import pymysql
import yaml

with open("./config.yml", "r", encoding="utf-8") as f:
    cfg = yaml.safe_load(f)
    DB = cfg["db"]


def get_conn():
    return pymysql.connect(**DB, cursorclass=pymysql.cursors.DictCursor)


def get_table(table_name):
    sql = """
    SELECT table_name, table_comment
    FROM information_schema.tables
    WHERE table_schema=%s AND table_name=%s
    """
    with get_conn() as conn:
        with conn.cursor() as cur:
            cur.execute(sql, (DB["database"], table_name))
            return cur.fetchone()


def get_all_tables(database=None):
    """获取指定数据库(默认当前库)的所有表"""
    schema = database or DB["database"]
    sql = """
    SELECT table_name, table_comment
    FROM information_schema.tables
    WHERE table_schema=%s AND table_type='BASE TABLE'
    ORDER BY table_name
    """
    with get_conn() as conn:
        with conn.cursor() as cur:
            cur.execute(sql, (schema,))
            return cur.fetchall()


def get_columns(table_name):
    sql = """
    SELECT column_name, data_type, column_comment
    FROM information_schema.columns
    WHERE table_schema=%s AND table_name=%s
    ORDER BY ordinal_position
    """
    with get_conn() as conn:
        with conn.cursor() as cur:
            cur.execute(sql, (DB["database"], table_name))
            return cur.fetchall()


def mysql_to_java(mysql_type):
    mapping = {
        "bigint": "Long",
        "int": "Integer",
        "varchar": "String",
        "datetime": "LocalDateTime",
        "decimal": "BigDecimal",
    }
    return mapping.get(mysql_type, "String")


def get_enum_field_names():
    """查询 enums 表所有未删除的 distinct enums_name。

    这些 enums_name 与业务表的 column_name (snake_case) 对应，
    脚手架生成时据此判断哪些字段应走 Select 下拉框。
    """
    sql = """
    SELECT DISTINCT enums_name
    FROM enums
    WHERE deleted_flag = 0 AND enums_name IS NOT NULL AND enums_name <> ''
    """
    with get_conn() as conn:
        with conn.cursor() as cur:
            cur.execute(sql)
            rows = cur.fetchall()
            return [r["enums_name"] for r in rows if r.get("enums_name")]