"use client";

import { useEffect, useState } from "react";
import QRCode from "react-qr-code";
import { Printer, AlertCircle } from "lucide-react";

export default function PrintPage() {
  const [items, setItems] = useState([]);
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState(null);

  useEffect(() => {
    const fetchItems = async () => {
      try {
        const res = await fetch("/api/inventory");
        if (!res.ok) throw new Error("Failed to fetch inventory from database");
        const data = await res.json();
        setItems(data);
      } catch (err) {
        setError(err.message);
      } finally {
        setLoading(false);
      }
    };
    fetchItems();
  }, []);

  const handlePrint = () => {
    window.print();
  };

  if (loading) return <div className="p-8 text-center">Loading inventory codes...</div>;
  if (error) return <div className="p-8 text-danger">Error: {error}</div>;

  return (
    <>
      {/* On-screen Controls (Hidden in Print) */}
      <div className="glass no-print" style={{ padding: "2rem", marginBottom: "2rem" }}>
        <div className="flex justify-between items-center">
          <div>
            <h2 className="flex items-center gap-2 mb-2">
              <Printer size={24} className="text-primary" />
              Print QR Labels
            </h2>
            <p className="text-muted">
              Designed for <strong>Avery 5160</strong> standard labels (1" x 2-5/8", 30 per sheet).
            </p>
          </div>
          <button className="btn btn-primary" onClick={handlePrint}>
            <Printer size={18} /> Print Now
          </button>
        </div>
        <div className="flex items-start gap-4 mt-4" style={{ backgroundColor: "rgba(59, 130, 246, 0.1)", padding: "1rem", borderRadius: "8px", border: "1px solid var(--primary)" }}>
          <AlertCircle size={24} className="text-primary flex-shrink-0" />
          <div style={{ fontSize: "0.9rem" }}>
            <strong>Printer Settings to check before printing:</strong>
            <ul style={{ listStyleType: "disc", marginLeft: "1.5rem", marginTop: "0.5rem" }}>
              <li>Scale: <strong>100%</strong> (Do not "Fit to Page")</li>
              <li>Margins: <strong>Custom / None</strong> (Layout handles margins natively)</li>
              <li>Paper Size: <strong>Letter (8.5x11)</strong></li>
              <li>Headers and Footers: <strong>Disable</strong></li>
            </ul>
          </div>
        </div>
      </div>

      {/* Printable Sheet Area */}
      {/* Printable Sheet Area */}
      {Array.from({ length: Math.ceil(items.length / 30) }, (_, pageIndex) => (
        <div key={pageIndex} className="print-container">
          {items.slice(pageIndex * 30, (pageIndex + 1) * 30).map((item) => (
            <div key={item.id} className="label-cell">
              <div className="qr-wrapper">
                <QRCode
                  value={item.qrCodeId || item.id}
                  size={64}
                  level="H"
                  style={{ height: "auto", maxWidth: "100%", width: "100%" }}
                />
              </div>
              <div className="label-text">
                <div className="item-name">{item.name}</div>
                <div className="item-sku">{item.qrCodeId}</div>
              </div>
            </div>
          ))}
        </div>
      ))}


      <style>{`
        /* Standard View Adjustments */
        .print-container {
          display: flex;
          flex-wrap: wrap;
          gap: 1rem;
          padding: 1rem;
          background: white;
          border-radius: 8px;
          min-height: 50vh;
          overflow-y: hidden;
        }

        .label-cell {
          width: calc(33.333% - 1rem); /* Desktop preview layout */
          height: 1in;
          border: 1px dashed #ccc;
          display: flex;
          align-items: center;
          padding: 0.125in;
          box-sizing: border-box;
          color: black;
          font-family: sans-serif;
        }

        .qr-wrapper {
          flex-shrink: 0;
          width: 0.75in;
          height: 0.75in;
          margin-right: 0.1in;
        }

        .label-text {
          display: flex;
          flex-direction: column;
          justify-content: center;
          overflow: hidden;
        }

        .item-name {
          font-weight: bold;
          font-size: 0.55rem;
          white-space: nowrap;
          overflow: hidden;
          text-overflow: ellipsis;
        }

        .item-sku {
          font-size: 0.65rem;
          color: #555;
          margin-top: 0.1rem;
          word-break: break-all;
        }

        @media print {
          @page {
            size: letter;
            margin: 0; /* Reset browser margins entirely */
          }

          body {
            background-color: white !important;
            -webkit-print-color-adjust: exact;
            margin: 0;
            padding: 0;
          }

          .no-print, nav, .navbar {
            display: none !important;
          }

          /* Avery 5160 Layout Grid */
          .print-container {
            display: grid;
            grid-template-columns: repeat(3, 2.625in);
            grid-template-rows: repeat(10, 1in);
            gap: 0;
            padding: 0.5in 0.1250in; /* Top/Bottom 0.5", Left/Right approx 0.1250" */
            width: 8.5in;
            height: 11in;
            background: white;
            border: none;
            border-radius: 0;
            break-after:page;
          }

          .print-container {
            column-gap: 0.125in;
            row-gap: 0;
          }

          .label-cell {
            width: 2.625in !important;
            height: 1in !important;
            border: none !important; /* Remove borders for actual print */
            margin: 0;
            page-break-inside: avoid;
          }
        }
      `}</style>
    </>
  );
}