<?php

$host = "localhost";
$user = "_";
$password = "_";
$database = "_";

$red = "\033[0;31m";
$green = "\033[0;32m";
$nc = "\033[0m";

$db = new mysqli($host, $user, $password, $database);

if ($db->connect_errno) {
    exit("ERROR can't connect to DB: (" . $db->connect_errno . ") " . $db->connect_error . "\n");
}

$db_version = 0;

$db_version_key = "db-version";
$check_version_sql = "select o_val from options where o_key='$db_version_key'";

$result = $db->query($check_version_sql);

if ($result->num_rows === 0) {
  echo "Initializing db-version option...\n\n";
  $insert_default_version_sql = "insert into options (o_key, o_val) values ('$db_version_key', '0')";
  if (!$db->query($insert_default_version_sql)) {
    exit("ERROR: can't initialize db-version option\n");
  }
}
elseif ($result->num_rows === 1) {
  $row = $result->fetch_assoc();
  $db_version = intval($row['o_val']);
  echo "DB version: $db_version\n";
}
else {
  exit("ERROR: db-version option is duplicated");
}

$result->free();

$scripts = explode("\n", `ls updates`);
$count = 0;
$new_version = $db_version;

function filter_output($msg) {
  $w = "mysql: [Warning] Using a password";
  $length = strlen($w);
  return (substr($msg, 0, $length) !== $w);
}

foreach ($scripts as $script) {
  $parts = explode(".", $script);
  if (count($parts) > 2 && end($parts) == "sql") {
    $script_version = intval($parts[0]);
    if ($script_version > 0 && $script_version > $db_version){
      echo "{$green}executing script $script ...$nc \n";

      $cmd = "mysql --user=$user --password=$password $database < updates/$script 2>&1";
      $output = array();
      $error_code = 0;
      exec($cmd, $output, $error_code);
      echo join("\n", array_filter($output, "filter_output")) . "\n\n";
      if ($error_code != 0) {
        exit("{$red}Something went wrong during script $script execution...\nFix the script and run DB update again.\n");
      }

      $update_version_sql = "update options set o_val = $script_version where o_key='$db_version_key'";
      if(!$db->query($update_version_sql)) {
        exit("ERROR: can't set new version in options\n");
      };
      $count++;
      $new_version = $script_version;
    }
  }
}

echo $count === 0 ?
  "{$green}Well... nothing to do here...{$nc}\n" :
  "{$green}$count updates applied\nDB $database was upgraded to version: $new_version{$nc}\n";

$db->close();

?>