#include "execute_sql_file.h"

#include <QRegularExpression>

ExecuteSqlFile::ExecuteSqlFile(QSqlDatabase &db)
    : db_(db), delimiter_(";") { // Default delimiter is ";"
  // Constructor does not open/close the connection
}

bool ExecuteSqlFile::operator()(const QString &filePath) {
  // Ensure the database connection is open
  if (!db_.isOpen()) {
    qWarning() << "Database connection is not open";
    return false;
  }

  QFile file(filePath);
  if (!file.open(QIODevice::ReadOnly | QIODevice::Text)) {
    qWarning() << "Failed to open file:" << filePath;
    return false;
  }

  QTextStream in(&file);
  QString sqlContent = in.readAll();
  file.close();

  QStringList statements = sqlContent.split("\n", Qt::SkipEmptyParts);

  qInfo() << "Executing SQL file:" << filePath;

  return processStatements(statements);
}

bool ExecuteSqlFile::processStatements(QStringList &statements) {
  QString currentStatement;

  for (QString &line : statements) {
    qInfo() << "Processing line:" << line;
    if (!processLine(line, currentStatement)) {
      return false;
    }
  }

  // Execute any remaining statement
  if (!currentStatement.isEmpty() && !executeStatement(currentStatement)) {
    return false;
  }

  return true;
}

bool ExecuteSqlFile::processLine(QString &line, QString &currentStatement) {
  if (!filterLine(line)) {
    qInfo() << "Line is empty after filtering";
    return true; // Line was empty after filtering
  }

  if (processDelimiterChange(line)) {
    qInfo() << "Delimiter changed to:" << delimiter_;
    return true;
  }

  currentStatement += line + " ";

  auto delimiterIndex = currentStatement.lastIndexOf(delimiter_);
  if (delimiterIndex == -1) {
    qInfo() << "Delimiter not found, current statement is not finished";
    return true;
  }
  qInfo() << "Statement finished, delimiter found at index:" << delimiterIndex;

  // Execute the current statement
  QString completedStatement =
      currentStatement.replace(delimiter_, ";").trimmed();
  if (!executeStatement(completedStatement)) {
    qWarning() << "Failed to execute statement:" << completedStatement;
    return false; // Execution failed
  }
  qInfo() << "Successfully executed statement:" << completedStatement;

  currentStatement.clear();

  return true;
}

bool ExecuteSqlFile::processDelimiterChange(QString &line) {
  QRegularExpression regex(R"(^DELIMITER\s+(\S+))");
  QRegularExpressionMatch match = regex.match(line);
  if (!match.hasMatch()) {
    return false;
  }
  delimiter_ = match.captured(1); // Update the delimiter_
  return true;
}

bool ExecuteSqlFile::filterLine(QString &line) {
  line = line.section("--", 0, 0).trimmed(); // Remove comments and trim
  return !line.isEmpty();                    // Return true if line is not empty
}

bool ExecuteSqlFile::executeStatement(const QString &statement) const {
  QSqlQuery query(db_);
  if (!query.exec(statement)) {
    qWarning() << "Error:" << query.lastError().text();
    return false;
  }
  return true;
}