database

type Client interface {
	// Dialect reports the SQL dialect this client speaks.
	//
	// It is on the client because the two always travel together: every package in
	// this module that emits SQL holds a Client and a dialect.Dialect side by side,
	// and nothing previously stopped the pair disagreeing — a caller could hand
	// dialect.MySQL to a store backed by a Postgres client and get syntactically
	// valid SQL that the server rejects at runtime. Sourcing the dialect from the
	// client makes that mismatch unrepresentable rather than merely unlikely.
	Dialect() dialect.Dialect
	// Reader returns an executor for the read database. It exposes no transaction
	// control by design; use WithTransaction for anything transactional.
	Reader() SQLQueryExecutor
	// Writer returns an executor for the write database, for single, non-transactional
	// statements. Multi-statement work belongs in WithTransaction.
	Writer() SQLQueryExecutor
	// WithTransaction begins a transaction on the write database, invokes fn with it as
	// the sole executor, commits on a nil return, and rolls back on error or panic.
	//
	// fn receives only an executor, not the transaction handle: it cannot commit or
	// roll back. Returning an error (or panicking) is the sole way to abort, and drives
	// exactly one rollback — so fn can't roll back and then also return an error, which
	// would otherwise trigger a redundant second rollback.
	WithTransaction(ctx context.Context, fn func(querier SQLQueryExecutor) error) error
	Close() error
	CurrentTime() time.Time
}

type ClientConfig interface {
	GetReadConnectionString() string
	GetWriteConnectionString() string
	GetMaxPingAttempts() uint64
	GetPingWaitPeriod() time.Duration
	GetMaxIdleConns() int
	GetMaxOpenConns() int
	GetConnMaxLifetime() time.Duration
}

type Manager interface {
	CreateUser(ctx context.Context, username, password string) error
	DeleteUser(ctx context.Context, username string) error

	CreateDatabase(ctx context.Context, dbName, owner string) error
	DeleteDatabase(ctx context.Context, dbName string) error

	UserExists(ctx context.Context, username string) (bool, error)
	DatabaseExists(ctx context.Context, dbName string) (bool, error)

	GrantUserAccessToTable(ctx context.Context, username, schema, table, privilege string) error
	UserCanAccessDatabase(ctx context.Context, username, dbName string) (bool, error)
}

type Migrator interface {
	Migrate(ctx context.Context, db *sql.DB) error
}

type RawAccess interface {
	ReadDB() *sql.DB
	WriteDB() *sql.DB
}

type ResultIterator interface {
	Next() bool
	Err() error
	Scanner
	io.Closer
}

type SQLQueryExecutor interface {
	ExecContext(ctx context.Context, query string, args ...any) (sql.Result, error)
	PrepareContext(context.Context, string) (*sql.Stmt, error)
	QueryContext(ctx context.Context, query string, args ...any) (*sql.Rows, error)
	QueryRowContext(ctx context.Context, query string, args ...any) *sql.Row
}

type SQLQueryExecutorAndTransactionManager interface {
	SQLQueryExecutor
	SQLTransactionManager
}

type SQLTransactionManager interface {
	Rollback() error
}

type Scanner interface {
	Scan(dest ...any) error
}