package hws

import (
	"errors"
	"fmt"
	"net/http"
)

type Route struct {
	Path    string       // Absolute path to the requested resource
	Method  Method       // HTTP Method
	Handler http.Handler // Handler to use for the request
}

type Method string

const (
	MethodGET     Method = "GET"
	MethodPOST    Method = "POST"
	MethodPUT     Method = "PUT"
	MethodHEAD    Method = "HEAD"
	MethodDELETE  Method = "DELETE"
	MethodCONNECT Method = "CONNECT"
	MethodOPTIONS Method = "OPTIONS"
	MethodTRACE   Method = "TRACE"
	MethodPATCH   Method = "PATCH"
)

// Server.AddRoutes registers the page handlers for the server.
// At least one route must be provided.
func (server *Server) AddRoutes(routes ...Route) error {
	if len(routes) == 0 {
		return errors.New("No routes provided")
	}
	mux := http.NewServeMux()
	mux.HandleFunc("GET /healthz", func(http.ResponseWriter, *http.Request) {})
	for _, route := range routes {
		if !validMethod(route.Method) {
			return fmt.Errorf("Invalid method %s for path %s", route.Method, route.Path)
		}
		if route.Handler == nil {
			return fmt.Errorf("No handler provided for %s %s", route.Method, route.Path)
		}
		pattern := fmt.Sprintf("%s %s", route.Method, route.Path)
		mux.Handle(pattern, route.Handler)
	}

	server.server.Handler = mux
	server.routes = true

	return nil
}

func validMethod(m Method) bool {
	switch m {
	case MethodGET, MethodPOST, MethodPUT, MethodHEAD,
		MethodDELETE, MethodCONNECT, MethodOPTIONS, MethodTRACE, MethodPATCH:
		return true
	default:
		return false
	}
}