"""KiloStar 统一配置管理：多 YAML 文件加载、组合校验、缓存、热重载。

配置目录：``config/``（项目根），含 config.yml、workflow.yaml、sandbox.yaml。
各文件独立维护，启动时统一加载到 ``AppConfig`` 并做 schema 校验。
"""

from __future__ import annotations

import os
from pathlib import Path
from typing import Any, List, Optional

import yaml
from pydantic import BaseModel, Field

_CONFIG_DIR = Path(__file__).resolve().parent.parent.parent / "config"
_WORKFLOW_YAML = _CONFIG_DIR / "workflow.yaml"
_CONFIG_YML = _CONFIG_DIR / "config.yml"
_SANDBOX_YAML = _CONFIG_DIR / "sandbox.yaml"


class RetryConfig(BaseModel):
    max_attempts: int = Field(default=5, ge=1, le=100)


class WorkflowConfig(BaseModel):
    retry: RetryConfig = Field(default_factory=RetryConfig)


# ─── Sandbox Models (镜像 sandbox.py 中的定义，供统一加载使用) ───


class FilesystemPolicy(BaseModel):
    workspace_root: str = "/tmp/kilostar_workspace"
    allowed_read_paths: List[str] = Field(default_factory=lambda: ["/tmp"])
    denied_paths: List[str] = Field(default_factory=list)


class ShellPolicy(BaseModel):
    enabled: bool = True
    blocked_commands: List[str] = Field(default_factory=list)
    blocked_operators: List[str] = Field(default_factory=list)
    max_timeout: int = 60


class PythonExecutorPolicy(BaseModel):
    enabled: bool = True
    max_timeout: int = 30
    blocked_imports: List[str] = Field(default_factory=list)
    blocked_builtins: List[str] = Field(default_factory=list)


class SandboxConfig(BaseModel):
    enabled: bool = True
    filesystem: FilesystemPolicy = Field(default_factory=FilesystemPolicy)
    shell: ShellPolicy = Field(default_factory=ShellPolicy)
    python_executor: PythonExecutorPolicy = Field(default_factory=PythonExecutorPolicy)


# ─── App-level Models ───


class AppInfo(BaseModel):
    version: str = "0.1.1-alpha"
    name: str = "Kilostar"


class AppConfig(BaseModel):
    app: AppInfo = Field(default_factory=AppInfo)
    workflow: WorkflowConfig = Field(default_factory=WorkflowConfig)
    sandbox: SandboxConfig = Field(default_factory=SandboxConfig)


# ─── Unified AppConfig Loading ───

_app_current: AppConfig | None = None


def _read_yaml(path: Path) -> dict:
    if not path.exists():
        return {}
    with open(path, "r", encoding="utf-8") as f:
        return yaml.safe_load(f) or {}


def load_app_config(config_dir: Path | None = None) -> AppConfig:
    """从 config/ 下多个 YAML 文件加载并组合校验。"""
    d = config_dir or _CONFIG_DIR

    app_raw = _read_yaml(d / "config.yml")
    workflow_raw = _read_yaml(d / "workflow.yaml")
    sandbox_raw = _read_yaml(d / "sandbox.yaml")

    sandbox_section = sandbox_raw.get("sandbox", sandbox_raw)

    return AppConfig.model_validate({
        "app": app_raw,
        "workflow": workflow_raw,
        "sandbox": sandbox_section,
    })


def get_app_config() -> AppConfig:
    global _app_current
    if _app_current is None:
        _app_current = load_app_config()
    return _app_current


def reload_app_config(section: str | None = None) -> AppConfig:
    """热重载配置。section=None 全量重载，指定 section 只刷新对应部分。"""
    global _app_current
    if section is None or _app_current is None:
        _app_current = load_app_config()
        return _app_current

    d = _CONFIG_DIR
    if section == "workflow":
        raw = _read_yaml(d / "workflow.yaml")
        _app_current = _app_current.model_copy(
            update={"workflow": WorkflowConfig.model_validate(raw)}
        )
    elif section == "sandbox":
        raw = _read_yaml(d / "sandbox.yaml")
        sandbox_section = raw.get("sandbox", raw)
        _app_current = _app_current.model_copy(
            update={"sandbox": SandboxConfig.model_validate(sandbox_section)}
        )
    else:
        _app_current = load_app_config()

    return _app_current


# ─── Backward-Compatible Workflow Accessors ───


def get_workflow_config() -> WorkflowConfig:
    return get_app_config().workflow


def reload_workflow_config() -> WorkflowConfig:
    reload_app_config(section="workflow")
    return get_app_config().workflow


def save_workflow_config(config: WorkflowConfig) -> None:
    _WORKFLOW_YAML.parent.mkdir(parents=True, exist_ok=True)
    data = config.model_dump()
    with open(_WORKFLOW_YAML, "w", encoding="utf-8") as f:
        yaml.dump(data, f, default_flow_style=False, allow_unicode=True)
    reload_app_config(section="workflow")