backend/app/core/logger.py

import sys
import os
from loguru import logger
from app.core.config import settings
from pathlib import Path
from app.core.request_id import get_request_id

# ── 1. Remove default loguru handler ──────────────────────────────────────────
logger.remove()

# ── 2. Inject request_id into every log record ───────────────────────────────
def _inject_request_id(record):
    req_id = get_request_id()
    record["extra"]["request_id"] = req_id if req_id else "SYSTEM"

logger.configure(patcher=_inject_request_id)

import logging
logging.getLogger("uvicorn.access").disabled = True

# ── 3. Log directory ──────────────────────────────────────────────────────────
log_dir = Path("app_logs")
log_dir.mkdir(parents=True, exist_ok=True)

# ── 4. Console — structured JSON for production, colorized text for local ─────
IS_PROD = os.environ.get("ENVIRONMENT", "development").lower() in ("production", "prod")

if IS_PROD:
    # Production: pure JSON, machine-readable — timestamp in 12-hour AM/PM UTC
    logger.add(
        sys.stdout,
        format="{message}",
        serialize=True,   # emits {"text":..., "record":{...}} JSON lines
        level=settings.LOG_LEVEL,
        enqueue=True,
    )
else:
    # Local dev: human-readable with color, 12-hour AM/PM format
    logger.add(
        sys.stdout,
        format=(
            "<green>{time:MM-DD-YYYY hh:mm:ss A}</green> | "
            "<level>{level:<8}</level> | "
            "<cyan>[{extra[request_id]}]</cyan> "
            "<white>{name}:{function}:{line}</white> — {message}"
        ),
        colorize=True,
        level=settings.LOG_LEVEL,
        enqueue=True,
    )

# ── 5. File logger — 12-hour AM/PM timestamp ─────────────────────────────────
logger.add(
    "app_logs/api_{time:YYYY-MM-DD}.log",
    rotation="00:00",
    retention="30 days",
    compression="zip",
    level="INFO",
    # hh = 12-hour clock, A = AM/PM
    format="{time:MM-DD-YYYY hh:mm:ss A} | {level:<8} | [{extra[request_id]}] {name}:{function}:{line} — {message}",
    enqueue=True,
)

# ── 6. New Relic sink (optional — never crashes the app) ──────────────────────
_NR_KEY = os.environ.get("NEW_RELIC_LICENSE_KEY", "")
if _NR_KEY:
    try:
        import newrelic.agent
        try:
            newrelic.agent.initialize()
        except Exception:
            pass

        def _newrelic_sink(message):
            record = message.record
            try:
                newrelic.agent.record_log_event(
                    message=record["message"],
                    level=record["level"].name,
                    timestamp=int(record["time"].timestamp() * 1000),
                    attributes={
                        "request_id": record["extra"].get("request_id", "SYSTEM"),
                        "method":     record["extra"].get("method", ""),
                        "path":       record["extra"].get("path", ""),
                        "status":     record["extra"].get("status", ""),
                        "duration_ms": record["extra"].get("duration_ms", ""),
                        "logger":     record["name"],
                        "function":   record["function"],
                        "line":       record["line"],
                    }
                )
            except Exception:
                pass  # Cloud logging must never affect the app

        logger.add(_newrelic_sink, level="INFO", enqueue=True)
    except ImportError:
        pass
    except Exception:
        pass