package sqlx

import (
	"context"
	"database/sql"
)

// Tx is an in-progress database transaction.
type Tx struct {
	raw *sql.Tx
	ctx context.Context
}

// Stmt creates a prepared statement for later queries or executions.
func (tx *Tx) Stmt(cmd string) *Stmt {
	stmt := &Stmt{ctx: tx.ctx}
	stmt.raw, stmt.err = tx.raw.PrepareContext(tx.ctx, cmd)
	if stmt.err == nil {
		names := regexpParam.FindAllString(cmd, -1)
		stmt.nargs = make(map[string]any, len(names))
		for _, name := range names {
			stmt.nargs[name[1:]] = nil
		}
	}
	return stmt
}

// Rollback aborts the transaction.
func (tx *Tx) Rollback() (err error) {
	if tx.raw == nil {
		err = sql.ErrTxDone
	} else if err = tx.raw.Rollback(); err == nil {
		tx.raw = nil
	}
	return
}

// Commit commits the transaction.
func (tx *Tx) Commit() (err error) {
	if tx.raw == nil {
		err = sql.ErrTxDone
	} else if err = tx.raw.Commit(); err == nil {
		tx.raw = nil
	}
	return
}