#!/bin/bash
# nas-system-upgrade — Apply system updates (apt full-upgrade)
# Usage: nas-system-upgrade
# Non-interactive mode (HA): applies directly, JSON output
# Terminal mode: shows summary + confirmation before applying

set -euo pipefail

if [ -t 1 ]; then INTERACTIVE=true; else INTERACTIVE=false; fi

# Colors (terminal mode only)
if $INTERACTIVE; then
    RED='\033[0;31m'
    GREEN='\033[0;32m'
    YELLOW='\033[1;33m'
    CYAN='\033[0;36m'
    BOLD='\033[1m'
    RESET='\033[0m'
else
    RED='' GREEN='' YELLOW='' CYAN='' BOLD='' RESET=''
fi

# Ensure package list is up to date
if $INTERACTIVE; then
    echo -e "${BOLD}--- Refreshing package list ---${RESET}"
fi
apt-get update -qq 2>/dev/null

# Get packages to install/upgrade via simulation
# Format:
#   Inst name (available_version ...) → new package
#   Inst name [current_version] (available_version ...) → upgrade
packages=()
while IFS= read -r line; do
    name=$(echo "$line" | awk '{print $2}')
    [ -z "$name" ] && continue
    current=$(echo "$line" | grep -oP '(?<=\[)[^\]]+' | awk '{print $1}' | head -1 | tr -d '[:space:]' || echo "")
    [ -z "$current" ] && current="N/A"
    available=$(echo "$line" | grep -oP '(?<=\()[^ ]+' | head -1)
    [ -z "$available" ] && continue
    packages+=("${name}|${current}|${available}")
done < <(apt-get --simulate full-upgrade 2>/dev/null | grep "^Inst")

count=${#packages[@]}

if [ "$count" -eq 0 ]; then
    if $INTERACTIVE; then
        echo -e "${GREEN}✅ System is already up to date, nothing to do.${RESET}"
    else
        printf '{"status":"already_up_to_date","upgraded":0,"reboot_required":false}\n'
    fi
    exit 0
fi

if $INTERACTIVE; then
    echo ""
    echo -e "${BOLD}--- Packages to upgrade (${count}) ---${RESET}"
    for entry in "${packages[@]}"; do
        name=$(echo "$entry" | cut -d'|' -f1)
        current=$(echo "$entry" | cut -d'|' -f2)
        available=$(echo "$entry" | cut -d'|' -f3)
        echo -e "  ${CYAN}${name}${RESET} : ${YELLOW}${current}${RESET} → ${GREEN}${available}${RESET}"
    done
    echo ""

    read -p "Apply upgrade for these ${count} package(s)? [y/n]: " confirm
    case "$confirm" in
        [yY]*) ;;
        *) echo -e "${YELLOW}Cancelled.${RESET}"; exit 0 ;;
    esac
    echo ""
    echo -e "${BOLD}--- Running apt full-upgrade ---${RESET}"
fi

# Apply
DEBIAN_FRONTEND=noninteractive apt-get full-upgrade -y \
    -o Dpkg::Options::="--force-confdef" \
    -o Dpkg::Options::="--force-confold" 2>&1

# Check if reboot is required
reboot_required=false
if [ -f /var/run/reboot-required ]; then
    reboot_required=true
fi

if $INTERACTIVE; then
    echo ""
    echo -e "${GREEN}✅ Upgrade complete.${RESET}"
    if $reboot_required; then
        echo -e "${RED}⚠️  Reboot required.${RESET}"
    fi
else
    printf '{"status":"upgraded","upgraded":%d,"reboot_required":%s}\n' \
        "$count" "$reboot_required"
fi