Installing AWS Palace on Windows via WSL
========================================


Install WSL
-----------

.. note::
    **You must be on Windows 10 version 2004 or Windows 11**. Check your windows version in settings, then system section, scroll down to  *about*.

Using the instructins from [here](https://learn.microsoft.com/en-us/windows/wsl/install), first **Open powershell in admin mode** (i.e. press start, type `powershell`, right click on it and select "Run as administrator") and type:

.. code-block:: powershell

    wsl --set-default-version 2
    wsl --install Ubuntu-22.04

If this fails (e.g. ``WslRegisterDistribution failed``), then run ``wsl --update --web-download`` first. Restart windows if it has pending updates. Note the username/password supplied during installation.

Note that you may also have to enable ``Windows Subsystem for Linux`` by checking the corresponding box in *Control Panel*'s *Windows Features*. It may also be required to enable Virtualization in the BIOS Setup, which can generally be accessed by using a manufacturer-specific shortcut key during boot.

From now onwards, when we state *enter WSL*, we mean:
- Enter powershell (administrative mode)
- Type ``wsl`` and hit ``ENTER``


Install spack basic on a new WSL system
---------------------------------------

Enter WSL and verify that the nameservers are correct by first running:

.. code-block:: bash

    sudo nano /etc/resolv.conf

Ensure it says ``nameserver 8.8.8.8`` (if not, edit it, hit ``CTRL-X`` and ``Y``).

Now install spack (see `here <https://spack.readthedocs.io/en/latest/installing_prerequisites.html#verify-spack-prerequisites>`__ for reference) by typing:

.. code-block:: bash

    sudo apt update
    sudo apt install file bzip2 ca-certificates g++ gcc gfortran git gzip lsb-release patch python3 tar unzip xz-utils zstd
    sudo apt install libxft-dev libglu1-mesa libxi-dev libxmu-dev libglu1-mesa-dev build-essential

**CLOSE THE POWERSHELL NOW AND REOPEN**.

Make a new directory where we clone all repositories:

.. code-block:: bash

    wsl
    cd ~
    mkdir repo
    cd repo

Note that we use `~/repo` as the default palace repository directory. Since we will be using virtual environments if it is in a different directory, then make sure to set `'palace_wsl_spack_repo_directory'` in the `user_options` dictionary in the palace simulation object later.

Now clone the spack source and enter its environment here:

.. code-block:: bash

    git clone --depth=2 https://github.com/spack/spack.git
    . spack/share/spack/setup-env.sh

Update spack compilers:

.. code-block:: bash

    spack compiler find


Install Palace
--------------

Clone palace and `install using spack <https://github.com/awslabs/palace/issues/360#issuecomment-2874057931>`__:

.. code-block:: bash

    git clone https://github.com/awslabs/palace.git

#Checkout cameron's branch, which has fixes that lets spack correctly install palace0.13.
#But these changes are now in master but need to be tested again.
#git checkout cameronrutherford/0.13.0-spack-cmake-constraints
```

Now the idea is that we create a local virtual environment in spack called `spack-env`, add local palace install as a repo in it and concretize+install. This is done via:

.. code-block:: bash

    source ./spack/share/spack/setup-env.sh
    spack env create -d ./spack-env
    spack env activate ./spack-env
    spack repo add ./palace/spack_repo/local
    spack add local.palace@develop

Now concretize+install via:

.. code-block:: bash

    spack concretize -f
    spack install --only-concrete

There is no need for EXTERNAL MFEM, libCEED or sundial as palace ships with its own versions. Now run:

.. code-block:: bash

    find -name palace*

The command will find the path of the Palace binary. Basically it's somewhere like:


.. code-block:: bash

    ./spack/opt/spack/linux-ubuntu24.04-zen2/gcc-13.3.0/palace-develop-36rxmgzatchgymg5tcbfz3qrmkf4jnmj/bin/palace

Executing the above block should show the command-line switches required for Palace. 

When running the simulations
----------------------------

When running Palace simulations, the simulation object receives a dictionary via the argument ``user_options``. Make sure to set:

- ``'palace_mode': 'wsl'``,
- ``'palace_wsl_spack_repo_directory': '~/repo'``
- ``'palace_dir':"~/repo/spack/opt/spack/linux-zen2/palace-develop-3ofp7n4fjqj5i6slvei3w6nptzdiwdma/bin/palace"``
- ``'palace_wsl_spack_env_name': 'spack-env'``

where the second key points to a different directory if the repository directory was chosen to be different during the installation procedure. Note that the final key must be the absolute path. Thus, one adds `~/repo` to the path found using `find -name palace*` earlier. If for some reason the spack venv was under a different name, specify `palace_wsl_spack_env_name`.