import sys
import os
from datetime import datetime, timedelta

_stdout_original = sys.stdout
_stderr_original = sys.stderr
_file_stream = None
_log_dir = "logs"

# ============================================================================
class MultiStream:
    def __init__(self, *streams):
        self.streams = list(streams)

    def write(self, data):
        for stream in self.streams:
            stream.write(data)
            stream.flush()

    def flush(self):
        for stream in self.streams:
            stream.flush()

    def reemplazar_file(self, old_fh, new_fh):
        for i, s in enumerate(self.streams):
            if s is old_fh:
                self.streams[i] = new_fh
                return

# ============================================================================
def _ruta_log(hoy=None):
    if hoy is None:
        hoy = datetime.now().strftime("%Y-%m-%d")
    if not os.path.exists(_log_dir):
        os.makedirs(_log_dir)
    return os.path.join(_log_dir, f"{hoy}.log")

# ============================================================================
def setup_logger():
    global _file_stream
    log_path = _ruta_log()
    _file_stream = open(log_path, "a", encoding="utf-8")
    sys.stdout = MultiStream(_stdout_original, _file_stream)
    sys.stderr = MultiStream(_stderr_original, _file_stream)
    return log_path

# ============================================================================
def rotar_log():
    global _file_stream
    hoy = datetime.now().strftime("%Y-%m-%d")
    log_path = _ruta_log(hoy)

    if _file_stream and os.path.abspath(_file_stream.name) == os.path.abspath(log_path):
        return

    nuevo_fh = open(log_path, "a", encoding="utf-8")
    if isinstance(sys.stdout, MultiStream):
        sys.stdout.reemplazar_file(_file_stream, nuevo_fh)
    if isinstance(sys.stderr, MultiStream):
        sys.stderr.reemplazar_file(_file_stream, nuevo_fh)
    try:
        _file_stream.close()
    except Exception:
        pass
    _file_stream = nuevo_fh
    print(f"📄 Log rotado a: {log_path}")

# ============================================================================
def limpiar_logs_antiguos(dias=7):
    """
    Elimina archivos de log con más de 'n' días de antigüedad.
    """
    log_dir = "logs"
    if not os.path.exists(log_dir):
        return
        
    limite = datetime.now() - timedelta(days=dias)
    count = 0
    
    for archivo in os.listdir(log_dir):
        ruta_archivo = os.path.join(log_dir, archivo)
        if os.path.isfile(ruta_archivo) and archivo.endswith(".log"):
            fecha_archivo = datetime.fromtimestamp(os.path.getmtime(ruta_archivo))
            if fecha_archivo < limite:
                try:
                    os.remove(ruta_archivo)
                    count += 1
                except Exception as e:
                    print(f"⚠️ Error al eliminar log {archivo}: {e}")
    
    if count > 0:
        print(f"🧹 Se eliminaron {count} archivos de log antiguos (más de {dias} días).")
# ============================================================================