app.py

from qiskit import QuantumCircuit, transpile, assemble, Aer, execute
from qiskit.visualization import plot_histogram
import gradio as gr

# This is just a placeholder for a basic quantum circuit that shows QFT
def run_basic_qft_demo(N):
    try:
        N = int(N)
        if N <= 0 or N > 8:
            return "Please enter a small integer (1–8) for demo."

        qc = QuantumCircuit(N)
        # Apply Hadamards to all qubits as a trivial QFT placeholder
        for i in range(N):
            qc.h(i)

        backend = Aer.get_backend("aer_simulator")
        qc.measure_all()

        result = execute(qc, backend, shots=1024).result()
        counts = result.get_counts()

        return f"Simulated simple QFT-like circuit for {N} qubits.\nResult: {counts}"

    except Exception as e:
        return str(e)

iface = gr.Interface(
    fn=run_basic_qft_demo,
    inputs=gr.Number(label="Enter number of qubits (1–8)"),
    outputs=gr.Textbox(label="Result"),
    title="Modern Qiskit Demo — QFT placeholder",
    description="Modern Qiskit 1.x example: runs a trivial circuit to show basic QFT structure. For real Shor, you’d build modular exponentiation + QFT manually."
)

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