import os
import uuid
from flask import Flask, request, jsonify, render_template, send_from_directory, url_for
from werkzeug.utils import secure_filename
from dotenv import load_dotenv
from tasks import (
    celery, 
    extract_audio_task,
    transcribe_audio_task,
    translate_segments_task,
    summarize_text_task
)

# --- Flask App 設定 ---
load_dotenv()
app = Flask(__name__)

project_root = os.path.dirname(os.path.abspath(__file__))
UPLOAD_FOLDER = os.path.join(project_root, 'uploads')

if not os.path.exists(UPLOAD_FOLDER):
    os.makedirs(UPLOAD_FOLDER)
app.config['UPLOAD_FOLDER'] = UPLOAD_FOLDER
app.config['MAX_CONTENT_LENGTH'] = 1024 * 1024 * 1024  # 限制上傳大小為 1GB

def save_uploaded_file(file_key='file'):
    """一個輔助函式，用於儲存上傳的檔案並回傳路徑。"""
    if file_key not in request.files:
        return None, (jsonify({'error': '請求中沒有檔案部分'}), 400)
    file = request.files[file_key]
    if file.filename == '':
        return None, (jsonify({'error': '未選擇檔案'}), 400)
    if file:
        original_filename = secure_filename(file.filename)
        file_extension = os.path.splitext(original_filename)[1]
        unique_filename = f"{uuid.uuid4()}{file_extension}"
        file_path = os.path.join(app.config['UPLOAD_FOLDER'], unique_filename)
        file.save(file_path)
        return file_path, None
    return None, (jsonify({'error': '未知的檔案錯誤'}), 500)

# --- API 路由 (Endpoints) ---
@app.route('/')
def index():
    return render_template('index.html')

@app.route('/extract_audio', methods=['POST'])
def handle_extract_audio():
    input_path, error = save_uploaded_file()
    if error: return error
    
    output_audio_path = os.path.splitext(input_path)[0] + ".wav"
    task = extract_audio_task.delay(input_path, output_audio_path)
    return jsonify({'task_id': task.id, 'status_url': url_for('get_task_status', task_id=task.id)}), 202

@app.route('/transcribe_audio', methods=['POST'])
def handle_transcribe_audio():
    input_path, error = save_uploaded_file()
    if error: return error
    
    language = request.form.get('language', 'auto')
    use_demucs = request.form.get('use_demucs') == 'on'
    
    output_txt_path = os.path.splitext(input_path)[0] + ".txt"
    
    task = transcribe_audio_task.delay(input_path, output_txt_path, language, use_demucs)
    
    return jsonify({'task_id': task.id, 'status_url': url_for('get_task_status', task_id=task.id)}), 202

@app.route('/translate_text', methods=['POST'])
def handle_translate_text():
    input_path, error = save_uploaded_file()
    if error: return error
        
    target_language = request.form.get('target_language', '繁體中文')
    output_txt_path = os.path.splitext(input_path)[0] + "_translated.txt"
    task = translate_segments_task.delay(input_path, output_txt_path, target_language)
    return jsonify({'task_id': task.id, 'status_url': url_for('get_task_status', task_id=task.id)}), 202
    
@app.route('/summarize_text', methods=['POST'])
def handle_summarize_text():
    data = request.get_json()
    if not data or 'text_content' not in data:
        return jsonify({'error': '請求中缺少 text_content'}), 400
        
    text_content = data['text_content']
    target_language = data.get('target_language', '繁體中文')
    conversation_id = data.get('conversation_id')
    revision_instruction = data.get('revision_instruction')

    task = summarize_text_task.delay(text_content, target_language, conversation_id, revision_instruction)
    return jsonify({'task_id': task.id, 'status_url': url_for('get_task_status', task_id=task.id)}), 202

# --- 通用狀態查詢和下載 ---
@app.route('/status/<task_id>')
def get_task_status(task_id):
    task = celery.AsyncResult(task_id)
    response_data = {'state': task.state, 'info': task.info if isinstance(task.info, dict) else str(task.info)}
    
    if task.state == 'SUCCESS' and isinstance(task.info, dict) and 'result_path' in task.info and task.info['result_path']:
        response_data['info']['download_url'] = url_for('download_file', filename=os.path.basename(task.info['result_path']))
        
    return jsonify(response_data)

@app.route('/download/<filename>')
def download_file(filename):
    return send_from_directory(app.config['UPLOAD_FOLDER'], filename, as_attachment=True)

# --- 主程式入口 ---
if __name__ == '__main__':
    port = int(os.environ.get("FLASK_RUN_PORT", 5000))
    app.run(host='0.0.0.0', port=port, debug=True)