'use client';

import Link from 'next/link';
import { zodResolver } from '@hookform/resolvers/zod';
import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query';
import { useEffect, useMemo, useState } from 'react';
import { useForm, useWatch } from 'react-hook-form';
import { z } from 'zod';

import { EmptyState } from '@/components/feedback/empty-state';
import { ErrorState } from '@/components/feedback/error-state';
import { InlineMessage } from '@/components/feedback/inline-message';
import { LoadingState } from '@/components/feedback/loading-state';
import { PageHeader } from '@/components/layout/page-header';
import { AppModal } from '@/components/ui/app-modal';
import { AppCard } from '@/components/ui/app-card';
import { StatusBadge } from '@/components/ui/status-badge';
import {
	createNode,
	deleteNode,
	getNodeBootstrapToken,
	getNodes,
	requestNodeAgentUpdate,
	rotateNodeBootstrapToken,
	updateNode,
} from '@/features/nodes/api/nodes';
import type { NodeItem, NodeMutationPayload } from '@/features/nodes/types';
import {
	CodeBlock,
	DangerButton,
	PrimaryButton,
	ResourceField,
	ResourceInput,
	SecondaryButton,
	ToggleField,
} from '@/features/shared/components/resource-primitives';
import { formatDateTime, formatRelativeTime } from '@/lib/utils/date';

const nodesQueryKey = ['nodes'];
const bootstrapQueryKey = ['nodes', 'bootstrap-token'];
const installerScriptUrl =
	'https://raw.githubusercontent.com/Rain-kl/ATSFlare/main/scripts/install-agent.sh';

const nodeSchema = z.object({
	name: z.string().trim().min(1, '请输入节点名').max(128, '节点名不能超过 128 个字符'),
	auto_update_enabled: z.boolean(),
});

type NodeFormValues = z.infer<typeof nodeSchema>;

type FeedbackState = {
	tone: 'info' | 'success' | 'danger';
	message: string;
};

const defaultValues: NodeFormValues = {
	name: '',
	auto_update_enabled: false,
};

function getErrorMessage(error: unknown) {
	return error instanceof Error ? error.message : '请求失败，请稍后重试。';
}

function toPayload(values: NodeFormValues): NodeMutationPayload {
	return {
		name: values.name.trim(),
		auto_update_enabled: values.auto_update_enabled,
	};
}

function isMeaningfulTime(value: string | null | undefined) {
	return Boolean(value) && !String(value).startsWith('0001-01-01');
}

function getStatusVariant(status: NodeItem['status']) {
	if (status === 'online') {
		return 'success';
	}

	if (status === 'pending') {
		return 'warning';
	}

	return 'danger';
}

function getStatusLabel(status: NodeItem['status']) {
	if (status === 'online') {
		return '在线';
	}

	if (status === 'pending') {
		return '待接入';
	}

	return '离线';
}

function getApplyVariant(result: NodeItem['latest_apply_result']) {
	if (result === 'success') {
		return 'success';
	}

	if (result === 'failed') {
		return 'danger';
	}

	return 'warning';
}

function getApplyLabel(result: NodeItem['latest_apply_result']) {
	if (result === 'success') {
		return '成功';
	}

	if (result === 'failed') {
		return '失败';
	}

	return '暂无';
}

function getUpdateMode(node: NodeItem) {
	if (node.update_requested) {
		return { label: '等待更新', variant: 'warning' as const };
	}

	if (node.auto_update_enabled) {
		return { label: '自动更新', variant: 'success' as const };
	}

	return { label: '手动更新', variant: 'info' as const };
}

function getServerUrl(value: string) {
	return value.trim().replace(/\/+$/, '');
}

function buildDiscoveryInstallCommand(serverUrl: string, discoveryToken: string) {
	return [
		`curl -fsSL ${installerScriptUrl} | bash -s -- \\`,
		`  --server-url ${serverUrl} \\`,
		`  --discovery-token ${discoveryToken}`,
	].join('\n');
}

function buildNodeInstallCommand(serverUrl: string, agentToken: string) {
	return [
		`curl -fsSL ${installerScriptUrl} | bash -s -- \\`,
		`  --server-url ${serverUrl} \\`,
		`  --agent-token ${agentToken}`,
	].join('\n');
}

async function copyToClipboard(value: string) {
	await navigator.clipboard.writeText(value);
}

export function NodesPage() {
	const queryClient = useQueryClient();
	const [feedback, setFeedback] = useState<FeedbackState | null>(null);
	const [editingNodeId, setEditingNodeId] = useState<number | null>(null);
	const [isEditorOpen, setIsEditorOpen] = useState(false);
	const [selectedNode, setSelectedNode] = useState<NodeItem | null>(null);
	const [serverUrl, setServerUrl] = useState('');
	const [, setRefreshTick] = useState(0);

	const form = useForm<NodeFormValues>({
		resolver: zodResolver(nodeSchema),
		defaultValues,
	});

	const watchedAutoUpdate = useWatch({
		control: form.control,
		name: 'auto_update_enabled',
	});

	const nodesQuery = useQuery({
		queryKey: nodesQueryKey,
		queryFn: getNodes,
	});

	const bootstrapQuery = useQuery({
		queryKey: bootstrapQueryKey,
		queryFn: getNodeBootstrapToken,
	});

	useEffect(() => {
		if (typeof window !== 'undefined' && !serverUrl) {
			setServerUrl(window.location.origin);
		}
	}, [serverUrl]);

	useEffect(() => {
		const timer = window.setInterval(() => {
			void queryClient.invalidateQueries({ queryKey: nodesQueryKey });
			setRefreshTick((value) => value + 1);
		}, 30000);

		return () => {
			window.clearInterval(timer);
		};
	}, [queryClient]);

	const saveMutation = useMutation({
		mutationFn: async (values: NodeFormValues) => {
			const payload = toPayload(values);
			return editingNodeId ? updateNode(editingNodeId, payload) : createNode(payload);
		},
		onSuccess: async (node) => {
			setFeedback({
				tone: 'success',
				message: editingNodeId ? '节点已更新。' : '节点已创建。',
			});
			setEditingNodeId(null);
			setIsEditorOpen(false);
			setSelectedNode(node);
			form.reset(defaultValues);
			await Promise.all([
				queryClient.invalidateQueries({ queryKey: nodesQueryKey }),
				queryClient.invalidateQueries({ queryKey: bootstrapQueryKey }),
			]);
		},
		onError: (error) => {
			setFeedback({ tone: 'danger', message: getErrorMessage(error) });
		},
	});

	const rotateMutation = useMutation({
		mutationFn: rotateNodeBootstrapToken,
		onSuccess: async () => {
			setFeedback({ tone: 'success', message: '全局 Discovery Token 已重新生成。' });
			await queryClient.invalidateQueries({ queryKey: bootstrapQueryKey });
		},
		onError: (error) => {
			setFeedback({ tone: 'danger', message: getErrorMessage(error) });
		},
	});

	const updateAgentMutation = useMutation({
		mutationFn: requestNodeAgentUpdate,
		onSuccess: async (node) => {
			setFeedback({ tone: 'success', message: `已向节点 ${node.name} 下发更新指令。` });
			setSelectedNode(node);
			await queryClient.invalidateQueries({ queryKey: nodesQueryKey });
		},
		onError: (error) => {
			setFeedback({ tone: 'danger', message: getErrorMessage(error) });
		},
	});

	const deleteMutation = useMutation({
		mutationFn: deleteNode,
		onSuccess: async () => {
			setFeedback({ tone: 'success', message: '节点已删除。' });
			setEditingNodeId(null);
			setSelectedNode(null);
			form.reset(defaultValues);
			await queryClient.invalidateQueries({ queryKey: nodesQueryKey });
		},
		onError: (error) => {
			setFeedback({ tone: 'danger', message: getErrorMessage(error) });
		},
	});

	const nodes = useMemo(() => nodesQuery.data ?? [], [nodesQuery.data]);
	const bootstrapToken = bootstrapQuery.data?.discovery_token ?? '';
	const normalizedServerUrl = getServerUrl(serverUrl);

	const selectedNodeFromList = useMemo(() => {
		if (!selectedNode) {
			return null;
		}

		return nodes.find((item) => item.id === selectedNode.id) ?? selectedNode;
	}, [nodes, selectedNode]);

	const summary = useMemo(() => {
		return [
			{ label: '节点总数', value: nodes.length },
			{ label: '在线节点', value: nodes.filter((item) => item.status === 'online').length },
			{ label: '待接入节点', value: nodes.filter((item) => item.status === 'pending').length },
			{ label: '自动更新', value: nodes.filter((item) => item.auto_update_enabled).length },
		];
	}, [nodes]);

	const handleReset = () => {
		setFeedback(null);
		setEditingNodeId(null);
		setIsEditorOpen(false);
		form.reset(defaultValues);
	};

	const handleCreate = () => {
		setFeedback(null);
		setEditingNodeId(null);
		form.reset(defaultValues);
		setIsEditorOpen(true);
	};

	const handleEdit = (node: NodeItem) => {
		setFeedback(null);
		setEditingNodeId(node.id);
		setSelectedNode(node);
		form.reset({
			name: node.name,
			auto_update_enabled: node.auto_update_enabled,
		});
		setIsEditorOpen(true);
	};

	const handleDelete = (node: NodeItem) => {
		if (
			!window.confirm(`确认删除节点“${node.name}”吗？删除后该节点需要重新创建并重新接入。`)
		) {
			return;
		}

		setFeedback(null);
		deleteMutation.mutate(node.id);
	};

	const handleRotateToken = () => {
		if (!window.confirm('确认重新生成全局 Discovery Token 吗？现有批量部署命令需要同步更新。')) {
			return;
		}

		setFeedback(null);
		rotateMutation.mutate();
	};

	const handleCopy = async (value: string, successMessage: string) => {
		try {
			await copyToClipboard(value);
			setFeedback({ tone: 'success', message: successMessage });
		} catch (error) {
			setFeedback({ tone: 'danger', message: getErrorMessage(error) });
		}
	};

	const handleSubmit = form.handleSubmit((values) => {
		setFeedback(null);
		saveMutation.mutate(values);
	});

	const discoveryCommand =
		normalizedServerUrl && bootstrapToken
			? buildDiscoveryInstallCommand(normalizedServerUrl, bootstrapToken)
			: '';

	const nodeInstallCommand =
		normalizedServerUrl && selectedNodeFromList?.agent_token
			? buildNodeInstallCommand(normalizedServerUrl, selectedNodeFromList.agent_token)
			: '';

	return (
		<>
			<div className='space-y-6'>
			<PageHeader
				title='节点管理'
				description='查看节点在线状态、最近心跳、部署命令与 Agent 更新动作，并支持预创建节点。'
				action={
					<>
						<SecondaryButton type='button' onClick={handleCreate}>
							新增节点
						</SecondaryButton>
						<Link
							href='/apply-log'
							className='inline-flex items-center justify-center rounded-2xl border border-[var(--border-default)] bg-[var(--control-background)] px-4 py-3 text-sm font-medium text-[var(--foreground-primary)] transition hover:bg-[var(--control-background-hover)]'
						>
							应用记录
						</Link>
					</>
				}
			/>

			{feedback ? <InlineMessage tone={feedback.tone} message={feedback.message} /> : null}

			<AppCard
				title='节点摘要'
				description='节点创建、编辑和更新动作均已收敛到列表页与弹窗，便于在生产环境快速处理。'
				action={
					<SecondaryButton
						type='button'
						onClick={() => void queryClient.invalidateQueries({ queryKey: nodesQueryKey })}
					>
						刷新列表
					</SecondaryButton>
				}
			>
				<div className='grid gap-4 md:grid-cols-2 xl:grid-cols-4'>
					{summary.map((item) => (
						<div
							key={item.label}
							className='rounded-2xl border border-[var(--border-default)] bg-[var(--surface-elevated)] px-4 py-4'
						>
							<p className='text-xs uppercase tracking-[0.2em] text-[var(--foreground-muted)]'>
								{item.label}
							</p>
							<p className='mt-2 text-lg font-semibold text-[var(--foreground-primary)]'>{item.value}</p>
						</div>
					))}
				</div>
			</AppCard>

			<div className='grid gap-6 xl:grid-cols-[1fr_1fr]'>
				<AppCard
					title='Discovery Token 部署'
					description='适用于新节点首次接入，Agent 会自动注册并换取节点专属 Token。'
					action={
						<div className='flex flex-wrap gap-2'>
							<SecondaryButton type='button' onClick={handleRotateToken} disabled={rotateMutation.isPending}>
								{rotateMutation.isPending ? '生成中...' : '重新生成 Token'}
							</SecondaryButton>
							{discoveryCommand ? (
								<PrimaryButton
									type='button'
									onClick={() => void handleCopy(discoveryCommand, 'Discovery 部署命令已复制。')}
								>
									复制命令
								</PrimaryButton>
							) : null}
						</div>
					}
				>
					{bootstrapQuery.isLoading ? (
						<LoadingState />
					) : bootstrapQuery.isError ? (
						<ErrorState title='Discovery Token 加载失败' description={getErrorMessage(bootstrapQuery.error)} />
					) : (
						<div className='space-y-4'>
							<ResourceField label='Server URL' hint='默认使用当前管理端来源，可按需改为对外访问地址。'>
								<ResourceInput value={serverUrl} onChange={(event) => setServerUrl(event.target.value)} />
							</ResourceField>

							<div className='grid gap-4 md:grid-cols-2'>
								<div className='rounded-2xl border border-[var(--border-default)] bg-[var(--surface-elevated)] px-4 py-4'>
									<p className='text-xs uppercase tracking-[0.2em] text-[var(--foreground-muted)]'>Discovery Token</p>
									<p className='mt-2 break-all text-sm text-[var(--foreground-primary)]'>
										{bootstrapToken || '暂无'}
									</p>
								</div>
								<div className='rounded-2xl border border-[var(--border-default)] bg-[var(--surface-elevated)] px-4 py-4 text-sm leading-6 text-[var(--foreground-secondary)]'>
									创建节点后也可以使用节点专属 Token 安装，这种方式适合预分配节点名与更新策略。
								</div>
							</div>

							{discoveryCommand ? <CodeBlock className='whitespace-pre-wrap'>{discoveryCommand}</CodeBlock> : null}
						</div>
					)}
				</AppCard>

				<AppCard
					title='节点专属部署命令'
					description='适用于已在管理端预创建节点的场景，可避免首次接入时匿名自动命名。'
					action={
						nodeInstallCommand ? (
							<PrimaryButton
								type='button'
								onClick={() => void handleCopy(nodeInstallCommand, '节点专属部署命令已复制。')}
							>
								复制命令
							</PrimaryButton>
						) : null
					}
				>
					{selectedNodeFromList ? (
						<div className='space-y-4'>
							<div className='grid gap-4 md:grid-cols-2'>
								<div className='rounded-2xl border border-[var(--border-default)] bg-[var(--surface-elevated)] px-4 py-4'>
									<div className='flex items-center justify-between gap-3'>
										<p className='text-sm font-semibold text-[var(--foreground-primary)]'>{selectedNodeFromList.name}</p>
										<StatusBadge
											label={selectedNodeFromList.pending ? '未占用' : '已绑定'}
											variant={selectedNodeFromList.pending ? 'warning' : 'success'}
										/>
									</div>
									<p className='mt-2 text-xs text-[var(--foreground-secondary)]'>Node ID：{selectedNodeFromList.node_id}</p>
								</div>
								<div className='rounded-2xl border border-[var(--border-default)] bg-[var(--surface-elevated)] px-4 py-4'>
									<p className='text-xs uppercase tracking-[0.2em] text-[var(--foreground-muted)]'>Agent Token</p>
									<p className='mt-2 break-all text-sm text-[var(--foreground-primary)]'>
										{selectedNodeFromList.agent_token || '暂无'}
									</p>
								</div>
							</div>

							{nodeInstallCommand ? <CodeBlock className='whitespace-pre-wrap'>{nodeInstallCommand}</CodeBlock> : null}
						</div>
					) : (
						<EmptyState title='尚未选择节点' description='可在下方节点列表中点击“部署命令”或创建节点后自动查看专属命令。' />
					)}
				</AppCard>
			</div>

			<AppCard title='节点列表' description='展示心跳、最近应用结果、版本信息与更新状态，可直接执行管理动作。'>
				{nodesQuery.isLoading ? (
					<LoadingState />
				) : nodesQuery.isError ? (
					<ErrorState title='节点列表加载失败' description={getErrorMessage(nodesQuery.error)} />
				) : nodes.length === 0 ? (
					<EmptyState title='暂无节点' description='请先创建一个节点，或使用 Discovery Token 在目标机器上接入新节点。' />
				) : (
					<div className='overflow-x-auto'>
						<table className='min-w-full divide-y divide-[var(--border-default)] text-left text-sm'>
							<thead>
								<tr className='text-[var(--foreground-secondary)]'>
									<th className='px-3 py-3 font-medium'>节点</th>
									<th className='px-3 py-3 font-medium'>状态</th>
									<th className='px-3 py-3 font-medium'>更新模式</th>
									<th className='px-3 py-3 font-medium'>Agent / Nginx</th>
									<th className='px-3 py-3 font-medium'>当前版本</th>
									<th className='px-3 py-3 font-medium'>最近应用</th>
									<th className='px-3 py-3 font-medium'>最近心跳</th>
									<th className='px-3 py-3 font-medium'>错误</th>
									<th className='px-3 py-3 font-medium'>操作</th>
								</tr>
							</thead>
							<tbody className='divide-y divide-[var(--border-default)]'>
								{nodes.map((node) => {
									const updateMode = getUpdateMode(node);

									return (
										<tr key={node.id} className='align-top'>
											<td className='px-3 py-4'>
												<div className='space-y-2'>
													<p className='font-medium text-[var(--foreground-primary)]'>{node.name}</p>
													<p className='text-xs text-[var(--foreground-secondary)]'>Node ID：{node.node_id}</p>
													<p className='break-all text-xs text-[var(--foreground-secondary)]'>
														Token：{node.agent_token || '暂无'}
													</p>
													<p className='text-xs text-[var(--foreground-secondary)]'>IP：{node.ip || '暂无'}</p>
												</div>
											</td>
											<td className='px-3 py-4'>
												<div className='space-y-2'>
													<StatusBadge label={getStatusLabel(node.status)} variant={getStatusVariant(node.status)} />
													<StatusBadge
														label={node.pending ? '未占用' : '已绑定'}
														variant={node.pending ? 'warning' : 'success'}
													/>
												</div>
											</td>
											<td className='px-3 py-4'>
												<StatusBadge label={updateMode.label} variant={updateMode.variant} />
											</td>
											<td className='px-3 py-4 text-[var(--foreground-secondary)]'>
												{node.agent_version || 'unknown'} / {node.nginx_version || 'unknown'}
											</td>
											<td className='px-3 py-4 text-[var(--foreground-secondary)]'>
												{node.current_version || '未应用'}
											</td>
											<td className='px-3 py-4'>
												<div className='space-y-2'>
													<StatusBadge
														label={getApplyLabel(node.latest_apply_result)}
														variant={getApplyVariant(node.latest_apply_result)}
													/>
													<p className='max-w-56 text-xs leading-5 text-[var(--foreground-secondary)]'>
														{node.latest_apply_message || '暂无记录'}
													</p>
													<p className='text-xs text-[var(--foreground-secondary)]'>
														{isMeaningfulTime(node.latest_apply_at)
															? `${formatRelativeTime(node.latest_apply_at)} · ${formatDateTime(node.latest_apply_at)}`
															: '暂无'}
													</p>
												</div>
											</td>
											<td className='px-3 py-4 text-[var(--foreground-secondary)]'>
												{isMeaningfulTime(node.last_seen_at)
													? `${formatRelativeTime(node.last_seen_at)} · ${formatDateTime(node.last_seen_at)}`
													: '暂无'}
											</td>
											<td className='px-3 py-4 text-[var(--foreground-secondary)]'>
												<p className='max-w-56 whitespace-pre-wrap break-words'>
													{node.last_error || '无'}
												</p>
											</td>
											<td className='px-3 py-4'>
												<div className='flex flex-wrap gap-2'>
													<PrimaryButton
														type='button'
														onClick={() => updateAgentMutation.mutate(node.id)}
														disabled={updateAgentMutation.isPending || node.update_requested}
														className='px-3 py-2 text-xs'
													>
														立即更新
													</PrimaryButton>
													<SecondaryButton
														type='button'
														onClick={() => setSelectedNode(node)}
														className='px-3 py-2 text-xs'
													>
														部署命令
													</SecondaryButton>
													<SecondaryButton
														type='button'
														onClick={() => handleEdit(node)}
														className='px-3 py-2 text-xs'
													>
														编辑
													</SecondaryButton>
													<DangerButton
														type='button'
														onClick={() => handleDelete(node)}
														disabled={deleteMutation.isPending}
														className='px-3 py-2 text-xs'
													>
														删除
													</DangerButton>
												</div>
											</td>
										</tr>
									);
								})}
							</tbody>
						</table>
					</div>
				)}
			</AppCard>
			</div>
			<AppModal
				isOpen={isEditorOpen}
				onClose={handleReset}
				title={editingNodeId ? '编辑节点' : '新增节点'}
				description='预创建节点后会立即生成节点专属 Token，可继续复制专属安装命令。'
				footer={
					<div className='flex flex-wrap justify-end gap-3'>
						<SecondaryButton type='button' onClick={handleReset} disabled={saveMutation.isPending}>
							取消
						</SecondaryButton>
						<PrimaryButton type='submit' form='node-editor-form' disabled={saveMutation.isPending}>
							{saveMutation.isPending ? '保存中...' : editingNodeId ? '保存修改' : '新增节点'}
						</PrimaryButton>
					</div>
				}
			>
				<form id='node-editor-form' className='space-y-5' onSubmit={handleSubmit}>
					<ResourceField label='节点名' hint='示例：shanghai-edge-1' error={form.formState.errors.name?.message}>
						<ResourceInput placeholder='shanghai-edge-1' {...form.register('name')} />
					</ResourceField>

					<ToggleField
						label='启用自动更新'
						description='开启后 Agent 心跳返回会提示节点自动执行自更新。'
						checked={watchedAutoUpdate}
						onChange={(checked) =>
							form.setValue('auto_update_enabled', checked, {
								shouldDirty: true,
								shouldValidate: true,
							})
						}
					/>
				</form>
			</AppModal>
		</>
	);
}