import mariadb
from sqlalchemy import create_engine, select, text, MetaData, join
from sqlalchemy.orm import DeclarativeBase, relationship, sessionmaker

from database.base import Base
from database.comic import Comic
from database.metadata import MetaDataTable, MetaDataColumn


class KontorDB:

    def __init__(self, db_config):
        self.db_conn = mariadb.connect(
            host=db_config['mariadb']['host'],
            port=db_config['mariadb']['port'],
            user=db_config['mariadb']['user'],
            password=db_config['mariadb']['password'],
            database=db_config['mariadb']['database']
        )
        connect_string = ('mariadb+mariadbconnector://{}:{}@{}:{}/{}'
        .format(
            db_config['mariadb']['user'],
            db_config['mariadb']['password'],
            db_config['mariadb']['host'],
            db_config['mariadb']['port'],
            db_config['mariadb']['database']))
        # engine = create_engine(connect_string, echo=True)
        engine = create_engine(connect_string)
        Base.metadata.create_all(bind=engine)
        __session__ = sessionmaker(bind=engine)
        self.session = __session__()

    def get_table_id(self, table_name):
        result = self.session.execute(select(MetaDataTable.id).where(MetaDataTable.table_name == table_name)).scalar()
        return result

    def get_table_names(self) -> list:
        tables = self.session.query(MetaDataTable).all()
        result = [table.table_name for table in tables]
        return result

    def get_column_meta_data(self, table_id: str, table_name: str) -> dict:
        meta_data = {}
        order = 0
        for (_, column) in self.session.query(MetaDataTable, MetaDataColumn).filter(MetaDataTable.id == MetaDataColumn.table_id).filter(MetaDataTable.table_name == table_name).filter(MetaDataColumn.is_shown == 1).all():
            meta_data[order] = {'column': column.column_name, 'label': column.column_label, 'order': column.column_order, 'ref_column': column.ref_column}
            order += 1
        return meta_data

    def get_filters(self, table_id):
        cursor = self.db_conn.cursor()
        filters = {}
        cursor.execute(
            "SELECT column_name, filter_label from meta_data_column WHERE table_id=? AND show_filter is true",
            (table_id,))
        rows = cursor.fetchall()
        for row in rows:
            filters[row[0]] = {'label': row[1], 'widget': None}
        cursor.close()
        # print(f"retrieved {len(rows)} filters: {filters}")
        return filters

    def get_data(self, table_name: str, columns: dict, where_clause: str) -> list:
        data = []
        cursor = self.db_conn.cursor()
        cursor.execute(self.get_statement(table_name, columns, where_clause))
        rows = cursor.fetchall()
        print(len(rows))
        for row in rows:
            # print(f"KontorDB.get_data: {row}")
            data.append(list(row))
        cursor.close()
        # print(f"KontorDB.getData: return {len(data)}")
        if table_name == 'comic' and len(where_clause) == 0:
            data.clear()
            comics = self.session.query(Comic).all()
            for item in comics:
                # print(item)
                row = []
                for order in columns.keys():
                    column_name = columns[order]['column']
                    if str(column_name).endswith("_id"):
                        ref_table = column_name[:-3]
                        # print(f"{ref_table=}")
                        ref = getattr(item, ref_table)
                        value = getattr(ref, "name")
                        # print(f"{value=}")
                        row.append(value)
                    else:
                        row.append(getattr(item, column_name))
                # print(repr(row))
                data.append(row)
        return data

    def get_statement(self, table: str, header: dict, where_clause):
        columns = ""
        for index, column in header.items():
            if index > 0:
                columns += ", "
            columns += column['column']
        if len(columns) == 0:
            columns = "*"
        statement = f"SELECT {columns} FROM {table} {where_clause}"
        print(f"{statement=}")
        return statement