github.com/bingoohuang/gg@v0.0.0-20240325092523-45da7dee9335/pkg/sqx/daoopt.go

package sqx

import (
	"context"
	"database/sql"
	"fmt"
	"reflect"

	"github.com/bingoohuang/gg/pkg/defaults"
	"github.com/bingoohuang/gg/pkg/reflector"
)

// CreateDaoOpt defines the options for CreateDao.
type CreateDaoOpt struct {
	Error              *error
	Ctx                context.Context
	QueryMaxRows       int `default:"-1"`
	RowScanInterceptor RowScanInterceptor
	DotSQL             func(name string) (SQLPart, error)
	Logger             DaoLogger
	ErrSetter          func(err error)
	DBGetter           DBGetter
}

// CreateDaoOpter defines the option pattern interface for CreateDaoOpt.
type CreateDaoOpter interface {
	ApplyCreateOpt(*CreateDaoOpt)
}

// CreateDaoOptFn defines the func prototype to option applying.
type CreateDaoOptFn func(*CreateDaoOpt)

// ApplyCreateOpt applies the option.
func (c CreateDaoOptFn) ApplyCreateOpt(opt *CreateDaoOpt) { c(opt) }

// WithError specifies the err pointer to receive error.
func WithError(err *error) CreateDaoOpter {
	return CreateDaoOptFn(func(opt *CreateDaoOpt) { opt.Error = err })
}

// WithCtx specifies the context.Context to sdb execution processes.
func WithCtx(ctx context.Context) CreateDaoOpter {
	return CreateDaoOptFn(func(opt *CreateDaoOpt) { opt.Ctx = ctx })
}

// WithLimit specifies the max rows to be fetched when execute query.
func WithLimit(maxRows int) CreateDaoOpter {
	return CreateDaoOptFn(func(opt *CreateDaoOpt) { opt.QueryMaxRows = maxRows })
}

// WithSQLFile imports SQL queries from the file.
func WithSQLFile(sqlFile string) CreateDaoOpter {
	return CreateDaoOptFn(func(opt *CreateDaoOpt) {
		ds, err := DotSQLLoadFile(sqlFile)
		if err != nil {
			panic(err)
		}

		opt.DotSQL = ds.Raw
	})
}

// WithDB imports a db.
func WithDB(db *sql.DB) CreateDaoOpter {
	return CreateDaoOptFn(func(opt *CreateDaoOpt) { opt.DBGetter = &StdDB{db: db} })
}

// WithSQLStr imports SQL queries from the string.
func WithSQLStr(s string) CreateDaoOpter {
	return CreateDaoOptFn(func(opt *CreateDaoOpt) {
		ds, err := DotSQLLoadString(s)
		if err != nil {
			panic(err)
		}

		opt.DotSQL = ds.Raw
	})
}

// WithRowScanInterceptor specifies the RowScanInterceptor after a row fetched.
func WithRowScanInterceptor(interceptor RowScanInterceptor) CreateDaoOpter {
	return CreateDaoOptFn(func(opt *CreateDaoOpt) { opt.RowScanInterceptor = interceptor })
}

// RowScanInterceptor defines the interceptor after a row scanning.
type RowScanInterceptor interface {
	After(rowIndex int, v ...interface{}) (bool, error)
}

// RowScanInterceptorFn defines the interceptor function after a row scanning.
type RowScanInterceptorFn func(rowIndex int, v ...interface{}) (bool, error)

// After is revoked after a row scanning.
func (r RowScanInterceptorFn) After(rowIndex int, v ...interface{}) (bool, error) {
	return r(rowIndex, v...)
}

func applyCreateDaoOption(createDaoOpts []CreateDaoOpter) (*CreateDaoOpt, error) {
	opt := &CreateDaoOpt{}
	if err := defaults.Set(opt); err != nil {
		return nil, fmt.Errorf("failed to set defaults for CreateDaoOpt error %w", err)
	}

	for _, v := range createDaoOpts {
		v.ApplyCreateOpt(opt)
	}

	if opt.Ctx == nil {
		opt.Ctx = context.Background()
	}

	if opt.DotSQL == nil {
		opt.DotSQL = func(string) (SQLPart, error) { return nil, nil }
	}

	return opt, nil
}

func createErrorSetter(v reflect.Value, option *CreateDaoOpt) {
	for i := 0; i < v.NumField(); i++ {
		fv := v.Field(i)
		f := v.Type().Field(i)

		if f.PkgPath != "" /* not exportable? */ {
			continue
		}

		if !reflector.IsError(f.Type) {
			continue
		}

		option.ErrSetter = func(err error) {
			if option.Error != nil {
				*option.Error = err
			}

			if fv.IsNil() && err == nil {
				return
			}

			if err == nil {
				fv.Set(reflect.Zero(f.Type))
			} else {
				fv.Set(reflect.ValueOf(err))
			}
		}

		return
	}

	option.ErrSetter = func(err error) {
		if option.Error != nil {
			*option.Error = err
		}
	}
}