#!/bin/sh
set -eu

SCRIPT_DIR=$(CDPATH= cd -- "$(dirname -- "$0")" && pwd)
APP_DIR=$(CDPATH= cd -- "$SCRIPT_DIR/.." && pwd)
CONFIG_PATH=${1:-"$APP_DIR/config_router.conf"}
CONFIG_DIR=$(CDPATH= cd -- "$(dirname -- "$CONFIG_PATH")" && pwd)

if [ ! -r "$CONFIG_PATH" ]; then
  echo "[router-http] config not found: $CONFIG_PATH" >&2
  exit 1
fi

# shellcheck disable=SC1090
. "$CONFIG_PATH"

BUSYBOX_BIN=${BUSYBOX_BIN:-"$APP_DIR/busybox_armv7l"}
RUNTIME_DIR=${RUNTIME_DIR:-"$APP_DIR/cfip_runtime"}
VALUE_TEXT_FILE=${VALUE_TEXT_FILE:-"current_ip.txt"}
HTTP_PORT=${HTTP_PORT:-8080}

# Trim possible CRLF endings from config values edited on Windows/Web UI.
CR=$(printf '\r')
BUSYBOX_BIN=${BUSYBOX_BIN%"$CR"}
RUNTIME_DIR=${RUNTIME_DIR%"$CR"}
VALUE_TEXT_FILE=${VALUE_TEXT_FILE%"$CR"}
HTTP_PORT=${HTTP_PORT%"$CR"}

TEXT_PATH="$RUNTIME_DIR/$VALUE_TEXT_FILE"
INDEX_PATH="$RUNTIME_DIR/index.html"

resolve_path_from_config() {
  p="$1"
  case "$p" in
    /*) printf '%s\n' "$p" ;;
    *) printf '%s/%s\n' "$CONFIG_DIR" "$p" ;;
  esac
}

resolve_busybox() {
  if [ -n "$BUSYBOX_BIN" ]; then
    busybox_from_cfg=$(resolve_path_from_config "$BUSYBOX_BIN")
    if [ -x "$busybox_from_cfg" ]; then
      printf '%s\n' "$busybox_from_cfg"
      return 0
    fi
  fi

  if [ -n "$BUSYBOX_BIN" ] && [ -x "$BUSYBOX_BIN" ]; then
    printf '%s\n' "$BUSYBOX_BIN"
    return 0
  fi

  if [ -x "$APP_DIR/busybox_armv7l" ]; then
    printf '%s\n' "$APP_DIR/busybox_armv7l"
    return 0
  fi

  if command -v busybox >/dev/null 2>&1; then
    command -v busybox
    return 0
  fi

  return 1
}

print_busybox_debug() {
  echo "[router-http] debug CONFIG_PATH=$CONFIG_PATH" >&2
  echo "[router-http] debug CONFIG_DIR=$CONFIG_DIR" >&2
  echo "[router-http] debug APP_DIR=$APP_DIR" >&2
  echo "[router-http] debug BUSYBOX_BIN(raw)=$BUSYBOX_BIN" >&2

  resolved_from_cfg=$(resolve_path_from_config "$BUSYBOX_BIN")
  echo "[router-http] debug BUSYBOX_BIN(resolved)=$resolved_from_cfg" >&2

  if [ -e "$resolved_from_cfg" ]; then
    if [ -x "$resolved_from_cfg" ]; then
      echo "[router-http] debug resolved BusyBox exists and is executable" >&2
    else
      echo "[router-http] debug resolved BusyBox exists but is NOT executable; run: chmod +x $resolved_from_cfg" >&2
    fi
  else
    echo "[router-http] debug resolved BusyBox does not exist" >&2
  fi

  if [ -e "$APP_DIR/busybox_armv7l" ]; then
    if [ -x "$APP_DIR/busybox_armv7l" ]; then
      echo "[router-http] debug fallback $APP_DIR/busybox_armv7l exists and is executable" >&2
    else
      echo "[router-http] debug fallback $APP_DIR/busybox_armv7l exists but is NOT executable; run: chmod +x $APP_DIR/busybox_armv7l" >&2
    fi
  else
    echo "[router-http] debug fallback $APP_DIR/busybox_armv7l does not exist" >&2
  fi
}

busybox_has_applet() {
  busybox_bin="$1"
  applet="$2"
  if "$busybox_bin" --list 2>/dev/null | grep "^$applet$" >/dev/null; then
    return 0
  fi
  "$busybox_bin" 2>/dev/null | grep "[[:space:]]$applet[,[:space:]]" >/dev/null
}

ensure_index() {
  if [ ! -f "$TEXT_PATH" ]; then
    return 0
  fi

  rm -f "$INDEX_PATH"
  cp "$TEXT_PATH" "$INDEX_PATH"
}

start_httpd() {
  busybox_bin=$(resolve_busybox || true)
  if [ -n "$busybox_bin" ] && busybox_has_applet "$busybox_bin" httpd; then
    echo "[router-http] serving $RUNTIME_DIR on 0.0.0.0:$HTTP_PORT via $busybox_bin httpd"
    "$busybox_bin" httpd -f -p "$HTTP_PORT" -h "$RUNTIME_DIR" &
    httpd_pid=$!
    trap 'kill "$httpd_pid" 2>/dev/null || true' INT TERM EXIT
    wait "$httpd_pid"
    exit $?
  fi

  if [ -n "$busybox_bin" ]; then
    echo "[router-http] selected BusyBox has no httpd applet: $busybox_bin" >&2
  fi
  if command -v httpd >/dev/null 2>&1; then
    echo "[router-http] found system httpd at $(command -v httpd), but it is not used" >&2
    echo "[router-http] ASUS firmware httpd is usually the router admin web server and does not support serving an arbitrary -h directory" >&2
  fi

  print_busybox_debug
  echo "[router-http] usable BusyBox httpd applet not found" >&2
  echo "[router-http] set BUSYBOX_BIN in config_router.conf to your full BusyBox binary, for example: BUSYBOX_BIN=\"./busybox_armv7l\"" >&2
  exit 1
}

if [ ! -d "$RUNTIME_DIR" ]; then
  echo "[router-http] runtime dir not found: $RUNTIME_DIR" >&2
  echo "[router-http] run: sh scripts/router_local_update.sh $CONFIG_PATH" >&2
  exit 1
fi

ensure_index
start_httpd