import { Component, createMemo, createSignal, Show } from "solid-js";
import { useLocation } from "@solidjs/router";
import { type FileNode, type TocNode } from "../data-loader";
import { useNavigateWithParams } from "./useNavigateWithParams";
import { useScrollContainer } from "../App";

/**
 * 检查当前文件路径是否在文件夹内
 */
function isPathInDir(currentPath: string, dirPath: string): boolean {
  // 确保 dirPath 以 / 结尾，用于前缀匹配
  const dirPathPrefix = dirPath.endsWith("/") ? dirPath : dirPath + "/";
  return currentPath.startsWith(dirPathPrefix);
}

/**
 * 文件树节点组件
 */
export const FileTreeNode: Component<{
  node: FileNode;
  currentPath: string;
  pathHeadings: Record<string, TocNode[]>;
  depth: number;
  onClose: () => void;
  isHidden?: (node: FileNode) => boolean;
}> = (props) => {
  const navigate = useNavigateWithParams();
  const location = useLocation();
  const isDir = !!props.node.children;
  const isActive = createMemo(() => props.currentPath === props.node.path);
  // 默认收起，除非当前文件在该文件夹内
  const [isExpanded, setIsExpanded] = createSignal(
    isDir && isPathInDir(props.currentPath, props.node.path),
  );

  const href = () => props.node.path + location.search;

  const handleClick = (e: MouseEvent) => {
    if (isDir) {
      e.preventDefault();
      setIsExpanded(!isExpanded());
    } else if (e.button === 0) {
      // Left-click: use SPA navigation
      e.preventDefault();
      navigate(props.node.path);
      props.onClose();
    }
    // Middle-click / right-click: let the browser handle the <a> natively
  };

  const indent = props.depth * 12;

  return (
    <div class={props.isHidden?.(props.node) === true ? "hidden" : ""}>
      <a
        href={href()}
        class={`flex items-center py-1 px-2 cursor-pointer hover:bg-gray-100 rounded no-underline ${
          isActive() ? "bg-blue-50 text-blue-700" : "text-gray-700"
        }`}
        style={{ "padding-left": `${indent + 8}px` }}
        onClick={handleClick}
      >
        <Show when={isDir}>
          <span class="mr-1 text-gray-400">{isExpanded() ? "📂" : "📁"}</span>
        </Show>
        <Show when={!isDir}>
          <span class="mr-1 text-gray-400">📄</span>
        </Show>
        <span class="text-sm truncate">{props.node.name}</span>
      </a>
      <Show when={isDir && isExpanded() && props.node.children}>
        <div>
          {props.node.children!.map((child) => (
            <FileTreeNode
              node={child}
              currentPath={props.currentPath}
              pathHeadings={props.pathHeadings}
              depth={props.depth + 1}
              onClose={props.onClose}
              isHidden={props.isHidden}
            />
          ))}
        </div>
      </Show>
    </div>
  );
};

/**
 * 标题节点组件
 */
export const HeadingNode: Component<{
  node: TocNode;
  basePath: string;
  depth: number;
  isHidden?: (node: TocNode) => boolean;
}> = (props) => {
  const navigate = useNavigateWithParams();
  const location = useLocation();
  const anchor = props.node.id || "";
  const href = () => `${props.basePath}${location.search}#${anchor}`;
  const hasChildren = !!props.node.children;
  // 默认收起，除非当前锚点在该节点内
  const [isExpanded, setIsExpanded] = createSignal(props.depth <= 0);

  const handleExpand = (e: MouseEvent) => {
    e.preventDefault();
    if (hasChildren) {
      setIsExpanded(!isExpanded());
    }
  };
  const scrollContainer = useScrollContainer();

  const handleClick = (e: MouseEvent) => {
    if (e.button === 0) {
      // Left-click: use SPA navigation
      e.preventDefault();
      navigate(`${props.basePath}#${anchor}`);
    }
    // Middle-click / right-click: let the browser handle the <a> natively
    // 滚动到目标元素，考虑导航栏高度偏移
    requestAnimationFrame(() => {
      const element = document.getElementById(anchor);
      if (element) {
        const scroller = scrollContainer();
        const navBarHeight = 80;
        const elementPosition = element.getBoundingClientRect().top;
        const containerTop = scroller?.getBoundingClientRect().top ?? 0;
        const relativePosition = elementPosition - containerTop;
        const currentScroll = scroller?.scrollTop ?? window.scrollY;
        const offsetPosition = currentScroll + relativePosition - navBarHeight;
        if (scroller) {
          scroller.scrollTo({ top: offsetPosition, behavior: "instant" });
        } else {
          window.scrollTo({ top: offsetPosition, behavior: "instant" });
        }
      }
    });
  };

  const indent = props.depth * 12;

  return (
    <div class={props.isHidden?.(props.node) === true ? "hidden" : ""}>
      <div class="flex flex-row">
        <span
          class={`cursor-pointer mr-1 text-gray-400 text-xs w-3 shrink-0`}
          style={{ "margin-left": `${indent + 8}px` }}
          onClick={handleExpand}
        >
          <span
            class={`${hasChildren ? "" : "invisible"} ${isExpanded() ? "rotate-90" : ""} mt-1 inline-block transition-transform `}
          >
            ▶
          </span>
        </span>
        <a
          href={href()}
          class="inline-flex items-center py-0.5 px-2 text-sm text-gray-600 hover:text-gray-900 hover:bg-gray-50 rounded truncate cursor-pointer"
          onClick={handleClick}
        >
          {props.node.title}
        </a>
      </div>
      <Show when={hasChildren && isExpanded()}>
        <div>
          {props.node.children!.map((child) => (
            <HeadingNode
              node={child}
              basePath={props.basePath}
              depth={props.depth + 1}
              isHidden={props.isHidden}
            />
          ))}
        </div>
      </Show>
    </div>
  );
};