import ctypes
import json
import os
import sys
from dataclasses import field, dataclass
from typing import Optional, Dict, Any, List, Union, TypeVar, Generic, Callable


def get_lib_filename(base_name):
    if sys.platform == "win32":
        return f"{base_name}.dll"
    elif sys.platform == "darwin":
        return f"lib{base_name}.dylib"
    else:
        return f"lib{base_name}.so"


T = TypeVar("T")


@dataclass
class FetchResultCard:
    text: str = ""
    path: List[str] = field(default_factory=list)

    @classmethod
    def from_dict(cls, data: Dict[str, Any]) -> "FetchResultCard":
        return cls(
            text=data.get("text", ""),
            # 兼容 Rust 中 PathBuf 序列化出的路径字符串列表
            path=[str(p) for p in data.get("path", [])],
        )


@dataclass
class FetchResultEvent:
    event_id: int = 0
    cards: List[FetchResultCard] = field(default_factory=list)

    @classmethod
    def from_dict(cls, data: Dict[str, Any]) -> "FetchResultEvent":
        return cls(
            event_id=data.get("event_id", 0),
            cards=[
                FetchResultCard.from_dict(card)
                for card in data.get("cards", [])
            ],
        )


@dataclass
class FetchResultUnlinkedCards:
    cards: List[FetchResultCard] = field(default_factory=list)

    @classmethod
    def from_dict(cls, data: Dict[str, Any]) -> "FetchResultUnlinkedCards":
        return cls(
            cards=[
                FetchResultCard.from_dict(card)
                for card in data.get("cards", [])
            ],
        )


FetchResultType = Union[FetchResultEvent, FetchResultUnlinkedCards]


class FetchResult:

    @classmethod
    def from_dict(cls, data: Dict[str, Any]) -> FetchResultType:
        tag = data.get("type")
        content = data.get("data", {})

        if tag == "Event":
            return FetchResultEvent.from_dict(content)
        elif tag == "UnlinkedCard":
            return FetchResultUnlinkedCards.from_dict(content)
        else:
            raise ValueError(f"Unknown FetchResult type: {tag}")


@dataclass
class ApiResultSuccess(Generic[T]):
    data: T

    @staticmethod
    def is_ok() -> bool:
        return True

    @staticmethod
    def is_err() -> bool:
        return False

    def unwrap(self) -> T:
        return self.data

    @classmethod
    def from_dict(cls, data: Dict[str, Any], parser: Callable[[Any], T] | None = None) -> "ApiResultSuccess[T]":
        data = parser(data) if parser else data
        return cls(data=data)


@dataclass
class ApiResultError(Generic[T]):
    error: str

    @staticmethod
    def is_ok() -> bool:
        return False

    @staticmethod
    def is_err() -> bool:
        return True

    def unwrap(self) -> T:
        raise Exception(f"ApiResultError: {self.error}")

    @classmethod
    def from_dict(cls, data: str) -> "ApiResultError[T]":
        return cls(error=data)


class ApiResult(Generic[T]):
    @classmethod
    def from_dict(cls, data: Dict[str, Any], parser: Callable[[Any], T] | None = None) -> ApiResultSuccess[T] | \
                                                                                          ApiResultError[T]:
        tag = data.get("type")
        content = data.get("data", {})

        if tag == "Ok":
            return ApiResultSuccess.from_dict(content, parser=parser)
        elif tag == "Err":
            return ApiResultError.from_dict(content)
        else:
            raise ValueError(f"Unknown ApiResult type: {tag}")


class SekaiSyncLib:
    def __init__(self):
        self.lib = ctypes.CDLL(os.path.join(os.path.dirname(__file__), get_lib_filename("sekai_sync_lib")))
        self._setup_signatures()

    def _setup_signatures(self):
        # proxy(x: *const c_char)
        self.lib.proxy.argtypes = [ctypes.c_char_p]
        self.lib.proxy.restype = None

        # pjsk_proxy(x: *const c_char)
        self.lib.pjsk_proxy.argtypes = [ctypes.c_char_p]
        self.lib.pjsk_proxy.restype = None

        # ghp(x: *const c_char)
        self.lib.ghp.argtypes = [ctypes.c_char_p]
        self.lib.ghp.restype = None

        # ghp(x: *const c_char)
        self.lib.log_level.argtypes = [ctypes.c_char_p]
        self.lib.log_level.restype = None

        # boot(cwd: *const c_char, name: *const c_char, as_path: *const c_char) -> c_int
        self.lib.boot.argtypes = [ctypes.c_char_p, ctypes.c_char_p, ctypes.c_char_p]
        self.lib.boot.restype = ctypes.c_int

        # stop() -> c_int
        self.lib.stop.argtypes = []
        self.lib.stop.restype = ctypes.c_int

        # fetch_data() -> *mut c_char
        # ⚠️ 这里必须用 c_void_p，不能用 c_char_p，否则会丢失指针地址导致内存泄漏
        self.lib.fetch_data.argtypes = []
        self.lib.fetch_data.restype = ctypes.c_void_p

        self.lib.refetch_event.argtypes = []
        self.lib.refetch_event.restype = ctypes.c_void_p

        # free_string(s: *mut c_char)
        self.lib.free_string.argtypes = [ctypes.c_void_p]
        self.lib.free_string.restype = None

    def _str_to_bytes(self, s: Optional[str]) -> bytes:
        """辅助函数：将 Python 字符串安全转换为 C 字符串字节"""
        if s is None:
            # 根据 Rust 端解析逻辑，传入空字符串将被视为 None
            return b""
        return s.encode('utf-8')

    def set_proxy(self, proxy_url: Optional[str]):
        """设置代理，传 None 或空字符串可清除"""
        self.lib.proxy(self._str_to_bytes(proxy_url))

    def set_pjsk_proxy(self, proxy_url: Optional[str]):
        """设置 pjsk_proxy，传 None 或空字符串可清除"""
        self.lib.pjsk_proxy(self._str_to_bytes(proxy_url))

    def set_ghp(self, token: Optional[str]):
        """设置 GitHub Token，传 None 或空字符串可清除"""
        self.lib.ghp(self._str_to_bytes(token))

    def set_log_level(self, log_evel: Optional[str]):
        """设置 Log level，传 None 或空字符串可清除"""
        self.lib.log_level(self._str_to_bytes(log_evel))

    def boot(self, cwd: str, name: str, as_path: str) -> int:
        """
        启动主循环与初始化状态
        """
        return self.lib.boot(
            self._str_to_bytes(cwd),
            self._str_to_bytes(name),
            self._str_to_bytes(as_path)
        )

    def stop(self) -> int:
        """
        停止主循环与清理状态
        """
        return self.lib.stop()

    def fetch_data(self) -> None | list[FetchResultEvent | FetchResultUnlinkedCards]:
        # 1. 获取裸指针
        ptr = self.lib.fetch_data()

        # 指针为空 (std::ptr::null_mut)
        if not ptr:
            return None

        try:
            # 2. 将 void_p 转换回 c_char_p 并读取里面的 bytes
            json_bytes = ctypes.cast(ptr, ctypes.c_char_p).value
            if not json_bytes:
                return None

            # 3. 解码并反序列化 JSON
            json_str = json_bytes.decode('utf-8')
            lst = json.loads(json_str)
            return [FetchResult.from_dict(item) for item in lst]

        finally:
            # 4. 无论是否发生 JSON 解析异常，绝对保证释放 Rust 内存！
            self.lib.free_string(ptr)

    def refetch_event(self) -> ApiResultSuccess[FetchResultEvent] | ApiResultError[FetchResultEvent]:
        # 1. 获取裸指针
        ptr = self.lib.refetch_event()

        try:
            # 2. 将 void_p 转换回 c_char_p 并读取里面的 bytes
            json_bytes = ctypes.cast(ptr, ctypes.c_char_p).value
            if not json_bytes:
                return ApiResultError(error="调用失败")

            # 3. 解码并反序列化 JSON
            json_str = json_bytes.decode('utf-8')
            return ApiResult.from_dict(json.loads(json_str), parser=FetchResultEvent.from_dict)

        finally:
            # 4. 无论是否发生 JSON 解析异常，绝对保证释放 Rust 内存！
            self.lib.free_string(ptr)


rlib = SekaiSyncLib()