Migrate.hpp

// SPDX-License-Identifier: Apache-2.0
 
#pragma once
 
#include "Core.hpp"
#include "MigrationPlan.hpp"
 
#include <reflection-cpp/reflection.hpp>
 
namespace Lightweight
{
 
/// @brief Query builder for building CREATE TABLE queries.
///
/// @see SqlQueryBuilder
/// @ingroup QueryBuilder
class [[nodiscard]] SqlCreateTableQueryBuilder final
{
  public:
    explicit SqlCreateTableQueryBuilder(SqlCreateTablePlan& plan):
        _plan { plan }
    {
    }
 
    /// Adds a new column to the table.
    LIGHTWEIGHT_API SqlCreateTableQueryBuilder& Column(SqlColumnDeclaration column);
 
    /// Creates a new nullable column.
    LIGHTWEIGHT_API SqlCreateTableQueryBuilder& Column(std::string columnName, SqlColumnTypeDefinition columnType);
 
    /// Creates a new column that is non-nullable.
    LIGHTWEIGHT_API SqlCreateTableQueryBuilder& RequiredColumn(std::string columnName, SqlColumnTypeDefinition columnType);
 
    /// Adds the created_at and updated_at columns to the table.
    LIGHTWEIGHT_API SqlCreateTableQueryBuilder& Timestamps();
 
    /// Creates a new primary key column.
    /// Primary keys are always required, unique, have an index, and are non-nullable.
    LIGHTWEIGHT_API SqlCreateTableQueryBuilder& PrimaryKey(std::string columnName, SqlColumnTypeDefinition columnType);
 
    LIGHTWEIGHT_API SqlCreateTableQueryBuilder& PrimaryKeyWithAutoIncrement(
        std::string columnName, SqlColumnTypeDefinition columnType = SqlColumnTypeDefinitions::Bigint {});
 
    /// Creates a new nullable foreign key column.
    LIGHTWEIGHT_API SqlCreateTableQueryBuilder& ForeignKey(std::string columnName,
                                                           SqlColumnTypeDefinition columnType,
                                                           SqlForeignKeyReferenceDefinition foreignKey);
 
    /// Creates a new non-nullable foreign key column.
    LIGHTWEIGHT_API SqlCreateTableQueryBuilder& RequiredForeignKey(std::string columnName,
                                                                   SqlColumnTypeDefinition columnType,
                                                                   SqlForeignKeyReferenceDefinition foreignKey);
 
    /// Enables the UNIQUE constraint on the last declared column.
    LIGHTWEIGHT_API SqlCreateTableQueryBuilder& Unique();
 
    /// Enables the INDEX constraint on the last declared column.
    LIGHTWEIGHT_API SqlCreateTableQueryBuilder& Index();
 
    /// Enables the UNIQUE and INDEX constraint on the last declared column and makes it an index.
    LIGHTWEIGHT_API SqlCreateTableQueryBuilder& UniqueIndex();
 
  private:
    SqlCreateTablePlan& _plan;
};
 
/// @brief Query builder for building ALTER TABLE queries.
///
/// @see SqlQueryBuilder
/// @ingroup QueryBuilder
class [[nodiscard]] SqlAlterTableQueryBuilder final
{
  public:
    explicit SqlAlterTableQueryBuilder(SqlAlterTablePlan& plan):
        _plan { plan }
    {
    }
 
    /// Renames the table.
    LIGHTWEIGHT_API SqlAlterTableQueryBuilder& RenameTo(std::string_view newTableName);
 
    /// Adds a new column to the table that is non-nullable.
    LIGHTWEIGHT_API SqlAlterTableQueryBuilder& AddColumn(std::string columnName, SqlColumnTypeDefinition columnType);
 
    /// Adds a new column to the table that is nullable.
    LIGHTWEIGHT_API SqlAlterTableQueryBuilder& AddNotRequiredColumn(std::string columnName,
                                                                    SqlColumnTypeDefinition columnType);
 
    /// @brief Alters the column to have a new non-nullable type.
    ///
    /// @param columnName The name of the column to alter.
    /// @param columnType The new type of the column.
    /// @param nullable The new nullable state of the column.
    ///
    /// @return The current query builder for chaining.
    ///
    /// @see SqlColumnTypeDefinition
    ///
    /// @code
    /// auto stmt = SqlStatement();
    /// auto sqlMigration = stmt.Migration()
    ///                         .AlterTable("Table")
    ///                         .AlterColumn("column", Integer {}, SqlNullable::NotNull)
    ///                         .GetPlan().ToSql();
    /// for (auto const& sql: sqlMigration)
    ///     stmt.ExecuteDirect(sql);
    /// @endcode
    LIGHTWEIGHT_API SqlAlterTableQueryBuilder& AlterColumn(std::string columnName,
                                                           SqlColumnTypeDefinition columnType,
                                                           SqlNullable nullable);
 
    /// Renames a column.
    /// @param oldColumnName The old column name.
    /// @param newColumnName The new column name.
    LIGHTWEIGHT_API SqlAlterTableQueryBuilder& RenameColumn(std::string_view oldColumnName, std::string_view newColumnName);
 
    /// Drops a column from the table.
    /// @param columnName The name of the column to drop.
    LIGHTWEIGHT_API SqlAlterTableQueryBuilder& DropColumn(std::string_view columnName);
 
    /// Add an index to the table for the specified column.
    /// @param columnName The name of the column to index.
    ///
    /// @code
    /// SqlQueryBuilder q;
    /// q.Migration().AlterTable("Table").AddIndex("column");
    /// // Will execute CREATE INDEX "Table_column_index" ON "Table"("column");
    /// @endcode
    LIGHTWEIGHT_API SqlAlterTableQueryBuilder& AddIndex(std::string_view columnName);
 
    /// Add an index to the table for the specified column that is unique.
    /// @param columnName The name of the column to index.
    ///
    /// @code
    /// SqlQueryBuilder q;
    /// q.Migration().AlterTable("Table").AddUniqueIndex("column");
    /// // Will execute CREATE UNIQUE INDEX "Table_column_index" ON "Table"("column");
    /// @endcode
    LIGHTWEIGHT_API SqlAlterTableQueryBuilder& AddUniqueIndex(std::string_view columnName);
 
    /// Drop an index from the table for the specified column.
    /// @param columnName The name of the column to drop the index from.
    ///
    /// @code
    /// SqlQueryBuilder q;
    /// q.Migration().AlterTable("Table").DropIndex("column");
    /// // Will execute DROP INDEX "Table_column_index";
    /// @endcode
    LIGHTWEIGHT_API SqlAlterTableQueryBuilder& DropIndex(std::string_view columnName);
 
    /// Adds a foreign key column @p columnName to @p referencedColumn to an existing column.
    ///
    /// @param columnName The name of the column to add.
    /// @param referencedColumn The column to reference.
    LIGHTWEIGHT_API SqlAlterTableQueryBuilder& AddForeignKey(std::string columnName,
                                                             SqlForeignKeyReferenceDefinition referencedColumn);
 
    /// Adds a foreign key column @p columnName of type @p columnType to @p referencedColumn.
    ///
    /// @param columnName The name of the column to add.
    /// @param columnType The type of the column to add.
    /// @param referencedColumn The column to reference.
    LIGHTWEIGHT_API SqlAlterTableQueryBuilder& AddForeignKeyColumn(std::string columnName,
                                                                   SqlColumnTypeDefinition columnType,
                                                                   SqlForeignKeyReferenceDefinition referencedColumn);
 
    /// Adds a nullable foreign key column @p columnName of type @p columnType to @p referencedColumn.
    ///
    /// @param columnName The name of the column to add.
    /// @param columnType The type of the column to add.
    /// @param referencedColumn The column to reference.
    LIGHTWEIGHT_API SqlAlterTableQueryBuilder& AddNotRequiredForeignKeyColumn(
        std::string columnName, SqlColumnTypeDefinition columnType, SqlForeignKeyReferenceDefinition referencedColumn);
 
    /// Drops a foreign key for the column @p columnName from the table.
    LIGHTWEIGHT_API SqlAlterTableQueryBuilder& DropForeignKey(std::string columnName);
 
  private:
    SqlAlterTablePlan& _plan;
};
 
/// @brief Query builder for building SQL migration queries.
/// @ingroup QueryBuilder
class [[nodiscard]] SqlMigrationQueryBuilder final
{
  public:
    explicit SqlMigrationQueryBuilder(SqlQueryFormatter const& formatter):
        _formatter { formatter },
        _migrationPlan { .formatter = formatter }
    {
    }
 
    /// Creates a new database.
    LIGHTWEIGHT_API SqlMigrationQueryBuilder& CreateDatabase(std::string_view databaseName);
 
    /// Drops a database.
    LIGHTWEIGHT_API SqlMigrationQueryBuilder& DropDatabase(std::string_view databaseName);
 
    /// Creates a new table.
    LIGHTWEIGHT_API SqlCreateTableQueryBuilder CreateTable(std::string_view tableName);
 
    /// Alters an existing table.
    LIGHTWEIGHT_API SqlAlterTableQueryBuilder AlterTable(std::string_view tableName);
 
    /// Drops a table.
    LIGHTWEIGHT_API SqlMigrationQueryBuilder& DropTable(std::string_view tableName);
 
    /// Executes raw SQL.
    LIGHTWEIGHT_API SqlMigrationQueryBuilder& RawSql(std::string_view sql);
 
    /// Executes SQL interactively via a callback.
    LIGHTWEIGHT_API SqlMigrationQueryBuilder& Native(std::function<std::string(SqlConnection&)> callback);
 
    /// Starts a transaction.
    LIGHTWEIGHT_API SqlMigrationQueryBuilder& BeginTransaction();
 
    /// Commits a transaction.
    LIGHTWEIGHT_API SqlMigrationQueryBuilder& CommitTransaction();
 
    /// Gets the migration plan.
    [[nodiscard]] LIGHTWEIGHT_API SqlMigrationPlan const& GetPlan() const&;
 
    /// Gets the migration plan.
    ///
    /// @note This method is destructive and will invalidate the current builder.
    LIGHTWEIGHT_API SqlMigrationPlan GetPlan() &&;
 
  private:
    SqlQueryFormatter const& _formatter;
    SqlMigrationPlan _migrationPlan;
};
 
} // namespace Lightweight