Investigate the possible flow for a `Create Environment` command

[brettcannon]

This would be taking the ideas from WWBD and bringing them here.

[brettcannon]

flowchart TD
    start([start])

    has_interpreter{Interpreter selected?}
    has_env_selected{Environment selected?}
    has_python{Is Python installed?}
    select_newest[Select newest Python]
    has_venv{Has `venv`?}
    create_env[`python -m venv .venv`]

    has_pip{"Has `pip`?"}
    
    has_requirements{Has requirements files?}
    select_requirements[/Select requirements files/]
    install_requirements["`python -m pip install -r requirements.txt`"]

    has_pyproject{Has a `pyproject.toml`?}
    select_extras[/Select extras/]
    install_extras["`python -m pip install -e .[extras]`"]

    error((Notify user of problem))

    finished([end])
    

    start --> has_interpreter

    subgraph Create Environment

    has_interpreter -- yes --> has_venv
    has_interpreter -- no --> has_env_selected

    %% error
    has_env_selected -- "no (nothing selected)" --> has_python

    has_python -- yes --> select_newest
    %% error
    

    select_newest --> has_venv

    has_venv -- yes --> create_env
    %% error
    end

    subgraph Installation
    create_env --> has_pip

    has_pip -- yes --> has_requirements
    %% error
    
    has_requirements -- yes --> select_requirements
    select_requirements --> install_requirements
    %% finished
    has_requirements -- no --> has_pyproject

    has_pyproject -- yes --> select_extras
    select_extras --> install_extras
    %% finished
    end

    has_venv -- "no (Debian)" --> error
    has_python -- no --> error
    has_env_selected -- yes --> error
    has_pip -- "no (Debian)" --> error

    error --> finished
    install_extras --> finished
    has_pyproject -- no --> finished
    install_requirements --> finished

Loading

[brettcannon]

Asked for feedback at https://twitter.com/brettsky/status/1557850636611268609 .

[karthiknadig]

If we are triggering environment creataion, we should probably skip the popup that we show when we detect env creation.

[brettcannon]

If we are triggering environment creataion, we should probably skip the popup that we show when we detect env creation.

We should probably skip it regardless and just select the environment with an option to turn off automatic environment detection/selection.

[karthiknadig]

For now the flow is like this:

1. User execute the create environment command.
2. We show a Quick pick allowing users to select from one of the providers (venv / conda / etc)
3. For venv :
   1. Select a workspace in multi root scenario. If single workspace this is not shown.
   2. Select a python from a list of global pythons (This required exposing the python picker as an internal API). If only one interpreter is found, then that is used.
   3. Initiate the command to create venv. Install any packages.
4. For conda:
   1. Select a workspace in multi root scenario. If single workspace this is not shown.
   2. Select a version of python to install in the new environment.
   3. Initiate the command to create conda env using --prefix.
5. Once env is created you will see a pop-up to select that env (this is temporary until we expose a way to pause that UI)