"use client";

import { useEffect, useState } from "react";
import { fetchPurchaseOrders } from "../lib/api";
import { PurchaseOrder } from "../lib/types";
import BrandLoader from "./BrandLoader";

export default function MarketMonitor() {
  const [ocs, setOcs] = useState<PurchaseOrder[]>([]);
  const [isLoading, setIsLoading] = useState(true);
  const [error, setError] = useState<string | null>(null);
  const [filter, setFilter] = useState("todos");
  const [page, setPage] = useState(1);
  const itemsPerPage = 50;

  useEffect(() => {
    loadOcs();
    setPage(1); // Reset page on filter change
  }, [filter]);

  async function loadOcs() {
    setIsLoading(true);
    setError(null);
    try {
      const data = await fetchPurchaseOrders(undefined, filter);
      if (!data || data.length === 0) {
        setError("No purchase orders found for today. Try again later or check your API connection.");
        setOcs([]);
      } else {
        // Sort by code descending (usually higher codes are newer)
        const sorted = [...data].sort((a, b) => b.code.localeCompare(a.code));
        setOcs(sorted);
      }
    } catch (e) {
      const errorMsg = e instanceof Error ? e.message : "Failed to load purchase orders. Check your backend connection.";
      console.error("OC Load Error:", e);
      setError(errorMsg);
      setOcs([]);
    } finally {
      setIsLoading(false);
    }
  }

  const formatCurrency = (amount: number | null, currency: string | null) => {
    if (!amount || amount === 0) return <span className="text-slate-600 italic">Pending...</span>;
    return new Intl.NumberFormat("es-CL", {
      style: "currency",
      currency: currency || "CLP",
      maximumFractionDigits: 0
    }).format(amount);
  };

  const paginatedOcs = ocs.slice((page - 1) * itemsPerPage, page * itemsPerPage);
  const totalPages = Math.ceil(ocs.length / itemsPerPage);

  return (
    <div className="space-y-8 animate-in fade-in duration-700">
      <div className="flex flex-col md:flex-row md:items-center justify-between gap-6">
        <div>
          <p className="text-[10px] uppercase tracking-[0.4em] text-cyan/60 font-black mb-2">Real-Time Intelligence</p>
          <h2 className="text-4xl font-black text-white tracking-tight">Market Monitor</h2>
          <div className="flex items-center gap-3 mt-2">
             <span className="flex h-2 w-2 rounded-full bg-green-500 animate-pulse" />
             <p className="text-slate-400 text-sm">
                Monitoring <span className="text-white font-bold">{ocs.length.toLocaleString()}</span> active orders from today.
             </p>
          </div>
        </div>

        <div className="flex bg-slate-900/50 p-1 rounded-2xl border border-white/5 backdrop-blur-xl">
          {["todos", "aceptada", "enviadaproveedor"].map((f) => (
            <button
              key={f}
              onClick={() => setFilter(f)}
              className={`px-6 py-2.5 rounded-xl text-[10px] uppercase font-black tracking-widest transition-all ${
                filter === f ? "bg-cyan text-slate-950 shadow-lg shadow-cyan/20" : "text-slate-500 hover:text-white"
              }`}
            >
              {f === "todos" ? "Live Stream" : f}
            </button>
          ))}
        </div>
      </div>

      <div className="grid gap-6">
        {isLoading ? (
          <div className="py-20">
            <BrandLoader />
          </div>
        ) : error ? (
          <div className="glass-card rounded-[2rem] p-8 border border-red-500/20 bg-red-500/5">
            <div className="flex items-start gap-4">
              <div className="text-2xl">⚠️</div>
              <div className="flex-1">
                <h3 className="text-white font-bold mb-2">Connection Error</h3>
                <p className="text-slate-300 text-sm mb-4">{error}</p>
                <div className="flex gap-3">
                  <button
                    onClick={loadOcs}
                    className="px-6 py-2 bg-cyan text-slate-950 font-bold rounded-lg hover:bg-cyan/90 transition-all"
                  >
                    🔄 Retry
                  </button>
                  <a
                    href="#"
                    className="px-6 py-2 bg-white/5 border border-white/10 text-white font-bold rounded-lg hover:bg-white/10 transition-all"
                  >
                    Troubleshoot
                  </a>
                </div>
              </div>
            </div>
          </div>
        ) : ocs.length > 0 ? (
          <>
            <div className="glass-card rounded-[2rem] overflow-hidden border border-white/5 shadow-2xl shadow-black/50">
              <div className="overflow-x-auto custom-scrollbar max-h-[600px]">
                <table className="w-full text-left text-xs border-collapse sticky-header">
                  <thead className="sticky top-0 z-10">
                    <tr className="bg-slate-900/95 backdrop-blur-md text-slate-500 uppercase font-black tracking-tighter border-b border-white/5">
                      <th className="px-4 sm:px-6 py-5">Order ID / Description</th>
                      <th className="px-6 py-5 hidden md:table-cell">Buyer</th>
                      <th className="px-6 py-5 hidden lg:table-cell">Vendor</th>
                      <th className="px-4 sm:px-6 py-5 text-right">Total</th>
                    </tr>
                  </thead>
                  <tbody className="divide-y divide-white/5">
                    {paginatedOcs.map((oc) => (
                      <tr key={oc.code} className="hover:bg-white/[0.03] transition-colors group">
                        <td className="px-4 sm:px-6 py-5 max-w-md">
                          <div className="flex items-center gap-2 mb-1">
                            <span className="text-cyan font-bold font-mono text-[9px] bg-cyan/5 px-2 py-0.5 rounded border border-cyan/10">
                              {oc.code}
                            </span>
                          </div>
                          <div className="text-white font-bold line-clamp-1 group-hover:line-clamp-none transition-all cursor-help text-xs sm:text-sm" title={oc.name}>
                            {oc.name || "Orden de Compra"}
                          </div>
                          <div className="md:hidden text-[10px] text-slate-500 mt-1 truncate max-w-[200px]">
                            {oc.buyer}
                          </div>
                        </td>
                        <td className="px-6 py-5 hidden md:table-cell">
                          <div className="text-slate-300 font-medium truncate max-w-[150px] text-[11px]">
                            {oc.buyer !== "Unknown" ? oc.buyer : <span className="opacity-30">...</span>}
                          </div>
                        </td>
                        <td className="px-6 py-5 hidden lg:table-cell">
                          <div className="text-sky-400 font-bold truncate max-w-[150px] text-[11px]">
                            {oc.provider !== "Unknown" ? oc.provider : <span className="opacity-30">...</span>}
                          </div>
                        </td>
                        <td className="px-4 sm:px-6 py-5 text-right">
                          <div className="text-white font-black text-xs sm:text-sm">
                            {formatCurrency(oc.total_amount, oc.currency)}
                          </div>
                        </td>
                      </tr>
                    ))}
                  </tbody>
                </table>
              </div>
            </div>

            {/* Pagination Controls */}
            <div className="flex items-center justify-between px-4">
              <div className="text-[10px] text-slate-500 font-bold uppercase tracking-widest">
                Showing {((page - 1) * itemsPerPage) + 1} to {Math.min(page * itemsPerPage, ocs.length)} of {ocs.length}
              </div>
              <div className="flex gap-2">
                <button 
                  disabled={page === 1}
                  onClick={() => setPage(p => p - 1)}
                  className="px-4 py-2 rounded-lg bg-white/5 border border-white/10 text-xs font-bold disabled:opacity-30 hover:bg-white/10"
                >
                  Previous
                </button>
                <button 
                  disabled={page === totalPages}
                  onClick={() => setPage(p => p + 1)}
                  className="px-4 py-2 rounded-lg bg-white/5 border border-white/10 text-xs font-bold disabled:opacity-30 hover:bg-white/10"
                >
                  Next
                </button>
              </div>
            </div>
          </>
        ) : (
          <div className="py-40 text-center glass-card rounded-[2rem] border border-white/5">
            <div className="text-4xl mb-4">🛒</div>
            <p className="text-slate-500 font-medium italic">No purchase orders detected in the last hour.</p>
          </div>
        )}
      </div>
    </div>
  );
}