#!/usr/bin/env python3
"""
╔══════════════════════════════════════════════════════════════════════════════════════╗
║  QUASAR RANKER — LOGS REST API                                                      ║
║  ──────────────────────────────────────────────────────────────────────────────────  ║
║  Flask blueprint for exposing ranker logs via REST endpoints.                       ║
║  VERSION: v1.0  |  2026-03-26                                                        ║
╚══════════════════════════════════════════════════════════════════════════════════════╝
"""

from flask import Blueprint, jsonify, request, send_file
from typing import Optional
from pathlib import Path

import re as _re
import json as _json

ranker_logs_bp = Blueprint("ranker_logs", __name__, url_prefix="/api/ranker/logs")

_logger: Optional[object] = None

# ── Training-metrics extractor ────────────────────────────────────────────────
# Parses the structured training line emitted by ranker_logging.training_update():
#   [ts] | DEBUG    | TRAINING        | step=1 | loss=0.1234 | lr=0.000100 | assets=7
_TRAINING_RE = _re.compile(
    r'step=(\d+)\s*\|\s*loss=([\d.]+)\s*\|\s*lr=([\d.eE+\-]+)\s*\|\s*assets=(\d+)'
)
_JSON_BLOB_RE = _re.compile(r'(\{.*\})\s*$')


def _enrich_entry(entry: dict) -> dict:
    """
    Attach a parsed `data` dict to TRAINING log entries so the dashboard
    KPI cards (Loss / LR / Step / Assets) always have structured values.
    Works from both the pipe-delimited text and any trailing JSON metadata blob.
    """
    if entry.get("category", "").upper() != "TRAINING":
        return entry
    if entry.get("data"):          # already enriched (e.g. from in-memory logger)
        return entry

    msg = entry.get("message", "")

    # 1. Try pipe-delimited format
    m = _TRAINING_RE.search(msg)
    if m:
        entry["data"] = {
            "step":        int(m.group(1)),
            "loss":        float(m.group(2)),
            "lr":          float(m.group(3)),
            "asset_count": int(m.group(4)),
        }
        return entry

    # 2. Fallback: trailing JSON blob
    jm = _JSON_BLOB_RE.search(msg)
    if jm:
        try:
            blob = _json.loads(jm.group(1))
            if "step" in blob:
                entry["data"] = {
                    "step":        blob.get("step", 0),
                    "loss":        blob.get("loss", 0.0),
                    "lr":          blob.get("lr", 0.0),
                    "asset_count": blob.get("asset_count", blob.get("assets", 0)),
                }
        except (ValueError, KeyError):
            pass

    return entry


def init_ranker_logs_api(ranker_logger):
    """Call this from hub_dashboard_service.py during initialization."""
    global _logger
    _logger = ranker_logger


@ranker_logs_bp.route("/recent", methods=["GET"])
def get_recent_logs():
    """GET /api/ranker/logs/recent?limit=50&category=signal"""
    if not _logger:
        return jsonify({"error": "Logger not initialized"}), 500
    
    limit    = int(request.args.get("limit", 50))
    category = request.args.get("category")
    
    entries = _logger.get_recent(n=limit, category=category)
    entries = [_enrich_entry(e) for e in entries]
    return jsonify({
        "logs":  entries,
        "count": len(entries),
        "stats": _logger.get_stats(),
    })


@ranker_logs_bp.route("/asset/<asset>", methods=["GET"])
def get_asset_logs(asset: str):
    """GET /api/ranker/logs/asset/V75?limit=30"""
    if not _logger:
        return jsonify({"error": "Logger not initialized"}), 500
    
    limit   = int(request.args.get("limit", 30))
    entries = _logger.get_by_asset(asset, n=limit)
    
    return jsonify({
        "asset": asset,
        "logs":  entries,
        "count": len(entries),
    })


@ranker_logs_bp.route("/level/<level>", methods=["GET"])
def get_level_logs(level: str):
    """GET /api/ranker/logs/level/ERROR?limit=50"""
    if not _logger:
        return jsonify({"error": "Logger not initialized"}), 500
    
    limit   = int(request.args.get("limit", 50))
    entries = _logger.get_by_level(level, n=limit)
    
    return jsonify({
        "level": level.upper(),
        "logs":  entries,
        "count": len(entries),
    })


@ranker_logs_bp.route("/stats", methods=["GET"])
def get_log_stats():
    """GET /api/ranker/logs/stats"""
    if not _logger:
        return jsonify({"error": "Logger not initialized"}), 500
    
    return jsonify(_logger.get_stats())


@ranker_logs_bp.route("/export", methods=["GET"])
def export_logs():
    """GET /api/ranker/logs/export?limit=500 → download JSON"""
    if not _logger:
        return jsonify({"error": "Logger not initialized"}), 500
    
    limit = int(request.args.get("limit", 500))
    export_path = Path("/tmp/ranker_logs_export.json")
    
    try:
        _logger.export_json(str(export_path), n=limit)
        return send_file(
            export_path,
            mimetype="application/json",
            as_attachment=True,
            download_name="ranker_logs_export.json"
        )
    except Exception as e:
        return jsonify({"error": str(e)}), 500


@ranker_logs_bp.route("/clear", methods=["POST"])
def clear_logs():
    """POST /api/ranker/logs/clear — Clear in-memory buffer"""
    if not _logger:
        return jsonify({"error": "Logger not initialized"}), 500
    
    try:
        _logger.clear_buffer()
        return jsonify({"status": "cleared"})
    except Exception as e:
        return jsonify({"error": str(e)}), 500


@ranker_logs_bp.errorhandler(404)
def not_found(error):
    return jsonify({"error": "Endpoint not found"}), 404