import importlib
import inspect
import logging
import copy
import pkgutil
import traceback
import types


__commands_tree__ = {}
"""命令树

结构：
{
    'cmd1': {
        'description': 'cmd1 description',
        'usage': 'cmd1 usage',
        'aliases': ['cmd1 alias1', 'cmd1 alias2'],
        'privilege': 0,
        'cls': <class 'pkg.qqbot.cmds.cmd1.CommandCmd1'>,
        'sub': {
            'cmd1-1': {
                'description': 'cmd1-1 description',
                'usage': 'cmd1-1 usage',
                'aliases': ['cmd1-1 alias1', 'cmd1-1 alias2'],
                'privilege': 0,
                'cls': <class 'pkg.qqbot.cmds.cmd1.CommandCmd1_1'>,
                'sub': {}
            },
        }
    },
    'cmd2': {
        'description': 'cmd2 description',
        'usage': 'cmd2 usage',
        'aliases': ['cmd2 alias1', 'cmd2 alias2'],
        'privilege': 0,
        'cls': <class 'pkg.qqbot.cmds.cmd2.CommandCmd2'>,
        'sub': {
            'cmd2-1': {
                'description': 'cmd2-1 description',
                'usage': 'cmd2-1 usage',
                'aliases': ['cmd2-1 alias1', 'cmd2-1 alias2'],
                'privilege': 0,
                'cls': <class 'pkg.qqbot.cmds.cmd2.CommandCmd2_1'>,
                'sub': {
                    'cmd2-1-1': {
                        'description': 'cmd2-1-1 description',
                        'usage': 'cmd2-1-1 usage',
                        'aliases': ['cmd2-1-1 alias1', 'cmd2-1-1 alias2'],
                        'privilege': 0,
                        'cls': <class 'pkg.qqbot.cmds.cmd2.CommandCmd2_1_1'>,
                        'sub': {}
                    },
                }
            },
        }
    }
}
"""

__tree_index__: dict[str, list] = {}
"""命令树索引

结构：
{
    'pkg.qqbot.cmds.cmd1.CommandCmd1': ['cmd1'],  # 顶级指令
    'pkg.qqbot.cmds.cmd1.CommandCmd1_1': ['cmd1', 'cmd1-1'],  # 类名: 节点路径
    'pkg.qqbot.cmds.cmd2.CommandCmd2': ['cmd2'],
    'pkg.qqbot.cmds.cmd2.CommandCmd2_1': ['cmd2', 'cmd2-1'],
    'pkg.qqbot.cmds.cmd2.CommandCmd2_1_1': ['cmd2', 'cmd2-1', 'cmd2-1-1'],
}
"""


class Context:
    """命令执行上下文"""
    command: str
    """顶级指令文本"""

    crt_command: str
    """当前子指令文本"""

    params: list
    """完整参数列表"""

    crt_params: list
    """当前子指令参数列表"""

    session_name: str
    """会话名"""

    text_message: str
    """指令完整文本"""

    launcher_type: str
    """指令发起者类型"""

    launcher_id: int
    """指令发起者ID"""

    sender_id: int
    """指令发送者ID"""

    is_admin: bool
    """[过时]指令发送者是否为管理员"""

    privilege: int
    """指令发送者权限等级"""

    def __init__(self, **kwargs):
        self.__dict__.update(kwargs)


class AbstractCommand:
    """指令抽象类"""

    parent: type
    """父指令类"""

    name: str
    """指令名"""

    description: str
    """指令描述"""

    usage: str
    """指令用法"""

    aliases: list[str]
    """指令别名"""

    privilege: int
    """指令权限等级, 权限大于等于此值的用户才能执行指令"""

    @classmethod
    def process(cls, ctx: Context) -> tuple[bool, list, str]:
        """指令处理函数
        
        :param ctx: 指令执行上下文

        :return: (是否执行, 回复列表(若执行), 下一级指令(若未执行))
        """
        raise NotImplementedError
    
    @staticmethod
    def register(cls: type, name: str, parent: type = None):
        """注册指令
        
        :param cls: 指令类
        :param name: 指令名
        :param parent: 父指令类
        """
        global __commands_tree__, __tree_index__

        if parent is None:
            # 顶级指令注册
            __commands_tree__[name] = {
                'description': cls.description,
                'usage': cls.usage,
                'aliases': cls.aliases,
                'privilege': cls.privilege,
                'cls': cls,
                'sub': {}
            }
            __tree_index__[cls.__module__ + '.' + cls.__name__] = [name]
        else:
            # 从索引取出路径
            path = []
            try:
                path = __tree_index__[parent.__module__ + '.' + parent.__name__]
            except KeyError:
                raise ValueError('register parent command first: {}'.format(parent.__name__))
            # 从树取出父节点
            node = __commands_tree__
            for p in path:
                node = node[p]['sub']

            # 注册子指令
            node[name] = {
                'description': cls.description,
                'usage': cls.usage,
                'aliases': cls.aliases,
                'privilege': cls.privilege,
                'cls': cls,
                'sub': {}
            }
            # 更新索引
            __tree_index__[cls.__module__ + '.' + cls.__name__] = path + [name]


class CommandPrivilegeError(Exception):
    """指令权限不足或不存在异常"""
    pass


# 传入Context对象，广搜命令树，返回执行结果
# 若命令被处理，返回reply列表
# 若命令未被处理，继续执行下一级指令
# 若命令不存在，报异常
def execute(context: Context) -> list:
    """执行指令
    
    :param ctx: 指令执行上下文

    :return: 回复列表
    """
    global __commands_tree__

    # 拷贝ctx
    ctx: Context = copy.deepcopy(context)

    # 从树取出顶级指令
    node = __commands_tree__
    
    path = ""

    # 搜当前顶层，找不到则报错
    while True:
        path = path + ctx.crt_command + "."
        try:
            # 检查权限
            if ctx.privilege < node[ctx.crt_command]['privilege']:
                raise CommandPrivilegeError('权限不足: {}'.format(path[:-1]))
            # 执行
            execed, reply, ctx.crt_command = node[ctx.crt_command]['cls'].process(ctx)
            if execed:
                return reply
            else:
                # 从树取出下一级指令
                node = node[ctx.crt_command]['sub']
                # 删除crt_params第一个参数
                ctx.crt_params.pop(0)
        except KeyError:
            raise CommandPrivilegeError('找不到指令: {}'.format(path[:-1]))


def register_all():
    """启动时调用此函数注册所有指令
    
    递归处理pkg.qqbot.cmds包下及其子包下所有模块的所有继承于AbstractCommand的类
    """
    # 模块：遍历其中的继承于AbstractCommand的类，进行注册
    # 包：递归处理包下的模块
    # 排除__开头的属性
    import pkg.qqbot.cmds

    def walk(module, prefix, path_prefix):
        # 排除不处于pkg.qqbot.cmds中的包
        if not module.__name__.startswith('pkg.qqbot.cmds'):
            return
        for item in pkgutil.iter_modules(module.__path__):
            if item.name.startswith('__'):
                continue

            if item.ispkg:
                walk(__import__(module.__name__ + '.' + item.name, fromlist=['']), prefix + item.name + '.', path_prefix + item.name + '/')
            else:
                m = __import__(module.__name__ + '.' + item.name, fromlist=[''])
                for name, cls in inspect.getmembers(m, inspect.isclass):
                    # 检查是否为指令类
                    if cls.__module__ == m.__name__ and issubclass(cls, AbstractCommand) and cls != AbstractCommand:
                        cls.register(cls, cls.name, cls.parent)

    walk(pkg.qqbot.cmds, '', '')
    logging.debug(__commands_tree__)