services/quotas.py

from datetime import date
from fastapi import HTTPException
from config.database import get_supabase_admin

async def check_quota(user_id: str, quota_type: str):
    """
    Checks if a user has exceeded their daily quota for a given action.
    quota_type can be 'analysis' or 'ai_input_converter'.
    """
    db = get_supabase_admin()
    
    # 1. Get user's role/tier
    user_res = db.table("users").select("role, daily_analyses_count, last_analysis_date, daily_ai_input_count, last_ai_input_date").eq("id", user_id).single().execute()
    if not user_res.data:
        raise HTTPException(status_code=404, detail="User not found")
    
    user = user_res.data
    role = user.get("role", "free")
    
    # 2. Master Admin Bypass
    if role == "admin":
        return True
        
    today = str(date.today())
    
    # 2. Get site-wide limits from site_settings
    settings_res = db.table("site_settings").select("value").eq("key", "quotas").single().execute()
    
    # Standardized limits as requested: Guest 3, Free 5, Pro 100
    default_limits = {
        "analysis": {"guest": 3, "free": 5, "pro": 100},
        "ai_input_converter": {"guest": 3, "free": 5, "pro": 25}
    }
    
    # Safe fetch from DB with fallback
    limits = settings_res.data.get("value", default_limits) if (settings_res.data and "value" in settings_res.data) else default_limits
    
    # Determine the specific limit for this action and user role
    type_limits = limits.get(quota_type, default_limits.get(quota_type, {}))
    limit = type_limits.get(role, type_limits.get("free", 5))
    
    # 3. Check and reset counter if it's a new day
    counter_field = "daily_analyses_count" if quota_type == "analysis" else "daily_ai_input_count"
    date_field = "last_analysis_date" if quota_type == "analysis" else "last_ai_input_date"
    
    current_count = user.get(counter_field, 0)
    last_date = user.get(date_field)
    
    if last_date != today:
        current_count = 0
        db.table("users").update({counter_field: 0, date_field: today}).eq("id", user_id).execute()
    
    if limit != -1 and current_count >= limit:
        raise HTTPException(
            status_code=429, 
            detail=f"Daily {quota_type} limit ({limit}) reached for {role} tier. Please upgrade to Pro for more access."
        )
    
    # 4. Increment count
    db.table("users").update({counter_field: current_count + 1, date_field: today}).eq("id", user_id).execute()
    
    return True

async def check_guest_quota(client_ip: str, quota_type: str):
    """
    Checks guest quota based on IP address. 
    Standard limits: 3 analyses per day.
    """
    db = get_supabase_admin()
    today = str(date.today())
    
    # Get guest limits from DB or fallback
    settings_res = db.table("site_settings").select("value").eq("key", "quotas").single().execute()
    
    default_guest_limit = 3
    limit = default_guest_limit
    
    if settings_res.data and "value" in settings_res.data:
        limit = settings_res.data["value"].get(quota_type, {}).get("guest", default_guest_limit)
    
    # Block immediately if limit is 0 — before any DB operations
    # This ensures the setting takes effect even if guest_usage table is missing
    if limit == 0:
        raise HTTPException(status_code=429, detail=f"Guest access to {quota_type} is currently disabled. Please sign in for access.")

    # Check IP usage in guest_usage table
    try:
        log_res = db.table("guest_usage").select("count").eq("ip", client_ip).eq("action_type", quota_type).eq("usage_date", today).single().execute()
        
        count = 0
        if log_res.data:
            count = log_res.data["count"]
            if count >= limit:
                raise HTTPException(status_code=429, detail=f"Guest limit of {limit} daily {quota_type}s reached. Please sign in for higher limits.")
            
            db.table("guest_usage").update({"count": count + 1}).eq("ip", client_ip).eq("action_type", quota_type).eq("usage_date", today).execute()
        else:
            db.table("guest_usage").insert({
                "ip": client_ip,
                "action_type": quota_type,
                "usage_date": today,
                "count": 1
            }).execute()
    except HTTPException:
        raise
    except Exception:
        # Ignore if the guest_usage table doesn't exist
        pass
    
    return True