"use client";
import { useEffect, useState } from "react";
import { fetchClient } from "@/lib/api-client";

interface Vendor {
  _id: string;
  username: string;
  isAdmin: boolean;
  createdAt: string;
  lastLogin?: string;
}

interface PaginationResponse {
  success: boolean;
  vendors: Vendor[];
  pagination: {
    page: number;
    limit: number;
    total: number;
    totalPages: number;
    hasNextPage: boolean;
    hasPrevPage: boolean;
  };
}

export default function VendorsCard() {
  const [vendors, setVendors] = useState<Vendor[]>([]);
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState<string | null>(null);
  const [resetTokens, setResetTokens] = useState<Record<string, string>>({});
  const [page, setPage] = useState(1);
  const [pagination, setPagination] = useState<PaginationResponse['pagination'] | null>(null);

  useEffect(() => {
    let mounted = true;
    (async () => {
      try {
        setLoading(true);
        const data = await fetchClient<PaginationResponse>(`/admin/vendors?page=${page}&limit=10`);
        if (mounted) {
          setVendors(data.vendors);
          setPagination(data.pagination);
        }
      } catch (e: any) {
        if (mounted) setError(e?.message || "Failed to load vendors");
      } finally {
        if (mounted) setLoading(false);
      }
    })();
    return () => { mounted = false; };
  }, [page]);

  async function generateResetToken(vendorId: string) {
    try {
      const res = await fetchClient<{ token: string; expiresAt: string }>("/admin/password-reset-token", {
        method: "POST",
        body: { vendorId }
      });
      setResetTokens(prev => ({ ...prev, [vendorId]: res.token }));
    } catch (e: any) {
      setError(e?.message || "Failed to generate reset token");
    }
  }

  return (
    <div className="rounded-lg border border-border/60 bg-background p-4 h-full min-h-[200px]">
      <h2 className="font-medium">Vendors</h2>
      <p className="text-sm text-muted-foreground mt-1">Manage vendor accounts and access</p>

      {loading ? (
        <p className="text-sm text-muted-foreground mt-3">Loading...</p>
      ) : error ? (
        <p className="text-sm text-muted-foreground mt-3">{error}</p>
      ) : vendors.length === 0 ? (
        <p className="text-sm text-muted-foreground mt-3">No vendors found</p>
      ) : (
        <>
          <div className="mt-3 space-y-2 max-h-64 overflow-y-auto">
            {vendors.map((vendor) => (
            <div key={vendor._id} className="rounded border border-border/50 p-3 text-sm">
              <div className="flex items-center justify-between">
                <div className="space-y-1">
                  <div className="font-medium">{vendor.username}</div>
                  <div className="text-xs text-muted-foreground">
                    Created: {new Date(vendor.createdAt).toLocaleDateString()}
                    {vendor.lastLogin && ` · Last login: ${new Date(vendor.lastLogin).toLocaleDateString()}`}
                  </div>
                </div>
                <div className="flex items-center gap-2">
                  {vendor.isAdmin && (
                    <span className="text-xs px-2 py-0.5 rounded bg-emerald-500/15 text-emerald-400">
                      Admin
                    </span>
                  )}
                  <button
                    onClick={() => generateResetToken(vendor._id)}
                    className="text-xs px-2 py-1 rounded border border-border hover:bg-muted/40"
                  >
                    Reset Password
                  </button>
                </div>
              </div>
              {resetTokens[vendor._id] && (
                <div className="mt-2 p-2 rounded bg-muted/40 text-xs">
                  <div className="font-mono break-all">{resetTokens[vendor._id]}</div>
                  <div className="text-muted-foreground mt-1">Copy this token to share with the vendor</div>
                </div>
              )}
            </div>
          ))}
          </div>
          {pagination && pagination.totalPages > 1 && (
            <div className="mt-3 flex items-center justify-between text-xs text-muted-foreground">
              <span>
                Page {pagination.page} of {pagination.totalPages} ({pagination.total} total)
              </span>
              <div className="flex gap-2">
                <button
                  onClick={() => setPage(p => Math.max(1, p - 1))}
                  disabled={!pagination.hasPrevPage}
                  className="px-2 py-1 rounded border border-border hover:bg-muted/40 disabled:opacity-50 disabled:cursor-not-allowed"
                >
                  Previous
                </button>
                <button
                  onClick={() => setPage(p => p + 1)}
                  disabled={!pagination.hasNextPage}
                  className="px-2 py-1 rounded border border-border hover:bg-muted/40 disabled:opacity-50 disabled:cursor-not-allowed"
                >
                  Next
                </button>
              </div>
            </div>
          )}
        </>
      )}
    </div>
  );
}