"""Reasoning mode controller for managing AI reasoning preferences."""

from __future__ import annotations

import json
import os
from dataclasses import dataclass, asdict
from pathlib import Path
from typing import Dict, Any


@dataclass
class PreferencesState:
    """User preferences for sidebar behavior."""
    reasoning_enabled: bool = False
    default_model: str | None = None
    theme: str = "default"


class ReasoningController:
    """Manages reasoning mode state and model selection."""
    
    # Model names for reasoning toggle
    INSTRUCT_MODEL = "hf.co/unsloth/Qwen3-4B-Instruct-2507-GGUF:Q8_K_XL"
    THINKING_MODEL = "hf.co/unsloth/Qwen3-4B-Thinking-2507-GGUF:Q8_K_XL"
    
    def __init__(self):
        """Initialize the reasoning controller with preference persistence."""
        # Set preference file path
        config_dir = Path.home() / ".config" / "aisidebar"
        config_dir.mkdir(parents=True, exist_ok=True)
        self._preference_file = config_dir / "preferences.json"
        
        # Load preferences from disk
        self._preferences = self._load_preferences()
    
    def is_enabled(self) -> bool:
        """Check if reasoning mode is active.
        
        Returns:
            True if reasoning mode is enabled, False otherwise
        """
        return self._preferences.reasoning_enabled
    
    def toggle(self) -> bool:
        """Toggle reasoning mode and persist preference.
        
        Returns:
            New state of reasoning mode (True if enabled, False if disabled)
        """
        self._preferences.reasoning_enabled = not self._preferences.reasoning_enabled
        self._save_preferences()
        return self._preferences.reasoning_enabled
    
    def get_model_name(self) -> str:
        """Return the appropriate model name based on reasoning mode.
        
        Returns:
            THINKING_MODEL if reasoning is enabled, INSTRUCT_MODEL otherwise
        """
        return self.THINKING_MODEL if self._preferences.reasoning_enabled else self.INSTRUCT_MODEL
    
    def get_model_options(self) -> Dict[str, Any]:
        """Return the optimal parameters for the current model.
        
        Returns:
            Dictionary of model-specific parameters
        """
        if self._preferences.reasoning_enabled:
            # Thinking model settings
            return {
                "temperature": 0.6,
                "top_p": 0.95,
                "top_k": 20,
                "min_p": 0.0,
                "num_predict": 32768,  # Adequate output length
            }
        else:
            # Instruct model settings
            return {
                "temperature": 0.7,
                "top_p": 0.8,
                "top_k": 20,
                "min_p": 0.0,
                "num_predict": 32768,
            }
    
    def _load_preferences(self) -> PreferencesState:
        """Load preferences from disk or create defaults.
        
        Returns:
            PreferencesState instance with loaded or default values
        """
        if not self._preference_file.exists():
            return PreferencesState()
        
        try:
            with self._preference_file.open("r", encoding="utf-8") as f:
                data = json.load(f)
                return PreferencesState(
                    reasoning_enabled=data.get("reasoning_enabled", False),
                    default_model=data.get("default_model"),
                    theme=data.get("theme", "default"),
                )
        except (json.JSONDecodeError, OSError):
            # If file is corrupted or unreadable, return defaults
            return PreferencesState()
    
    def _save_preferences(self) -> None:
        """Persist preferences to disk atomically."""
        try:
            # Convert dataclass to dict
            data = asdict(self._preferences)
            
            # Write to temporary file first
            temp_file = self._preference_file.with_suffix(".tmp")
            with temp_file.open("w", encoding="utf-8") as f:
                json.dump(data, f, indent=2, ensure_ascii=False)
                f.flush()
                os.fsync(f.fileno())
            
            # Atomic replace
            os.replace(temp_file, self._preference_file)
        except OSError:
            # If save fails, continue without crashing
            # Preferences will revert to previous state on next load
            pass