import logging
import os
import time
from datetime import datetime, timezone
from pathlib import Path

BASE_DIR = Path(__file__).resolve().parent.parent

UPLOAD_DIR = BASE_DIR / "uploads"
UPLOAD_DIR.mkdir(parents=True, exist_ok=True)

VIDEO_UPLOAD_DIR = UPLOAD_DIR / "videos"
VIDEO_UPLOAD_DIR.mkdir(parents=True, exist_ok=True)

OUTPUT_DIR = BASE_DIR / "outputs"
OUTPUT_DIR.mkdir(parents=True, exist_ok=True)

VIDEO_OUTPUT_DIR = OUTPUT_DIR / "videos"
VIDEO_OUTPUT_DIR.mkdir(parents=True, exist_ok=True)

TEXTURE_DIR = BASE_DIR / "texturas"
TEXTURE_DIR.mkdir(parents=True, exist_ok=True)

LOG_DIR = BASE_DIR / "logs"
LOG_DIR.mkdir(exist_ok=True)

TEMPLATES_DIR = BASE_DIR / "templates"
TEMPLATES_DIR.mkdir(parents=True, exist_ok=True)

CLASSIC_DASHBOARD_HTML_PATH = TEMPLATES_DIR / "classic_dashboard.html"

logging.basicConfig(
    level=logging.INFO,
    format="%(asctime)s %(levelname)s %(name)s: %(message)s",
    handlers=[
        logging.FileHandler(LOG_DIR / "app.log", encoding="utf-8"),
        logging.StreamHandler(),
    ],
)
logger = logging.getLogger("backend.segmentation")

SAM2_CONFIG_PATH = os.getenv("SAM2_CONFIG_PATH", "configs/sam2.1/sam2.1_hiera_l.yaml")
SAM2_MODEL_PATH = os.getenv("SAM2_MODEL_PATH")
SAM2_DEFAULT_MODEL_NAMES = (
    "sam2.1_hiera_large_fresh.pt",
    "sam2.1_hiera_large.pt",
    "sam2.1_hiera_large.pth",
    "sam2_hiera_large.pt",
)
SAM2_MODEL_DIR_CANDIDATES = ("models", "modelo")
SAM2_UNLOAD_AFTER_USE = str(os.getenv("SAM2_UNLOAD_AFTER_USE", "0")).strip().lower() in {"1", "true", "yes"}
FRONTEND_DEBUG = str(os.getenv("FRONTEND_DEBUG", "0")).strip().lower() in {"1", "true", "yes", "on"}

# URL del Space de Gradio GPU (principal). Si falla, se usa el CPU fallback.
# Local:      http://localhost:7860
# Producción: https://<tu-space>.hf.space
GRADIO_SPACE_URL: str = os.getenv("GRADIO_SPACE_URL", "").rstrip("/")

# URL del Space de Gradio CPU (respaldo automático si el GPU falla o agota quota).
GRADIO_CPU_FALLBACK_URL: str = os.getenv("GRADIO_CPU_FALLBACK_URL", "").rstrip("/")

MAX_UPLOAD_WIDTH = 1024
UPLOAD_JPEG_QUALITY = 82
SD_JOB_STALE_SECONDS = 120
UPLOAD_JOB_STALE_SECONDS = 900
UPLOAD_BASE_SECONDS = 8.0
UPLOAD_SECONDS_PER_MEGAPIXEL = 70.0
SD_QUICK_TIMEOUT_SECONDS = 15.0

SEMANTIC_MODEL_ID = "nvidia/segformer-b5-finetuned-ade-640-640"
DEPTH_MODEL_ID = "Intel/dpt-hybrid-midas"


def utc_now_iso() -> str:
    return datetime.now(timezone.utc).isoformat()


def log_timing_start(step_name: str) -> float:
    started = time.perf_counter()
    logger.info(f"[{step_name}] START at {utc_now_iso()}")
    return started


def log_timing_end(step_name: str, started: float) -> None:
    elapsed = time.perf_counter() - started
    logger.info(f"[{step_name}] DONE {elapsed:.3f}s at {utc_now_iso()}")


def load_classic_dashboard_html() -> str:
    if not CLASSIC_DASHBOARD_HTML_PATH.exists() or not CLASSIC_DASHBOARD_HTML_PATH.is_file():
        raise RuntimeError(f"Dashboard HTML template not found: {CLASSIC_DASHBOARD_HTML_PATH}")
    return CLASSIC_DASHBOARD_HTML_PATH.read_text(encoding="utf-8")