#!/usr/bin/env bash

MAPDNS_BIN="${MAPDNS_BIN:-${BANGER_MAPDNS_BIN:-mapdns}}"
MAPDNS_DATA_FILE="${MAPDNS_DATA_FILE:-${BANGER_MAPDNS_DATA_FILE:-}}"

banger_mapdns_cmd() {
  local subcommand="$1"
  shift

  if [[ -n "$MAPDNS_DATA_FILE" ]]; then
    "$MAPDNS_BIN" "$subcommand" --data-file "$MAPDNS_DATA_FILE" "$@"
    return
  fi
  "$MAPDNS_BIN" "$subcommand" "$@"
}

banger_dns_name() {
  local vm_name="$1"
  printf '%s.vm' "$vm_name"
}

banger_dns_write_record() {
  local vm_name="$1"
  local guest_ip="$2"
  local dns_name

  if [[ -n "$MAPDNS_DATA_FILE" ]]; then
    mkdir -p "$(dirname "$MAPDNS_DATA_FILE")"
  fi
  dns_name="$(banger_dns_name "$vm_name")"
  banger_mapdns_cmd set "$dns_name" "$guest_ip" >/dev/null
}

banger_dns_record_exists() {
  local dns_name="$1"

  [[ -n "$dns_name" ]] || return 1
  banger_mapdns_cmd list | awk '{print $1}' | rg -Fxq "$dns_name"
}

banger_dns_remove_record_name() {
  local dns_name="${1:-}"
  [[ -n "$dns_name" ]] || return 0
  if ! banger_dns_record_exists "$dns_name"; then
    return 0
  fi
  banger_mapdns_cmd rm "$dns_name" >/dev/null
}

banger_vm_process_running() {
  local pid="$1"
  local api_sock="$2"

  [[ -n "$pid" && -n "$api_sock" ]] || return 1
  ps -p "$pid" -o comm=,args= 2>/dev/null | rg -q "firecracker.*--api-sock $api_sock"
}

banger_wait_for_vm_exit() {
  local pid="$1"
  local api_sock="$2"
  local timeout_secs="${3:-30}"
  local deadline=$((SECONDS + timeout_secs))

  while banger_vm_process_running "$pid" "$api_sock"; do
    if (( SECONDS >= deadline )); then
      return 1
    fi
    sleep 0.1
  done
}

banger_teardown_vm_runtime() {
  local tap="${1:-}"
  local api_sock="${2:-}"
  local dm_name="${3:-}"
  local dm_dev="${4:-}"
  local cow_loop="${5:-}"
  local base_loop="${6:-}"

  if [[ -n "$tap" ]]; then
    sudo ip link del "$tap" 2>/dev/null || true
  fi
  if [[ -n "$api_sock" ]]; then
    rm -f "$api_sock"
  fi
  if [[ -n "$dm_name" || -n "$dm_dev" ]]; then
    sudo dmsetup remove "${dm_name:-$dm_dev}" 2>/dev/null || true
  fi
  if [[ -n "$cow_loop" ]]; then
    sudo losetup -d "$cow_loop" 2>/dev/null || true
  fi
  if [[ -n "$base_loop" ]]; then
    sudo losetup -d "$base_loop" 2>/dev/null || true
  fi
}

banger_mark_vm_stopped() {
  local vm_json="$1"

  [[ -f "$vm_json" ]] || return 0
  jq \
    'del(.meta.pid, .meta.base_loop, .meta.cow_loop, .meta.dm_dev)' \
    "$vm_json" > "$vm_json.tmp" && mv "$vm_json.tmp" "$vm_json"
}