import {
	ArrowLeftRight,
	Clock,
	DoorOpen,
	MessageSquare,
	TrendingUp,
	Users,
} from "lucide-react";
import { redirect } from "next/navigation";
import { DashboardChart } from "@/components/admin/dashboard-chart";
import { PeakHoursHeatmap } from "@/components/admin/peak-hours-heatmap";
import { StatsCard } from "@/components/admin/stats-card";
import { Card, CardContent, CardHeader, CardTitle } from "@/components/ui/card";
import { canAccess, getAdminContext, PERMS } from "@/lib/permissions";
import { prisma } from "@/lib/prisma";

type AnalyticsData = {
	totalUsers: number;
	onlineUsers: number;
	weekRegistrations: number;
	monthRegistrations: number;
	totalRooms: number;
	activeRooms: number;
	weekChatMessages: number;
	weekTrades: number;
	weekBans: number;
	registrationChart: { label: string; value: number }[];
	peakHours: { grid: number[][]; max: number };
};

const EMPTY: AnalyticsData = {
	totalUsers: 0,
	onlineUsers: 0,
	weekRegistrations: 0,
	monthRegistrations: 0,
	totalRooms: 0,
	activeRooms: 0,
	weekChatMessages: 0,
	weekTrades: 0,
	weekBans: 0,
	registrationChart: [],
	peakHours: {
		grid: Array.from({ length: 7 }, () => Array(24).fill(0)),
		max: 0,
	},
};

async function safeCount(fn: () => Promise<number>): Promise<number> {
	try {
		return await fn();
	} catch {
		return 0;
	}
}

async function getAnalyticsData(): Promise<AnalyticsData> {
	const now = Math.floor(Date.now() / 1000);
	const todayStart = now - (now % 86400);
	const weekAgo = now - 7 * 86400;
	const monthAgo = now - 30 * 86400;

	try {
		const [
			totalUsers,
			onlineUsers,
			weekRegistrations,
			monthRegistrations,
			totalRooms,
			activeRooms,
			weekChatMessages,
			weekTrades,
			weekBans,
		] = await Promise.all([
			safeCount(() => prisma.user.count()),
			safeCount(() => prisma.user.count({ where: { online: "1" } })),
			safeCount(() =>
				prisma.user.count({ where: { accountCreated: { gte: weekAgo } } }),
			),
			safeCount(() =>
				prisma.user.count({ where: { accountCreated: { gte: monthAgo } } }),
			),
			safeCount(() => prisma.rooms.count()),
			safeCount(() => prisma.rooms.count({ where: { users: { gt: 0 } } })),
			(async () => {
				try {
					const rows = await prisma.$queryRaw<{ count: bigint }[]>`
            SELECT COUNT(*) AS count FROM chatlogs_room WHERE timestamp >= ${weekAgo}`;
					return Number(rows[0]?.count ?? 0);
				} catch {
					return 0;
				}
			})(),
			safeCount(() =>
				prisma.roomTradeLog.count({ where: { timestamp: { gte: weekAgo } } }),
			),
			safeCount(() =>
				prisma.ban.count({ where: { timestamp: { gte: weekAgo } } }),
			),
		]);

		let registrationChart: { label: string; value: number }[] = [];
		try {
			const regRows = await prisma.$queryRaw<
				{ day_bucket: bigint; count: bigint }[]
			>`
        SELECT FLOOR(account_created / 86400) AS day_bucket, COUNT(*) AS count
        FROM users
        WHERE account_created >= ${monthAgo}
        GROUP BY day_bucket ORDER BY day_bucket
      `;
			const regCountMap = new Map(
				regRows.map((r) => [Number(r.day_bucket), Number(r.count)]),
			);
			for (let i = 29; i >= 0; i--) {
				const dayStart = todayStart - i * 86400;
				const bucket = Math.floor(dayStart / 86400);
				const date = new Date(dayStart * 1000);
				registrationChart.push({
					label: date.toLocaleDateString("en", {
						month: "short",
						day: "numeric",
					}),
					value: regCountMap.get(bucket) ?? 0,
				});
			}
		} catch {
			registrationChart = [];
		}

		const grid: number[][] = Array.from({ length: 7 }, () => Array(24).fill(0));
		let max = 0;
		try {
			const peakRows = await prisma.$queryRaw<
				{ d: number; h: number; c: bigint }[]
			>`
        SELECT ((DAYOFWEEK(FROM_UNIXTIME(last_online)) + 5) % 7) AS d,
               HOUR(FROM_UNIXTIME(last_online)) AS h,
               COUNT(*) AS c
        FROM users
        WHERE last_online >= ${weekAgo}
        GROUP BY d, h
      `;
			for (const r of peakRows) {
				const day = Number(r.d);
				const hour = Number(r.h);
				if (day < 0 || day > 6 || hour < 0 || hour > 23) continue;
				const count = Number(r.c);
				grid[day][hour] = count;
				if (count > max) max = count;
			}
		} catch {
			/* keep empty grid */
		}

		return {
			totalUsers,
			onlineUsers,
			weekRegistrations,
			monthRegistrations,
			totalRooms,
			activeRooms,
			weekChatMessages,
			weekTrades,
			weekBans,
			registrationChart,
			peakHours: { grid, max },
		};
	} catch {
		return EMPTY;
	}
}

export default async function AnalyticsPage() {
	const { session, permissions } = await getAdminContext();
	if (!canAccess(permissions, PERMS.ANALYTICS_VIEW, session.user.rank)) {
		redirect("/admin");
	}

	const data = await getAnalyticsData();

	return (
		<div className="space-y-6">
			<div className="grid gap-4 md:grid-cols-2 lg:grid-cols-4">
				<StatsCard
					title="Total Users"
					value={data.totalUsers.toLocaleString()}
					description={`${data.onlineUsers} online now`}
					icon={<Users className="h-4 w-4" />}
				/>
				<StatsCard
					title="Week Registrations"
					value={data.weekRegistrations.toLocaleString()}
					description={`${data.monthRegistrations} this month`}
					icon={<TrendingUp className="h-4 w-4" />}
				/>
				<StatsCard
					title="Active Rooms"
					value={data.activeRooms.toLocaleString()}
					description={`${data.totalRooms} total rooms`}
					icon={<DoorOpen className="h-4 w-4" />}
				/>
				<StatsCard
					title="Weekly Activity"
					value={data.weekChatMessages.toLocaleString()}
					description={`${data.weekTrades} trades, ${data.weekBans} bans`}
					icon={<MessageSquare className="h-4 w-4" />}
				/>
			</div>

			<div className="grid gap-6 md:grid-cols-2">
				<DashboardChart
					title="Registrations (30 days)"
					data={data.registrationChart}
					color="hsl(262, 83%, 58%)"
					description="New user registrations over the last 30 days"
				/>
				<PeakHoursHeatmap data={data.peakHours} />
			</div>

			<div className="grid gap-6 md:grid-cols-3">
				<Card>
					<CardHeader>
						<CardTitle className="flex items-center gap-2">
							<MessageSquare className="h-4 w-4" /> Chat Activity
						</CardTitle>
					</CardHeader>
					<CardContent>
						<div className="text-3xl font-bold">
							{data.weekChatMessages.toLocaleString()}
						</div>
						<p className="text-sm text-muted-foreground">
							Messages in the last 7 days
						</p>
					</CardContent>
				</Card>
				<Card>
					<CardHeader>
						<CardTitle className="flex items-center gap-2">
							<ArrowLeftRight className="h-4 w-4" /> Trades
						</CardTitle>
					</CardHeader>
					<CardContent>
						<div className="text-3xl font-bold">
							{data.weekTrades.toLocaleString()}
						</div>
						<p className="text-sm text-muted-foreground">
							Trades in the last 7 days
						</p>
					</CardContent>
				</Card>
				<Card>
					<CardHeader>
						<CardTitle className="flex items-center gap-2">
							<Clock className="h-4 w-4" /> Retention
						</CardTitle>
					</CardHeader>
					<CardContent>
						<div className="text-3xl font-bold">
							{data.totalUsers > 0
								? Math.round((data.onlineUsers / data.totalUsers) * 100)
								: 0}
							%
						</div>
						<p className="text-sm text-muted-foreground">
							Users online / total
						</p>
					</CardContent>
				</Card>
			</div>
		</div>
	);
}