# ============================================================
# PhishGuard AI - feedback_store.py
# Thread-safe feedback storage, retraining trigger, analytics.
#
# Storage: feedback_data.jsonl (append-only, one JSON per line)
# Lock: asyncio.Lock prevents concurrent writes & double-retrain
# ============================================================

from __future__ import annotations

import os
import json
import time
import asyncio
import shutil
import logging
from datetime import datetime, timezone
from typing import Optional

logger = logging.getLogger("phishguard.feedback")

_BASE_DIR     = os.path.dirname(os.path.abspath(__file__))
FEEDBACK_FILE = os.path.join(_BASE_DIR, "feedback_data.jsonl")
STATE_FILE    = os.path.join(_BASE_DIR, "retrain_state.json")

# ── Async lock for thread-safe writes ────────────────────────────────────────
_write_lock   = asyncio.Lock()

# ── Retrain state (persisted to retrain_state.json) ──────────────────────────
_retrain_state = {
    "model_version":       1,
    "total_feedback":      0,
    "unprocessed_count":   0,
    "phishing_corrections": 0,
    "safe_corrections":    0,
    "last_retrain":        None,      # ISO 8601 timestamp
    "retrain_history":     [],        # [{ts, samples, accuracy, version}]
}


def _load_state():
    """Load persisted retrain state from disk."""
    global _retrain_state
    if os.path.exists(STATE_FILE):
        try:
            with open(STATE_FILE, "r") as f:
                saved = json.load(f)
            _retrain_state.update(saved)
            logger.info(f"[FeedbackStore] State loaded | version={_retrain_state['model_version']} | total={_retrain_state['total_feedback']}")
        except Exception as e:
            logger.warning(f"[FeedbackStore] Could not load state: {e}")


def _save_state():
    """Persist retrain state to disk (atomic write)."""
    try:
        tmp = STATE_FILE + ".tmp"
        with open(tmp, "w") as f:
            json.dump(_retrain_state, f, indent=2, default=str)
        os.replace(tmp, STATE_FILE)
    except Exception as e:
        logger.warning(f"[FeedbackStore] Could not save state: {e}")


# Load state on module import
_load_state()


# ══════════════════════════════════════════════════════════════════════════════
#  FEEDBACK STORAGE
# ══════════════════════════════════════════════════════════════════════════════

async def append_feedback(
    url: str,
    label: str,
    source: str = "user_feedback",
    original_prediction: Optional[float] = None,
) -> dict:
    """
    Thread-safe append of a feedback entry to feedback_data.jsonl.

    Returns: {"success": True, "feedback_count": N, "unprocessed": M}
    """
    entry = {
        "url":                 url,
        "label":               label,              # "phishing" or "safe"
        "timestamp":           datetime.now(timezone.utc).isoformat(),
        "source":              source,
        "original_prediction": round(original_prediction, 4) if original_prediction is not None else None,
    }

    async with _write_lock:
        try:
            with open(FEEDBACK_FILE, "a") as f:
                f.write(json.dumps(entry) + "\n")
        except Exception as e:
            logger.error(f"[FeedbackStore] Write failed: {e}")
            return {"success": False, "error": str(e)}

        # Update in-memory state
        _retrain_state["total_feedback"]    += 1
        _retrain_state["unprocessed_count"] += 1
        if label == "phishing":
            _retrain_state["phishing_corrections"] += 1
        elif label == "safe":
            _retrain_state["safe_corrections"] += 1

        _save_state()

    logger.info(f"[FeedbackStore] Saved | url={url} | label={label} | total={_retrain_state['total_feedback']}")

    return {
        "success":        True,
        "feedback_count": _retrain_state["total_feedback"],
        "unprocessed":    _retrain_state["unprocessed_count"],
    }


def get_unprocessed_count() -> int:
    """Number of feedback entries since last retraining."""
    return _retrain_state["unprocessed_count"]


def get_model_version() -> int:
    """Current model version number."""
    return _retrain_state["model_version"]


def get_stats() -> dict:
    """Return feedback analytics for the /feedback/stats endpoint."""
    return {
        "total_feedback":       _retrain_state["total_feedback"],
        "phishing_corrections": _retrain_state["phishing_corrections"],
        "safe_corrections":     _retrain_state["safe_corrections"],
        "unprocessed_count":    _retrain_state["unprocessed_count"],
        "last_retrain":         _retrain_state["last_retrain"],
        "model_version":        _retrain_state["model_version"],
        "retrain_history":      _retrain_state["retrain_history"][-10:],  # last 10
    }


def get_recent_entries(n: int = 50) -> list:
    """Read the last N feedback entries from the JSONL file."""
    if not os.path.exists(FEEDBACK_FILE):
        return []
    try:
        with open(FEEDBACK_FILE, "r") as f:
            lines = f.readlines()
        entries = []
        for line in lines[-(n):]:
            line = line.strip()
            if line:
                entries.append(json.loads(line))
        return entries
    except Exception:
        return []


# ══════════════════════════════════════════════════════════════════════════════
#  RETRAINING PIPELINE
# ══════════════════════════════════════════════════════════════════════════════

RETRAIN_THRESHOLD = 50
_retrain_running  = False


def should_retrain() -> bool:
    """Check if retraining should be triggered."""
    return (
        _retrain_state["unprocessed_count"] >= RETRAIN_THRESHOLD
        and not _retrain_running
    )


def mark_retrain_complete(samples: int, accuracy: float):
    """
    Called after successful retraining.
    Increments model_version, resets unprocessed counter, logs history.
    """
    _retrain_state["model_version"]     += 1
    _retrain_state["unprocessed_count"]  = 0
    _retrain_state["last_retrain"]       = datetime.now(timezone.utc).isoformat()
    _retrain_state["retrain_history"].append({
        "timestamp": _retrain_state["last_retrain"],
        "samples":   samples,
        "accuracy":  round(accuracy, 4),
        "version":   _retrain_state["model_version"],
    })
    # Keep only last 50 history entries
    if len(_retrain_state["retrain_history"]) > 50:
        _retrain_state["retrain_history"] = _retrain_state["retrain_history"][-50:]
    _save_state()
    logger.info(
        f"[FeedbackStore] Retrained on {samples} feedback samples. "
        f"New accuracy: {accuracy:.2%}. Model version: {_retrain_state['model_version']}"
    )


def archive_feedback_file():
    """Move the processed feedback file to a timestamped backup."""
    if os.path.exists(FEEDBACK_FILE):
        archive = FEEDBACK_FILE + f".{int(time.time())}.bak"
        try:
            shutil.move(FEEDBACK_FILE, archive)
            logger.info(f"[FeedbackStore] Archived feedback → {archive}")
        except Exception as e:
            logger.warning(f"[FeedbackStore] Archive failed: {e}")


def load_feedback_entries() -> list:
    """Load ALL entries from the feedback JSONL file."""
    if not os.path.exists(FEEDBACK_FILE):
        return []
    entries = []
    try:
        with open(FEEDBACK_FILE, "r") as f:
            for line in f:
                line = line.strip()
                if line:
                    entries.append(json.loads(line))
    except Exception as e:
        logger.error(f"[FeedbackStore] Read failed: {e}")
    return entries