#!/usr/bin/env bash
set -euo pipefail

BASE_DIR="${PANEL_BASE_DIR:-/var/lib/containers}"
STACKS_DIR="${BASE_DIR}/stacks"
VOLUMES_DIR="${BASE_DIR}/volumes"
ROUTES_DIR="${BASE_DIR}/routes"
STATE_DIR="${BASE_DIR}/state"
APPS_DIR="${STATE_DIR}/apps"
BACKUPS_DIR="${BASE_DIR}/backups"

FORWARD_AUTH_BLOCK='  forward_auth 127.0.0.1:9091 {
    uri /api/authz/forward-auth
    copy_headers Remote-User Remote-Groups Remote-Email Remote-Name
  }
'

usage() {
  cat <<'EOF'
panelctl - minimal app panel helper

Usage:
  panelctl init <name> <domains> <port> [auth]
  panelctl render-route <name>
  panelctl deploy <name>
  panelctl restart <name>
  panelctl stop <name>
  panelctl status <name>
  panelctl logs <name> [--tail N]
  panelctl remove <name> [--keep-volumes]
  panelctl backup <name>
  panelctl list-backups <name>
  panelctl restore <name> <backup-file>
  panelctl validate-compose <name>
  panelctl list
  panelctl show <name>

Domains can be comma-separated for multiple domains:
  panelctl init myapp "app.example.com,www.example.com" 18080 true

Wildcard domains are supported (requires DNS challenge in Caddy):
  panelctl init myapp "*.example.com" 18080 true

Examples:
  panelctl init whoami whoami.srazka.com 18080 true
  panelctl deploy whoami
  panelctl restart whoami
  panelctl status whoami
  panelctl logs whoami --tail 50
  panelctl backup whoami
  panelctl list-backups whoami
  panelctl restore whoami whoami-20260101-120000.zip
EOF
}

fail() {
  echo "error: $*" >&2
  exit 1
}

log() {
  local level="${1:-info}"
  local msg="${2:-}"
  echo "${msg}" | systemd-cat -t panelctl -p "${level}" 2>/dev/null || true
}

ensure_base_dirs() {
  mkdir -p "${STACKS_DIR}" "${VOLUMES_DIR}" "${ROUTES_DIR}" "${APPS_DIR}" "${BACKUPS_DIR}"
}

validate_name() {
  local name="$1"
  [[ "${name}" =~ ^[a-z0-9]([a-z0-9-]*[a-z0-9])?$ ]] || fail "invalid name '${name}' (use lowercase slug)"
}

validate_single_domain() {
  local domain="$1"
  # Allow wildcard prefix *.
  local check="${domain}"
  if [[ "${check}" == \*.* ]]; then
    check="${check#\*.}"
  fi
  [[ "${check}" =~ ^[A-Za-z0-9]([A-Za-z0-9.-]*[A-Za-z0-9])?$ ]] || fail "invalid domain '${domain}'"
  [[ "${domain}" == *.* ]] || fail "domain '${domain}' must include a dot"
}

validate_domains() {
  local domains_str="$1"
  IFS=',' read -ra domains <<< "${domains_str}"
  [[ ${#domains[@]} -ge 1 ]] || fail "at least one domain is required"
  for d in "${domains[@]}"; do
    d="$(echo "${d}" | xargs)" # trim whitespace
    validate_single_domain "${d}"
  done
}

validate_port() {
  local port="$1"
  [[ "${port}" =~ ^[0-9]+$ ]] || fail "port must be numeric"
  (( port >= 1024 && port <= 65535 )) || fail "port must be in range 1024-65535"
}

app_manifest() {
  local name="$1"
  echo "${APPS_DIR}/${name}.env"
}

app_stack_dir() {
  local name="$1"
  echo "${STACKS_DIR}/${name}"
}

app_volume_dir() {
  local name="$1"
  echo "${VOLUMES_DIR}/${name}"
}

# All routes go into a single aggregate file that Caddy imports.
app_route_file() {
  echo "${ROUTES_DIR}/routes.caddy"
}

load_app() {
  local name="$1"
  local manifest
  manifest="$(app_manifest "${name}")"
  [[ -f "${manifest}" ]] || fail "app '${name}' does not exist"
  # shellcheck disable=SC1090
  source "${manifest}"
}

compose_command() {
  local podman_bin=""
  local podman_compose_bin=""

  if command -v podman >/dev/null 2>&1; then
    podman_bin="$(command -v podman)"
  elif [[ -x /run/current-system/sw/bin/podman ]]; then
    podman_bin="/run/current-system/sw/bin/podman"
  fi

  if command -v podman-compose >/dev/null 2>&1; then
    podman_compose_bin="$(command -v podman-compose)"
  elif [[ -x /run/current-system/sw/bin/podman-compose ]]; then
    podman_compose_bin="/run/current-system/sw/bin/podman-compose"
  fi

  if [[ -n "${podman_bin}" ]] && "${podman_bin}" compose version >/dev/null 2>&1; then
    echo "${podman_bin} compose"
    return
  fi

  if [[ -n "${podman_compose_bin}" ]]; then
    echo "${podman_compose_bin}"
    return
  fi

  fail "no compose command available (need 'podman compose' or 'podman-compose')"
}

ensure_podman_runtime_env() {
  local uid
  uid="$(id -u)"

  if [[ -z "${HOME:-}" ]]; then
    HOME="$(getent passwd "${uid}" | cut -d: -f6 || true)"
    export HOME
  fi

  if [[ -z "${XDG_RUNTIME_DIR:-}" ]]; then
    XDG_RUNTIME_DIR="/run/user/${uid}"
    export XDG_RUNTIME_DIR
  fi

  if [[ ! -d "${XDG_RUNTIME_DIR}" ]]; then
    fail "XDG_RUNTIME_DIR '${XDG_RUNTIME_DIR}' does not exist for uid ${uid}. Ensure user runtime is available (e.g. loginctl enable-linger $(id -un))."
  fi

  if [[ -z "${DBUS_SESSION_BUS_ADDRESS:-}" && -S "${XDG_RUNTIME_DIR}/bus" ]]; then
    DBUS_SESSION_BUS_ADDRESS="unix:path=${XDG_RUNTIME_DIR}/bus"
    export DBUS_SESSION_BUS_ADDRESS
  fi

  unset DOCKER_HOST
  unset CONTAINER_HOST
}

run_compose() {
  local compose
  compose="$(compose_command)"

  ensure_podman_runtime_env

  if [[ "${compose}" == *" compose" ]]; then
    local podman_bin="${compose% compose}"
    "${podman_bin}" compose "$@"
    return
  fi

  "${compose}" "$@"
}

write_default_compose() {
  local name="$1"
  local port="$2"
  local stack_dir
  local volume_dir
  stack_dir="$(app_stack_dir "${name}")"
  volume_dir="$(app_volume_dir "${name}")"

  cat >"${stack_dir}/compose.yaml" <<EOF
services:
  app:
    image: docker.io/traefik/whoami:latest
    restart: unless-stopped
    ports:
      - "127.0.0.1:${port}:80"
    volumes:
      - ${volume_dir}/data:/data
EOF
}

write_manifest() {
  local name="$1"
  local domains="$2"
  local port="$3"
  local auth="$4"
  local manifest
  local stack_dir
  local volume_dir
  local route_file

  manifest="$(app_manifest "${name}")"
  stack_dir="$(app_stack_dir "${name}")"
  volume_dir="$(app_volume_dir "${name}")"
  route_file="$(app_route_file)"

  # First domain is the primary (used for APP_DOMAIN backward compat)
  local primary_domain
  IFS=',' read -ra domain_arr <<< "${domains}"
  primary_domain="$(echo "${domain_arr[0]}" | xargs)"

  cat >"${manifest}" <<EOF
APP_NAME="${name}"
APP_DOMAIN="${primary_domain}"
APP_DOMAINS="${domains}"
APP_PORT="${port}"
APP_UPSTREAM="127.0.0.1:${port}"
APP_AUTH_PROTECTED="${auth}"
APP_STACK_DIR="${stack_dir}"
APP_COMPOSE_FILE="${stack_dir}/compose.yaml"
APP_VOLUME_DIR="${volume_dir}"
APP_ROUTE_FILE="${route_file}"
EOF
}

cmd_init() {
  local name="$1"
  local domains="$2"
  local port="$3"
  local auth="${4:-true}"

  validate_name "${name}"
  validate_domains "${domains}"
  validate_port "${port}"
  [[ "${auth}" == "true" || "${auth}" == "false" ]] || fail "auth must be true or false"

  ensure_base_dirs

  local manifest
  local stack_dir
  local volume_dir
  manifest="$(app_manifest "${name}")"
  stack_dir="$(app_stack_dir "${name}")"
  volume_dir="$(app_volume_dir "${name}")"

  [[ ! -f "${manifest}" ]] || fail "app '${name}' already exists"

  mkdir -p "${stack_dir}" "${volume_dir}/data"
  write_default_compose "${name}" "${port}"
  write_manifest "${name}" "${domains}" "${port}" "${auth}"
  cmd_render_route "${name}"

  log info "initialized app '${name}'"
}

cmd_render_route() {
  local name="$1"
  validate_name "${name}"
  load_app "${name}"

  local auth_block=""
  if [[ "${APP_AUTH_PROTECTED}" == "true" ]]; then
    auth_block="${FORWARD_AUTH_BLOCK}"
  fi

  # Build domain list for Caddy block header.
  local caddy_domains=""
  local domains_str="${APP_DOMAINS:-${APP_DOMAIN}}"
  IFS=',' read -ra domain_arr <<< "${domains_str}"
  for d in "${domain_arr[@]}"; do
    d="$(echo "${d}" | xargs)"
    if [[ -n "${caddy_domains}" ]]; then
      caddy_domains="${caddy_domains}, ${d}"
    else
      caddy_domains="${d}"
    fi
  done

  local route_file
  route_file="$(app_route_file)"

  # Strip any existing block for this app from the aggregate file.
  local tmp
  tmp="$(mktemp)"

  if [[ -f "${route_file}" ]]; then
    sed "/^# route:${name}:start$/,/^# route:${name}:end$/d" "${route_file}" >"${tmp}" || true
  else
    printf "" >"${tmp}"
  fi

  {
    printf "# route:%s:start\n" "${name}"
    printf "%s {\n" "${caddy_domains}"
    if [[ -n "${auth_block}" ]]; then
      printf "%s\n" "${auth_block}"
    fi
    printf "  reverse_proxy %s\n" "${APP_UPSTREAM}"
    printf "}\n"
    printf "# route:%s:end\n" "${name}"
  } >>"${tmp}"

  install -m 0664 -o reudy -g panelroutes "${tmp}" "${route_file}"
  log info "rendered route ${route_file}"
}

# maybe_reload_caddy() {
#   # Try Caddy admin API first (no root required)
#   if curl -sf -X POST http://localhost:2019/config/ >/dev/null 2>&1; then
#     log info "reloaded caddy via admin API"
#     return
#   fi

#   # Validate config if caddy binary is available
#   if [[ -x /run/current-system/sw/bin/caddy && -f /etc/caddy/Caddyfile ]]; then
#     /run/current-system/sw/bin/caddy validate \
#       --config /etc/caddy/Caddyfile --adapter caddyfile \
#       || echo "warning: caddy validation failed" >&2
#   fi

#   # Fall back to systemctl (sudo if needed)
#   if [[ "${EUID}" -eq 0 ]]; then
#     systemctl reload caddy && log info "reloaded caddy"
#   elif sudo -n /run/current-system/sw/bin/systemctl reload caddy 2>/dev/null; then
#     log info "reloaded caddy via sudo"
#   else
#     log warning "caddy reload requires root; run: sudo systemctl reload caddy"
#   fi
# }

cmd_deploy() {
  local name="$1"
  validate_name "${name}"
  load_app "${name}"

  log info "Starting deployment for app '${name}'"

  cmd_render_route "${name}"

  if ! run_compose -f "${APP_COMPOSE_FILE}" up -d 2>&1 | systemd-cat -t panelctl -p info 2>/dev/null; then
    log err "Deployment failed for app '${name}'"
    fail "compose up failed"
  fi

  maybe_reload_caddy

  log info "Successfully deployed app '${name}'"
  log info "deployed app '${name}'"
}

cmd_restart() {
  local name="$1"
  validate_name "${name}"
  load_app "${name}"

  log info "Restarting app '${name}'"

  run_compose -f "${APP_COMPOSE_FILE}" down || fail "compose down failed"

  if ! run_compose -f "${APP_COMPOSE_FILE}" up -d 2>&1; then
    fail "compose up failed during restart"
  fi

  log info "restarted app '${name}'"
}

cmd_stop() {
  local name="$1"
  validate_name "${name}"
  load_app "${name}"

  run_compose -f "${APP_COMPOSE_FILE}" down || fail "compose down failed"
  log info "stopped app '${name}'"
}

cmd_status() {
  local name="$1"
  validate_name "${name}"
  load_app "${name}"

  run_compose -f "${APP_COMPOSE_FILE}" ps --format json 2>/dev/null || \
    run_compose -f "${APP_COMPOSE_FILE}" ps 2>/dev/null || \
    log info "no containers running"
}

cmd_logs() {
  local name="$1"
  shift
  validate_name "${name}"
  load_app "${name}"

  local tail_lines="100"
  while [[ $# -gt 0 ]]; do
    case "$1" in
      --tail)
        tail_lines="$2"
        shift 2
        ;;
      *)
        shift
        ;;
    esac
  done

  run_compose -f "${APP_COMPOSE_FILE}" logs --tail "${tail_lines}" 2>&1 || log info "no logs available"
}

cmd_validate_compose() {
  local name="$1"
  validate_name "${name}"
  load_app "${name}"

  if run_compose -f "${APP_COMPOSE_FILE}" config >/dev/null 2>&1; then
    log info "compose file is valid"
  else
    local output
    output="$(run_compose -f "${APP_COMPOSE_FILE}" config 2>&1 || true)"
    fail "compose validation failed: ${output}"
  fi
}

cmd_remove() {
  local name="$1"
  local keep_volumes="${2:-}"
  validate_name "${name}"
  load_app "${name}"

  run_compose -f "${APP_COMPOSE_FILE}" down 2>/dev/null || true

  # Remove this app's block from the aggregate routes file.
  local route_file
  route_file="$(app_route_file)"
  if [[ -f "${route_file}" ]]; then
    local tmp
    tmp="$(mktemp)"
    sed "/^# route:${name}:start$/,/^# route:${name}:end$/d" "${route_file}" >"${tmp}" || true
    install -m 0664 -o reudy -g panelroutes "${tmp}" "${route_file}"
  fi

  rm -f "$(app_manifest "${name}")"
  rm -rf "${APP_STACK_DIR}"

  if [[ "${keep_volumes}" != "--keep-volumes" ]]; then
    rm -rf "${APP_VOLUME_DIR}"
  fi

  maybe_reload_caddy
  log info "removed app '${name}'"
}

cmd_backup() {
  local name="$1"
  validate_name "${name}"
  load_app "${name}"

  ensure_base_dirs

  local volume_dir
  volume_dir="$(app_volume_dir "${name}")"
  [[ -d "${volume_dir}" ]] || fail "volume directory '${volume_dir}' does not exist"

  local timestamp
  timestamp="$(date +%Y%m%d-%H%M%S)"
  local backup_file="${BACKUPS_DIR}/${name}-${timestamp}.zip"

  # Stop containers before backup for consistency
  local was_running=false
  if run_compose -f "${APP_COMPOSE_FILE}" ps --format json 2>/dev/null | grep -q '"running"' 2>/dev/null; then
    was_running=true
    log info "stopping containers for consistent backup..."
    run_compose -f "${APP_COMPOSE_FILE}" down 2>/dev/null || true
  fi

  (cd "${volume_dir}" && zip -r "${backup_file}" .) || fail "zip failed"

  # Also include the compose file in the backup
  local stack_dir
  stack_dir="$(app_stack_dir "${name}")"
  if [[ -f "${stack_dir}/compose.yaml" ]]; then
    (cd "${stack_dir}" && zip -j "${backup_file}" compose.yaml) || true
  fi

  # Restart if it was running
  if [[ "${was_running}" == "true" ]]; then
    log info "restarting containers after backup..."
    run_compose -f "${APP_COMPOSE_FILE}" up -d 2>/dev/null || true
  fi

  local size
  size="$(du -h "${backup_file}" | cut -f1)"
  log info "backup created: ${backup_file} (${size})"
}

cmd_list_backups() {
  local name="$1"
  validate_name "${name}"

  ensure_base_dirs

  local found=0
  for bf in "${BACKUPS_DIR}/${name}"-*.zip; do
    [[ -e "${bf}" ]] || continue
    found=1
    local fname size mtime
    fname="$(basename "${bf}")"
    size="$(du -h "${bf}" | cut -f1)"
    mtime="$(stat -c '%Y' "${bf}" 2>/dev/null || stat -f '%m' "${bf}" 2>/dev/null || echo "0")"
    echo "${fname} ${size} ${mtime}"
  done

  if [[ "${found}" -eq 0 ]]; then
    log info "no backups found for '${name}'"
  fi
}

cmd_restore() {
  local name="$1"
  local backup_file="$2"
  validate_name "${name}"
  load_app "${name}"

  # Resolve backup file path
  local full_path="${backup_file}"
  if [[ ! -f "${full_path}" ]]; then
    full_path="${BACKUPS_DIR}/${backup_file}"
  fi
  [[ -f "${full_path}" ]] || fail "backup file '${backup_file}' not found"

  # Ensure it's a zip file within the backups directory
  local norm_path
  norm_path="$(realpath "${full_path}")"
  local norm_backups
  norm_backups="$(realpath "${BACKUPS_DIR}")"
  [[ "${norm_path}" == "${norm_backups}"/* ]] || fail "backup file must be in the backups directory"

  local volume_dir
  volume_dir="$(app_volume_dir "${name}")"

  # Stop containers before restore
  log info "stopping containers for restore..."
  run_compose -f "${APP_COMPOSE_FILE}" down 2>/dev/null || true

  # Clear existing volume data and extract backup
  rm -rf "${volume_dir:?}"/*
  mkdir -p "${volume_dir}"
  (cd "${volume_dir}" && unzip -o "${norm_path}") || fail "unzip failed"

  log info "restored '${name}' from $(basename "${norm_path}")"
  log info "run 'panelctl deploy ${name}' to start the app'"
}

cmd_list() {
  ensure_base_dirs
  local found=0
  for mf in "${APPS_DIR}"/*.env; do
    [[ -e "${mf}" ]] || continue
    found=1
    # shellcheck disable=SC1090
    source "${mf}"
    local domains="${APP_DOMAINS:-${APP_DOMAIN}}"
    echo "${APP_NAME} ${domains} ${APP_UPSTREAM} auth=${APP_AUTH_PROTECTED}"
  done

  if [[ "${found}" -eq 0 ]]; then
    log info "no apps found"
  fi
}

cmd_show() {
  local name="$1"
  validate_name "${name}"
  local mf
  mf="$(app_manifest "${name}")"
  [[ -f "${mf}" ]] || fail "app '${name}' does not exist"
  cat "${mf}"
}

main() {
  local cmd="${1:-}"

  case "${cmd}" in
    init)
      [[ $# -ge 4 ]] || fail "usage: panelctl init <name> <domains> <port> [auth]"
      cmd_init "$2" "$3" "$4" "${5:-true}"
      ;;
    render-route)
      [[ $# -eq 2 ]] || fail "usage: panelctl render-route <name>"
      cmd_render_route "$2"
      ;;
    deploy)
      [[ $# -eq 2 ]] || fail "usage: panelctl deploy <name>"
      cmd_deploy "$2"
      ;;
    restart)
      [[ $# -eq 2 ]] || fail "usage: panelctl restart <name>"
      cmd_restart "$2"
      ;;
    stop)
      [[ $# -eq 2 ]] || fail "usage: panelctl stop <name>"
      cmd_stop "$2"
      ;;
    status)
      [[ $# -eq 2 ]] || fail "usage: panelctl status <name>"
      cmd_status "$2"
      ;;
    logs)
      [[ $# -ge 2 ]] || fail "usage: panelctl logs <name> [--tail N]"
      cmd_logs "$2" "${@:3}"
      ;;
    validate-compose)
      [[ $# -eq 2 ]] || fail "usage: panelctl validate-compose <name>"
      cmd_validate_compose "$2"
      ;;
    remove)
      [[ $# -ge 2 ]] || fail "usage: panelctl remove <name> [--keep-volumes]"
      cmd_remove "$2" "${3:-}"
      ;;
    backup)
      [[ $# -eq 2 ]] || fail "usage: panelctl backup <name>"
      cmd_backup "$2"
      ;;
    list-backups)
      [[ $# -eq 2 ]] || fail "usage: panelctl list-backups <name>"
      cmd_list_backups "$2"
      ;;
    restore)
      [[ $# -eq 3 ]] || fail "usage: panelctl restore <name> <backup-file>"
      cmd_restore "$2" "$3"
      ;;
    list)
      [[ $# -eq 1 ]] || fail "usage: panelctl list"
      cmd_list
      ;;
    show)
      [[ $# -eq 2 ]] || fail "usage: panelctl show <name>"
      cmd_show "$2"
      ;;
    ""|-h|--help|help)
      usage
      ;;
    *)
      fail "unknown command '${cmd}'"
      ;;
  esac
}

main "$@"