# Copyright (C) 2021-2024 Université Gustave Eiffel.
# Copyright (C) 2025-2026 Université Gustave Eiffel, INRIA.
# This file is part of the EasyFEA project.
# EasyFEA is distributed under the terms of the GNU General Public License v3, see LICENSE.txt and CREDITS.md for more information.

"""
Beam4
=====

Frame with two beams.
"""

import matplotlib.pyplot as plt

from EasyFEA import Display, Models, Mesher, ElemType, Simulations
from EasyFEA.Geoms import Domain, Line

if __name__ == "__main__":
    Display.Clear()

    # ----------------------------------------------
    # Configuration
    # ----------------------------------------------

    # geom
    L = 120
    h = 13
    b = 13

    # model
    E = 210000
    v = 0.3

    # load
    load = 800

    # ----------------------------------------------
    # Mesh
    # ----------------------------------------------

    elemType = ElemType.SEG2

    # Create a section object for the beam mesh
    mesher = Mesher()
    section = mesher.Mesh_2D(Domain((0, 0), (b, h)))

    p1 = (0, 0)
    p2 = (0, L)
    p3 = (L / 2, L)
    line1 = Line(p1, p2, L / 9)
    line2 = Line(p2, p3, L / 9)
    beam1 = Models.Beam.Isotropic(3, line1, section, E, v)
    beam2 = Models.Beam.Isotropic(3, line2, section, E, v)
    beams = [beam1, beam2]

    mesh = mesher.Mesh_Beams(beams=beams, elemType=elemType)

    # ----------------------------------------------
    # Simulation
    # ----------------------------------------------

    # Initialize the beam structure with the defined beam segments
    beamStructure = Models.Beam.BeamStructure(beams)

    # Create the beam simulation
    simu = Simulations.Beam(mesh, beamStructure)
    dof_n = simu.Get_dof_n()

    # Apply boundary conditions
    simu.add_dirichlet(mesh.Nodes_Point(p1), [0] * dof_n, simu.Get_unknowns())
    simu.add_neumann(mesh.Nodes_Point(p3), [-load, load], ["y", "z"])
    if beamStructure.nBeam > 1:
        simu.add_connection_fixed(mesh.Nodes_Point(p2))

    # Solve the beam problem and get displacement results
    sol = simu.Solve()
    simu.Save_Iter()

    # ----------------------------------------------
    # Results
    # ----------------------------------------------

    Display.Plot_Mesh(simu, L / 10 / sol.max())
    Display.Plot_BoundaryConditions(simu)
    Display.Plot_Result(simu, "ux", L / 10 / sol.max())
    Display.Plot_Result(simu, "uy", L / 10 / sol.max())

    print(simu)

    plt.show()