#!/bin/bash
# ==============================================================================================
# ================================= Server Reboot ==============================================
# ==============================================================================================
# Gracefully reboots the unRAID server with full pre-flight checks and clean shutdown sequence.
# Warns all users, checks for active processes, stops services, syncs disks, then reboots.
#
# ── SHUTDOWN SEQUENCE ─────────────────────────────────────────────────────────────────────────
#   1. Pre-flight warnings — rsync, mover, active Emby sessions (warn not block)
#   2. Wall message to all logged-in terminal users
#   3. unRAID notification to dashboard
#   4. Wait REBOOT_SLEEP seconds (default 30) — gives users time to save work
#   5. Gracefully shutdown VMs (virsh shutdown each, then wait)
#   6. Stop libvirt (VM Manager)
#   7. Stop Docker service
#   8. Sync filesystem buffers to disk
#   9. Reboot
#
# ── PRE-FLIGHT WARNINGS ───────────────────────────────────────────────────────────────────────
# The following are warnings only — they do not block the reboot. You called this script,
# so you know what you're doing. The warnings give you context before the countdown starts.
#   - rsync running → partial files possible if mid-transfer
#   - mover running → files may be left on cache or array mid-move
#   - Emby sessions → active streams/transcodes will be interrupted
#
# ── VM GRACEFUL SHUTDOWN ──────────────────────────────────────────────────────────────────────
# virsh shutdown sends ACPI power button signal to each VM — same as pressing power button.
# VM gets a chance to flush its own buffers and shutdown cleanly.
# Waits REBOOT_VM_WAIT seconds (default 30) for VMs to shut down before stopping libvirt.
# If VMs don't shut down in time libvirt stops anyway — system reboot takes priority.
#
# ── HOST AWARENESS ────────────────────────────────────────────────────────────────────────────
# detect_hosts() sets MY_ID — used in wall message, notification, and summary.
# Critical on a two-server setup — wall and notifications show WHICH server is rebooting.
#
# ── SAFEGUARDS ────────────────────────────────────────────────────────────────────────────────
#   Root check           — reboot requires root
#   acquire_lock         — prevents concurrent reboot calls
#   detect_hosts()       — MY_ID in all user-facing messages
#   validate_unraid_cmd  — notify validated before use
#   Graceful VM shutdown — VMs get clean ACPI signal before libvirt stops
#   sync before reboot   — filesystem buffers flushed to disk
#
# ── CONFIGURATION (master.conf) ───────────────────────────────────────────────────────────────
#   REBOOT_SLEEP    — seconds to warn users before starting shutdown sequence (default 30)
#   REBOOT_VM_WAIT  — seconds to wait for VMs to shut down gracefully (default 30)
#
# ── USAGE ─────────────────────────────────────────────────────────────────────────────────────
#   server_reboot.sh                        — reboot with 30s warning
#   server_reboot.sh --dry-run              — walk through sequence without rebooting
#   server_reboot.sh --status               — show running processes that would be affected
#   server_reboot.sh --reason="maintenance" — log reason for reboot
#   server_reboot.sh --log                  — verbose output
# ==============================================================================================

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"

source "$SCRIPT_DIR/../load_config.sh"

# ── Parse --reason flag before parse_args ─────────────────────────────────────────────────────
REBOOT_REASON="manual"
FILTERED_ARGS=()
for arg in "$@"; do
    case "$arg" in
        --reason=*) REBOOT_REASON="${arg#--reason=}" ;;
        *)          FILTERED_ARGS+=("$arg") ;;
    esac
done

parse_args "${FILTERED_ARGS[@]}"

# ==============================================================================================
# ━━━ Setup ━━━
# ==============================================================================================
if [[ "$EUID" -ne 0 ]]; then
    error "Must be run as root — reboot requires root"
    exit 1
fi

validate_unraid_cmd \
    "/usr/local/emhttp/plugins/dynamix/scripts/notify" \
    "" "" \
    "unRAID notify script" || warn "unRAID notify script not found — native notifications disabled"

validate_int REBOOT_SLEEP "$REBOOT_SLEEP"

acquire_lock

detect_hosts

[[ "$DRY_RUN" == true ]] && warn "DRY RUN — no changes will be made, no reboot will occur"

# ==============================================================================================
# ━━━ Status ━━━
# ==============================================================================================
if [[ "$SHOW_STATUS" == true ]]; then
    echo ""
    echo "━━━━━ $ICON_SUMMARY REBOOT STATUS ━━━━━"
    echo "$ICON_HOST    Identity:    $MY_ID ($LOCAL_SERVER_NAME)"
    echo "$ICON_REBOOT  Delay:       ${REBOOT_SLEEP}s"
    echo "$ICON_GEAR    VM wait:     ${REBOOT_VM_WAIT:-30}s"
    echo "$ICON_GEAR    Reason:      $REBOOT_REASON"
    echo ""
    echo "━━━ Active Processes ━━━"

    pgrep -x rsync >/dev/null 2>&1 && \
        warn "  rsync: RUNNING — partial files if rebooted now" || \
        log "  rsync: not running"

    pgrep -f "emhttp.*Mover" >/dev/null 2>&1 && \
        warn "  mover: RUNNING — files may be left mid-move" || \
        log "  mover: not running"

    if command -v virsh >/dev/null 2>&1; then
        VM_COUNT=$(virsh list --name 2>/dev/null | grep -c "." || echo 0)
        [[ "$VM_COUNT" -gt 0 ]] && \
            warn "  VMs:   $VM_COUNT running — will be gracefully shut down" || \
            log "  VMs:   none running"
    fi

    if command -v docker >/dev/null 2>&1; then
        CONTAINER_COUNT=$(docker ps -q 2>/dev/null | wc -l || echo 0)
        log "  Docker: $CONTAINER_COUNT container(s) running"
    fi
    echo "━━━━━━━━━━━━━━━━━━━━━━━"
    exit 0
fi

# ==============================================================================================
# ━━━ Pre-flight Warnings ━━━
# ==============================================================================================
echo ""
echo "━━━ $ICON_SHIELD Pre-flight ━━━"
WARNINGS=()

# rsync check — partial files if killed mid-transfer
if pgrep -x rsync >/dev/null 2>&1; then
    RSYNC_PIDS=$(pgrep -x rsync | tr '\n' ' ')
    warn "rsync is running (PIDs: $RSYNC_PIDS) — partial files possible"
    warn "Consider: rsync_stop.sh before rebooting"
    WARNINGS+=("rsync running")
fi

# mover check — files may be left mid-move
if pgrep -f "emhttp.*Mover" >/dev/null 2>&1; then
    warn "Mover is running — files may be left mid-move on cache or array"
    warn "Consider: mover_stop.sh before rebooting"
    WARNINGS+=("mover running")
fi

# Emby sessions check — active streams interrupted
if [[ -n "${EMBY_URL:-}" ]] && [[ -n "${EMBY_API_KEY:-}" ]]; then
    ACTIVE_STREAMS=$(curl -sf --max-time 5 \
        -H "X-Emby-Token: $EMBY_API_KEY" \
        "${EMBY_URL}/Sessions" 2>/dev/null | \
        grep -c "NowPlayingItem" 2>/dev/null || echo 0)
    ACTIVE_STREAMS="${ACTIVE_STREAMS//[^0-9]/}"
    if [[ "${ACTIVE_STREAMS:-0}" -gt 0 ]]; then
        warn "$ACTIVE_STREAMS active Emby stream(s) — will be interrupted"
        WARNINGS+=("${ACTIVE_STREAMS} Emby sessions")
    fi
fi

if [[ ${#WARNINGS[@]} -eq 0 ]]; then
    log "Pre-flight clean — no active processes to warn about"
else
    warn "Proceeding with reboot despite warnings — ${WARNINGS[*]}"
fi

# ==============================================================================================
# ━━━ Notify and Wait ━━━
# ==============================================================================================
echo ""
echo "━━━ $ICON_REBOOT Reboot Sequence — $MY_ID ━━━"
echo "  Reason:  $REBOOT_REASON"
echo "  Delay:   ${REBOOT_SLEEP}s"
echo "  Dry Run: $DRY_RUN"
echo ""

START=$(date +%s)

if [[ "$REBOOT_SLEEP" -gt 0 ]]; then
    # Wall message — terminal users
    wall "$ICON_WARN $MY_ID ($LOCAL_SERVER_NAME) rebooting in ${REBOOT_SLEEP}s — reason: $REBOOT_REASON. Save your work now."

    # unRAID notification — dashboard
    if [[ "$DRY_RUN" == false ]]; then
        notify "$MY_ID ($LOCAL_SERVER_NAME) rebooting in ${REBOOT_SLEEP}s — reason: $REBOOT_REASON${WARNINGS:+ — warnings: ${WARNINGS[*]}}" \
            "Server Reboot" "warning"
    fi

    warn "Waiting ${REBOOT_SLEEP}s before shutdown sequence..."
    if [[ "$DRY_RUN" == false ]]; then
        sleep "$REBOOT_SLEEP"
    else
        warn "DRY RUN — skipping sleep"
    fi
fi

# ==============================================================================================
# ━━━ Graceful VM Shutdown ━━━
# ==============================================================================================
if command -v virsh >/dev/null 2>&1; then
    VM_LIST=$(virsh list --name 2>/dev/null | grep -v "^$" || true)
    if [[ -n "$VM_LIST" ]]; then
        echo ""
        echo "━━━ $ICON_GEAR Graceful VM Shutdown ━━━"
        while IFS= read -r vm; do
            [[ -z "$vm" ]] && continue
            warn "Sending ACPI shutdown to VM: $vm"
            if [[ "$DRY_RUN" == false ]]; then
                virsh shutdown "$vm" >/dev/null 2>&1 || true
            else
                warn "DRY RUN — would virsh shutdown $vm"
            fi
        done <<< "$VM_LIST"

        if [[ "$DRY_RUN" == false ]]; then
            VM_WAIT="${REBOOT_VM_WAIT:-30}"
            log "Waiting ${VM_WAIT}s for VMs to shut down..."
            sleep "$VM_WAIT"
        fi
    fi
fi

# ==============================================================================================
# ━━━ Stop VM Manager ━━━
# ==============================================================================================
echo ""
echo "━━━ $ICON_GEAR Stop VM Manager ━━━"
if [[ "$DRY_RUN" == true ]]; then
    warn "DRY RUN — would stop VM Manager (libvirt)"
else
    if /etc/rc.d/rc.libvirt stop >/dev/null 2>&1; then
        warn "VM Manager stopped ✅"
    else
        warn "VM Manager stop returned non-zero — may already be stopped"
    fi
fi

# ==============================================================================================
# ━━━ Stop Docker ━━━
# ==============================================================================================
echo ""
echo "━━━ $ICON_CONTAINERS Stop Docker ━━━"
if [[ "$DRY_RUN" == true ]]; then
    warn "DRY RUN — would stop Docker service"
else
    if /etc/rc.d/rc.docker stop >/dev/null 2>&1; then
        warn "Docker stopped ✅"
    else
        warn "Docker stop returned non-zero — may already be stopped"
    fi
fi

# ==============================================================================================
# ━━━ Sync Disks ━━━
# ==============================================================================================
echo ""
echo "━━━ $ICON_DISK Sync Disks ━━━"
if [[ "$DRY_RUN" == true ]]; then
    warn "DRY RUN — would sync filesystem buffers"
else
    sync
    log "Filesystem buffers flushed ✅"
fi

# ==============================================================================================
# ━━━ Reboot ━━━
# ==============================================================================================
END=$(date +%s)

echo ""
echo "━━━━━ $ICON_SUMMARY REBOOT SUMMARY ━━━━━"
echo "$ICON_HOST    Identity: $MY_ID ($LOCAL_SERVER_NAME)"
echo "$ICON_REBOOT  Reason:   $REBOOT_REASON"
echo "$ICON_TIME    Duration: $(format_duration $(( END - START )))"
[[ ${#WARNINGS[@]} -gt 0 ]] && warn "Warnings: ${WARNINGS[*]}"
echo ""

if [[ "$DRY_RUN" == true ]]; then
    warn "DRY RUN — sequence complete, no reboot executed"
    echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
else
    warn "$ICON_REBOOT Rebooting $MY_ID now..."
    echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
    /sbin/reboot
fi