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

script_dir="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
repo_root="$(cd "${script_dir}/.." && pwd)"

env_file="${repo_root}/.env.devprod"
ram_gb_override=""
apply_changes="0"
force_overwrite="0"
print_json="0"

usage() {
  cat <<'USAGE'
Usage: ./scripts/evaluate-set-size-defaults.sh [options]

Recommend Docker/Nextcloud publish-size defaults based on host RAM and,
optionally, write them into the env file.

This script targets the current repo's Apache-based Nextcloud image
(`nextcloud:34-apache`). It does not tune PHP-FPM pool.d because this stack
does not use PHP-FPM by default.

Options:
  --env-file <path>     Env file to inspect/update (default: .env.devprod)
  --ram-gb <number>     Override detected host RAM in GiB for evaluation
  --apply               Write recommended values into the env file
  --force               Overwrite existing values when used with --apply
  --json                Print recommendations as JSON
  -h, --help            Show this help
USAGE
}

while [[ $# -gt 0 ]]; do
  case "$1" in
    --env-file)
      env_file="${2:-}"
      shift 2
      ;;
    --env-file=*)
      env_file="${1#*=}"
      shift
      ;;
    --ram-gb)
      ram_gb_override="${2:-}"
      shift 2
      ;;
    --ram-gb=*)
      ram_gb_override="${1#*=}"
      shift
      ;;
    --apply)
      apply_changes="1"
      shift
      ;;
    --force)
      force_overwrite="1"
      shift
      ;;
    --json)
      print_json="1"
      shift
      ;;
    -h|--help)
      usage
      exit 0
      ;;
    *)
      echo "Unknown option: $1"
      usage
      exit 1
      ;;
  esac
done

if [[ "${env_file}" != /* ]]; then
  env_file="${repo_root}/${env_file}"
fi

if [[ ! -f "${env_file}" ]]; then
  echo "Missing env file: ${env_file}"
  exit 1
fi

read_kv() {
  local key="$1"
  local line
  line="$(grep -m1 -E "^${key}=" "${env_file}" || true)"
  if [[ -z "${line}" ]]; then
    return 1
  fi
  echo "${line#*=}"
}

set_kv() {
  local key="$1"
  local value="$2"
  local esc
  esc="${value//\\/\\\\}"
  esc="${esc//&/\\&}"
  esc="${esc//|/\\|}"
  if grep -q "^${key}=" "${env_file}"; then
    sed -i -E "s|^${key}=.*|${key}=${esc}|" "${env_file}"
  else
    printf '%s=%s\n' "${key}" "${value}" >> "${env_file}"
  fi
}

detect_ram_gb() {
  if [[ -n "${ram_gb_override}" ]]; then
    printf '%s\n' "${ram_gb_override}"
    return 0
  fi
  if [[ -r /proc/meminfo ]]; then
    local mem_kib
    mem_kib="$(awk '/^MemTotal:/ { print $2 }' /proc/meminfo)"
    if [[ -n "${mem_kib}" ]]; then
      awk -v kib="${mem_kib}" 'BEGIN { printf "%.1f\n", kib / 1024 / 1024 }'
      return 0
    fi
  fi
  echo "0"
}

format_one_decimal() {
  awk -v value="${1:-0}" 'BEGIN { printf "%.1f", value }'
}

recommend_for_ram_gb() {
  local ram_gb="$1"
  if awk -v n="${ram_gb}" 'BEGIN { exit !(n < 8) }'; then
    echo "32mb|5G|5G|512M|blank"
    return 0
  fi
  if awk -v n="${ram_gb}" 'BEGIN { exit !(n < 16) }'; then
    echo "64mb|5G|5G|768M|blank"
    return 0
  fi
  if awk -v n="${ram_gb}" 'BEGIN { exit !(n < 32) }'; then
    echo "128mb|5G|5G|1024M|blank"
    return 0
  fi
  if awk -v n="${ram_gb}" 'BEGIN { exit !(n < 64) }'; then
    echo "192mb|5G|5G|1536M|blank"
    return 0
  fi
  echo "256mb|5G|5G|2048M|blank"
}

should_write_key() {
  local key="$1"
  local current_value
  current_value="$(read_kv "${key}" || true)"
  if [[ "${force_overwrite}" == "1" ]]; then
    return 0
  fi
  [[ -z "${current_value}" ]]
}

ram_gb_detected="$(detect_ram_gb)"
if ! [[ "${ram_gb_detected}" =~ ^[0-9]+([.][0-9]+)?$ ]]; then
  echo "Could not determine RAM in GiB."
  exit 1
fi

IFS='|' read -r broker_limit upload_limit post_limit php_memory_limit publish_limit_mode <<<"$(recommend_for_ram_gb "${ram_gb_detected}")"

nextcloud_image="$(read_kv "NEXTCLOUD_IMAGE" || true)"
nextcloud_image="${nextcloud_image:-nextcloud:34-apache}"

if [[ "${print_json}" == "1" ]]; then
  printf '{\n'
  printf '  "envFile": "%s",\n' "${env_file}"
  printf '  "detectedRamGiB": %s,\n' "$(format_one_decimal "${ram_gb_detected}")"
  printf '  "nextcloudImage": "%s",\n' "${nextcloud_image}"
  printf '  "phpRuntimeModel": "apache_mod_php",\n'
  printf '  "recommendations": {\n'
  printf '    "BROKER_REQUEST_BODY_LIMIT": "%s",\n' "${broker_limit}"
  printf '    "NEXTCLOUD_PHP_UPLOAD_MAX_FILESIZE": "%s",\n' "${upload_limit}"
  printf '    "NEXTCLOUD_PHP_POST_MAX_SIZE": "%s",\n' "${post_limit}"
  printf '    "NEXTCLOUD_PHP_MEMORY_LIMIT": "%s",\n' "${php_memory_limit}"
  printf '    "QORTAL_FILES_PUBLISH_MAX_SIZE": ""\n'
  printf '  },\n'
  printf '  "notes": [\n'
  printf '    "This stack uses nextcloud:34-apache by default, so PHP-FPM pool.d tuning does not apply.",\n'
  printf '    "Nextcloud PHP upload/post limits are intentionally decoupled from QDN publish limits and default to 5G.",\n'
  printf '    "QORTAL_FILES_PUBLISH_MAX_SIZE is intentionally left blank so publish limits stay broker-oriented unless explicitly overridden.",\n'
  printf '    "For a VM with about 30 GiB RAM, the recommended profile is 128mb broker body limit, 5G PHP upload/post, and 1024M PHP memory."\n'
  printf '  ]\n'
  printf '}\n'
  exit 0
fi

echo "Size default evaluation"
echo "  Env file: ${env_file}"
echo "  Detected RAM: $(format_one_decimal "${ram_gb_detected}") GiB"
echo "  Nextcloud image: ${nextcloud_image}"
echo "  PHP runtime model: Apache mod_php"
echo
echo "Recommended values"
echo "  BROKER_REQUEST_BODY_LIMIT=${broker_limit}"
echo "  NEXTCLOUD_PHP_UPLOAD_MAX_FILESIZE=${upload_limit}"
echo "  NEXTCLOUD_PHP_POST_MAX_SIZE=${post_limit}"
echo "  NEXTCLOUD_PHP_MEMORY_LIMIT=${php_memory_limit}"
echo "  QORTAL_FILES_PUBLISH_MAX_SIZE="
echo
echo "Notes"
echo "  - This stack is Apache-based, so PHP-FPM pool.d tuning does not apply."
echo "  - Nextcloud PHP upload/post limits are intentionally decoupled from QDN publish limits and default to 5G."
echo "  - Leaving QORTAL_FILES_PUBLISH_MAX_SIZE blank keeps publish size broker-oriented unless explicitly overridden."
echo "  - For a VM with about 30 GiB RAM, the recommended profile is 128mb broker body limit, 5G PHP upload/post, and 1024M PHP memory."

if [[ "${apply_changes}" != "1" ]]; then
  echo
  echo "Dry run only. Re-run with --apply to write missing values."
  echo "Use --force with --apply if you want to overwrite existing values."
  exit 0
fi

changed_keys=()
skipped_keys=()

for pair in \
  "BROKER_REQUEST_BODY_LIMIT=${broker_limit}" \
  "NEXTCLOUD_PHP_UPLOAD_MAX_FILESIZE=${upload_limit}" \
  "NEXTCLOUD_PHP_POST_MAX_SIZE=${post_limit}" \
  "NEXTCLOUD_PHP_MEMORY_LIMIT=${php_memory_limit}"
do
  key="${pair%%=*}"
  value="${pair#*=}"
  if should_write_key "${key}"; then
    set_kv "${key}" "${value}"
    changed_keys+=("${key}")
  else
    skipped_keys+=("${key}")
  fi
done

if should_write_key "QORTAL_FILES_PUBLISH_MAX_SIZE"; then
  set_kv "QORTAL_FILES_PUBLISH_MAX_SIZE" ""
  changed_keys+=("QORTAL_FILES_PUBLISH_MAX_SIZE")
else
  skipped_keys+=("QORTAL_FILES_PUBLISH_MAX_SIZE")
fi

echo
if [[ "${#changed_keys[@]}" -gt 0 ]]; then
  echo "Updated ${env_file}:"
  printf '  %s\n' "${changed_keys[@]}"
else
  echo "No env values were changed."
fi

if [[ "${#skipped_keys[@]}" -gt 0 ]]; then
  echo "Skipped existing keys:"
  printf '  %s\n' "${skipped_keys[@]}"
fi