"use client";

import { useEffect, useState } from "react";
import { Card } from "@heroui/react";
import { Thunderbolt, PlugConnection, CreditCard, ChartColumn, TagDollar } from "@gravity-ui/icons";
import { useSession } from "@/lib/auth-client";
import { api, type Stats, type UserStats } from "@/lib/api";

type CardColor = "accent" | "success" | "warning" | "default";

const colorStyles: Record<CardColor, { border: string; bg: string; icon: string }> = {
  accent: { border: "border-accent", bg: "bg-accent/10", icon: "text-accent" },
  success: { border: "border-success", bg: "bg-success/10", icon: "text-success" },
  warning: { border: "border-warning", bg: "bg-warning/10", icon: "text-warning" },
  default: { border: "border-border", bg: "bg-default", icon: "text-muted" },
};

function StatusDot({ color }: { color: "success" | "warning" | "muted" }) {
  const cls =
    color === "success" ? "bg-success" : color === "warning" ? "bg-warning" : "bg-muted/40";
  return <span className={`inline-block h-1.5 w-1.5 shrink-0 rounded-full ${cls}`} />;
}

function StatCard({
  title,
  value,
  footer,
  icon: Icon,
  color = "default",
}: {
  title: string;
  value: string | number;
  footer?: React.ReactNode;
  icon?: React.ComponentType<{ className?: string }>;
  color?: CardColor;
}) {
  const s = colorStyles[color];
  return (
    <Card className={`border-t-2 ${s.border}`}>
      <Card.Content className="flex flex-col gap-3">
        <div className="flex items-start justify-between gap-2">
          <p className="text-sm text-muted">{title}</p>
          {Icon && (
            <div className={`flex size-9 shrink-0 items-center justify-center rounded-xl ${s.bg}`}>
              <Icon className={`size-4.5 ${s.icon}`} />
            </div>
          )}
        </div>
        <p className="text-3xl font-bold tabular-nums leading-none text-foreground">{value}</p>
        {footer && (
          <div className="flex flex-wrap items-center gap-x-1.5 gap-y-1 text-xs text-muted">
            {footer}
          </div>
        )}
      </Card.Content>
    </Card>
  );
}

export default function DashboardPage() {
  const { data: sessionData, isPending } = useSession();
  const isAdmin = sessionData?.user?.role === "admin";

  const [adminStats, setAdminStats] = useState<Stats | null>(null);
  const [userStats, setUserStats] = useState<UserStats | null>(null);

  useEffect(() => {
    if (isPending) return;
    api.stats
      .get()
      .then((data) => {
        if ("todayEnergyWh" in data) {
          setAdminStats(data);
          return;
        }
        setUserStats(data);
      })
      .catch(() => {});
  }, [isPending, isAdmin]);

  if (isPending) {
    return (
      <div className="space-y-6">
        <div>
          <h1 className="text-xl font-semibold text-foreground">概览</h1>
          <p className="mt-0.5 text-sm text-muted">加载中…</p>
        </div>
      </div>
    );
  }

  if (isAdmin) {
    const stats = adminStats;
    const todayKwh = stats ? (stats.todayEnergyWh / 1000).toFixed(1) : "—";
    const offlineCount = (stats?.totalChargePoints ?? 0) - (stats?.onlineChargePoints ?? 0);

    return (
      <div className="space-y-6">
        <div>
          <h1 className="text-xl font-semibold text-foreground">概览</h1>
          <p className="mt-0.5 text-sm text-muted">实时运营状态</p>
        </div>

        <div className="grid grid-cols-1 gap-4 sm:grid-cols-2 xl:grid-cols-5">
          <StatCard
            title="充电桩总数"
            value={stats?.totalChargePoints ?? "—"}
            icon={PlugConnection}
            color="accent"
            footer={
              <>
                <StatusDot color="success" />
                <span className="font-medium text-success">
                  {stats?.onlineChargePoints ?? 0} 在线
                </span>
                <span className="text-border">·</span>
                <span>{offlineCount} 离线</span>
              </>
            }
          />
          <StatCard
            title="在线充电桩"
            value={stats?.onlineChargePoints ?? "—"}
            icon={PlugConnection}
            color="success"
            footer={<span>最近 2 分钟有心跳</span>}
          />
          <StatCard
            title="进行中充电"
            value={stats?.activeTransactions ?? "—"}
            icon={Thunderbolt}
            color={stats?.activeTransactions ? "warning" : "default"}
            footer={
              <>
                <StatusDot color={stats?.activeTransactions ? "success" : "muted"} />
                <span className={stats?.activeTransactions ? "font-medium text-success" : ""}>
                  {stats?.activeTransactions ? "活跃中" : "当前空闲"}
                </span>
              </>
            }
          />
          <StatCard
            title="储值卡总数"
            value={stats?.totalIdTags ?? "—"}
            icon={CreditCard}
            color="default"
            footer={<span>已注册卡片总量</span>}
          />
          <StatCard
            title="今日充电量"
            value={`${todayKwh} kWh`}
            icon={ChartColumn}
            color="accent"
            footer={<span>当日 00:00 起累计</span>}
          />
        </div>
      </div>
    );
  }

  // User view
  const stats = userStats;
  const totalYuan = stats ? (stats.totalBalance / 100).toFixed(2) : "—";

  return (
    <div className="space-y-6">
      <div>
        <h1 className="text-xl font-semibold text-foreground">概览</h1>
        <p className="mt-0.5 text-sm text-muted">
          {sessionData?.user?.name ?? sessionData?.user?.email} 的账户概览
        </p>
      </div>

      <div className="grid grid-cols-1 gap-4 sm:grid-cols-2 xl:grid-cols-4">
        <StatCard
          title="我的储值卡"
          value={stats?.totalIdTags ?? "—"}
          icon={CreditCard}
          color="accent"
          footer={<span>已绑定的储值卡数量</span>}
        />
        <StatCard
          title="账户总余额"
          value={`¥${totalYuan}`}
          icon={TagDollar}
          color="success"
          footer={<span>所有储值卡余额合计</span>}
        />
        <StatCard
          title="进行中充电"
          value={stats?.activeTransactions ?? "—"}
          icon={Thunderbolt}
          color={stats?.activeTransactions ? "warning" : "default"}
          footer={
            <>
              <StatusDot color={stats?.activeTransactions ? "success" : "muted"} />
              <span className={stats?.activeTransactions ? "font-medium text-success" : ""}>
                {stats?.activeTransactions ? "充电中" : "当前空闲"}
              </span>
            </>
          }
        />
        <StatCard
          title="累计充电次数"
          value={stats?.totalTransactions ?? "—"}
          icon={ChartColumn}
          color="default"
          footer={<span>历史总交易笔数</span>}
        />
      </div>
    </div>
  );
}