import cv2
import gradio as gr
from ultralytics import YOLO

# ── Config ─────────────────────────────────────────────
MODEL_PATH = "yolov8n.pt"
CONF_THRES  = 0.30
LINE_RATIO  = 0.50
# ───────────────────────────────────────────────────────

model = YOLO(MODEL_PATH)

memory, in_count, out_count = {}, 0, 0


def count_people(frame_rgb):
    global memory, in_count, out_count

    if frame_rgb is None:
        return None, ""

    frame_bgr = cv2.cvtColor(frame_rgb, cv2.COLOR_RGB2BGR)
    h, w      = frame_bgr.shape[:2]
    line_y    = int(h * LINE_RATIO)

    results = model.track(frame_bgr,
                          classes=[0], conf=CONF_THRES,
                          persist=True, verbose=False)

    annotated = frame_bgr.copy()
    cv2.line(annotated, (0, line_y), (w, line_y), (0, 255, 255), 2)

    if results:
        for box in results[0].boxes:
            x1, y1, x2, y2 = map(int, box.xyxy[0])
            cx, cy         = (x1 + x2) // 2, (y1 + y2) // 2
            tid            = int(box.id[0]) if box.id is not None else -1

            prev_cy = memory.get(tid, cy)
            if prev_cy < line_y <= cy:
                in_count += 1          # entró
            elif prev_cy > line_y >= cy:
                out_count += 1         # salió
            memory[tid] = cy

            cv2.rectangle(annotated, (x1, y1), (x2, y2), (0, 255, 0), 1)
            cv2.circle(annotated, (cx, cy), 3, (0, 0, 255), -1)
            cv2.putText(annotated, str(tid), (x1, y1 - 5),
                        cv2.FONT_HERSHEY_SIMPLEX, 0.5, (255, 0, 0), 1)

    total = in_count - out_count
    label = f"In: {in_count} | Out: {out_count} | Ocupación: {total}"

    annotated_rgb = cv2.cvtColor(annotated, cv2.COLOR_BGR2RGB)
    return annotated_rgb, label


def reset_counts():
    global memory, in_count, out_count
    memory, in_count, out_count = {}, 0, 0
    return None, ""


with gr.Blocks(title="Contador de personas (entrada única)") as demo:
    gr.Markdown("# Contador de personas (entrada única)")

    with gr.Row():
        cam      = gr.Image(sources=["webcam"], streaming=True, label="frame")
        out_img  = gr.Image(label="Video")
    out_lbl = gr.Text(label="Contador")

    btn_clear = gr.Button("Limpiar")

    cam.stream(count_people, inputs=[cam], outputs=[out_img, out_lbl])
    btn_clear.click(reset_counts, outputs=[out_img, out_lbl])

# límite de cola (para que no se llene si baja el FPS)
demo.queue(max_size=60)
demo.launch()