"""
Extract maximum displacement from structural analysis
Auto-generated by Atomizer Phase 3 - pyNastran Research Agent

Pattern: displacement
Element Type: General
Result Type: displacement
API: model.displacements[subcase]
"""

from pathlib import Path
from typing import Dict, Any
import numpy as np
from pyNastran.op2.op2 import OP2


def extract_displacement(op2_file: Path, subcase: int = 1):
    """Extract displacement results from OP2 file."""
    from pyNastran.op2.op2 import OP2
    import numpy as np

    model = OP2()
    model.read_op2(str(op2_file))

    # NX Nastran often uses empty string '' as subcase key
    available_subcases = list(model.displacements.keys())
    if not available_subcases:
        raise ValueError(f"No displacement data found in OP2 file")

    # Use the first available subcase (often '' for NX Nastran)
    actual_subcase = available_subcases[0]
    disp = model.displacements[actual_subcase]

    itime = 0  # static case

    # Extract translation components
    txyz = disp.data[itime, :, :3]  # [tx, ty, tz]

    # Calculate total displacement
    total_disp = np.linalg.norm(txyz, axis=1)
    max_disp = np.max(total_disp)

    # Get node info
    node_ids = [nid for (nid, grid_type) in disp.node_gridtype]
    max_disp_node = node_ids[np.argmax(total_disp)]

    return {
        'max_displacement': float(max_disp),
        'max_disp_node': int(max_disp_node),
        'max_disp_x': float(np.max(np.abs(txyz[:, 0]))),
        'max_disp_y': float(np.max(np.abs(txyz[:, 1]))),
        'max_disp_z': float(np.max(np.abs(txyz[:, 2])))
    }


if __name__ == '__main__':
    # Example usage
    import sys
    if len(sys.argv) > 1:
        op2_file = Path(sys.argv[1])
        result = extract_displacement(op2_file)
        print(f"Extraction result: {result}")
    else:
        print("Usage: python {sys.argv[0]} <op2_file>")