"""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,
        "per_step_timeout_s": 15,
        "code_timeout_s": 10,
    },
    "architect": {
        "model": "deepseek-v4-flash",
        "base_url": "https://api.deepseek.com",
        "api_key": "",
    },
    "pipeline": {
        "fast_path": True,
        "rounds_cap": 6,
        "api_token_cap": 8000,
        "breach_policy": "architect_do",
    },
    "agent": {
        "workspace_dir": "agent_workspace",  # 智能体工作区根目录（越界即拒）
        "recent_workspaces": [],             # 最近打开的工作区（供快速切换）
        "max_rounds": 8,                     # 工具循环轮数上限
        "token_cap": 20000,                  # 单次智能体任务 token 熔断
        "allow_shell": False,                # 允许 run_command 执行 shell（默认关）
        "shell_timeout_s": 20,               # shell 命令超时
        "allow_net": True,                   # 允许 web_fetch 抓取公网页面（SSRF 防护内置）
        "max_handoffs": 2,                   # 两级模式：规划者<->执行者交接轮数上限
        "approval_policy": "dangerous",      # 审批策略：off | dangerous（写/编辑/命令询问）| all
        "approval_timeout_s": 120,           # 审批等待超时（超时自动拒绝）
    },
    # 校园 AI 代理层（T-P0；结构见《实施方案_代理层与缓存层.md》§4）
    "proxy": {
        "enabled": False,                    # D-P7：默认关，开启需显式配置（重启生效）
        "admin_key": "",                     # 管理面密钥；空 = 仅 loopback 放行
        "db_path": "data/proxy.sqlite3",
        "buckets": {                         # 桶配置（嵌套对象原样存储）
            "default": {"system_template": "你是校园学习助手。",
                        "doc_prefix_file": None, "doc_version": 1, "ttl_hours": 72},
        },
        "pricing": {                         # 元/1M tokens（加载期转毫元整数，D-P1）
            "deepseek-chat": {"in_miss": 3.0, "in_hit": 0.1, "out": 9.0},
            "peak_window": {"start": "08:30", "end": "23:59"},
            "offpeak_factor": 0.5,
            "sale_discount": {"in": 0.5, "out": 0.8},   # 差异化（设计文档 §2.5）
        },
        "limits": {"rpm_per_key": 10, "day_req_cap": 200,
                   "concurrent_per_key": 2, "max_body_chars": 60000},
        "semcache": {"enabled": True, "sim_threshold": 0.92,
                     "max_entries": 300000, "promote_frequency": 5},
    },
    # 语义分析器与三级分级（T-G0；结构见《实施方案_语义分析器与三级分级.md》§5）
    "sense": {
        "enabled": False,                    # D-G7 总开关：默认关
        "mode": "collect",                   # collect | shadow | live（collect 攒满标签前禁 live）
        "db_path": "data/sense.sqlite3",
        "admin_key": "",
        "embedder": {"base_url": "http://127.0.0.1:8902/v1",
                     "model": "bge-m3-Q4_K_M", "timeout_s": 5, "dim": 1024},
        "features": {"t1_max_tokens": 512, "t1_max_turns": 2,
                     "intent_blacklist": ["重构", "脚手架", "迁移", "实现", "多文件", "项目"],
                     "code_t1_kinds": ["解释", "补全"]},
        "policy": {"alpha": 0.05, "min_labels": 500,
                   "t2_prefer_local_when_idle": True},
        "consumers": {"proxy": {"t1": "local-small", "t2": "budget", "t3": "premium"}},
    },
}


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)