"""Bond dimension sweep for 32-qubit variational circuit."""
import os
import sys
import numpy as np

sys.path.insert(0, os.path.dirname(__file__))
from benchmark_mps import make_circuit, run_qibojit, run_quimb_mps, compare, jit_cache_path, DATA_DIR

NQUBITS = 32
NLAYERS = 5
BOND_VALUES = [1, 8, 16, 32, 64, 128, 256]
SVD_CUTOFF = 1e-6
OPTIMIZER = "auto-hq"

if __name__ == "__main__":
    cache_path = jit_cache_path("variational", NQUBITS, NLAYERS)

    if os.path.exists(cache_path):
        sv_ref = np.load(cache_path)
        print(f"[qibojit] loaded from cache: {cache_path}\n")
    else:
        np.random.seed(42)
        circuit_ref = make_circuit("variational", NQUBITS, NLAYERS)
        sv_ref, t_ref = run_qibojit(circuit_ref)
        np.save(cache_path, sv_ref)
        print(f"[qibojit] time={t_ref:.4f}s  (saved to {cache_path})\n")

    print(f"{'bond':>6}  {'time(s)':>10}  {'fidelity':>12}  {'l2_err':>10}")
    print("-" * 46)

    for bond in BOND_VALUES:
        np.random.seed(42)
        circuit_mps = make_circuit("variational", NQUBITS, NLAYERS)
        try:
            sv_mps, t_mps = run_quimb_mps(circuit_mps, bond, SVD_CUTOFF, OPTIMIZER)
            fidelity, l2_err = compare(sv_ref, sv_mps)
            print(f"{bond:>6}  {t_mps:>10.4f}  {fidelity:>12.8f}  {l2_err:>10.2e}")
        except Exception as e:
            print(f"{bond:>6}  FAILED: {e}")