from ultralytics import YOLO
from huggingface_hub import hf_hub_download
from PIL import Image
import numpy as np

_model_general = None
_model_litter  = None

WASTE_KEYWORDS = [
    "bottle", "cup", "bag", "wrapper", "can", "trash", "bin",
    "cardboard", "paper", "plastic", "litter", "garbage", "waste",
    "box", "container", "food", "fruit", "banana", "orange",
    "fork", "knife", "spoon", "bowl", "sandwich", "hotdog",
    "pizza", "donut", "cake", "suitcase", "backpack", "handbag"
]

def get_general_model():
    global _model_general
    if _model_general is None:
        _model_general = YOLO("yolov8n.pt")
    return _model_general

def get_litter_model():
    global _model_litter
    if _model_litter is None:
        try:
            path = hf_hub_download(
                repo_id="BowerApp/bowie-yolov8-multihead-trash-detection",
                filename="best.pt"
            )
            _model_litter = YOLO(path)
        except Exception:
            _model_litter = None
    return _model_litter

def analyze_image(image) -> tuple[str, float]:
    if image is None:
        return "Please upload an image.", 0.5

    detected_all = []
    methods_used = []

    # ── Model 1: YOLOv8n COCO ─────────────────────────────────────────
    try:
        model_g = get_general_model()
        results = model_g.predict(image, conf=0.05, verbose=False)
        for box in results[0].boxes:
            cls_name = model_g.names[int(box.cls[0])]
            conf     = float(box.conf[0])
            detected_all.append({
                "object":     cls_name,
                "confidence": f"{conf:.1%}",
                "source":     "YOLOv8-COCO"
            })
        methods_used.append("YOLOv8n-COCO")
    except Exception as e:
        methods_used.append(f"YOLOv8n failed: {e}")

    # ── Model 2: Litter-specific ──────────────────────────────────────
    try:
        model_l = get_litter_model()
        if model_l:
            results2 = model_l.predict(image, conf=0.05, verbose=False)
            for box in results2[0].boxes:
                cls_name = model_l.names[int(box.cls[0])]
                conf     = float(box.conf[0])
                detected_all.append({
                    "object":     cls_name,
                    "confidence": f"{conf:.1%}",
                    "source":     "Litter-Model"
                })
            methods_used.append("Litter-Detection")
    except Exception as e:
        methods_used.append(f"Litter model failed: {e}")

    # ── Pixel heuristic ───────────────────────────────────────────────
    try:
        arr         = np.array(Image.fromarray(np.array(image)).convert("RGB"))
        r, g, b     = arr[:,:,0], arr[:,:,1], arr[:,:,2]
        dirty_brown = float(np.mean((r>120)&(g>80)&(g<140)&(b<80)))
        dirty_grey  = float(np.mean((r>100)&(g>100)&(b>100)&
                            (np.abs(r.astype(int)-g.astype(int))<20)))
        pixel_risk  = round(min((dirty_brown*0.6 + dirty_grey*0.4)*4, 1.0), 3)
    except Exception:
        pixel_risk = 0.0

    # ── Tính risk ─────────────────────────────────────────────────────
    waste_items = [
        d for d in detected_all
        if any(kw in d["object"].lower() for kw in WASTE_KEYWORDS)
    ]
    seen = set()
    unique_waste = []
    for item in waste_items:
        if item["object"] not in seen:
            seen.add(item["object"])
            unique_waste.append(item)

    waste_count = len(unique_waste)
    yolo_risk   = round(min(waste_count / 5, 1.0), 3)
    img_risk    = round(min(yolo_risk * 0.7 + pixel_risk * 0.3, 1.0), 3)

    # ── Verdict ───────────────────────────────────────────────────────
    if img_risk > 0.5:
        verdict = "🚨 Visible waste detected"
    elif img_risk > 0.2:
        verdict = "⚠️ Some waste indicators found"
    else:
        verdict = "✅ Image appears clean"

    output = f"""## {verdict}

| Metric | Value |
|--------|-------|
| Models used | {', '.join(methods_used)} |
| Waste objects found | {waste_count} |
| **Image Risk Score** | **{img_risk:.3f} / 1.0** |
"""
    return output, img_risk