters<
    BlockNoteEditor<BSchema, ISchema, SSchema>["onChange"]
  >[0];

  /**
   * Whether to render the editor element itself.
   * When `false`, you're responsible for rendering the editor yourself using the {@link BlockNoteViewEditor} component.
   *
   * @default true
   */
  renderEditor?: boolean;

  /**
   * Pass child elements to the {@link BlockNoteView} to create or customize toolbars, menus, or other UI components. See [UI Components](https://www.blocknotejs.org/docs/ui-components) for more.
   */
  children?: ReactNode;

  ref?: Ref<HTMLDivElement> | undefined; // only here to get types working with the generics. Regular form doesn't work
} & BlockNoteDefaultUIProps;

// `portalElements` is part of `BlockNoteDefaultUIProps`, but we re-export the
// types here for convenience so consumers can import them from `@blocknote/react`.
export type { PortalElementsMap, PortalTarget } from "./portalElements.js";

function BlockNoteViewComponent<
  BSchema extends BlockSchema,
  ISchema extends InlineContentSchema,
  SSchema extends StyleSchema,
>(
  props: BlockNoteViewProps<BSchema, ISchema, SSchema> &
    Omit<
      HTMLAttributes<HTMLDivElement>,
      "onChange" | "onSelectionChange" | "children"
    >,
  ref: React.Ref<HTMLDivElement>,
) {
  const {
    editor,
    className,
    theme,
    children,
    editable,
    onSelectionChange,
    onChange,
    formattingToolbar,
    linkToolbar,
    slashMenu,
    emojiPicker,
    sideMenu,
    filePanel,
    tableHandles,
    comments,
    portalElements,
    autoFocus,
    renderEditor = true,
    ...rest
  } = props;

  // Resolved once and handed to `editor.mount()` via context. When omitted,
  // `mount()` falls back to `element.parentElement` (i.e. `bn-container`).
  // Changing this prop requires remounting the editor (use a `key`).
  const portalTarget = useMemo(
    () => resolvePortalTarget(portalElements?.default) ?? null,
    [portalElements?.default],
  );

  // Used so other components (suggestion menu) can set
  // aria related props to the contenteditable div
  const [contentEditableProps, setContentEditableProps] =
    useState<Record<string, any>>();

  const existingContext = useBlockNoteContext();
  const systemColorScheme = usePrefersColorScheme();
  const defaultColorScheme =
    existingContext?.colorSchemePreference || systemColorScheme;

  const editorColorScheme =
    theme || (defaultColorScheme === "dark" ? "dark" : "light");

  // Disable default UI components if no components context is found.
  const componentsContext = useComponentsContext();
  const defaultUIProps: BlockNoteDefaultUIProps = useMemo(
    () => ({
      formattingToolbar: componentsContext ? formattingToolbar : false,
      linkToolbar: componentsContext ? linkToolbar : false,
      sideMenu: componentsContext ? sideMenu : false,
      slashMenu: componentsContext ? slashMenu : false,
      filePanel: componentsContext ? filePanel : false,
      tableHandles: componentsContext ? tableHandles : false,
      emojiPicker: componentsContext ? emojiPicker : false,
      comments: componentsContext ? comments : false,
      portalElements,
    }),
    [
      comments,
      componentsContext,
      emojiPicker,
      filePanel,
      formattingToolbar,
      linkToolbar,
      sideMenu,
      slashMenu,
      tableHandles,
      portalElements,
    ],
  );

  useEditorChange(onChange || emptyFn, editor);
  useEditorSelectionChange(onSelectionChange || emptyFn, editor);

  const setElementRenderer = useCallback(
    (ref: (typeof editor)["elementRenderer"]) => {
      editor.elementRenderer = ref;
    },
    [editor],
  );

  useEffect(() => {
    if (!editor.portalElement) {
      throw new Error("Portal element not found");
    }
    editor.portalElement.className = mergeCSSClasses(
      "bn-root",
      editorColorScheme,
      className || "",
    );
    editor.portalElement.setAttribute("data-color-scheme", editorColorScheme);
  }, [editor, editorColorScheme, className]);

  // The BlockNoteContext makes sure the editor and some helper methods
  // are always available to nesteed compoenents
  const blockNoteContext: BlockNoteContextValue<any, any, any> = useMemo(() => {
    return {
      ...existingContext,
      editor,
      setContentEditableProps,
      colorSchemePreference: editorColorScheme,
    };
  }, [existingContext, editor, editorColorScheme]);

  // We set defaultUIProps and editorProps on a different context, the BlockNoteViewContext.
  // This BlockNoteViewContext is used to render the editor and the default UI.
  const blockNoteViewContextValue = useMemo(() => {
    return {
      editorProps: {
        autoFocus,
        contentEditableProps,
        editable,
        portalTarget,
      },
      defaultUIProps,
    };
  }, [autoFocus, contentEditableProps, editable, defaultUIProps, portalTarget]);

  return (
    <BlockNoteContext.Provider value={blockNoteContext}>
      <BlockNoteViewContext.Provider value={blockNoteViewContextValue}>
        <ElementRenderer ref={setElementRenderer} />
        <BlockNoteViewContainer
          className={className}
          renderEditor={renderEditor}
          editorColorScheme={editorColorScheme}
          ref={ref}
          {...rest}
        >
          {children}
        </BlockNoteViewContainer>
      </BlockNoteViewContext.Provider>
    </BlockNoteContext.Provider>
  );
}

/**
 * Renders the div that wraps the editor and all default UI elements
 * (.bn-container element).
 */
const BlockNoteViewContainer = React.forwardRef<
  HTMLDivElement,
  {
    renderEditor: boolean;
    editorColorScheme: "light" | "dark";
    children: ReactNode;
  } & Omit<
    HTMLAttributes<HTMLDivElement>,
    "onChange" | "onSelectionChange" | "children"
  >
>(({ className, renderEditor, editorColorScheme, children, ...rest }, ref) => (
  <div
    className={mergeCSSClasses(
      "bn-root",
      "bn-container",
      editorColorScheme,
      className,
    )}
    data-color-scheme={editorColorScheme}
    {...rest}
    ref={ref}
  >
    {renderEditor ? (
      <BlockNoteViewEditor>{children}</BlockNoteViewEditor>
    ) : (
      children
    )}
  </div>
));

// https://fettblog.eu/typescript-react-generic-forward-refs/
export const BlockNoteViewRaw = React.forwardRef(BlockNoteViewComponent) as <
  BSchema extends BlockSchema,
  ISchema extends InlineContentSchema,
  SSchema extends StyleSchema,
>(
  props: BlockNoteViewProps<BSchema, ISchema, SSchema> & {
    ref?: React.ForwardedRef<HTMLDivElement>;
  } & Omit<
      HTMLAttributes<HTMLDivElement>,
      "onChange" | "onSelectionChange" | "children"
    >,
) => ReturnType<typeof BlockNoteViewComponent<BSchema, ISchema, SSchema>>;

/**
 * Renders the contentEditable editor itself (.bn-editor element) and the
 * default UI elements.
 */
export const BlockNoteViewEditor = (props: { children?: ReactNode }) => {
  const ctx = useBlockNoteViewContext()!;
  const editor = useBlockNoteEditor();

  const portalManager = useMemo(() => {
    return getContentComponent();
  }, []);

  const portalTarget = ctx.editorProps.portalTarget;

  const mount = useCallback(
    (element: HTMLElement | null) => {
      // Set editable state of the actual editor.
      // We need to re-mount the editor when changing `isEditable` as TipTap
      // removes the `tabIndex="0"` attribute we set (see
      // `BlockNoteEditor.ts`). Ideally though, this logic would exist in a
      // separate hook.
      editor.isEditable = ctx.editorProps.editable !== false;
      // Since we are not using TipTap's React Components, we need to set up the contentComponent it expects
      // This is a simple replacement for the state management that Tiptap does internally
      editor._tiptapEditor.contentComponent = portalManager;
      if (element) {
        editor.mount(element, { portalTarget });
      } else {
        editor.unmount();
      }
    },
    [ctx.editorProps.editable, editor, portalManager, portalTarget],
  );

  return (
    <>
      <Portals contentComponent={portalManager} />
      <ContentEditableElement {...ctx.editorProps} {...props} mount={mount} />
      {/* Renders the UI elements such as formatting toolbar, etc, unless they have been explicitly disabled  in defaultUIProps */}
      <BlockNoteDefaultUI {...ctx.defaultUIProps} />
      {/* Manually passed in children, such as customized UI elements / controllers */}
      {props.children}
    </>
  );
};

/**
 * Renders the contentEditable editor itself (.bn-editor element).
 */
const ContentEditableElement = (props: {
  autoFocus?: boolean;
  mount: (element: HTMLElement | null) => void;
  contentEditableProps?: Record<string, any>;
  portalTarget?: HTMLElement | null;
}) => {
  const { autoFocus, mount, contentEditableProps } = props;
  return (
    <div
      aria-autocomplete="list"
      aria-haspopup="listbox"
      data-bn-autofocus={autoFocus}
      ref={mount}
      {...contentEditableProps}
    />
  );
};