"use client";

import { useEffect, useState, useCallback } from "react";
import { createClient } from "@/lib/supabase/client";
import Card, { CardHeader } from "@/components/ui/Card";
import KpiCard from "@/components/ui/KpiCard";
import { Table, Td, EmptyRow } from "@/components/ui/Table";
import Spinner from "@/components/ui/Spinner";
import { formatDate } from "@/lib/format";
import { Award, TrendingUp } from "lucide-react";

export default function MyMerit() {
  const supabase = createClient();
  const [loading, setLoading] = useState(true);
  const [total, setTotal] = useState(0);
  const [rows, setRows] = useState<any[]>([]);

  const load = useCallback(async () => {
    const { data: u } = await supabase.auth.getUser();
    if (!u.user) return;
    const [prof, tx] = await Promise.all([
      supabase.from("profiles").select("total_merit").eq("id", u.user.id).single(),
      supabase
        .from("merit_transactions")
        .select("id, points, reason, created_at, programs(title)")
        .eq("volunteer_id", u.user.id)
        .order("created_at", { ascending: false }),
    ]);
    setTotal(prof.data?.total_merit ?? 0);
    setRows(tx.data ?? []);
    setLoading(false);
  }, [supabase]);

  useEffect(() => {
    load();
  }, [load]);

  if (loading) return <Spinner label="Loading your merit…" />;

  const earned = rows.length;

  return (
    <div className="space-y-6">
      <div>
        <h1 className="text-2xl font-extrabold text-ink">My Merit</h1>
        <p className="text-sm text-muted">Points you've earned through volunteering.</p>
      </div>

      <div className="grid gap-4 sm:grid-cols-2">
        <KpiCard label="Total Merit" value={total} icon={<Award size={20} />} tone="emerald" />
        <KpiCard label="Awards Received" value={earned} icon={<TrendingUp size={20} />} tone="teal" />
      </div>

      <Card>
        <CardHeader title="Merit history" />
        <Table headers={["Date", "Program", "Reason", "Points"]}>
          {rows.length === 0 ? (
            <EmptyRow colSpan={4} message="No merit points yet. Join a program to start earning!" />
          ) : (
            rows.map((r) => (
              <tr key={r.id}>
                <Td>{formatDate(r.created_at)}</Td>
                <Td className="font-semibold">{r.programs?.title ?? "—"}</Td>
                <Td>{r.reason || "—"}</Td>
                <Td>
                  <span className={r.points >= 0 ? "font-bold text-emerald" : "font-bold text-error"}>
                    {r.points >= 0 ? `+${r.points}` : r.points}
                  </span>
                </Td>
              </tr>
            ))
          )}
        </Table>
      </Card>
    </div>
  );
}