import os
import psycopg as pg
from psycopg.rows import dict_row
from .connection import g_conn_dict as conn

# no undo/redo

_server_databases = ['template0', 'template1', 'postgres', 'project']


def list_project() -> list[str]:
    ps = []
    with pg.connect(conninfo="dbname=postgres host=127.0.0.1", autocommit=True) as conn:
        with conn.cursor(row_factory=dict_row) as cur:
            for p in cur.execute(f"select datname from pg_database where datname <> 'postgres' and datname <> 'template0' and datname <> 'template1' and datname <> 'project'"):
                ps.append(p['datname'])
    return ps


def have_project(name: str) -> bool:
    with pg.connect(conninfo="dbname=postgres host=127.0.0.1", autocommit=True) as conn:
        with conn.cursor() as cur:
            cur.execute(f"select * from pg_database where datname = '{name}'")
            return cur.rowcount > 0


def copy_project(source: str, new: str) -> None:
    with pg.connect(conninfo="dbname=postgres host=127.0.0.1", autocommit=True) as conn:
        with conn.cursor() as cur:
            cur.execute(f'create database "{new}" with template = {source}')

# 2025-02-07, WMH
# copyproject会把pg中operation这个表的全部内容也加进去，我们实际项目运行一周后operation这个表会变得特别大，导致CopyProject花费的时间很长，CopyProjectEx把operation的在复制时没有一块复制过去，节省时间
class CopyProjectEx:
    @ staticmethod
    def create_database(connection, new_db):
        with connection.cursor() as cursor:
            cursor.execute(f'create database "{new_db}"')
        connection.commit()

    @staticmethod
    def execute_pg_dump(hostname, source_db, exclude_table_list):
        dump_command_structure = (
            f'pg_dump -h {hostname} -F c -s -f source_db_structure.dump {source_db}'
        )
        os.system(dump_command_structure)

        if exclude_table_list is not None:
            exclude_table = ' '.join(['-T {}'.format(i) for i in exclude_table_list])
            dump_command_db = (
                f'pg_dump -h {hostname} -F c -a {exclude_table} -f source_db.dump {source_db}'
            )
        else:
            dump_command_db = (
                f'pg_dump -h {hostname} -F c -a -f source_db.dump {source_db}'
            )
        os.system(dump_command_db)

    @staticmethod
    def execute_pg_restore(hostname, new_db):
        restore_command_structure = (
            f'pg_restore -h {hostname} -d {new_db} source_db_structure.dump'
        )
        os.system(restore_command_structure)

        restore_command_db = (
            f'pg_restore -h {hostname} -d {new_db} source_db.dump'
        )
        os.system(restore_command_db)

    @staticmethod
    def init_operation_table(connection, excluded_table):
        with connection.cursor() as cursor:
            if 'operation' in excluded_table:
                insert_query \
                    = "insert into operation (id, redo, undo, redo_cs, undo_cs) values (0, '', '', '', '')"
                cursor.execute(insert_query)

            if 'current_operation' in excluded_table:
                insert_query \
                    = "insert into current_operation (id) values (0)"
                cursor.execute(insert_query)

            if 'restore_operation' in excluded_table:
                insert_query \
                    = "insert into restore_operation (id) values (0)"
                cursor.execute(insert_query)

            if 'batch_operation' in excluded_table:
                insert_query \
                    = "insert into batch_operation (id, redo, undo, redo_cs, undo_cs) values (0, '', '', '', '')"
                cursor.execute(insert_query)

            if 'operation_table' in excluded_table:
                insert_query \
                    = "insert into operation_table (option) values ('operation')"
                cursor.execute(insert_query)
        connection.commit()

    def __call__(self, source: str, new: str, excluded_table: [str] = None) -> None:
        connection = pg.connect(conninfo="dbname=postgres host=127.0.0.1", autocommit=True)

        self.create_database(connection, new)
        self.execute_pg_dump('127.0.0.1', source, excluded_table)
        self.execute_pg_restore('127.0.0.1', new)

        connection = pg.connect(conninfo=f"dbname='{new}' host=127.0.0.1", autocommit=True)
        self.init_operation_table(connection, excluded_table)


def create_project(name: str) -> None:
    return copy_project('project', name)


def delete_project(name: str) -> None:
    with pg.connect(conninfo="dbname=postgres host=127.0.0.1", autocommit=True) as conn:
        with conn.cursor() as cur:
            cur.execute(f"select pg_terminate_backend(pid) from pg_stat_activity where datname = '{name}'")
            cur.execute(f'drop database "{name}"')


def clean_project(excluded: list[str] = []) -> None:
    projects = list_project()
    with pg.connect(conninfo="dbname=postgres host=127.0.0.1", autocommit=True) as conn:
        with conn.cursor(row_factory=dict_row) as cur:
            row = cur.execute(f"select current_database()").fetchone()
            if row != None:
                current_db = row['current_database']
                if current_db in projects:
                    projects.remove(current_db)
            for project in projects:
                if project in _server_databases or project in excluded:
                    continue
                cur.execute(f"select pg_terminate_backend(pid) from pg_stat_activity where datname = '{project}'")
                cur.execute(f'drop database "{project}"')


def open_project(name: str) -> None:
    if name not in conn:
        conn[name] = pg.connect(conninfo=f"dbname={name} host=127.0.0.1", autocommit=True)


def is_project_open(name: str) -> bool:
    return name in conn


def close_project(name: str) -> None:
    if name in conn:
        conn[name].close()
        del conn[name]