"""Configuration for the Cortex.0 / OpenHands fusion."""

from __future__ import annotations

import os
from dataclasses import dataclass, field
from pathlib import Path

import yaml

DEFAULT_SYSTEM_PROMPT = Path(__file__).resolve().parent.parent / "prompts" / "cortex0_system.txt"


@dataclass
class Cortex0Settings:
    """Everything needed to reach Cortex.0 and configure the agent."""

    # --- inference endpoint -------------------------------------------------
    base_url: str = "http://127.0.0.1:8080/v1"
    api_key: str = "cortex0-local"
    # Name the endpoint actually serves.
    served_model_name: str = "cortex0"
    # litellm routes by provider prefix; any OpenAI-compatible server is
    # reached through the "openai/" prefix plus an explicit base_url.
    model: str = "openai/cortex0"

    # --- generation ---------------------------------------------------------
    max_output_tokens: int = 32768
    temperature: float = 1.0
    top_p: float = 0.95
    top_k: int = 20
    context_window: int = 262144

    # --- robustness ---------------------------------------------------------
    num_retries: int = 5
    timeout: float = 600.0
    native_tool_calling: bool = True

    # --- agent --------------------------------------------------------------
    tools: list[str] = field(
        default_factory=lambda: [
            "terminal",
            "file_editor",
            "task_tracker",
            "glob",
            "grep",
        ]
    )
    max_iterations_per_run: int = 500
    condenser_max_size: int = 240
    system_prompt_path: str = str(DEFAULT_SYSTEM_PROMPT)
    workspace: str = "workspace/project"

    @classmethod
    def load(cls, path: str | Path | None = None) -> "Cortex0Settings":
        """Load settings from YAML, then let environment variables win.

        Precedence: defaults < YAML file < CORTEX0_* environment variables.
        """
        data: dict = {}
        candidate = Path(path) if path else Path("configs/cortex0.yaml")
        if candidate.is_file():
            loaded = yaml.safe_load(candidate.read_text(encoding="utf-8")) or {}
            if not isinstance(loaded, dict):
                raise ValueError(f"{candidate} must contain a YAML mapping")
            data = loaded

        for key in cls.__dataclass_fields__:
            env_key = f"CORTEX0_{key.upper()}"
            if env_key in os.environ:
                raw = os.environ[env_key]
                data[key] = _coerce(raw, cls.__dataclass_fields__[key].default)

        known = {k: v for k, v in data.items() if k in cls.__dataclass_fields__}
        return cls(**known)

    def system_prompt(self) -> str:
        path = Path(self.system_prompt_path)
        if not path.is_file():
            raise FileNotFoundError(
                f"System prompt not found: {path}. Set system_prompt_path or create the file."
            )
        return path.read_text(encoding="utf-8")


def _coerce(raw: str, default: object) -> object:
    """Turn an environment string into the type of the dataclass default."""
    if isinstance(default, bool):
        return raw.strip().lower() in {"1", "true", "yes", "on"}
    if isinstance(default, int) and not isinstance(default, bool):
        return int(raw)
    if isinstance(default, float):
        return float(raw)
    if isinstance(default, list):
        return [item.strip() for item in raw.split(",") if item.strip()]
    return raw