#!/usr/bin/env bash

# ============================================
# Lifecycle
# ============================================

function config::on_load() {
  config::_init_defaults
  config::load
  config::validate
  fmt::set_date_format "${_FMT_DATE_FORMAT:-iso}"
}

# ============================================
# Defaults
# ============================================

function config::_init_defaults() {
  _WG_INTERFACE="${WG_INTERFACE:-wg0}"
  _WG_DNS="${WG_DNS:-10.0.0.103}"
  _WG_LAN="${WG_LAN:-10.0.0.0/24}"
  _WG_SUBNET="${WG_SUBNET:-10.1.0.0/16}"
  _WG_PORT="${WG_PORT:-51820}"
  _WG_ENDPOINT="${WG_ENDPOINT:-}"

  # Derived
  _WG_CONFIG="$(ctx::wg)/${_WG_INTERFACE}.conf"
  _WG_SERVER_PUBLIC_KEY_FILE="$(ctx::wg)/server_public.key"
  _WG_SERVER_PRIVATE_KEY_FILE="$(ctx::wg)/server_private.key"
  _WG_TUNNEL_SPLIT="${_WG_SUBNET}, ${_WG_LAN}"
  _WG_TUNNEL_FULL="0.0.0.0/0, ::/0"
}

# ============================================
# Load overrides from .wgctl/wgctl.conf
# ============================================

function config::load() {
  local conf_file
  conf_file="$(ctx::data)/wgctl.conf"
  [[ ! -f "$conf_file" ]] && return 0
  while IFS='=' read -r key value || [[ -n "$key" ]]; do
    [[ "$key" =~ ^[[:space:]]*# ]] && continue
    [[ -z "${key// }" ]] && continue
    key="${key// /}"
    value="${value// /}"
    case "$key" in
      WG_INTERFACE)   _WG_INTERFACE="$value"        ;;
      WG_ENDPOINT)    _WG_ENDPOINT="$value"         ;;
      WG_DNS)         _WG_DNS="$value"              ;;
      WG_PORT)        _WG_PORT="$value"             ;;
      WG_SUBNET)      _WG_SUBNET="$value"           ;;
      WG_LAN)         _WG_LAN="$value"              ;;
      # Add debug temporarily to config::load:
      DATE_FORMAT)
        log::debug "config: setting date format to $value"
        _FMT_DATE_FORMAT="$value"
        fmt::set_date_format "$value"
        ;;
    esac
  done < "$conf_file"

  # Recompute derived values after overrides
  _WG_CONFIG="$(ctx::wg)/${_WG_INTERFACE}.conf"
  _WG_TUNNEL_SPLIT="${_WG_SUBNET}, ${_WG_LAN}"
}

# ============================================
# Device Type → Subnet Mapping
# ============================================

declare -gA DEVICE_SUBNETS=(
  [desktop]="10.1.1"
  [laptop]="10.1.2"
  [phone]="10.1.3"
  [tablet]="10.1.4"
  [guest]="10.1.100"
  [guest-desktop]="10.1.101"
  [guest-laptop]="10.1.102"
  [guest-phone]="10.1.103"
  [guest-tablet]="10.1.104"
)

# ============================================
# Tunnel Modes
# ============================================

declare -gA DEVICE_TUNNEL_MODE=(
  [desktop]="split"
  [laptop]="split"
  [phone]="split"
  [tablet]="split"
  [guest]="split"
  [guest-desktop]="split"
  [guest-laptop]="split"
  [guest-phone]="split"
  [guest-tablet]="split"
)

# ============================================
# Accessors
# ============================================

function config::interface()    { echo "$_WG_INTERFACE"; }
function config::config_file()  { echo "$_WG_CONFIG"; }
function config::endpoint()     { echo "$_WG_ENDPOINT"; }
function config::dns()          { echo "$_WG_DNS"; }
function config::port()         { echo "$_WG_PORT"; }
function config::subnet()       { echo "$_WG_SUBNET"; }
function config::lan()          { echo "$_WG_LAN"; }
function config::tunnel_split() { echo "$_WG_TUNNEL_SPLIT"; }
function config::tunnel_full()  { echo "$_WG_TUNNEL_FULL"; }

function config::server_public_key() {
  cat "$_WG_SERVER_PUBLIC_KEY_FILE"
}

function config::device_types() {
  local types
  { set +u; types="${!DEVICE_SUBNETS[@]}"; set -u; }
  echo "$types"
}

function config::is_valid_type() {
  local type="$1"
  local subnet
  subnet=$(config::subnet_for "$type")
  [[ -n "$subnet" ]]
}

function config::is_guest_type() {
  local type="$1"
  [[ "$type" == "guest" || "$type" == guest-* ]]
}

function config::subnet_for() {
  local type="$1"
  local result
  { set +u; result="${DEVICE_SUBNETS[$type]:-}"; set -u; }
  echo "$result"
}

function config::default_tunnel_for() {
  local type="$1"
  local result
  { set +u; result="${DEVICE_TUNNEL_MODE[$type]:-split}"; set -u; }
  echo "$result"
}

function config::allowed_ips_for() {
  local type="$1"
  local tunnel="${2:-}"

  if [[ -z "$tunnel" ]]; then
    tunnel=$(config::default_tunnel_for "$type")
  fi

  case "$tunnel" in
    full)  echo "$_WG_TUNNEL_FULL"  ;;
    split) echo "$_WG_TUNNEL_SPLIT" ;;
    *)
      log::error "Unknown tunnel mode: ${tunnel} (use 'split' or 'full')"
      return 1
      ;;
  esac
}

# ============================================
# Validation
# ============================================

function config::validate() {
  if [[ ! -f "$_WG_SERVER_PUBLIC_KEY_FILE" ]]; then
    log::error "Server public key not found: ${_WG_SERVER_PUBLIC_KEY_FILE}"
    exit 1
  fi

  if [[ ! -f "$_WG_SERVER_PRIVATE_KEY_FILE" ]]; then
    log::error "Server private key not found: ${_WG_SERVER_PRIVATE_KEY_FILE}"
    exit 1
  fi

  if [[ ! -f "$_WG_CONFIG" ]]; then
    log::error "WireGuard config not found: ${_WG_CONFIG}"
    exit 1
  fi
}