# Utilities

function blue
    set_color blue; printf $argv; set_color normal
end
function normal
    set_color normal; printf $argv; set_color normal
end

function displayed_string_length
    string replace -ra -- '\x1b.*?[mGKH]' '' "$argv" | string length
end

function padding
    printf "%-"$argv[1]"s%s" " " "$output"
end

# Current working directory prompt
function fish_cwd_prompt
    set -l cwd (pwd)
    switch "$cwd" 
        case "$HOME"
            printf "~"
        case "/"
            printf "/"
        case "*"
           set -l parent_dir (basename (dirname $cwd))
           test $parent_dir = "/" || printf "%s" $parent_dir
           printf '/%s' (basename $cwd)
    end
end

# Guix environment prompt
function fish_environment_prompt
    normal "(env "; blue "%s" (basename $GUIX_ENVIRONMENT); normal ")"
end

# Actual prompt
function fish_prompt
    if test -n "$GUIX_ENVIRONMENT"
        set -l fish_environment_prompt_length \
               (displayed_string_length (fish_environment_prompt))
        set -l fish_git_prompt_length \
               (displayed_string_length (fish_git_prompt))

        fish_environment_prompt
        printf (padding (math $COLUMNS - $fish_environment_prompt_length \
                                       - $fish_git_prompt_length))
        fish_git_prompt | string replace -ra ' ' ''
        printf '\n'
    else
        function fish_right_prompt
            fish_git_prompt
        end
    end 

    switch "$fish_key_bindings" 
        case fish_vi_key_bindings fish_hybrid_key_bindings
            test $fish_bind_mode = 'default' && normal ':' || normal '+'
    end

    blue (whoami); normal ' at '; blue (prompt_hostname)
                   normal ' in '; blue (fish_cwd_prompt)
    normal ' > '
end

function fish_default_mode_prompt -d "Display vi prompt mode"
    # Do nothing
end