"use client";

import { useEffect, useState } from "react";
import {
  $createParagraphNode,
  $getSelection,
  $isRangeSelection,
  COMMAND_PRIORITY_LOW,
  FORMAT_TEXT_COMMAND,
  mergeRegister,
  SELECTION_CHANGE_COMMAND,
  type LexicalEditor,
  type LexicalNode,
  type RangeSelection,
} from "lexical";
import {
  $createHeadingNode,
  $createQuoteNode,
  $isHeadingNode,
  $isQuoteNode,
} from "@lexical/rich-text";
import { $setBlocksType } from "@lexical/selection";
import {
  $isListNode,
  INSERT_CHECK_LIST_COMMAND,
  INSERT_ORDERED_LIST_COMMAND,
  INSERT_UNORDERED_LIST_COMMAND,
  type ListType,
} from "@lexical/list";
import {
  Bold,
  Code2,
  Italic,
  List,
  ListChecks,
  ListOrdered,
  Minus,
  Quote,
  Strikethrough,
  Underline,
  type LucideIcon,
} from "lucide-react";
import { useLexicalComposerContext } from "@lexical/react/LexicalComposerContext";
import { INSERT_HORIZONTAL_RULE_COMMAND } from "@lexical/extension";
import { Separator } from "@/components/ui/separator";
import { LexicalRichTextToolbarButton } from "./LexicalRichTextToolbarButton";

type BlockType = "paragraph" | "h2" | "h3" | "h4" | "quote";

interface ToolbarState {
  bold: boolean;
  italic: boolean;
  underline: boolean;
  strikethrough: boolean;
  code: boolean;
  blockType: BlockType;
  listType: ListType | null;
}

const DEFAULT_TOOLBAR_STATE: ToolbarState = {
  blockType: "paragraph",
  bold: false,
  code: false,
  italic: false,
  listType: null,
  strikethrough: false,
  underline: false,
};

function getBlockType(selection: RangeSelection): BlockType {
  const topLevelElement = selection.anchor.getNode().getTopLevelElement();
  if ($isHeadingNode(topLevelElement)) {
    const tag = topLevelElement.getTag();
    if (tag === "h2" || tag === "h3" || tag === "h4") return tag;
  }
  if ($isQuoteNode(topLevelElement)) return "quote";
  return "paragraph";
}

function getListType(selection: RangeSelection): ListType | null {
  let node: LexicalNode | null = selection.anchor.getNode();
  while (node) {
    if ($isListNode(node)) return node.getListType();
    node = node.getParent();
  }
  return null;
}

function readToolbarState(editor: LexicalEditor): ToolbarState {
  let state = DEFAULT_TOOLBAR_STATE;
  editor.getEditorState().read(() => {
    const selection = $getSelection();
    if (!$isRangeSelection(selection)) return;
    state = {
      blockType: getBlockType(selection),
      bold: selection.hasFormat("bold"),
      code: selection.hasFormat("code"),
      italic: selection.hasFormat("italic"),
      listType: getListType(selection),
      strikethrough: selection.hasFormat("strikethrough"),
      underline: selection.hasFormat("underline"),
    };
  });
  return state;
}

export function LexicalRichTextToolbar({ disabled }: { disabled: boolean }) {
  const [editor] = useLexicalComposerContext();
  const [state, setState] = useState(DEFAULT_TOOLBAR_STATE);

  useEffect(() => {
    const update = () => setState(readToolbarState(editor));
    update();
    return mergeRegister(
      editor.registerUpdateListener(update),
      editor.registerCommand(
        SELECTION_CHANGE_COMMAND,
        () => {
          update();
          return false;
        },
        COMMAND_PRIORITY_LOW,
      ),
    );
  }, [editor]);

  function formatText(format: "bold" | "italic" | "underline" | "strikethrough" | "code") {
    editor.dispatchCommand(FORMAT_TEXT_COMMAND, format);
  }

  function setBlockType(type: BlockType) {
    editor.update(() => {
      const selection = $getSelection();
      if (!$isRangeSelection(selection)) return;
      const nextType = state.blockType === type && type !== "paragraph" ? "paragraph" : type;
      if (nextType === "paragraph") {
        $setBlocksType(selection, () => $createParagraphNode());
      } else if (nextType === "quote") {
        $setBlocksType(selection, () => $createQuoteNode());
      } else {
        $setBlocksType(selection, () => $createHeadingNode(nextType));
      }
    });
  }

  const inlineButtons: {
    label: string;
    icon: LucideIcon;
    active: boolean;
    onClick: () => void;
  }[] = [
    { label: "Bold", icon: Bold, active: state.bold, onClick: () => formatText("bold") },
    { label: "Italic", icon: Italic, active: state.italic, onClick: () => formatText("italic") },
    {
      label: "Underline",
      icon: Underline,
      active: state.underline,
      onClick: () => formatText("underline"),
    },
    {
      label: "Strikethrough",
      icon: Strikethrough,
      active: state.strikethrough,
      onClick: () => formatText("strikethrough"),
    },
    { label: "Inline code", icon: Code2, active: state.code, onClick: () => formatText("code") },
  ];
  const blockButtons: {
    label: string;
    icon: LucideIcon;
    active: boolean;
    pressed?: boolean;
    onClick: () => void;
  }[] = [
    {
      label: "Bulleted list",
      icon: List,
      active: state.listType === "bullet",
      onClick: () => editor.dispatchCommand(INSERT_UNORDERED_LIST_COMMAND, undefined),
    },
    {
      label: "Numbered list",
      icon: ListOrdered,
      active: state.listType === "number",
      onClick: () => editor.dispatchCommand(INSERT_ORDERED_LIST_COMMAND, undefined),
    },
    {
      label: "Checklist",
      icon: ListChecks,
      active: state.listType === "check",
      onClick: () => editor.dispatchCommand(INSERT_CHECK_LIST_COMMAND, undefined),
    },
    {
      label: "Blockquote",
      icon: Quote,
      active: state.blockType === "quote",
      onClick: () => setBlockType("quote"),
    },
    {
      label: "Horizontal rule",
      icon: Minus,
      active: false,
      pressed: false,
      onClick: () => editor.dispatchCommand(INSERT_HORIZONTAL_RULE_COMMAND, undefined),
    },
  ];

  return (
    <div
      className="flex min-w-0 flex-wrap items-center gap-1 rounded-t-md border-b bg-muted/20 p-1"
      role="toolbar"
      aria-label="Rich text formatting toolbar"
    >
      <div className="flex flex-wrap items-center gap-1" aria-label="Text formatting">
        {inlineButtons.map((button) => (
          <LexicalRichTextToolbarButton key={button.label} {...button} disabled={disabled} />
        ))}
      </div>
      <Separator orientation="vertical" className="mx-1 hidden h-6 sm:block" />
      <div className="flex flex-wrap items-center gap-1" aria-label="Block style">
        {(["paragraph", "h2", "h3", "h4"] as const).map((type) => (
          <LexicalRichTextToolbarButton
            key={type}
            label={type === "paragraph" ? "Text" : type.toUpperCase()}
            active={state.blockType === type}
            disabled={disabled}
            onClick={() => setBlockType(type)}
          >
            {type === "paragraph" ? "Text" : type.toUpperCase()}
          </LexicalRichTextToolbarButton>
        ))}
      </div>
      <Separator orientation="vertical" className="mx-1 hidden h-6 sm:block" />
      <div className="flex flex-wrap items-center gap-1" aria-label="Lists and blocks">
        {blockButtons.map((button) => (
          <LexicalRichTextToolbarButton key={button.label} {...button} disabled={disabled} />
        ))}
      </div>
    </div>
  );
}