Slab
====

The `OneWaySlab` class models a one-way slab strip for flexure and shear analysis and design.
It inherits all check and design logic from `RectangularBeam`, but uses bar **diameter + spacing**
instead of bar count for longitudinal reinforcement — consistent with standard slab detailing practice.

Key Concepts
------------

- **Geometry**: Defined by a strip `width` (typically 1 m or 100 cm) and slab `height` (thickness).
- **Material Properties**: Requires a `Concrete` object and a `SteelBar` object.
- **Reinforcement**: Specified by bar diameter and spacing, not bar count.
- **Checks and design**: Performed through a `Node` object, exactly as for beams.

Usage
-----

Below is a step-by-step guide on how to use the `OneWaySlab` class.

1. Creating a Slab Object
*************************

To define a slab strip, specify its geometry, material properties, and clear cover.
The `width` represents the analysis strip width; `height` is the slab thickness.

.. code-block:: python

    from mento import Concrete_ACI_318_19, SteelBar, mm, cm, MPa
    from mento.slab import OneWaySlab

    # Define materials
    concrete = Concrete_ACI_318_19(name="C25", f_c=25 * MPa)
    steel = SteelBar(name="ADN 420", f_y=420 * MPa)

    # Define slab strip geometry (1 m wide strip, 20 cm thick)
    slab = OneWaySlab(label="S101", concrete=concrete, steel_bar=steel,
                      width=100 * cm, height=20 * cm, c_c=25 * mm)

2. Setting Reinforcement
************************

Slab reinforcement is defined by bar diameter and spacing. Each layer accepts a primary
bar group (position 1) and an optional secondary bar group (position 3, second layer).

- **Bottom Longitudinal Reinforcement**: Use `set_slab_longitudinal_rebar_bot`.
- **Top Longitudinal Reinforcement**: Use `set_slab_longitudinal_rebar_top`.
- **Transverse Reinforcement**: Use `set_slab_transverse_rebar` (shear stirrups, rarely needed for slabs).

.. note::

    Unlike beams, slabs do not use positions 2 and 4 (inner bars per layer).
    All bars in a layer must have the same diameter. If no reinforcement is defined,
    *Mento* will assume no rebar and will not perform a check — provide at least a minimum
    rebar before running checks.

.. code-block:: python

    # Bottom reinforcement: Ø12 every 15 cm (layer 1)
    slab.set_slab_longitudinal_rebar_bot(d_b1=12 * mm, s_b1=15 * cm)

    # Top reinforcement: Ø10 every 20 cm (layer 1)
    slab.set_slab_longitudinal_rebar_top(d_b1=10 * mm, s_b1=20 * cm)

    # Two-layer bottom reinforcement: Ø12 @ 15 cm (layer 1) + Ø10 @ 20 cm (layer 2)
    slab.set_slab_longitudinal_rebar_bot(d_b1=12 * mm, s_b1=15 * cm,
                                         d_b3=10 * mm, s_b3=20 * cm)

3. Assigning Forces to the Slab
*******************************

Forces are applied through a `Node` object, the same way as for beams.
See the `Node` section for full details.

.. code-block:: python

    from mento import Forces, Node, kN, kNm

    f1 = Forces(label="ELU 1", V_z=30 * kN, M_y=25 * kNm)

    node = Node(section=slab, forces=[f1])

4. Performing Checks
********************

Once forces are assigned, call `check_shear()` and `check_flexure()` on the node.
*Mento* applies the appropriate design code formulas based on the `Concrete` type.

.. code-block:: python

    # Shear check
    node.check_shear()

    # Flexure check
    node.check_flexure()

See the `Node` section for details on interpreting the returned DataFrames.

5. Design the Section
*********************

If no reinforcement is assigned, *Mento* can design flexure and shear automatically.

.. code-block:: python

    node.design_flexure()
    node.design_shear()

6. Jupyter Notebook Results
***************************

After performing checks or design, view formatted results with:

.. code-block:: python

    slab.results

The output includes longitudinal and shear reinforcement, applied forces, and DCR values.
See the `Node` section for more information on detailed results and Word report generation.

7. Detailed Results
*******************

See the `Node` section for how to display and save detailed per-load-case results using
`shear_results_detailed()`, `flexure_results_detailed()`, and their `_doc()` variants.