arttime's simple online installer

arttime_online_installer.sh

#!/usr/bin/env zsh
autoload -Uz is-at-least
if ! is-at-least "5.7"; then
    echo "Error: your zsh version $ZSH_VERSION is less than the required version: 5.7"
    exit 1
fi
tmpdir=""
dirstatus=1
if command -v mktemp &>/dev/null; then
    tmpdir=$(mktemp -d)
    if [[ $? == 0 && -d $tmpdir && -w $tmpdir ]]; then
        dirstatus=0
    fi
fi
if [[ $dirstatus == 1 ]]; then
    tmpdir=$HOME/.local/state/arttime/installer
    mkdir -p $tmpdir
fi
trap "/bin/rm -rf $tmpdir" EXIT TERM HUP QUIT INT
cd $tmpdir
machine="$(uname -s)"
if [[ $machine =~ ^Darwin.*$ ]]; then
    if command -v git &>/dev/null && xcode-select -p &>/dev/null; then
        usegit="1"
    else
        usegit="0"
    fi
else
   if command -v git &>/dev/null; then
       usegit="1"
   else
       usegit="0"
   fi
fi
if [[ $usegit == "1" ]]; then
    if [[ ! -d "arttime" ]]; then
        echo "Downloading arttime's git repository..."
        git clone https://github.com/poetaman/arttime.git
    fi
    cd arttime
    if git rev-parse --is-inside-work-tree &>/dev/null; then
        echo "Downloading latest arttime assets..."
        git pull
        if [[ "$?" != "0" ]]; then
            echo "Note: git pull failed in $PWD, try resolving merge conflicts before trying again."
            exit 1
        fi
    else
        echo "Note: $PWD is not a git repository, nothing will be updated"
    fi
else
    echo "Note: git not found. Trying curl or wget to download arttime's git archive."
    if command -v curl &>/dev/null; then
        downloader="curl -L -O"
    elif command -v wget &>/dev/null; then
        downloader="wget"
    else
        echo "Error: neither curl nor wget found. Install git or curl or wget before trying again."
        exit 1
    fi
    if command -v tar &>/dev/null; then
        echo "Downloading latest arttime assets..."
        $(printf $downloader) https://github.com/poetaman/arttime/archive/main.tar.gz
        tar xvf main.tar.gz && command rm main.tar.gz &>/dev/null
    elif command -v unzip &>/dev/null; then
        echo "Downloading latest arttime assets..."
        $(printf $downloader) https://github.com/poetaman/arttime/archive/main.zip
        unzip main.zip && command rm main.zip &>/dev/null
    else
        echo "Error: neither tar nor unzip found. Install tar or unzip before trying again."
        exit 1
    fi
    /bin/rm -rf arttime-notgit 2>/dev/null
    mv arttime-main arttime-notgit
    cd arttime-notgit
    newlinestr="\n     "
    echo "NOTE: This is not a git repository. DON'T use this directory for development.${newlinestr} Contents of this directory will be overriten if online installer is run${newlinestr} again (with no git installed on system). For development either do a git${newlinestr} clone or rename this directory before using. This directory was left${newlinestr} here only for you to see what files were installed to your system from${newlinestr} matching standard directory paths in this directory." >README_FIRST.txt
fi
./install.sh