# ----------------------------------------------------------------------
# IMPORTS
# ----------------------------------------------------------------------
import torch
import logging
import spaces
import sys
import traceback
from typing import List, Tuple
from src.utils import LOG_LEVEL_MAP, EMOJI_MAP

# ----------------------------------------------------------------------
# HEAD MODEL CONSTANTS
# ----------------------------------------------------------------------
HEAD_DETECTION_THRESHOLD = 0.2

# ----------------------------------------------------------------------
# MODEL LABEL CONFIGURATION
# ----------------------------------------------------------------------
MODEL_LABEL_CONFIG = {
    "head_model": {
        "person_list": {},
        "product_type_list": {},
        "head_list": {
            "head": ["head", "face"]
        },
        "shoes_list": {},
        "clothing_features_list": {},
        "artifacts_list": {}
    }
}

# ----------------------------------------------------------------------
# HEAD MODEL HELPER FUNCTIONS
# ----------------------------------------------------------------------
def get_label_name_from_model(model, label_id):
    if hasattr(model, 'config') and hasattr(model.config, 'id2label'):
        return model.config.id2label.get(label_id, f"unknown_{label_id}").lower()
    if hasattr(model, 'model_labels') and isinstance(model.model_labels, dict):
        return model.model_labels.get(label_id, f"unknown_{label_id}").lower()
    return f"unknown_{label_id}"

def clamp_box_to_region(box: List[int], region: List[int]) -> List[int]:
    x1, y1, x2, y2 = box
    rx1, ry1, rx2, ry2 = region
    xx1 = max(rx1, min(x1, rx2))
    yy1 = max(ry1, min(y1, ry2))
    xx2 = max(rx1, min(x2, rx2))
    yy2 = max(ry1, min(y2, ry2))
    return [xx1, yy1, xx2, yy2]

# ----------------------------------------------------------------------
# HEAD DETECTION FUNCTIONS
# ----------------------------------------------------------------------
def detect_head_in_roi(roi_rgb, rx1, ry1, rW, rH, HEAD_PROCESSOR, HEAD_MODEL, HEAD_DETECTION_FULL_PRECISION, DEVICE, log_item):
    boxes = []
    labels = []
    scores = []
    raw_labels = []
    
    try:
        hd_in = HEAD_PROCESSOR(
            images=roi_rgb,
            return_tensors="pt",
            do_resize=False,
            do_normalize=True
        ).to(DEVICE)
        
        if not HEAD_DETECTION_FULL_PRECISION and HEAD_MODEL.dtype == torch.float16:
            hd_in = {k: v.half() if v.dtype == torch.float32 else v for k, v in hd_in.items()}
        
        with torch.no_grad():
            hd_out = HEAD_MODEL(**hd_in)
        
        hd_logits = hd_out.logits[0]
        hd_boxes = hd_out.pred_boxes[0]
        
        if hd_logits.size(-1) > 1:
            softmax_scores = torch.softmax(hd_logits, dim=-1)
            if softmax_scores.size(-1) > 1:
                class_scores = softmax_scores[:, :-1]
                max_scores, max_score_indices = torch.max(class_scores, dim=1)
                above_threshold_indices = torch.where(max_scores >= HEAD_DETECTION_THRESHOLD)[0].cpu().tolist()
                
                for i_ in above_threshold_indices:
                    score_val = max_scores[i_].item()
                    label_idx = max_score_indices[i_].item()
                    
                    label_name = get_label_name_from_model(HEAD_MODEL, label_idx)
                    if label_name in ["face", "head"]:
                        if i_ < len(hd_boxes):
                            box_data = hd_boxes[i_].tolist()
                            if len(box_data) >= 4:
                                cx, cy, w_, h_ = box_data
                                x1 = int(rx1 + (cx - 0.5 * w_) * rW)
                                y1 = int(ry1 + (cy - 0.5 * h_) * rH)
                                x2 = int(rx1 + (cx + 0.5 * w_) * rW)
                                y2 = int(ry1 + (cy + 0.5 * h_) * rH)
                                
                                x1, y1, x2, y2 = clamp_box_to_region(
                                    [x1, y1, x2, y2], 
                                    [rx1, ry1, rx1 + rW, ry1 + rH]
                                )
                                
                                boxes.append([x1, y1, x2, y2])
                                labels.append(9999)
                                scores.append(score_val)
                                raw_labels.append(label_name)
                                logging.log(LOG_LEVEL_MAP["INFO"], f"{EMOJI_MAP['INFO']} Head detected: {label_name} at score {score_val:.3f}")
    except Exception as e:
        error_msg = f"Head detection error: {str(e)}"
        error_trace = traceback.format_exc()
        
        logging.log(LOG_LEVEL_MAP["WARNING"], f"{EMOJI_MAP['WARNING']} {error_msg}")
        logging.error(f"Traceback:\n{error_trace}")
        
        log_item["warnings"] = log_item.get("warnings", []) + [error_msg]
        log_item["traceback"] = error_trace
        
        if "CUDA must not be initialized" in str(e):
            logging.critical("CUDA initialization error in Spaces Zero GPU environment")
            sys.exit(1)
    
    return boxes, labels, scores, raw_labels