r"""
Multiple solid bodies
---------------------

.. topic:: Learn how to add three solid bodies to a job.

   * merge a **FieldContainer** and generate a top-level field container

   * evaluate a **Job** with a top-level field

This tutorial shows how to handle multiple solid bodies. There are different ways to
approach this, but the method presented here is by far the most straightforward. We'll
start with the meshes, regions, and fields. After that, a top-level field container will
be introduced for the boundary conditions. When creating the solid bodies, make sure to
use the fields from this merged container.
"""

import felupe as fem

mesh_1 = fem.Rectangle(a=(0, 0), b=(0.5, 1), n=(3, 5))
field_1 = fem.FieldAxisymmetric(region=fem.RegionQuad(mesh_1), dim=2)

mesh_2 = fem.Rectangle(a=(0.5, 0), b=(1.5, 1), n=5)
field_2 = fem.FieldAxisymmetric(region=fem.RegionQuad(mesh_2), dim=2)

mesh_3 = fem.Rectangle(a=(1.5, 0), b=(2, 1), n=(3, 5))
field_3 = fem.FieldAxisymmetric(region=fem.RegionQuad(mesh_3), dim=2)

fields, x0 = fem.FieldContainer([field_1, field_2, field_3]).merge()
boundaries = fem.dof.uniaxial(x0, clamped=True, sym=False, return_loadcase=False)

umat_a = fem.NeoHookeCompressible(mu=3, lmbda=6)
umat_b = fem.NeoHookeCompressible(mu=1, lmbda=2)

solid_1 = fem.SolidBody(umat=umat_a, field=fields[0])
solid_2 = fem.SolidBody(umat=umat_b, field=fields[1])
solid_3 = fem.SolidBody(umat=umat_a, field=fields[2])

# %%
# The ramped prescribed displacements for 5 substeps are created with
# :func:`~felupe.math.linsteps`. A :class:`~felupe.Step` is created with a list of items
# to be considered (here, three solid bodies) and a dict of ramped boundary
# conditions along with the prescribed values.
move = fem.math.linsteps([0, 0.5], num=5)
uniaxial = fem.Step(
    items=[solid_1, solid_2, solid_3],
    ramp={boundaries["move"]: move},
    boundaries=boundaries,
)

# %%
# This step is now added to a :class:`~felupe.Job`. The top-level field ``x0`` is passed
# to :meth:`~felupe.Job.evaluate`.
job = fem.Job(steps=[uniaxial])
job.evaluate(x0=x0)

plotter = solid_1.plot(style="wireframe")
plotter = solid_3.plot(style="wireframe", plotter=plotter)
solid_2.plot("Principal Values of Logarithmic Strain", plotter=plotter).show()