"""Gradio demo for Local UI Locator — standalone HF Space version.

Upload a Windows screenshot → detect interactive elements → view overlay + JSON.
Self-contained: downloads model weights from HF Hub automatically.
"""

from __future__ import annotations

import json
from collections import Counter

import cv2
import gradio as gr
import numpy as np
from huggingface_hub import hf_hub_download
from ultralytics import YOLO

CLASS_NAMES = [
    "button", "textbox", "checkbox", "dropdown", "icon", "tab", "menu_item",
]

CLASS_COLORS = {
    "button":    (255, 127,   0),
    "textbox":   (  0, 200,   0),
    "checkbox":  (  0, 127, 255),
    "dropdown":  (200,   0, 200),
    "icon":      (  0, 150, 255),
    "tab":       (255,   0, 100),
    "menu_item": (100, 255, 255),
}

# Download model weights from HF Hub on startup.
_weights_path = hf_hub_download(
    repo_id="IndextDataLab/windows-ui-locator",
    filename="best.pt",
)
_model = YOLO(_weights_path)


def _draw_overlay(img_rgb: np.ndarray, results: list[dict]) -> np.ndarray:
    overlay = cv2.cvtColor(img_rgb, cv2.COLOR_RGB2BGR)
    for r in results:
        x1, y1, x2, y2 = r["bbox"]
        color = CLASS_COLORS.get(r["type"], (200, 200, 200))
        label = f"{r['type']} {r['score']:.0%}"

        cv2.rectangle(overlay, (x1, y1), (x2, y2), color, 2)
        (tw, th), _ = cv2.getTextSize(label, cv2.FONT_HERSHEY_SIMPLEX, 0.5, 1)
        cv2.rectangle(overlay, (x1, y1 - th - 6), (x1 + tw + 4, y1), color, -1)
        cv2.putText(overlay, label, (x1 + 2, y1 - 4),
                    cv2.FONT_HERSHEY_SIMPLEX, 0.5, (255, 255, 255), 1, cv2.LINE_AA)

    return cv2.cvtColor(overlay, cv2.COLOR_BGR2RGB)


def detect(
    image: np.ndarray | None,
    conf: float,
    iou: float,
    class_filter: list[str],
) -> tuple[np.ndarray | None, str, str]:
    if image is None:
        return None, "Upload an image first.", "[]"

    preds = _model.predict(
        source=image, conf=conf, iou=iou, verbose=False, max_det=300,
    )

    results = []
    if preds and len(preds) > 0:
        boxes = preds[0].boxes
        if boxes is not None:
            xyxy = boxes.xyxy.cpu().numpy()
            confs = boxes.conf.cpu().numpy()
            clss = boxes.cls.cpu().numpy().astype(int)

            for i, (box, c, cls_id) in enumerate(zip(xyxy, confs, clss)):
                cls_name = CLASS_NAMES[cls_id] if cls_id < len(CLASS_NAMES) else f"class_{cls_id}"
                if class_filter and cls_name not in class_filter:
                    continue
                results.append({
                    "id": i,
                    "type": cls_name,
                    "bbox": [int(box[0]), int(box[1]), int(box[2]), int(box[3])],
                    "score": round(float(c), 4),
                    "center": [int((box[0] + box[2]) / 2), int((box[1] + box[3]) / 2)],
                })

    overlay = _draw_overlay(image, results)

    counts = Counter(d["type"] for d in results)
    summary_parts = [f"**{len(results)} elements detected**"]
    for cls_name in sorted(counts):
        summary_parts.append(f"- {cls_name}: {counts[cls_name]}")

    return overlay, "\n".join(summary_parts), json.dumps(results, indent=2)


with gr.Blocks(title="Windows UI Element Detector") as demo:
    gr.Markdown(
        "# Windows UI Element Detector\n"
        "Upload a Windows screenshot to detect interactive UI elements "
        "(buttons, textboxes, checkboxes, dropdowns, icons, tabs, menu items).\n\n"
        "**Model:** YOLO11s &nbsp;|&nbsp; **Classes:** 7 &nbsp;|&nbsp; **Dataset:** 3 000 synthetic images"
    )

    with gr.Row():
        with gr.Column(scale=1):
            input_image = gr.Image(label="Screenshot", type="numpy")
            with gr.Row():
                conf_slider = gr.Slider(
                    minimum=0.05, maximum=0.95, value=0.3, step=0.05,
                    label="Confidence threshold",
                )
                iou_slider = gr.Slider(
                    minimum=0.1, maximum=0.9, value=0.5, step=0.05,
                    label="IoU threshold (NMS)",
                )
            class_filter = gr.CheckboxGroup(
                choices=CLASS_NAMES,
                label="Filter classes (empty = all)",
            )
            detect_btn = gr.Button("Detect", variant="primary")

        with gr.Column(scale=1):
            output_image = gr.Image(label="Detection overlay")
            summary_md = gr.Markdown(label="Summary")

    with gr.Accordion("JSON output", open=False):
        json_output = gr.Code(language="json", label="Detections JSON")

    detect_btn.click(
        fn=detect,
        inputs=[input_image, conf_slider, iou_slider, class_filter],
        outputs=[output_image, summary_md, json_output],
    )

    gr.Markdown(
        "---\n"
        "MIT License &nbsp;|&nbsp; "
        "[GitHub](https://github.com/Indext-Data-Lab/windows-ui-synth) &nbsp;|&nbsp; "
        "YOLO11s + EasyOCR + rapidfuzz &nbsp;|&nbsp; "
        "Commission a similar tool or a fully integrated AI solution for your business -> "
        "[Visit indext.io](https://indext.io/) | "
        "[Connect on LinkedIn](https://www.linkedin.com/company/indext-data-lab/)"
    )

if __name__ == "__main__":
    demo.launch()