"""
Persistence layer for V2 autonomous system.
Saves and restores critical context data across bot restarts.
"""

import json
import time
from pathlib import Path
from typing import Dict, Optional
from datetime import datetime, timezone

CONTEXT_FILE = Path("memory/autonomous_context.json")


def save_autonomous_context(server_contexts: dict, server_last_action: dict):
    """
    Save critical context data to disk.
    Only saves data that makes sense to persist (not ephemeral stats).
    """
    now = time.time()
    
    data = {
        "saved_at": now,
        "saved_at_readable": datetime.now(timezone.utc).isoformat(),
        "servers": {}
    }
    
    for guild_id, ctx in server_contexts.items():
        data["servers"][str(guild_id)] = {
            # Critical timing data
            "time_since_last_action": ctx.time_since_last_action,
            "time_since_last_interaction": ctx.time_since_last_interaction,
            "messages_since_last_appearance": ctx.messages_since_last_appearance,
            
            # Decay-able activity data (will be aged on restore)
            "conversation_momentum": ctx.conversation_momentum,
            "unique_users_active": ctx.unique_users_active,
            
            # Last action timestamp (absolute time)
            "last_action_timestamp": server_last_action.get(guild_id, 0),
            
            # Mood state (already persisted in servers_config.json, but include for completeness)
            "current_mood": ctx.current_mood,
            "mood_energy_level": ctx.mood_energy_level
        }
    
    try:
        CONTEXT_FILE.parent.mkdir(parents=True, exist_ok=True)
        with open(CONTEXT_FILE, 'w') as f:
            json.dump(data, f, indent=2)
        print(f"💾 [V2] Saved autonomous context for {len(server_contexts)} servers")
    except Exception as e:
        print(f"⚠️ [V2] Failed to save autonomous context: {e}")


def load_autonomous_context() -> tuple[Dict[int, dict], Dict[int, float]]:
    """
    Load and restore context data from disk.
    Returns (server_context_data, server_last_action).
    
    Applies staleness/decay rules based on downtime:
    - conversation_momentum decays over time
    - Timestamps are adjusted for elapsed time
    """
    if not CONTEXT_FILE.exists():
        print("ℹ️ [V2] No saved context found, starting fresh")
        return {}, {}
    
    try:
        with open(CONTEXT_FILE, 'r') as f:
            data = json.load(f)
        
        saved_at = data.get("saved_at", 0)
        downtime = time.time() - saved_at
        downtime_minutes = downtime / 60
        
        print(f"📂 [V2] Loading context from {downtime_minutes:.1f} minutes ago")
        
        context_data = {}
        last_action = {}
        
        for guild_id_str, server_data in data.get("servers", {}).items():
            guild_id = int(guild_id_str)
            
            # Apply decay/staleness rules
            momentum = server_data.get("conversation_momentum", 0.0)
            
            # Momentum decays: half-life of 10 minutes
            if downtime > 0:
                decay_factor = 0.5 ** (downtime_minutes / 10)
                momentum = momentum * decay_factor
            
            # Restore data with adjustments
            context_data[guild_id] = {
                "time_since_last_action": server_data.get("time_since_last_action", 0) + downtime,
                "time_since_last_interaction": server_data.get("time_since_last_interaction", 0) + downtime,
                "messages_since_last_appearance": server_data.get("messages_since_last_appearance", 0),
                "conversation_momentum": momentum,
                "unique_users_active": 0,  # Reset (stale data)
                "current_mood": server_data.get("current_mood", "neutral"),
                "mood_energy_level": server_data.get("mood_energy_level", 0.5)
            }
            
            # Restore last action timestamp
            last_action_timestamp = server_data.get("last_action_timestamp", 0)
            if last_action_timestamp > 0:
                last_action[guild_id] = last_action_timestamp
        
        print(f"✅ [V2] Restored context for {len(context_data)} servers")
        print(f"   └─ Momentum decay factor: {decay_factor:.3f} (from {downtime_minutes:.1f}min downtime)")
        
        return context_data, last_action
        
    except Exception as e:
        print(f"⚠️ [V2] Failed to load autonomous context: {e}")
        return {}, {}


def apply_context_to_signals(context_data: dict, context_signals):
    """
    Apply loaded context data to a ContextSignals object.
    Call this after creating a fresh ContextSignals instance.
    """
    for key, value in context_data.items():
        if hasattr(context_signals, key):
            setattr(context_signals, key, value)