package nf

import (
	"fmt"
	"strings"
)

func verifyHandlers(path string, handlers ...HandlerFunc) {
	if len(handlers) == 0 {
		panic(fmt.Sprintf("missing handler in route: %s", path))
	}

	for _, handler := range handlers {
		if handler == nil {
			panic(fmt.Sprintf("nil handler found in route: %s", path))
		}
	}
}

// parseVendorSpecificContentType check if content type is vendor specific and
// if it is parsable to any known types. If it's not vendor specific then returns
// the original content type.
func parseVendorSpecificContentType(cType string) string {
	plusIndex := strings.Index(cType, "+")

	if plusIndex == -1 {
		return cType
	}

	var parsableType string
	if semiColonIndex := strings.Index(cType, ";"); semiColonIndex == -1 {
		parsableType = cType[plusIndex+1:]
	} else if plusIndex < semiColonIndex {
		parsableType = cType[plusIndex+1 : semiColonIndex]
	} else {
		return cType[:semiColonIndex]
	}

	slashIndex := strings.Index(cType, "/")

	if slashIndex == -1 {
		return cType
	}

	return cType[0:slashIndex+1] + parsableType
}