import React, { Fragment, useContext, useEffect, useState } from "react";
import { Route, Routes, useNavigate } from "react-router-dom";
import { Dropdown, Layout, Menu, MenuProps } from "antd";
import UserOutlined from "@ant-design/icons/UserOutlined";
import webUiPackage from "../../package.json";

import { useAccount } from "../model/account";
import ErrorBoundary from "./ErrorBoundary";
import ErrorPage from "./ErrorPage";
import ControlContext from "./ControlContext";
import { pages } from "../pages";
import { DraggingContext } from "../model/is_dragging";

type MenuItem = Required<MenuProps>["items"][number];

const { Header, Sider } = Layout;

function isActiveDropzone(element: HTMLElement | null): boolean {
	if (!element) {
		return false;
	}
	const checkDepth = 5;
	let depth = 0;
	while (element && depth < checkDepth) {
		if (element.classList.contains("dropzone")) {
			return element.classList.contains("enabled");
		}
		element = element.parentElement;
		depth += 1;
	}
	return false;
}

export default function SiteLayout() {
	let navigate = useNavigate();
	let [currentSidebarPath, setCurrentSidebarPath] = useState<string | null>(null);
	let account = useAccount();
	let plugins = useContext(ControlContext).plugins;
	const [dragging, setDragging] = useState(0);

	function SetSidebar(props: { path: string | null }) {
		useEffect(() => {
			setCurrentSidebarPath(props.path);
		});
		return null;
	}

	let accountMenuProps: MenuProps = {
		onClick: ({ key }: { key: string }) => {
			if (key === "user") {
				navigate(`/users/${account.name}/view`);
			} else if (key === "logOut") {
				account.logOut();
			}
		},
		items: [
			{ label: account.name, key: "user" },
			{ type: "divider" },
			{ label: "Log out", danger: true, key: "logOut" },
		],
	};

	let combinedPages = [...pages];
	for (let plugin of plugins.values()) {
		combinedPages.push(...plugin.pages);
	}

	let menuItems: MenuItem[] = [];
	let menuGroups = new Map();
	for (let { sidebarName, sidebarGroup, permission, path } of combinedPages) {
		if (
			!sidebarName || permission && (
				typeof permission === "function"
					? !permission(account)
					: !account.hasPermission(permission)
			)
		) {
			continue;
		}
		if (sidebarGroup) {
			let group = menuGroups.get(sidebarGroup);
			if (!group) {
				group = [];
				menuGroups.set(sidebarGroup, group);
			}
			group.push({ label: sidebarName, key: path });
		} else {
			menuItems.push({ label: sidebarName, key: path });
		}
	}
	for (let [name, group] of menuGroups) {
		menuItems.push({ type: "group", label: name, children: group, key: name });
	}

	// Prevent issues with event ordering
	let dragChange = 0;
	function setDraggingProxy(value: number) {
		dragChange += value;
		setDragging(dragging + dragChange);
	}

	return <Layout
		style={{ minHeight: "100vh" }}
		onDragEnter={() => setDraggingProxy(1)}
		onDragLeave={() => setDraggingProxy(-1)}
		// Reset dragging state when dropped
		onDrop={(e) => {
			setDragging(0);
			// Prevent dropping outside of dropzone
			if (!isActiveDropzone(e.target as HTMLElement)) {
				e.preventDefault();
				e.stopPropagation();
			}
		}}
		// Allow entire document to be a drag target
		onDragOver={(e) => {
			e.preventDefault();
			// Change cursor
			if (isActiveDropzone(e.target as HTMLElement)) {
				e.dataTransfer.dropEffect = "copy";
			} else {
				e.dataTransfer.dropEffect = "none";
			}
		}}
	>
		<DraggingContext.Provider value={dragging > 0}>
			<Header className="header">
				<div className="site-logo" />
				<span className="site-name">Clusterio</span>
				<span className="site-version">{webUiPackage.version}</span>
				<Menu
					theme="dark"
					mode="horizontal"
					defaultSelectedKeys={["1"]}
					items={[{ label: "Dashboard", key: "1" }]}
				/>
				<Dropdown
					className="account-dropdown-header"
					placement="bottomRight"
					trigger={["click"]}
					menu={accountMenuProps}
				>
					<UserOutlined />
				</Dropdown>
			</Header>
			<Layout className="site-layout">
				<Sider
					collapsible
					collapsedWidth={0}
					breakpoint="md"
					zeroWidthTriggerStyle={{ top: 6, zIndex: -1 }}
					width={250}
					className="site-layout-sider"
				>
					<Menu
						mode="inline"
						defaultOpenKeys={[...menuGroups.keys()]}
						selectedKeys={currentSidebarPath ? [currentSidebarPath] : []}
						style={{ height: "100%", borderRight: 0 }}
						onClick={({ key }) => navigate(key)}
						items={menuItems}
					/>
				</Sider>
				<Layout className="site-layout-content-container">
					<Routes>
						{combinedPages.map(({ path, sidebarPath, content }) => <Route
							path={path}
							key={path}
							element={<Fragment key={path}>
								<SetSidebar path={sidebarPath ? sidebarPath : path} />
								<ErrorBoundary Component={ErrorPage}>
									{content}
								</ErrorBoundary>
							</Fragment>}
						/>)}
						<Route element={<SetSidebar path={null} />} />
					</Routes>
				</Layout>
			</Layout>
		</DraggingContext.Provider>
	</Layout>;
}