"""可调整的运行设置（SettingsStore）—— 让用户自定义内置小模型 / 大模型 / 管线。

用户可在 Web 界面"模型设置"里调整并持久化到 config/settings.json（gitignore），
重启后保留。调整会触发 v2 管线重建（gateway.api.build_v2_pipeline 重新读取）。

默认值与 config/config.yaml 的 v2 段一致；settings.json 只存用户改动覆盖项。
"""
from __future__ import annotations

import json
from pathlib import Path
from typing import Any, Dict, Optional

_SETTINGS_PATH = Path(__file__).resolve().parent.parent / "config" / "settings.json"

# 可调整项（含默认值）；用户改动存这里
DEFAULTS: Dict[str, Any] = {
    "worker": {
        "backend": "llama_server",      # mock | openai/api | llama_server
        "model": "models/qwen3.5-4b-q4_k_m.gguf",
        "base_url": "",                 # openai 后端填 http://127.0.0.1:11434/v1 等
        "port": 8901,                   # llama_server 端口
        "temperature": 0.3,
        "max_fix_attempts": 2,
        "code_timeout_s": 10,
    },
    "architect": {
        "model": "deepseek-chat",
        "base_url": "https://api.deepseek.com/v1",
        "api_key_env": "DEEPSEEK_API_KEY",
    },
    "pipeline": {
        "fast_path": True,
        "rounds_cap": 6,
        "api_token_cap": 8000,
        "breach_policy": "architect_do",
    },
}


class SettingsStore:
    """用户可调整设置（内存 + settings.json 持久化）。"""

    def __init__(self, path: Optional[Path] = None):
        self._path = Path(path) if path else _SETTINGS_PATH
        self._data: Dict[str, Any] = {}
        self.load()

    # ---------- 持久化 ----------
    def load(self) -> None:
        if self._path.exists():
            try:
                self._data = json.loads(self._path.read_text(encoding="utf-8"))
            except Exception:
                self._data = {}
        else:
            self._data = {}

    def save(self) -> None:
        self._path.parent.mkdir(parents=True, exist_ok=True)
        self._path.write_text(
            json.dumps(self._data, ensure_ascii=False, indent=2), encoding="utf-8")

    # ---------- 访问 ----------
    def to_dict(self) -> Dict[str, Any]:
        """返回 默认值 + 用户覆盖 合并后的完整设置。"""
        merged: Dict[str, Any] = {}
        for section, defaults in DEFAULTS.items():
            ov = self._data.get(section, {})
            merged[section] = {**defaults, **(ov if isinstance(ov, dict) else {})}
        return merged

    def get(self, section: str, key: str, default: Any = None) -> Any:
        merged = self.to_dict()
        return merged.get(section, {}).get(key, default)

    def update(self, patch: Dict[str, Any]) -> Dict[str, Any]:
        """应用部分更新（可只传改动的 section/key）。返回合并后的完整设置。"""
        for section, values in patch.items():
            if section not in DEFAULTS or not isinstance(values, dict):
                continue
            cur = self._data.setdefault(section, {})
            for k, v in values.items():
                if k in DEFAULTS[section]:
                    cur[k] = _coerce(v, DEFAULTS[section][k])
        self.save()
        return self.to_dict()

    def reset(self) -> Dict[str, Any]:
        """恢复默认。"""
        self._data = {}
        self.save()
        return self.to_dict()


def _coerce(value: Any, template: Any) -> Any:
    """按默认值的类型把输入转成一致类型（数值容错）。"""
    if isinstance(template, bool):
        return bool(value)
    if isinstance(template, int):
        try:
            return int(float(value))
        except (TypeError, ValueError):
            return template
    if isinstance(template, float):
        try:
            return float(value)
        except (TypeError, ValueError):
            return template
    return value


def load_settings(path: Optional[Path] = None) -> SettingsStore:
    return SettingsStore(path)