package types

import (
	"encoding/json"
	"fmt"
	"net/http"
)

type Path string

func (p Path) String() string {
	return string(p)
}

const (
	PathMasterJoin      Path = "/master/join"
	PathMasterLeave     Path = "/master/leave"
	PathMasterKeepalive Path = "/master/keepalive"

	PathNodeHealthcheck Path = "/node/healthcheck"
	PathNodeJoin        Path = "/node/join"
	PathNodeLeave       Path = "/node/leave"

	PathDnsCallback Path = "/dns/callback"

	PathHostCallback Path = "/host/callback"
	PathHostDns      Path = "/host/dns"
	PathHostNs       Path = "/host/ns"
)

type Response[T any] struct {
	Ok   bool   `json:"ok"`
	Data T      `json:"data,omitempty"`
	Err  string `json:"err,omitempty"`
}

type Route interface {
	Path() string
	Handle([]byte) (any, error)
}

type endpoint struct {
	path    string
	handler func([]byte) (any, error)
}

func (e endpoint) Path() string { return e.path }

func (e endpoint) Handle(v []byte) (any, error) { return e.handler(v) }

func PostEndpoint[T any, V any](path Path, handler func(T) (V, error)) Route {
	return endpoint{
		path: "POST " + path.String(),
		handler: func(a []byte) (any, error) {
			var r T
			if err := json.Unmarshal(a, &r); err != nil {
				return nil, fmt.Errorf("unable to unmarshal json: %w", err)
			}
			return handler(r)
		},
	}
}

func GetEndpoint[T any](path Path, handler func() (T, error)) Route {
	return endpoint{
		path: "GET " + path.String(),
		handler: func(a []byte) (any, error) {
			return handler()
		},
	}
}

type Registrator interface {
	Register(endpoint Route)
	RegisterRaw(method string, pattern string, handler func(http.ResponseWriter, *http.Request))
}