import sqlite3

from flask import Blueprint, request, jsonify, current_app
from .model import predict, train_and_save_model
import pandas as pd
from . import db  # 从 app 包导入 db 实例
from sqlalchemy.engine.reflection import Inspector
from .database_models import Models, ModelParameters, Datasets, CurrentReduce, CurrentReflux
import os
from .utils import create_dynamic_table, allowed_file
from sqlalchemy.orm import sessionmaker
from sqlalchemy.schema import MetaData, Table
import logging
from sqlalchemy import text, select

# 配置日志
logging.basicConfig(level=logging.DEBUG)
logger = logging.getLogger(__name__)
# 创建蓝图 (Blueprint)，用于分离路由
bp = Blueprint('routes', __name__)

def infer_column_types(df):
    type_map = {
        'object': 'str',
        'int64': 'int',
        'float64': 'float',
        'datetime64[ns]': 'datetime'  # 适应Pandas datetime类型
    }
    # 提取列和其数据类型
    return {col: type_map.get(str(df[col].dtype), 'str') for col in df.columns}


@bp.route('/upload-dataset', methods=['POST'])
def upload_dataset():
    try:
        if 'file' not in request.files:
            return jsonify({'error': 'No file part'}), 400
        file = request.files['file']
        if file.filename == '' or not allowed_file(file.filename):
            return jsonify({'error': 'No selected file or invalid file type'}), 400

        dataset_name = request.form.get('dataset_name')
        dataset_description = request.form.get('dataset_description', 'No description provided')
        dataset_type = request.form.get('dataset_type')
        if not dataset_type:
            return jsonify({'error': 'Dataset type is required'}), 400

        # 创建 sessionmaker 实例
        Session = sessionmaker(bind=db.engine)
        session = Session()
        new_dataset = Datasets(
            Dataset_name=dataset_name,
            Dataset_description=dataset_description,
            Row_count=0,
            Status='pending',
            Dataset_type=dataset_type
        )
        session.add(new_dataset)
        session.commit()

        unique_filename = f"dataset_{new_dataset.Dataset_ID}.xlsx"
        upload_folder = current_app.config['UPLOAD_FOLDER']
        file_path = os.path.join(upload_folder, unique_filename)
        file.save(file_path)

        dataset_df = pd.read_excel(file_path)
        new_dataset.Row_count = len(dataset_df)
        new_dataset.Status = 'processed'
        session.commit()

        # 清理列名
        dataset_df = clean_column_names(dataset_df)
        # 重命名 DataFrame 列以匹配模型字段
        dataset_df = rename_columns_for_model(dataset_df, dataset_type)

        column_types = infer_column_types(dataset_df)
        dynamic_table_class = create_dynamic_table(new_dataset.Dataset_ID, column_types)
        insert_data_into_dynamic_table(session, dataset_df, dynamic_table_class)

        # 根据 dataset_type 决定插入到哪个已有表
        if dataset_type == 'reduce':
            insert_data_into_existing_table(session, dataset_df, CurrentReduce)
        elif dataset_type == 'reflux':
            insert_data_into_existing_table(session, dataset_df, CurrentReflux)

        session.commit()

        return jsonify({
            'message': f'Dataset {dataset_name} uploaded successfully!',
            'dataset_id': new_dataset.Dataset_ID,
            'filename': unique_filename
        }), 201

    except Exception as e:
        if session:
            session.rollback()
        logging.error('Failed to process the dataset upload:', exc_info=True)
        return jsonify({'error': str(e)}), 500
    finally:
        session.close()

@bp.route('/train-and-save-model', methods=['POST'])
def train_and_save_model_endpoint():
    # 创建 sessionmaker 实例
    Session = sessionmaker(bind=db.engine)
    session = Session()

    # 从请求中解析参数
    data = request.get_json()
    model_type = data.get('model_type')
    model_name = data.get('model_name')
    model_description = data.get('model_description')
    data_type = data.get('data_type')
    dataset_id = data.get('dataset_id', None)  # 默认为 None，如果未提供

    try:
        # 调用训练和保存模型的函数
        result = train_and_save_model(session, model_type, model_name, model_description, data_type, dataset_id)

        # 返回成功响应
        return jsonify({'message': 'Model trained and saved successfully', 'result': result}), 200

    except Exception as e:
        session.rollback()
        logging.error('Failed to process the dataset upload:', exc_info=True)
        return jsonify({'error': 'Failed to train and save model', 'message': str(e)}), 500
    finally:
        session.close()


def clean_column_names(dataframe):
    # Strip whitespace and replace non-breaking spaces and other non-printable characters
    dataframe.columns = [col.strip().replace('\xa0', '') for col in dataframe.columns]
    return dataframe


def rename_columns_for_model(dataframe, dataset_type):
    if dataset_type == 'reduce':
        rename_map = {
            '1/b': 'Q_over_b',
            'pH': 'pH',
            'OM': 'OM',
            'CL': 'CL',
            'H': 'H',
            'Al': 'Al'
        }
    elif dataset_type == 'reflux':
        rename_map = {
            'OM g/kg': 'OM',
            'CL g/kg': 'CL',
            'CEC cmol/kg': 'CEC',
            'H+ cmol/kg': 'H_plus',
            'HN mg/kg': 'HN',
            'Al3+cmol/kg': 'Al3_plus',
            'Free alumina g/kg': 'Free_alumina',
            'Free iron oxides g/kg': 'Free_iron_oxides',
            'ΔpH': 'Delta_pH'
        }

    # 使用 rename() 方法更新列名
    dataframe = dataframe.rename(columns=rename_map)
    return dataframe


def insert_data_into_existing_table(session, dataframe, model_class):
    """Insert data from a DataFrame into an existing SQLAlchemy model table."""
    for index, row in dataframe.iterrows():
        record = model_class(**row.to_dict())
        session.add(record)

def insert_data_into_dynamic_table(session, dataset_df, dynamic_table_class):
    for _, row in dataset_df.iterrows():
        record_data = row.to_dict()
        session.execute(dynamic_table_class.__table__.insert(), [record_data])

def insert_data_by_type(session, dataset_df, dataset_type):
    if dataset_type == 'reduce':
        for _, row in dataset_df.iterrows():
            record = CurrentReduce(**row.to_dict())
            session.add(record)
    elif dataset_type == 'reflux':
        for _, row in dataset_df.iterrows():
            record = CurrentReflux(**row.to_dict())
            session.add(record)


def get_current_data(session, data_type):
    # 根据数据类型选择相应的表模型
    if data_type == 'reduce':
        model = CurrentReduce
    elif data_type == 'reflux':
        model = CurrentReflux
    else:
        raise ValueError("Invalid data type provided. Choose 'reduce' or 'reflux'.")

    # 从数据库中查询所有记录
    result = session.execute(select(model))

    # 将结果转换为DataFrame
    dataframe = pd.DataFrame([dict(row) for row in result])
    return dataframe

def get_dataset_by_id(session, dataset_id):
    # 动态获取表的元数据
    metadata = MetaData(bind=session.bind)
    dataset_table = Table(dataset_id, metadata, autoload=True, autoload_with=session.bind)

    # 从数据库中查询整个表的数据
    query = select(dataset_table)
    result = session.execute(query).fetchall()

    # 检查是否有数据返回
    if not result:
        raise ValueError(f"No data found for dataset {dataset_id}.")

    # 将结果转换为DataFrame
    dataframe = pd.DataFrame(result, columns=[column.name for column in dataset_table.columns])

    return dataframe


@bp.route('/delete-dataset/<int:dataset_id>', methods=['DELETE'])
def delete_dataset(dataset_id):
    # 创建 sessionmaker 实例
    Session = sessionmaker(bind=db.engine)
    session = Session()
    try:
        # 查询数据集
        dataset = session.query(Datasets).filter_by(Dataset_ID=dataset_id).first()
        if not dataset:
            return jsonify({'error': 'Dataset not found'}), 404

        # 删除文件
        filename = f"dataset_{dataset.Dataset_ID}.xlsx"
        file_path = os.path.join(current_app.config['UPLOAD_FOLDER'], filename)
        if os.path.exists(file_path):
            os.remove(file_path)

        # 删除数据表
        table_name = f"dataset_{dataset.Dataset_ID}"
        session.execute(text(f"DROP TABLE IF EXISTS {table_name}"))

        # 删除数据集记录
        session.delete(dataset)
        session.commit()

        return jsonify({'message': 'Dataset deleted successfully'}), 200

    except Exception as e:
        session.rollback()
        logging.error(f'Failed to delete dataset {dataset_id}:', exc_info=True)
        return jsonify({'error': str(e)}), 500
    finally:
        session.close()


@bp.route('/tables', methods=['GET'])
def list_tables():
    engine = db.engine  # 使用 db 实例的 engine
    inspector = Inspector.from_engine(engine)  # 创建 Inspector 对象
    table_names = inspector.get_table_names()  # 获取所有表名
    return jsonify(table_names)  # 以 JSON 形式返回表名列表


@bp.route('/models/<int:model_id>', methods=['GET'])
def get_model(model_id):
    try:
        model = Models.query.filter_by(ModelID=model_id).first()
        if model:
            return jsonify({
                'ModelID': model.ModelID,
                'ModelName': model.ModelName,
                'ModelType': model.ModelType,
                'CreatedAt': model.CreatedAt.strftime('%Y-%m-%d %H:%M:%S'),
                'Description': model.Description
            })
        else:
            return jsonify({'message': 'Model not found'}), 404
    except Exception as e:
        return jsonify({'error': 'Internal server error', 'message': str(e)}), 500


@bp.route('/models', methods=['GET'])
def get_all_models():
    try:
        models = Models.query.all()  # 获取所有模型数据
        if models:
            result = [
                {
                    'ModelID': model.ModelID,
                    'ModelName': model.ModelName,
                    'ModelType': model.ModelType,
                    'CreatedAt': model.CreatedAt.strftime('%Y-%m-%d %H:%M:%S'),
                    'Description': model.Description
                }
                for model in models
            ]
            return jsonify(result)
        else:
            return jsonify({'message': 'No models found'}), 404
    except Exception as e:
        return jsonify({'error': 'Internal server error', 'message': str(e)}), 500


@bp.route('/model-parameters', methods=['GET'])
def get_all_model_parameters():
    try:
        parameters = ModelParameters.query.all()  # 获取所有参数数据
        if parameters:
            result = [
                {
                    'ParamID': param.ParamID,
                    'ModelID': param.ModelID,
                    'ParamName': param.ParamName,
                    'ParamValue': param.ParamValue
                }
                for param in parameters
            ]
            return jsonify(result)
        else:
            return jsonify({'message': 'No parameters found'}), 404
    except Exception as e:
        return jsonify({'error': 'Internal server error', 'message': str(e)}), 500


@bp.route('/models/<int:model_id>/parameters', methods=['GET'])
def get_model_parameters(model_id):
    try:
        model = Models.query.filter_by(ModelID=model_id).first()
        if model:
            # 获取该模型的所有参数
            parameters = [
                {
                    'ParamID': param.ParamID,
                    'ParamName': param.ParamName,
                    'ParamValue': param.ParamValue
                }
                for param in model.parameters
            ]
            
            # 返回模型参数信息
            return jsonify({
                'ModelID': model.ModelID,
                'ModelName': model.ModelName,
                'ModelType': model.ModelType,
                'CreatedAt': model.CreatedAt.strftime('%Y-%m-%d %H:%M:%S'),
                'Description': model.Description,
                'Parameters': parameters
            })
        else:
            return jsonify({'message': 'Model not found'}), 404
    except Exception as e:
        return jsonify({'error': 'Internal server error', 'message': str(e)}), 500


@bp.route('/predict', methods=['POST'])
def predict_route():
    try:
        data = request.get_json()
        model_name = data.get('model_name')  # 提取模型名称
        parameters = data.get('parameters', {})  # 提取所有参数

        input_data = pd.DataFrame([parameters])  # 转换参数为DataFrame
        predictions = predict(input_data, model_name)  # 调用预测函数
        return jsonify({'predictions': predictions}), 200
    except Exception as e:
        return jsonify({'error': str(e)}), 400


# 定义添加数据库记录的 API 接口
@bp.route('/add_item', methods=['POST'])
def add_item():
    """
    接收 JSON 格式的请求体，包含表名和要插入的数据。
    尝试将数据插入到指定的表中。
    :return:
    """
    try:
        # 确保请求体是JSON格式
        data = request.get_json()
        if not data:
            raise ValueError("No JSON data provided")

        table_name = data.get('table')
        item_data = data.get('item')

        if not table_name or not item_data:
            return jsonify({'error': 'Missing table name or item data'}), 400
        cur = db.cursor()

        # 动态构建 SQL 语句
        columns = ', '.join(item_data.keys())
        placeholders = ', '.join(['?'] * len(item_data))
        sql = f"INSERT INTO {table_name} ({columns}) VALUES ({placeholders})"
        cur.execute(sql, tuple(item_data.values()))
        db.commit()

        # 返回更详细的成功响应
        return jsonify({'success': True, 'message': 'Item added successfully'}), 201

    except ValueError as e:
        return jsonify({'error': str(e)}), 400
    except KeyError as e:
        return jsonify({'error': f'Missing data field: {e}'}), 400
    except sqlite3.IntegrityError as e:
        # 处理例如唯一性约束违反等数据库完整性错误
        return jsonify({'error': 'Database integrity error', 'details': str(e)}), 409
    except sqlite3.Error as e:
        # 处理其他数据库错误
        return jsonify({'error': 'Database error', 'details': str(e)}), 500
    finally:
        db.close()


# 定义删除数据库记录的 API 接口
@bp.route('/delete_item', methods=['POST'])
def delete_item():
    data = request.get_json()
    table_name = data.get('table')
    condition = data.get('condition')

    # 检查表名和条件是否提供
    if not table_name or not condition:
        return jsonify({
            "success": False,
            "message": "缺少表名或条件参数"
        }), 400

    # 尝试从条件字符串中分离键和值
    try:
        key, value = condition.split('=')
    except ValueError:
        return jsonify({
            "success": False,
            "message": "条件格式错误，应为 'key=value'"
        }), 400

    cur = db.cursor()

    try:
        # 执行删除操作
        cur.execute(f"DELETE FROM {table_name} WHERE {key} = ?", (value,))
        db.commit()
        # 如果没有错误发生，返回成功响应
        return jsonify({
            "success": True,
            "message": "记录删除成功"
        }), 200
    except sqlite3.Error as e:
        # 发生错误，回滚事务
        db.rollback()
        # 返回失败响应，并包含错误信息
        return jsonify({
            "success": False,
            "message": f"删除失败: {e}"
        }), 400


# 定义修改数据库记录的 API 接口
@bp.route('/update_item', methods=['PUT'])
def update_record():
    data = request.get_json()

    # 检查必要的数据是否提供
    if not data or 'table' not in data or 'item' not in data:
        return jsonify({
            "success": False,
            "message": "请求数据不完整"
        }), 400

    table_name = data['table']
    item = data['item']

    # 假设 item 的第一个元素是 ID
    if not item or next(iter(item.keys())) is None:
        return jsonify({
            "success": False,
            "message": "记录数据为空"
        }), 400

    # 获取 ID 和其他字段值
    id_key = next(iter(item.keys()))
    record_id = item[id_key]
    updates = {key: value for key, value in item.items() if key != id_key}  # 排除 ID

    cur = db.cursor()

    try:
        record_id = int(record_id)  # 确保 ID 是整数
    except ValueError:
        return jsonify({
            "success": False,
            "message": "ID 必须是整数"
        }), 400

    # 准备参数列表，包括更新的值和 ID
    parameters = list(updates.values()) + [record_id]

    # 执行更新操作
    set_clause = ','.join([f"{k} = ?" for k in updates.keys()])
    sql = f"UPDATE {table_name} SET {set_clause} WHERE {id_key} = ?"
    try:
        cur.execute(sql, parameters)
        db.commit()
        if cur.rowcount == 0:
            return jsonify({
                "success": False,
                "message": "未找到要更新的记录"
            }), 404
        return jsonify({
            "success": True,
            "message": "数据更新成功"
        }), 200
    except sqlite3.Error as e:
        db.rollback()
        return jsonify({
            "success": False,
            "message": f"更新失败: {e}"
        }), 400


# 定义查询数据库记录的 API 接口
@bp.route('/search/record', methods=['GET'])
def sql_search():
    """
    接收 JSON 格式的请求体，包含表名和要查询的 ID。
    尝试查询指定 ID 的记录并返回结果。
    :return:
    """
    try:
        data = request.get_json()

        # 表名
        sql_table = data['table']

        # 要搜索的 ID
        Id = data['id']

        # 连接到数据库
        cur = db.cursor()

        # 构造查询语句
        sql = f"SELECT * FROM {sql_table} WHERE id = ?"

        # 执行查询
        cur.execute(sql, (Id,))

        # 获取查询结果
        rows = cur.fetchall()
        column_names = [desc[0] for desc in cur.description]

        # 检查是否有结果
        if not rows:
            return jsonify({'error': '未查找到对应数据。'}), 400

        # 构造响应数据
        results = []
        for row in rows:
            result = {column_names[i]: row[i] for i in range(len(row))}
            results.append(result)

        # 关闭游标和数据库连接
        cur.close()
        db.close()

        # 返回 JSON 响应
        return jsonify(results), 200

    except sqlite3.Error as e:
        # 如果发生数据库错误，返回错误信息
        return jsonify({'error': str(e)}), 400
    except KeyError as e:
        # 如果请求数据中缺少必要的键，返回错误信息
        return jsonify({'error': f'缺少必要的数据字段: {e}'}), 400


# 定义提供数据库列表，用于展示表格的 API 接口
@bp.route('/table', methods=['POST'])
def get_table():
    data = request.get_json()
    table_name = data.get('table')
    if not table_name:
        return jsonify({'error': '需要表名'}), 400

    try:
        # 创建 sessionmaker 实例
        Session = sessionmaker(bind=db.engine)
        session = Session()

        # 动态获取表的元数据
        metadata = MetaData()
        table = Table(table_name, metadata, autoload_with=db.engine)

        # 从数据库中查询所有记录
        query = select(table)
        result = session.execute(query).fetchall()

        # 将结果转换为列表字典形式
        rows = [dict(zip([column.name for column in table.columns], row)) for row in result]

        # 获取列名
        headers = [column.name for column in table.columns]

        return jsonify(rows=rows, headers=headers), 200

    except Exception as e:
        return jsonify({'error': str(e)}), 400
    finally:
        # 关闭 session
        session.close()