import ctypes
import json
import os
import sys
from typing import Optional, Dict, Any, List


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"


class FetchData:
    event_id: int
    card_paths: List[str]

    @classmethod
    def from_dict(cls, data: Dict[str, Any]) -> 'FetchData':
        instance = cls()
        instance.event_id = data.get("event_id", 0)
        instance.card_paths = data.get("card_paths", [])
        return instance

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

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

        # boot(cwd: *const c_char, name: *const c_char, as_path: *const c_char) -> i32
        self.lib.boot.argtypes = [ctypes.c_char_p, ctypes.c_char_p, ctypes.c_char_p]
        self.lib.boot.restype = ctypes.c_int32

        # 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

        # 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_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 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 fetch_data(self) -> Optional[FetchData]:
        # 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')
            return FetchData.from_dict(json.loads(json_str))

        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()