import sqlite3
import json
import uuid
from datetime import datetime

def get_db_connection():
    """获取数据库连接"""
    conn = sqlite3.connect('prediction_history.db', check_same_thread=False)
    conn.row_factory = sqlite3.Row
    return conn

def save_model_to_db(model_data: dict):
    """
    将训练完成的模型元数据保存到数据库的 models 表中。
    """
    conn = get_db_connection()
    cursor = conn.cursor()
    
    try:
        # 生成唯一的模型UID
        model_uid = f"{model_data.get('training_mode', 'model')}_{model_data.get('model_type', 'default')}_{uuid.uuid4().hex[:8]}"

        cursor.execute(
            """
            INSERT INTO models (
                model_uid, display_name, model_type, training_mode, 
                training_scope, parent_model_id, version, status, 
                training_params, performance_metrics, artifacts, created_at
            ) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
            """,
            (
                model_uid,
                model_data.get('display_name'),
                model_data.get('model_type'),
                model_data.get('training_mode'),
                json.dumps(model_data.get('training_scope')),
                model_data.get('parent_model_id'),
                model_data.get('version'),
                'active',
                json.dumps(model_data.get('training_params')),
                json.dumps(model_data.get('performance_metrics')),
                json.dumps(model_data.get('artifacts')),
                datetime.now().isoformat()
            )
        )
        conn.commit()
        print(f"✅ 模型元数据已成功保存到数据库，UID: {model_uid}")
        return model_uid
    except Exception as e:
        print(f"❌ 保存模型元数据到数据库失败: {e}")
        conn.rollback()
        return None
    finally:
        conn.close()

def query_models_from_db(filters: dict, page: int = 1, page_size: int = 10):
    """
    从数据库查询模型列表，支持筛选和分页。
    """
    conn = get_db_connection()
    cursor = conn.cursor()
    
    try:
        query = "SELECT * FROM models"
        conditions = []
        params = []
        
        if filters.get('product_id'):
            conditions.append("json_extract(training_scope, '$.product.id') = ?")
            params.append(filters['product_id'])
        
        if filters.get('model_type'):
            conditions.append("model_type = ?")
            params.append(filters['model_type'])
        
        if filters.get('store_id'):
            conditions.append("json_extract(training_scope, '$.store.id') = ?")
            params.append(filters['store_id'])
            
        if filters.get('training_mode'):
            conditions.append("training_mode = ?")
            params.append(filters['training_mode'])
            
        if conditions:
            query += " WHERE " + " AND ".join(conditions)
            
        # 获取总数
        count_query = query.replace("*", "COUNT(*)")
        cursor.execute(count_query, params)
        total_count = cursor.fetchone()[0]
        
        # 添加分页
        offset = (page - 1) * page_size
        query += " ORDER BY created_at DESC LIMIT ? OFFSET ?"
        params.extend([page_size, offset])
        
        cursor.execute(query, params)
        models = [dict(row) for row in cursor.fetchall()]
        
        return {
            "models": models,
            "pagination": {
                "total": total_count,
                "page": page,
                "page_size": page_size,
                "total_pages": (total_count + page_size - 1) // page_size
            }
        }
        
    except Exception as e:
        print(f"❌ 从数据库查询模型失败: {e}")
        return {"models": [], "pagination": {}}
    finally:
        conn.close()

def save_prediction_to_db(prediction_data: dict):
    """
    将单次预测记录保存到数据库。
    """
    conn = get_db_connection()
    cursor = conn.cursor()
    try:
        cursor.execute('''
            INSERT INTO prediction_history (
                prediction_uid, model_id, model_type, product_name,
                prediction_scope, prediction_params, metrics, result_file_path
            ) VALUES (?, ?, ?, ?, ?, ?, ?, ?)
        ''', (
            prediction_data.get('prediction_uid'),
            prediction_data.get('model_id'), # This should be the model_uid from the 'models' table
            prediction_data.get('model_type'),
            prediction_data.get('product_name'),
            json.dumps(prediction_data.get('prediction_scope')),
            json.dumps(prediction_data.get('prediction_params')),
            json.dumps(prediction_data.get('metrics')),
            prediction_data.get('result_file_path')
        ))
        conn.commit()
        print(f"✅ 预测记录 {prediction_data.get('prediction_uid')} 已保存到数据库。")
    except Exception as e:
        print(f"❌ 保存预测记录到数据库失败: {e}")
        conn.rollback()
    finally:
        conn.close()

def find_model_by_uid(model_uid: str):
    """
    根据 model_uid 从数据库中查找模型。
    """
    conn = get_db_connection()
    cursor = conn.cursor()
    try:
        cursor.execute("SELECT * FROM models WHERE model_uid = ?", (model_uid,))
        model_record = cursor.fetchone()
        if model_record:
            return dict(model_record)
        return None
    except Exception as e:
        print(f"❌ 根据UID查找模型失败: {e}")
        return None
    finally:
        conn.close()