#!/bin/bash

switch-git-folder() {
    if [[ -z "$1" ]]; then
        echo '$1/branch is empty.'
        exit
    fi
    if [[ -z "$2" ]]; then
        echo '$2/path is empty.'
        exit
    fi

    local git_branch="$1"
    local git_folders=$(ls-git-folder "$2")
    for git_folder in $git_folders; do
        git_folder="${git_folder#./}"

        local shallow=$(git config --file .gitmodules --get submodule."$git_folder".shallow)
        local git_folder_path=$(git config --file .gitmodules --get submodule."$git_folder".path)
        local git_folder_url=$(git config --file .gitmodules --get submodule."$git_folder".url)
        
        if [[ -z "$git_folder_path" ]] || [[ -z "$git_folder_url" ]]; then
            echo "Skipping: '$git_folder' not defined in .gitmodules."
            continue
        fi

        if [[ "$shallow" = "true" ]]; then
            echo "Fetch branch $git_branch (shallow) from origin and then switch."
            git -C "$git_folder" fetch origin "$git_branch:$git_branch"
            git -C "$git_folder" switch "$git_branch"
        else
            echo "Switch git folder branch to $git_branch: $git_folder"
            git -C "$git_folder" stash
            git -C "$git_folder" switch "$git_branch"
        fi
    done
}
swgf() {
    switch-git-folder "$@"
}