import os
import json
import logging
from datetime import datetime
from constants import OUTPUT_DIR

DIAGNOSTICS_DIR = os.path.join(OUTPUT_DIR, "diagnostics")
os.makedirs(DIAGNOSTICS_DIR, exist_ok=True)

class TraceManager:
    _instance = None

    def __new__(cls):
        if cls._instance is None:
            cls._instance = super(TraceManager, cls).__new__(cls)
            cls._instance.active_tasks = {}
        return cls._instance

    def start_trace(self, task_id: str):
        self.active_tasks[task_id] = []
        self._save(task_id)

    def add_flag(self, task_id: str, flag: str, details: str = ""):
        if not task_id:
            return
        if task_id not in self.active_tasks:
            self.active_tasks[task_id] = []
        entry = {
            "timestamp": datetime.utcnow().isoformat(),
            "flag": flag,
            "details": str(details)[:500]  # truncate details to keep json small
        }
        self.active_tasks[task_id].append(entry)
        self._save(task_id)
        # Also log to standard logger
        logging.getLogger("wealth_engine").info(f"[{flag}] {details}")
        
    def _save(self, task_id: str):
        try:
            path = os.path.join(DIAGNOSTICS_DIR, f"trace_{task_id}.json")
            with open(path, "w") as f:
                json.dump({
                    "task_id": task_id,
                    "last_updated": datetime.utcnow().isoformat(),
                    "flags": self.active_tasks[task_id]
                }, f, indent=4)
        except Exception:
            pass

    def get_trace(self, task_id: str):
        return self.active_tasks.get(task_id, [])

tracer = TraceManager()