import logging
import time
import timeout_decorator
import io
import os
import zipfile
import json
import cv2
import torch
import numpy as np
from PIL import Image

from registry import get_model
from core.describe_scene import describe_scene
from utils.helpers import generate_session_id, log_runtime

# Setup logging
logging.basicConfig(level=logging.INFO, format='%(asctime)s - %(levelname)s - %(message)s')
logger = logging.getLogger(__name__)

# Model mappings
DETECTION_MODEL_MAP = {
    "YOLOv8-Nano": "yolov8n",
    "YOLOv8-Small": "yolov8s",
    "YOLOv8-Large": "yolov8l",
    "YOLOv11-Beta": "yolov11b"
}

SEGMENTATION_MODEL_MAP = {
    "SegFormer-B0": "segformer_b0",
    "SegFormer-B5": "segformer_b5",
    "DeepLabV3-ResNet50": "deeplabv3_resnet50"
}

DEPTH_MODEL_MAP = {
    "MiDaS v21 Small 256": "midas_v21_small_256",
    "MiDaS v21 384": "midas_v21_384",
    "DPT Hybrid 384": "dpt_hybrid_384",
    "DPT Swin2 Large 384": "dpt_swin2_large_384",
    "DPT Beit Large 512": "dpt_beit_large_512"
}

def process_video(
    video_path: str,
    run_det: bool,
    det_model: str,
    det_confidence: float,
    run_seg: bool,
    seg_model: str,
    run_depth: bool,
    depth_model: str,
    blend: float
):
    """
    Reads each frame from `video_path`, runs your existing `process_image()` on it,
    and writes out a new MP4 in outputs/processed_<name>.mp4.

    Returns:
        (None, scene_json: dict, output_video_path: str)
    """
    logger.info(f"Starting video processing for {video_path}")
    cap = cv2.VideoCapture(video_path)
    if not cap.isOpened():
        raise RuntimeError(f"Cannot open video: {video_path}")

    fps    = cap.get(cv2.CAP_PROP_FPS) or 25.0
    width  = int(cap.get(cv2.CAP_PROP_FRAME_WIDTH))
    height = int(cap.get(cv2.CAP_PROP_FRAME_HEIGHT))
    fourcc = cv2.VideoWriter_fourcc(*"mp4v")

    os.makedirs("outputs", exist_ok=True)
    base = os.path.basename(video_path)
    out_path = os.path.join("outputs", f"processed_{base}")
    writer = cv2.VideoWriter(out_path, fourcc, fps, (width, height))
    if not writer.isOpened():
        cap.release()
        raise RuntimeError(f"Cannot write to: {out_path}")

    frame_idx = 0
    scene_info = {"video": base, "frames_processed": 0}

    while True:
        ret, frame_bgr = cap.read()
        if not ret:
            break

        # BGR→RGB→PIL
        frame_rgb = cv2.cvtColor(frame_bgr, cv2.COLOR_BGR2RGB)
        pil_frame = Image.fromarray(frame_rgb)

        # Run your existing image pipeline
        try:
            processed_img, _, _ = process_image(
                image=pil_frame,
                run_det=run_det,
                det_model=det_model,
                det_confidence=det_confidence,
                run_seg=run_seg,
                seg_model=seg_model,
                run_depth=run_depth,
                depth_model=depth_model,
                blend=blend
            )
        except Exception as e:
            cap.release()
            writer.release()
            raise RuntimeError(f"Error on frame {frame_idx}: {e}")

        # PIL→BGR numpy
        out_bgr = cv2.cvtColor(np.array(processed_img), cv2.COLOR_RGB2BGR)
        writer.write(out_bgr)

        frame_idx += 1
        scene_info["frames_processed"] = frame_idx

    cap.release()
    writer.release()
    logger.info(f"Finished video. Wrote {frame_idx} frames to {out_path}")

    # Minimal JSON summary
    scene_json = {
        "video": scene_info["video"],
        "frames_processed": scene_info["frames_processed"]
    }

    return None, scene_json, out_path
    
#@timeout_decorator.timeout(35, use_signals=False)  # 35 sec limit per image
def process_image(
    image: Image.Image,
    run_det: bool,
    det_model: str,
    det_confidence: float,
    run_seg: bool,
    seg_model: str,
    run_depth: bool,
    depth_model: str,
    blend: float
):
    """
    Runs selected perception tasks on the input image and packages results.
    Args:
        image (PIL.Image): Input image.
        run_det (bool): Run object detection.
        det_model (str): Detection model key.
        det_confidence (float): Detection confidence threshold.
        run_seg (bool): Run segmentation.
        seg_model (str): Segmentation model key.
        run_depth (bool): Run depth estimation.
        depth_model (str): Depth model key.
        blend (float): Overlay blend alpha (0.0 - 1.0).
    Returns:
        Tuple[Image, dict, Tuple[str, bytes]]: Final image, scene JSON, and downloadable ZIP.
    """
    logger.info("Starting image processing pipeline.")
    start_time = time.time()
    outputs, scene = {}, {}
    combined_np = np.array(image)

    try:
        # Detection
        if run_det:
            logger.info(f"Running detection with model: {det_model}")
            load_start = time.time()
            model = get_model("detection", det_model, device="cpu")
            model.load_model()
            logger.info(f"{det_model} detection model loaded in {time.time() - load_start:.2f} seconds.")
            boxes = model.predict(image, conf_threshold=det_confidence)
            overlay = model.draw(image, boxes)
            combined_np = np.array(overlay)
            buf = io.BytesIO()
            overlay.save(buf, format="PNG")
            outputs["detection.png"] = buf.getvalue()
            scene["detection"] = boxes

        # Segmentation
        if run_seg:
            logger.info(f"Running segmentation with model: {seg_model}")
            load_start = time.time()
            model = get_model("segmentation", seg_model, device="cpu")
            logger.info(f"{seg_model} segmentation model loaded in {time.time() - load_start:.2f} seconds.")
            mask = model.predict(image)
            overlay = model.draw(image, mask, alpha=blend)
            combined_np = cv2.addWeighted(combined_np, 1 - blend, np.array(overlay), blend, 0)
            buf = io.BytesIO()
            overlay.save(buf, format="PNG")
            outputs["segmentation.png"] = buf.getvalue()
            scene["segmentation"] = mask.tolist()

        # Depth Estimation
        if run_depth:
            logger.info(f"Running depth estimation with model: {depth_model}")
            load_start = time.time()
            model = get_model("depth", depth_model, device="cpu")
            logger.info(f"{depth_model} depth model loaded in {time.time() - load_start:.2f} seconds.")
            dmap = model.predict(image)
            norm_dmap = ((dmap - dmap.min()) / (dmap.ptp()) * 255).astype(np.uint8)
            d_pil = Image.fromarray(norm_dmap)
            combined_np = cv2.addWeighted(combined_np, 1 - blend, np.array(d_pil.convert("RGB")), blend, 0)
            buf = io.BytesIO()
            d_pil.save(buf, format="PNG")
            outputs["depth_map.png"] = buf.getvalue()
            scene["depth"] = dmap.tolist()

        # Final image overlay
        final_img = Image.fromarray(combined_np)
        buf = io.BytesIO()
        final_img.save(buf, format="PNG")
        outputs["scene_blueprint.png"] = buf.getvalue()

        # Scene description
        try:
            scene_json = describe_scene(**scene)
        except Exception as e:
            logger.warning(f"describe_scene failed: {e}")
            scene_json = {"error": str(e)}
        telemetry = {
        "session_id": generate_session_id(),
        "runtime_sec": round(log_runtime(start_time), 2),
        "used_models": {
            "detection": det_model if run_det else None,
            "segmentation": seg_model if run_seg else None,
            "depth": depth_model if run_depth else None
            }
        }
        scene_json["telemetry"] = telemetry

        outputs["scene_description.json"] = json.dumps(scene_json, indent=2).encode("utf-8")

        # ZIP file creation
        zip_buf = io.BytesIO()
        with zipfile.ZipFile(zip_buf, "w") as zipf:
            for name, data in outputs.items():
                zipf.writestr(name, data)

        elapsed = log_runtime(start_time)
        logger.info(f"Image processing completed in {elapsed:.2f} seconds.")

        #return final_img, scene_json, ("uvis_results.zip", zip_buf.getvalue())
        # Save ZIP to disk for Gradio file output
        zip_path = "outputs/uvis_results.zip"
        os.makedirs("outputs", exist_ok=True)
        with open(zip_path, "wb") as f:
            f.write(zip_buf.getvalue())
        
        return final_img, scene_json, zip_path


    except Exception as e:
        logger.error(f"Error in processing pipeline: {e}")
        return None, {"error": str(e)}, None