import os
from flask import Flask, request, render_template, send_from_directory, flash, redirect, url_for
from werkzeug.utils import secure_filename
from transform_data import process_with_rounding

# --- 設定 ---
UPLOAD_FOLDER = 'uploads' # 用於儲存上傳和處理後的檔案
ALLOWED_EXTENSIONS = {'xls', 'xlsx'}

app = Flask(__name__)
app.config['UPLOAD_FOLDER'] = UPLOAD_FOLDER
app.config['SECRET_KEY'] = 'supersecretkey' # Flask 需要一個密鑰來顯示提示訊息

# --- 輔助函式 ---
def allowed_file(filename):
    return '.' in filename and \
           filename.rsplit('.', 1)[1].lower() in ALLOWED_EXTENSIONS

# --- 路由定義 ---
@app.route('/', methods=['GET', 'POST'])
def upload_file():
    if request.method == 'POST':
        # 檢查是否有上傳檔案
        if 'file' not in request.files:
            flash('沒有檔案部分')
            return redirect(request.url)
        file = request.files['file']
        # 如果使用者未選擇檔案，瀏覽器也會送出一個沒有檔名的空檔案
        if file.filename == '':
            flash('未選擇檔案')
            return redirect(request.url)
        
        if file and allowed_file(file.filename):
            filename = secure_filename(file.filename)
            
            # 建立上傳資料夾 (如果不存在)
            if not os.path.exists(app.config['UPLOAD_FOLDER']):
                os.makedirs(app.config['UPLOAD_FOLDER'])
                
            input_path = os.path.join(app.config['UPLOAD_FOLDER'], filename)
            file.save(input_path)
            
            # 產生最終檔案名稱
            base, ext = os.path.splitext(filename)
            final_filename = f"{base}_final_rounded.xlsx"
            
            # 呼叫您既有的處理函式
            try:
                process_with_rounding(input_path, final_filename)
                # 提供下載連結
                return redirect(url_for('download_file', name=final_filename))
            except Exception as e:
                flash(f'處理檔案時發生錯誤: {e}')
                return redirect(request.url)

    return render_template('index.html')

@app.route('/uploads/<name>')
def download_file(name):
    return send_from_directory(app.config['UPLOAD_FOLDER'], name)

# --- 啟動伺服器 ---
if __name__ == '__main__':
    # 使用 host='0.0.0.0' 讓區域網路中的其他電腦可以存取
    # 在生產環境中，建議設置 debug=False
    app.run(debug=False, host='0.0.0.0', port=12001)