#!/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
}

strip_matching_quotes() {
  local value="$1"

  if [[ ${#value} -ge 2 ]]; then
    if [[ "${value:0:1}" == '"' && "${value: -1}" == '"' ]]; then
      value="${value:1:${#value}-2}"
    elif [[ "${value:0:1}" == "'" && "${value: -1}" == "'" ]]; then
      value="${value:1:${#value}-2}"
    fi
  fi
  printf '%s\n' "$value"
}

read_env_value() {
  local key="$1"
  local value=""

  if [[ -f "$ENV_FILE" ]]; then
    value="$(grep -E "^${key}=" "$ENV_FILE" | tail -n 1 | cut -d '=' -f 2- || true)"
  fi
  strip_matching_quotes "$value"
}

set_env_value() {
  local key="$1"
  local value="$2"
  local temp_file

  temp_file="$(mktemp "${ENV_FILE}.tmp.XXXXXX")"
  awk -v key="$key" -v value="$value" '
    BEGIN { updated = 0 }
    $0 ~ ("^" key "=") {
      if (!updated) {
        print key "=" value
        updated = 1
      }
      next
    }
    { print }
    END {
      if (!updated) print key "=" value
    }
  ' "$ENV_FILE" > "$temp_file"
  chmod --reference="$ENV_FILE" "$temp_file"
  mv -f -- "$temp_file" "$ENV_FILE"
}

ensure_secret_key_base() {
  local secret_key_base

  secret_key_base="$(read_env_value SECRET_KEY_BASE)"
  if [[ ${#secret_key_base} -lt 64 ]]; then
    printf '%s\n' "SECRET_KEY_BASE is shorter than 64 characters; replacing it with a generated 128-character hexadecimal secret." >&2
    secret_key_base="$(od -An -N64 -tx1 /dev/urandom | tr -d ' \n')"
    set_env_value SECRET_KEY_BASE "$secret_key_base"
  fi
}

path_is_dotenv_safe() {
  local value="$1"

  case "$value" in
    *$'\n'* | *$'\r'* | *\\* | *'$'* | *'#'* | *'"'* | *"'"*) return 1 ;;
    *) return 0 ;;
  esac
}

[[ -f "$ENV_FILE" ]] || fail "Environment file not found: ${ENV_FILE}"
ensure_secret_key_base

if [[ ${APP_DATA_DIR+x} ]]; then
  APP_DATA_DIR_RAW="$APP_DATA_DIR"
else
  APP_DATA_DIR_RAW="$(read_env_value APP_DATA_DIR)"
fi
APP_DATA_DIR_RAW="$(strip_matching_quotes "${APP_DATA_DIR_RAW:-./data}")"

[[ -n "$APP_DATA_DIR_RAW" ]] || fail "APP_DATA_DIR must not be empty"
path_is_dotenv_safe "$APP_DATA_DIR_RAW" || fail "APP_DATA_DIR contains unsupported dotenv characters"

case "$APP_DATA_DIR_RAW" in
  /*)
    APP_DATA_DIR_ABS="$(realpath -m -- "$APP_DATA_DIR_RAW")"
    ;;
  *)
    APP_DATA_DIR_ABS="$(realpath -m -- "${ROOT_DIR}/${APP_DATA_DIR_RAW#./}")"
    case "$APP_DATA_DIR_ABS" in
      "${ROOT_DIR}" | "${ROOT_DIR}"/*) ;;
      *) fail "Relative APP_DATA_DIR must stay inside the application directory" ;;
    esac
    ;;
esac

[[ "$APP_DATA_DIR_ABS" != "/" ]] || fail "APP_DATA_DIR must not be the filesystem root"
[[ ! -L "$APP_DATA_DIR_ABS" ]] || fail "APP_DATA_DIR must not be a symbolic link"
if [[ -e "$APP_DATA_DIR_ABS" && ! -d "$APP_DATA_DIR_ABS" ]]; then
  fail "APP_DATA_DIR must be a directory"
fi

mkdir -p -- "${APP_DATA_DIR_ABS}/uploads"
chmod 750 -- "$APP_DATA_DIR_ABS" "${APP_DATA_DIR_ABS}/uploads"