package operations

import (
	"git.sxidc.com/go-tools/utils/template"
	"github.com/iancoleman/strcase"
	"github.com/pkg/errors"
	"reflect"
)

const (
	tagTpl = `gorm:"column:{{ .Name }};type:{{ .Type }};comment:{{ .Comment }};
{{- if .PrimaryKey -}}primaryKey;{{- end -}}
{{- if .Size -}}size:{{ .Size }};{{- end -}}
{{- if .Unique -}}unique;{{- end -}}
{{- if .NotNull -}}not null;{{- end -}}
{{- if .Index -}}index;{{- end -}}
{{- if .UniqueIndex -}}uniqueIndex:{{ .UniqueIndex }};{{- end -}}
{{- if .Default -}}default:{{ .Default }};{{- end -}}
"`
)

type Table struct {
	TableName string
	Columns   []TableColumn
}

func (spec *Table) ToDBModel() (any, error) {
	dbModelFields := make([]reflect.StructField, 0)
	for _, column := range spec.Columns {
		dbModelField, err := column.ToDBModelField()
		if err != nil {
			return nil, err
		}

		dbModelFields = append(dbModelFields, *dbModelField)
	}

	structType := reflect.StructOf(dbModelFields)
	structVar := reflect.New(structType).Elem().Addr().Interface()

	return structVar, nil
}

type TableColumn struct {
	Name        string
	Type        string
	Comment     string
	PrimaryKey  bool
	Size        int
	Unique      bool
	NotNull     bool
	Index       bool
	UniqueIndex string
	Default     any
}

func (column *TableColumn) ToDBModelField() (*reflect.StructField, error) {
	tag, err := template.ParseTemplateStringToString(tagTpl, column)
	if err != nil {
		return nil, errors.New(err.Error())
	}

	return &reflect.StructField{
		Name: strcase.ToCamel(column.Name),
		Type: reflect.TypeOf(""),
		Tag:  reflect.StructTag(tag),
	}, nil
}