from __future__ import annotations

import os
from typing import Any


UNITY_EDITOR_PREFS_REG_PATH = r"Software\Unity Technologies\Unity Editor 5.x"

UNITY_OSS_PREF_KEYS = {
    "access_key_id": "OssDownload_AccessKeyId",
    "access_key_secret": "OssDownload_AccessKeySecret",
    "endpoint": "OssDownload_Endpoint",
    "bucket": "OssDownload_Bucket",
}

ENV_OSS_KEYS = {
    "access_key_id": (
        "TH1_OSS_ACCESS_KEY_ID",
        "OSS_ACCESS_KEY_ID",
        "ALIYUN_ACCESS_KEY_ID",
        "ALIBABA_CLOUD_ACCESS_KEY_ID",
    ),
    "access_key_secret": (
        "TH1_OSS_ACCESS_KEY_SECRET",
        "OSS_ACCESS_KEY_SECRET",
        "ALIYUN_ACCESS_KEY_SECRET",
        "ALIBABA_CLOUD_ACCESS_KEY_SECRET",
    ),
    "endpoint": ("TH1_OSS_ENDPOINT", "OSS_ENDPOINT"),
    "bucket": ("TH1_OSS_BUCKET", "OSS_BUCKET"),
}


def _clean_string(value: str) -> str:
    return value.replace("\x00", "").strip()


def _decode_editor_prefs_value(value: Any) -> str:
    if isinstance(value, bytes):
        raw = value.split(b"\x00", 1)[0]
        for encoding in ("utf-8", "mbcs", "latin-1"):
            try:
                return _clean_string(raw.decode(encoding))
            except Exception:
                pass
        return ""
    if isinstance(value, str):
        return _clean_string(value)
    return ""


def _read_windows_unity_pref(pref_key: str) -> str:
    try:
        import winreg
    except Exception:
        return ""

    try:
        with winreg.OpenKey(winreg.HKEY_CURRENT_USER, UNITY_EDITOR_PREFS_REG_PATH) as key:
            index = 0
            while True:
                try:
                    name, value, _value_type = winreg.EnumValue(key, index)
                except OSError:
                    break
                index += 1
                if name == pref_key or name.startswith(f"{pref_key}_h"):
                    decoded = _decode_editor_prefs_value(value)
                    if decoded:
                        return decoded
    except OSError:
        return ""

    return ""


def load_unity_oss_editor_prefs() -> dict[str, str]:
    config: dict[str, str] = {}
    for field, pref_key in UNITY_OSS_PREF_KEYS.items():
        value = _read_windows_unity_pref(pref_key)
        if value:
            config[field] = value
    return config


def load_env_oss_config() -> dict[str, str]:
    config: dict[str, str] = {}
    for field, env_names in ENV_OSS_KEYS.items():
        for env_name in env_names:
            value = os.environ.get(env_name, "").strip()
            if value:
                config[field] = value
                break
    return config


def merge_default_oss_config(config: dict[str, Any]) -> dict[str, Any]:
    merged = dict(config)
    merged.update(load_unity_oss_editor_prefs())
    merged.update(load_env_oss_config())
    return merged


def merge_local_oss_config(config: dict[str, Any], local_config: dict[str, Any]) -> dict[str, Any]:
    merged = dict(config)
    for key, value in local_config.items():
        if key in UNITY_OSS_PREF_KEYS and isinstance(value, str) and not value.strip():
            continue
        merged[key] = value
    return merged