#!/bin/bash
set -Eeuo pipefail

ERROR_MSG=""
BACKUP_OK=0
DA_USER=""
DB_NAME=""
JOB_ID=""
LOG_FILE=""

JOB_FILE="${1:-}"
if [ -z "$JOB_FILE" ] || [ ! -f "$JOB_FILE" ]; then
  echo "mysql: missing job file" >&2
  exit 1
fi

PLUGIN_DIR="$(cd "$(dirname "$0")/.." && pwd)"
CONFIG_FILE="${PLUGIN_DIR}/plugin-settings.conf"
LOG_DIR="${PLUGIN_DIR}/data/logs"
COMMON_FILE="${PLUGIN_DIR}/scripts/setup/mysql_common.sh"
mkdir -p "$LOG_DIR"

urlencode() {
  local s="$1"
  local out=""
  local i c
  for ((i=0; i<${#s}; i++)); do
    c="${s:i:1}"
    case "$c" in
      [a-zA-Z0-9.~_-]) out+="$c" ;;
      ' ') out+='%20' ;;
      *) printf -v c '%%%02X' "'$c"; out+="$c" ;;
    esac
  done
  printf '%s' "$out"
}

notify_user() {
  local code="$1"
  if [ -z "${DA_USER:-}" ]; then
    return 0
  fi

  local subject message
  if [ "$code" -eq 0 ] && [ "$BACKUP_OK" -eq 1 ]; then
    subject="Backup bazy MySQL zakończony pomyślnie"
    message="Backup bazy ${DB_NAME} został wykonany. Plik: ${TARGET_FILE:-nieznany}."
  else
    subject="Błąd wykonywania backupu bazy MySQL"
    if [ -n "$ERROR_MSG" ]; then
      message="Backup bazy ${DB_NAME} nie powiódł się: ${ERROR_MSG}"
    else
      message="Backup bazy ${DB_NAME} nie powiódł się. Sprawdź log zadania."
    fi
  fi

  local task_queue="/usr/local/directadmin/data/task.queue"
  local users="select1%3D$(urlencode "$DA_USER")"
  local line="action=notify&value=users&subject=$(urlencode "$subject")&message=$(urlencode "$message")&users=${users}"
  printf "%s\n" "$line" >> "$task_queue"
}

fail() {
  local msg="$1"
  ERROR_MSG="$msg"
  if [ -n "${LOG_FILE:-}" ]; then
    echo "[$(date '+%Y-%m-%d %H:%M:%S')] ERROR: ${msg}" >> "$LOG_FILE"
  fi
}

log_unexpected_error() {
  local line_no="$1"
  local command="$2"
  local code="$3"
  if [ -z "${LOG_FILE:-}" ]; then
    return 0
  fi
  if [ -n "${ERROR_MSG:-}" ]; then
    return 0
  fi

  ERROR_MSG="Nieoczekiwany błąd wykonywania backupu (kod ${code}, linia ${line_no})."
  echo "[$(date '+%Y-%m-%d %H:%M:%S')] ERROR: ${ERROR_MSG} CMD: ${command}" >> "$LOG_FILE"
}

load_plugin_settings() {
  if [ ! -f "$CONFIG_FILE" ]; then
    fail "Brak pliku konfiguracyjnego pluginu: $CONFIG_FILE"
    exit 1
  fi
  # shellcheck disable=SC1090
  source "$CONFIG_FILE"
}

quote_sh_value() {
  local value="$1"
  value="${value//\'/\'\\\'\'}"
  printf "'%s'" "$value"
}

set_job_var() {
  local key="$1"
  local value="$2"
  local tmp
  local owner_group=""
  if [ -f "$JOB_FILE" ]; then
    owner_group="$(stat -c '%u:%g' "$JOB_FILE" 2>/dev/null || stat -f '%u:%g' "$JOB_FILE" 2>/dev/null || true)"
  fi
  tmp="$(mktemp)"
  grep -v "^${key}=" "$JOB_FILE" > "$tmp" 2>/dev/null || true
  printf "%s=%s\n" "$key" "$(quote_sh_value "$value")" >> "$tmp"
  mv "$tmp" "$JOB_FILE"
  chmod 600 "$JOB_FILE" 2>/dev/null || true
  if [ "$(id -u)" -eq 0 ] && [ -n "$owner_group" ]; then
    chown "$owner_group" "$JOB_FILE" 2>/dev/null || true
  fi
}

on_exit() {
  local code="$1"
  if [ "$code" -ne 0 ] && [ -z "${ERROR_MSG:-}" ] && [ -n "${LOG_FILE:-}" ]; then
    ERROR_MSG="Zadanie backupu zakończyło się błędem (kod ${code}) bez zarejestrowanego szczegółu."
    echo "[$(date '+%Y-%m-%d %H:%M:%S')] ERROR: ${ERROR_MSG}" >> "$LOG_FILE"
  fi
  notify_user "$code"
}
trap 'log_unexpected_error "$LINENO" "$BASH_COMMAND" "$?"' ERR
trap 'on_exit $?' EXIT

[ -f "$COMMON_FILE" ] || {
  echo "Brak helpera MySQL: $COMMON_FILE" >&2
  exit 1
}
# shellcheck disable=SC1090
source "$COMMON_FILE"

# shellcheck disable=SC1090
source "$JOB_FILE"

JOB_ID="${JOB_ID:-$(basename "$JOB_FILE" .env)}"
DA_USER="${DA_USER:-}"
DB_NAME="${DB_NAME:-}"
DATE_DIR="${DATE_DIR:-$(date +%Y-%m-%d)}"
COMPRESS_BACKUP="${COMPRESS_BACKUP:-1}"
USER_BASE_BACKUP_DIR="${USER_BASE_BACKUP_DIR:-/home/${DA_USER}/mysql_backup}"
JOB_COMPRESS_BACKUP="${COMPRESS_BACKUP}"
JOB_USER_BASE_BACKUP_DIR="${USER_BASE_BACKUP_DIR}"

LOG_FILE="${LOG_DIR}/${JOB_ID}.log"
echo "[$(date '+%Y-%m-%d %H:%M:%S')] Start backup job ${JOB_ID}" > "$LOG_FILE"

if [ -z "$DA_USER" ] || [ -z "$DB_NAME" ]; then
  fail "Brak DA_USER lub DB_NAME w pliku zadania."
  exit 1
fi

if [[ "$DB_NAME" != "${DA_USER}_"* ]]; then
  fail "Baza ${DB_NAME} nie należy do użytkownika ${DA_USER}."
  exit 1
fi

load_plugin_settings
COMPRESS_BACKUP="${JOB_COMPRESS_BACKUP:-$COMPRESS_BACKUP}"
USER_BASE_BACKUP_DIR="${JOB_USER_BASE_BACKUP_DIR:-$USER_BASE_BACKUP_DIR}"
mysql_load_alt_credentials
MYSQL_BIN="$(mysql_alt_binary mysql)" || {
  fail "Brak binarium mysql."
  exit 1
}
MYSQLDUMP_BIN="$(mysql_alt_binary mysqldump)" || {
  fail "Brak binarium mysqldump."
  exit 1
}
mapfile -t MYSQL_ARGS < <(mysql_base_args)

if [[ "$COMPRESS_BACKUP" =~ ^(true|yes|on)$ ]]; then
  COMPRESS_BACKUP="1"
fi
if [[ "$COMPRESS_BACKUP" =~ ^(false|no|off)$ ]]; then
  COMPRESS_BACKUP="0"
fi

TARGET_DIR="${USER_BASE_BACKUP_DIR%/}/${DATE_DIR}"
mkdir -p "$TARGET_DIR"
chmod 700 "$TARGET_DIR" 2>/dev/null || true

if [ "$COMPRESS_BACKUP" = "1" ]; then
  TARGET_FILE="${TARGET_DIR}/${DB_NAME}.sql.gz"
else
  TARGET_FILE="${TARGET_DIR}/${DB_NAME}.sql"
fi
TMP_FILE="${TARGET_FILE}.tmp.$$"

echo "[$(date '+%Y-%m-%d %H:%M:%S')] Backup source DB: ${DB_NAME}" >> "$LOG_FILE"
echo "[$(date '+%Y-%m-%d %H:%M:%S')] Backup target file: ${TARGET_FILE}" >> "$LOG_FILE"

set +e
if [ "$COMPRESS_BACKUP" = "1" ]; then
  MYSQL_PWD="$MYSQL_PASSWORD" "$MYSQLDUMP_BIN" \
    "${MYSQL_ARGS[@]}" \
    --single-transaction \
    --quick \
    --skip-lock-tables \
    --routines \
    --triggers \
    --events \
    --default-character-set=utf8mb4 \
    "$DB_NAME" 2>>"$LOG_FILE" | gzip -c > "$TMP_FILE"
  RC=${PIPESTATUS[0]}
else
  MYSQL_PWD="$MYSQL_PASSWORD" "$MYSQLDUMP_BIN" \
    "${MYSQL_ARGS[@]}" \
    --single-transaction \
    --quick \
    --skip-lock-tables \
    --routines \
    --triggers \
    --events \
    --default-character-set=utf8mb4 \
    "$DB_NAME" > "$TMP_FILE" 2>>"$LOG_FILE"
  RC=$?
fi
set -e

if [ "$RC" -ne 0 ]; then
  rm -f "$TMP_FILE"
  fail "mysqldump zakończył się błędem dla bazy ${DB_NAME}."
  exit 1
fi

mv "$TMP_FILE" "$TARGET_FILE"
chmod 600 "$TARGET_FILE" 2>/dev/null || true
set_job_var "TARGET_FILE" "$TARGET_FILE"
set_job_var "END_TS" "$(date +%s)"

echo "[$(date '+%Y-%m-%d %H:%M:%S')] Backup completed successfully." >> "$LOG_FILE"
BACKUP_OK=1
exit 0