html/query.go

package html

type nameQuery struct {
	value string
}

type attributesQuery struct {
	value Attributes
}

type attributeQuery struct {
	name  string
	value any
	found bool
}

type childrenQuery struct {
	value []any
}

type validator struct {
	err error
}

type renderGuidesQuery struct {
	value []renderGuide
}

func groupChildren(c []any) ([]Attributes, []any, []renderGuide) {
	var (
		a  []Attributes
		cc []any
		rg []renderGuide
	)

	for _, ci := range c {
		if ai, ok := ci.(Attributes); ok {
			a = append(a, ai)
			continue
		}

		if rgi, ok := ci.(renderGuide); ok {
			rg = append(rg, rgi)
			continue
		}

		cc = append(cc, ci)
	}

	return a, cc, rg
}

func mergeAttributes(c []any) Attributes {
	a, _, _ := groupChildren(c)
	if len(a) == 0 {
		return nil
	}

	to := make(Attributes)
	for _, ai := range a {
		for name, value := range ai {
			to[name] = value
		}
	}

	return to
}

func findAttribute(c []any, name string) (any, bool) {
	a, _, _ := groupChildren(c)
	for i := len(a) - 1; i >= 0; i-- {
		value, ok := a[i][name]
		if ok {
			return value, true
		}
	}

	return nil, false
}

func handleQuery(name string, children []any) bool {
	if len(children) == 0 {
		return false
	}

	last := len(children) - 1
	lastChild := children[last]
	if q, ok := lastChild.(*nameQuery); ok {
		q.value = name
		return true
	}

	if q, ok := lastChild.(*attributesQuery); ok {
		q.value = mergeAttributes(children[:last])
		return true
	}

	if q, ok := lastChild.(*attributeQuery); ok {
		q.value, q.found = findAttribute(children[:last], q.name)
		return true
	}

	if q, ok := lastChild.(*childrenQuery); ok {
		_, q.value, _ = groupChildren(children[:last])
		return true
	}

	if q, ok := lastChild.(*renderGuidesQuery); ok {
		_, _, q.value = groupChildren(children[:last])
		return true
	}

	if v, ok := lastChild.(*validator); ok {
		v.err = validate(name, children[:last])
		return true
	}

	if r, ok := lastChild.(*renderer); ok {
		if err := validate(name, children[:last]); err != nil {
			r.err = err
			return true
		}

		r.render(name, children[:last])
		return true
	}

	return false
}