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

ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd -P)"
ENV_FILE="${ENV_FILE:-${ROOT_DIR}/.env}"

fail() {
  printf '%s\n' "$1" >&2
  exit 1
}

[[ -f "$ENV_FILE" ]] || fail "$ENV_FILE not found"
[[ ! -L "$ENV_FILE" ]] || fail "$ENV_FILE must not be a symbolic link"

read_env_value() {
  local key="$1"
  local value
  value="$(sed -n "s/^${key}=//p" "$ENV_FILE" | tail -n 1)"
  case "$value" in
    \"*\") value="${value#\"}"; value="${value%\"}" ;;
    \'*\') value="${value#\'}"; value="${value%\'}" ;;
  esac
  printf '%s\n' "$value"
}

bind_address="$(read_env_value PANEL_APP_BIND_ADDRESS)"
[[ "$bind_address" =~ ^[0-9]{1,3}(\.[0-9]{1,3}){3}$ ]] || fail "PANEL_APP_BIND_ADDRESS must be an IPv4 address"
IFS=. read -r octet1 octet2 octet3 octet4 <<< "$bind_address"
for octet in "$octet1" "$octet2" "$octet3" "$octet4"; do
  ((10#$octet <= 255)) || fail "PANEL_APP_BIND_ADDRESS contains an invalid IPv4 octet"
done

data_raw="$(read_env_value APP_DATA_DIR)"
[[ -n "$data_raw" && "$data_raw" != /* ]] || fail "APP_DATA_DIR must be a non-empty relative path"
data_candidate="${ROOT_DIR}/${data_raw#./}"
[[ ! -L "$data_candidate" ]] || fail "APP_DATA_DIR must not be a symbolic link"
data_dir="$(realpath -m -- "$data_candidate")"
case "$data_dir" in
  "${ROOT_DIR}"/*) ;;
  *) fail "APP_DATA_DIR must remain inside the application version directory" ;;
esac

install -d -m 0750 "$data_dir"
data_dir="$(realpath -e -- "$data_dir")"
case "$data_dir" in
  "${ROOT_DIR}"/*) ;;
  *) fail "APP_DATA_DIR resolves outside the application version directory" ;;
esac

for directory in "$data_dir/config" "$data_dir/files"; do
  [[ ! -L "$directory" ]] || fail "$directory must not be a symbolic link"
  install -d -m 0750 "$directory"
done

chown 100:101 "$data_dir" "$data_dir/config" "$data_dir/files"
chmod 0750 "$data_dir" "$data_dir/config" "$data_dir/files"