#!/usr/bin/env bash
# Save slot and VM snapshot management for Sysadmin Chronicles.
#
# Usage:
#   manage-saves.sh                   Interactive menu
#   manage-saves.sh --list            List save slots (non-interactive)
#   manage-saves.sh --reset           Reset current save
#   manage-saves.sh --reset slot-1    Reset a specific slot

set -euo pipefail

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

source "$PROJECT_ROOT/tools/lib/ui.sh"
source "$PROJECT_ROOT/tools/lib/config.sh"
source "$PROJECT_ROOT/tools/lib/save.sh"
source "$PROJECT_ROOT/tools/lib/libvirt.sh"
source "$PROJECT_ROOT/tools/lib/vm.sh"

config_read || true
export LIBVIRT_DEFAULT_URI="${SC_LIBVIRT_URI:-${LIBVIRT_DEFAULT_URI:-qemu:///system}}"

# Non-interactive flags
for arg in "$@"; do
    case "$arg" in
        --list)
            save_list
            exit 0
            ;;
    esac
done

if [[ "${1:-}" == "--reset" ]]; then
    slot="${2:-}"
    if [ -n "$slot" ]; then
        save_reset "$slot"
    else
        save_reset
    fi
    exit 0
fi

# ---------------------------------------------------------------------------
# Interactive menu
# ---------------------------------------------------------------------------

declare -A VM_LABEL=(
    [sc-workstation]="workstation (ares)"
    [sc-web-server]="web server (hermes)"
    [sc-build-machine]="build server (vulcan)"
)
ALL_VMS=(sc-workstation sc-web-server sc-build-machine)

sc_header "SYSADMIN CHRONICLES — SAVE MANAGEMENT"

_main_menu() {
    while true; do
        echo ""
        save_list
        echo ""
        echo "  ── Save Actions ─────────────────────────────"
        echo "  s) Switch active save slot"
        echo "  n) New save slot"
        echo "  r) Reset a save slot"
        echo "  e) Export save to file"
        echo "  i) Import save from file"
        echo ""
        echo "  ── VM Snapshots ─────────────────────────────"
        echo "  v) View and manage VM snapshots"
        echo ""
        echo "  q) Quit"
        echo ""
        printf "  > " >/dev/tty
        read -r choice </dev/tty
        echo ""

        case "$choice" in
            s|S) _switch_slot ;;
            n|N) _new_slot ;;
            r|R) _reset_slot ;;
            e|E) _export_slot ;;
            i|I) _import_slot ;;
            v|V) _vm_snapshots ;;
            q|Q) break ;;
            *) sc_warn "Unknown choice." ;;
        esac
    done
}

_switch_slot() {
    echo "  Switch to which slot? (autosave / slot-1 / slot-2 / slot-3)"
    printf "  > " >/dev/tty
    read -r slot </dev/tty
    echo ""
    save_switch "$slot" || true

    # Warn if VM state may not match
    local active_day
    active_day="$(grep -o '"day":[0-9]*' "$SC_SAVE_DIR/${slot}.json" 2>/dev/null | head -1 | cut -d: -f2 || echo '')"
    if [ -n "$active_day" ] && [ "$active_day" -gt 1 ] 2>/dev/null; then
        echo ""
        sc_warn "This save is on Day $active_day. Your VMs may not match this slot's expected state."
        sc_info "If things look wrong, use 'tools/vm/rebuild-vms.sh' to revert VMs."
    fi
}

_new_slot() {
    echo "  Create in which slot? (slot-1 / slot-2 / slot-3)"
    printf "  > " >/dev/tty
    read -r slot </dev/tty
    echo ""
    save_new "$slot" || true
}

_reset_slot() {
    echo "  Reset which slot? (autosave / slot-1 / slot-2 / slot-3)"
    printf "  > " >/dev/tty
    read -r slot </dev/tty
    echo ""
    if sc_confirm "  Reset $slot to new game state? This cannot be undone." "N"; then
        save_reset "$slot"
    fi
}

_export_slot() {
    echo "  Export which slot? (autosave / slot-1 / slot-2 / slot-3)"
    printf "  > " >/dev/tty
    read -r slot </dev/tty
    echo ""
    echo "  Save to (full path, e.g. ~/Desktop/my-save.json):"
    printf "  > " >/dev/tty
    read -r dest </dev/tty
    dest="${dest/#\~/$HOME}"
    echo ""
    save_export "$slot" "$dest" || true
}

_import_slot() {
    echo "  Path to save file to import:"
    printf "  > " >/dev/tty
    read -r src </dev/tty
    src="${src/#\~/$HOME}"
    echo ""
    echo "  Import into which slot? (autosave / slot-1 / slot-2 / slot-3)"
    printf "  > " >/dev/tty
    read -r slot </dev/tty
    echo ""
    save_import "$src" "$slot" || true
}

_vm_snapshots() {
    while true; do
        echo ""
        echo "  VM Snapshots"
        echo ""

        local vm label snaps snap ts prot
        for vm in "${ALL_VMS[@]}"; do
            label="${VM_LABEL[$vm]:-$vm}"
            echo "  $label"
            if domain_exists "$vm" 2>/dev/null; then
                snaps="$(virsh snapshot-list "$vm" --name 2>/dev/null | grep -v '^$' || true)"
                if [ -n "$snaps" ]; then
                    while IFS= read -r snap; do
                        ts="$(virsh snapshot-info "$vm" "$snap" 2>/dev/null | grep 'Creation Time' | awk '{print $3}' || true)"
                        if [[ "$snap" == baseline.* ]] || [[ "$snap" == checkpoint.* ]]; then
                            prot="  [protected]"
                        else
                            prot=""
                        fi
                        printf "    %-36s %-12s%s\n" "$snap" "$ts" "$prot"
                    done <<< "$snaps"
                else
                    echo "    (no snapshots)"
                fi
            else
                echo "    (VM not found)"
            fi
            echo ""
        done

        echo "  Actions: [t]ake snapshot  [r]evert  [d]elete  [q]uit"
        echo ""
        printf "  > " >/dev/tty
        local snap_action
        read -r snap_action </dev/tty
        echo ""

        case "$snap_action" in
            t|T)
                _pick_vm vm_id "  Snapshot which VM? (workstation / web-server / build-machine)"
                echo "  Snapshot name (letters, numbers, hyphens):"
                printf "  > " >/dev/tty
                read -r snap_name </dev/tty
                echo ""
                vm_snapshot_create "sc-${vm_id}" "$snap_name" \
                    && sc_ok "Snapshot taken: $snap_name on $vm_id" \
                    || sc_warn "Snapshot failed."
                ;;
            r|R)
                _pick_vm vm_id "  Revert which VM?"
                echo "  Snapshot name:"
                printf "  > " >/dev/tty
                read -r snap_name </dev/tty
                echo ""
                if sc_confirm "  Revert $vm_id to '$snap_name'?" "N"; then
                    vm_snapshot_revert "sc-${vm_id}" "$snap_name" \
                        && sc_ok "Reverted to $snap_name" \
                        || sc_warn "Revert failed."
                fi
                ;;
            d|D)
                _pick_vm vm_id "  Delete snapshot from which VM?"
                echo "  Snapshot name:"
                printf "  > " >/dev/tty
                read -r snap_name </dev/tty
                echo ""
                vm_snapshot_delete "sc-${vm_id}" "$snap_name" \
                    && sc_ok "Deleted $snap_name from $vm_id" \
                    || true
                ;;
            q|Q) break ;;
            *) sc_warn "Unknown action." ;;
        esac
    done
}

_pick_vm() {
    local -n _result_ref="$1"
    local _prompt="$2"
    echo "  $_prompt (workstation / web-server / build-machine)"
    printf "  > " >/dev/tty
    read -r _result_ref </dev/tty
    echo ""
}

_main_menu