frontend/src/components/UploadStep.jsx

import React, { useState } from 'react';
import axios from 'axios';
import { FaCloudUploadAlt, FaFileExcel, FaFilePdf, FaSpinner } from 'react-icons/fa';
import { motion } from 'framer-motion';

const UploadStep = ({ onUploadSuccess }) => {
    const [excelFile, setExcelFile] = useState(null);
    const [pdfFile, setPdfFile] = useState(null);
    const [loading, setLoading] = useState(false);
    const [error, setError] = useState(null);

    const handleUpload = async () => {
        if (!excelFile || !pdfFile) {
            setError("Please select both files.");
            return;
        }

        setLoading(true);
        setError(null);

        const formData = new FormData();
        formData.append("excel_file", excelFile);
        formData.append("pdf_file", pdfFile);

        try {
            const response = await axios.post("/api/certificates/upload", formData, {
                headers: { "Content-Type": "multipart/form-data" }
            });
            onUploadSuccess(response.data);
        } catch (err) {
            setError("Upload failed. Please try again.");
            console.error(err);
        } finally {
            setLoading(false);
        }
    };

    const FileInput = ({ accept, label, icon: Icon, file, setFile }) => (
        <motion.div
            whileHover={{ y: -4 }}
            className={`relative border-2 border-dashed rounded-lg p-8 text-center transition-all cursor-pointer ${file ? 'border-blue-500 bg-blue-50' : 'border-gray-300 bg-white hover:border-blue-400 hover:bg-gray-50'
                }`}
        >
            <input
                type="file"
                accept={accept}
                onChange={(e) => setFile(e.target.files[0])}
                className="absolute inset-0 w-full h-full opacity-0 cursor-pointer z-10"
            />
            <div className="flex flex-col items-center pointer-events-none">
                <div className={`w-16 h-16 rounded-full flex items-center justify-center mb-4 ${file ? 'bg-blue-100' : 'bg-gray-100'
                    }`}>
                    <Icon className={`text-3xl ${file ? 'text-blue-600' : 'text-gray-400'}`} />
                </div>
                <h3 className="text-base font-semibold text-gray-900 mb-1">{label}</h3>
                <p className="text-sm text-gray-500">
                    {file ? (
                        <span className="text-blue-600 font-medium">{file.name}</span>
                    ) : (
                        "Click to browse or drag & drop"
                    )}
                </p>
            </div>
        </motion.div>
    );

    return (
        <div className="max-w-3xl mx-auto">
            <div className="text-center mb-8">
                <h2 className="text-2xl font-bold text-gray-900 mb-2">Upload Files</h2>
                <p className="text-gray-600">Upload your attendee list and certificate template to begin.</p>
            </div>

            <div className="grid grid-cols-1 md:grid-cols-2 gap-6 mb-8">
                <FileInput
                    accept=".xlsx"
                    label="Attendee Data (.xlsx)"
                    icon={FaFileExcel}
                    file={excelFile}
                    setFile={setExcelFile}
                />
                <FileInput
                    accept=".pdf"
                    label="Certificate Template (.pdf)"
                    icon={FaFilePdf}
                    file={pdfFile}
                    setFile={setPdfFile}
                />
            </div>

            {error && (
                <motion.div
                    initial={{ opacity: 0, y: -10 }}
                    animate={{ opacity: 1, y: 0 }}
                    className="bg-red-50 border border-red-200 text-red-700 px-4 py-3 rounded-lg mb-6 text-center text-sm"
                >
                    {error}
                </motion.div>
            )}

            <div className="flex justify-center">
                <motion.button
                    whileHover={{ scale: 1.02 }}
                    whileTap={{ scale: 0.98 }}
                    onClick={handleUpload}
                    disabled={loading}
                    className={`flex items-center justify-center space-x-2 py-3 px-8 rounded-lg text-white font-semibold shadow-md transition-all ${loading ? 'bg-gray-400 cursor-not-allowed' : 'bg-blue-600 hover:bg-blue-700 hover:shadow-lg'
                        }`}
                >
                    {loading ? (
                        <>
                            <FaSpinner className="animate-spin" />
                            <span>Processing...</span>
                        </>
                    ) : (
                        <>
                            <FaCloudUploadAlt className="text-xl" />
                            <span>Upload & Continue</span>
                        </>
                    )}
                </motion.button>
            </div>
        </div>
    );
};

export default UploadStep;