from flask import Flask, render_template, request, send_file
import pandas as pd
from compare_gst_excel import find_unmatched_rows
import os
from werkzeug.utils import secure_filename

app = Flask(__name__)
UPLOAD_FOLDER = 'uploads'
RESULT_FILE = 'unmatched_result.xlsx'

if not os.path.exists(UPLOAD_FOLDER):
    os.makedirs(UPLOAD_FOLDER)

@app.route('/')
def index():
    return render_template('upload.html')

@app.route('/upload', methods=['POST'])
def upload_file():
    file = request.files['excel_file']
    if not file:
        return "No file uploaded.", 400

    filename = secure_filename(file.filename)
    filepath = os.path.join(UPLOAD_FOLDER, filename)
    file.save(filepath)

    try:
        # Read Excel with header in row 8 (0-indexed), so header=7
        df1 = pd.read_excel(filepath, sheet_name=0, header=7)
        df2 = pd.read_excel(filepath, sheet_name=1, header=7)

        unmatched = find_unmatched_rows(df1, df2)
        unmatched.to_excel(RESULT_FILE, index=False)

        return send_file(RESULT_FILE, as_attachment=True)

    except Exception as e:
        return f"Error processing file: {e}", 500

if __name__ == '__main__':
    app.run(host='0.0.0.0', port=5000,debug=True)