#!/bin/sh

osreleaseprop() {
    cat /etc/os-release | grep -e "^$1=" | sed 's/ID=//'
}

elevated() {
    s=${SUDO:-sudo}
    if [ ! "$s" = "none" ]; then
        if ! which $s &> /dev/null; then
            echo "command \"$s\" not found"
            exit 1
        fi
    else
        s=""
    fi
    $s $@
}

DISTRO=$(osreleaseprop ID)
if [ ! -d "distros/$DISTRO" ]; then
    echo "$DISTRO is not supported."
    exit 1
fi

pm() {
    elevated "sh distros/$DISTRO/pm.sh $@"
}

install_package_list() {
    pkgs=""
    [ -f "distros/${1:-$DISTRO}/package.list" ] || return 1
    for pkg in $(cat distros/${1:-$DISTRO}/package.list | sed 's/#.*$//'); do
        pkgs="$pkgs $pkg"
    done
    pm -i $pkgs
}

run_scripts() {
    cmd=$1
    shift
    case $cmd in
        sys)
            dir="distros/${1:-$DISTRO}/sys-scripts"
            [ -d "$dir" ] || return
            for s in $(ls $dir); do
                echo "# running $dir/$s..."
                elevated sh $dir/$s || exit 1
            done
        ;;
        user)
            dir="distros/${1:-$DISTRO}/user-scripts"
            [ -d "$dir" ] || return
            for s in $(ls $dir); do
                echo "# running $dir/$s..."
                sh $dir/$s || exit 1
            done
        ;;
    esac
}

overlay() {
    [ -d "distros/${1:-$DISTRO}/root" ] || return 0
    elevated cp -r distros/${1:-$DISTRO}/root /
}

__step_update() {
    echo "# updating system..."
    pm -u
}

__step_install_package_list() {
    echo "# installing package lists..."
    install_package_list any
    install_package_list
}

__step_run_system_scripts() {
    echo "# running system scripts..."
    run_scripts sys any
    run_scripts sys
}

__step_run_user_scripts() {
    echo "# running user scripts..."
    run_scripts user any
    run_scripts user
}

__step_overlay() {
    echo "# overlaying root directories..."
    overlay any
    overlay
}

__step_link_home() {
    echo "# linking all home files..."
    trackingfile=".dotfiles/$(git rev-parse HEAD)-links"
    for item in $(find ./home -type f); do
        path=$(echo $item | sed "s/\.\/home//")
        [ -z "$path" ] && continue
        path="$HOME$path"
        mkdir -p $(dirname $path) &> /dev/null
        ln $item $path && echo "$path" >> $trackingfile
    done
}

mkdir -p .dotfiles &> /dev/null

if [ -n "$1" ]; then
    $(printf "__step_%s" "$1")
else
    __step_update
    __step_install_package_list
    __step_run_system_scripts
    __step_run_user_scripts
    __step_link_home
    __step_overlay
fi