// Copyright (C) 2019 Storj Labs, Inc.
// See LICENSE for copying information.

package satellitedb

import (
	"context"
	"fmt"

	"github.com/zeebo/errs"
)

//go:generate dbx.v1 schema -d postgres -d sqlite3 satellitedb.dbx .
//go:generate dbx.v1 golang -d postgres -d sqlite3 satellitedb.dbx .

func init() {
	// catch dbx errors
	class := errs.Class("satellitedb")
	WrapErr = func(e *Error) error {
		switch e.Code {
		case ErrorCode_NoRows:
			return e.Err
		case ErrorCode_ConstraintViolation:
			return class.Wrap(&constraintError{e.Constraint, e.Err})
		}
		return class.Wrap(e)
	}
}

// Unwrap returns the underlying error.
func (e *Error) Unwrap() error { return e.Err }

// Cause returns the underlying error.
func (e *Error) Cause() error { return e.Err }

type constraintError struct {
	constraint string
	err        error
}

// Unwrap returns the underlying error.
func (err *constraintError) Unwrap() error { return err.err }

// Cause returns the underlying error.
func (err *constraintError) Cause() error { return err.err }

// Error implements the error interface.
func (err *constraintError) Error() string {
	return fmt.Sprintf("violates constraint %q: %v", err.constraint, err.err)
}

// WithTx wraps DB code in a transaction
func (db *DB) WithTx(ctx context.Context, fn func(context.Context, *Tx) error) (err error) {
	tx, err := db.Open(ctx)
	if err != nil {
		return err
	}
	defer func() {
		if err == nil {
			err = tx.Commit()
		} else {
			err = errs.Combine(err, tx.Rollback())
		}
	}()
	return fn(ctx, tx)
}