#!/usr/bin/env bash
# ------------------------------------------------------------
# SCE OS – centered TUI (simple “SCE OS” banner) using gum
# ------------------------------------------------------------

set -euo pipefail

# ------------------------------------------------------------
# 1️⃣  Install gum (pacman) if missing
# ------------------------------------------------------------
install_gum() {
    if ! command -v pacman &>/dev/null; then
        echo "Error: pacman not found – this script works only on Arch‑based systems."
        exit 1
    fi

    if command -v gum &>/dev/null; then
        echo "gum already installed (version: $(gum --version))."
        return
    fi

    echo "Updating package database..."
    sudo pacman -Sy --noconfirm

    echo "Installing gum..."
    sudo pacman -S --noconfirm gum

    echo "gum installed successfully (version: $(gum --version))."
}
install_gum

# ------------------------------------------------------------
# 2️⃣  Helpers for centering
# ------------------------------------------------------------
term_width()  { tput cols;  }
term_height() { tput lines; }

center_horiz() {
    local text="$1"
    local width=$(term_width)
    local pad=$(( (width - ${#text}) / 2 ))
    printf "%*s%s" "$pad" "" "$text"
}

center_vertically() {
    local lines=$1
    local height=$(term_height)
    local pad=$(( (height - lines) / 2 ))
    for ((i=0;i<pad;i++)); do echo; done
}

# ------------------------------------------------------------
# 3️⃣  Simple banner – “SCE OS”
# ------------------------------------------------------------
BANNER="SCE OS"

# ------------------------------------------------------------
# 4️⃣  Pause helper
# ------------------------------------------------------------
pause() {
    read -rp $'\nPress ENTER to return to the previous menu…' </dev/tty
}

# ------------------------------------------------------------
# 5️⃣  Render a centered menu (banner + choices)
# ------------------------------------------------------------
render_menu() {
    local -n items=$1          # name‑reference to array of choices
    local title="${2:-}"       # optional title (already centred)

    # total lines = banner + optional title + blank line + number of items
    local total=$(( 1 + ( [[ -n $title ]] && echo 1 || echo 0 ) + 1 + ${#items[@]} ))

    clear
    center_vertically "$total"

    echo "$(center_horiz "$BANNER")"
    echo                     # blank line after banner
    [[ -n $title ]] && echo "$(center_horiz "$title")"

    # write centred choices to a temp file for gum
    local tmp; tmp=$(mktemp)
    for choice in "${items[@]}"; do
        echo "$(center_horiz "$choice")" >>"$tmp"
    done

    gum choose --cursor.foreground 212 --selected.foreground 212 <"$tmp"
    rm "$tmp"
}

# ------------------------------------------------------------
# 6️⃣  Sub‑menus
# ------------------------------------------------------------
terminal_menu() {
    local opts=(
        "Open new terminal session"
        "Back to main menu"
    )
    while true; do
        sel=$(render_menu opts "Terminal")
        case "$sel" in
            *"Open new terminal session"*)
                echo "Launching a new terminal…"
                gnome-terminal &
                pause
                ;;
            *"Back to main menu"*)
                break
                ;;
        esac
    done
}

system_menu() {
    local opts=(
        "Get repository update"
        "Full‑system update and upgrade"
        "Back to main menu"
    )
    while true; do
        sel=$(render_menu opts "System")
        case "$sel" in
            *"Get repository update"*)
                echo "Running repository update (git pull …)"
                (cd ~/myrepo && git pull)   # adjust as needed
                pause
                ;;
            *"Full‑system update and upgrade"*)
                echo "Performing full system upgrade…"
                sudo pacman -Syu --noconfirm
                pause
                ;;
            *"Back to main menu"*)
                break
                ;;
        esac
    done
}

software_menu() {
    local opts=(
        "Install / update Blender (~/Programs/Blender-version)"
        "Install / update Nekoray (~/Programs/nekoray.appimage)"
        "Back to main menu"
    )
    while true; do
        sel=$(render_menu opts "Software")
        case "$sel" in
            *"Blender"* )
                echo "Downloading latest Blender into ~/Programs/Blender-version …"
                mkdir -p "$HOME/Programs/Blender-version"
                wget -qO- "https://download.blender.org/release/Blender3.6/blender-3.6.0-linux-x64.tar.xz" |
                    tar -xJ -C "$HOME/Programs/Blender-version" --strip-components=1
                pause
                ;;
            *"Nekoray"* )
                echo "Fetching latest Nekoray AppImage into ~/Programs …"
                mkdir -p "$HOME/Programs"
                wget -O "$HOME/Programs/nekoray.appimage" \
                     "https://github.com/nekoray/nekoray/releases/download/v2.16.0/nekoray-2.16.0-x86_64.AppImage"
                chmod +x "$HOME/Programs/nekoray.appimage"
                pause
                ;;
            *"Back to main menu"* )
                break
                ;;
        esac
    done
}

# ------------------------------------------------------------
# 7️⃣  Main menu (centered)
# ------------------------------------------------------------
main_menu() {
    local opts=(
        "Terminal"
        "System"
        "Software"
        "Quit"
    )
    while true; do
        choice=$(render_menu opts "SCE OS")
        case "$choice" in
            *"Terminal"*)  terminal_menu ;;
            *"System"*)    system_menu   ;;
            *"Software"*)  software_menu ;;
            *"Quit"*)      clear; echo "Good‑bye!"; exit 0 ;;
        esac
    done
}

main_menu