package http

import (
	"fmt"
	"reflect"
	"strconv"
	"strings"

	"go-micro.dev/v4/registry"
	"go-micro.dev/v4/server"
	"go-micro.dev/v4/util/addr"
)

func serviceDef(opts server.Options) *registry.Service {
	var advt, host string
	var port int

	if len(opts.Advertise) > 0 {
		advt = opts.Advertise
	} else {
		advt = opts.Address
	}

	parts := strings.Split(advt, ":")
	if len(parts) > 1 {
		host = strings.Join(parts[:len(parts)-1], ":")
		port, _ = strconv.Atoi(parts[len(parts)-1])
	} else {
		host = parts[0]
	}

	addr, err := addr.Extract(host)
	if err != nil {
		addr = host
	}

	node := &registry.Node{
		Id:       opts.Name + "-" + opts.Id,
		Address:  fmt.Sprintf("%s:%d", addr, port),
		Metadata: opts.Metadata,
	}

	node.Metadata["server"] = "http"
	node.Metadata["broker"] = opts.Broker.String()
	node.Metadata["registry"] = opts.Registry.String()
	node.Metadata["protocol"] = "http"

	return &registry.Service{
		Name:    opts.Name,
		Version: opts.Version,
		Nodes:   []*registry.Node{node},
	}
}

func extractValue(v reflect.Type, d int) *registry.Value {
	if d == 3 {
		return nil
	}
	if v == nil {
		return nil
	}

	if v.Kind() == reflect.Ptr {
		v = v.Elem()
	}

	arg := &registry.Value{
		Name: v.Name(),
		Type: v.Name(),
	}

	switch v.Kind() {
	case reflect.Struct:
		for i := 0; i < v.NumField(); i++ {
			f := v.Field(i)
			val := extractValue(f.Type, d+1)
			if val == nil {
				continue
			}

			// if we can find a json tag use it
			if tags := f.Tag.Get("json"); len(tags) > 0 {
				parts := strings.Split(tags, ",")
				val.Name = parts[0]
			}

			// if there's no name default it
			if len(val.Name) == 0 {
				val.Name = v.Field(i).Name
			}

			arg.Values = append(arg.Values, val)
		}
	case reflect.Slice:
		p := v.Elem()
		if p.Kind() == reflect.Ptr {
			p = p.Elem()
		}
		arg.Type = "[]" + p.Name()
		val := extractValue(v.Elem(), d+1)
		if val != nil {
			arg.Values = append(arg.Values, val)
		}
	}

	return arg
}

func extractEndpoint(method reflect.Method) *registry.Endpoint {
	if method.PkgPath != "" {
		return nil
	}

	var rspType, reqType reflect.Type
	var stream bool
	mt := method.Type

	switch mt.NumIn() {
	case 3:
		reqType = mt.In(1)
		rspType = mt.In(2)
	case 4:
		reqType = mt.In(2)
		rspType = mt.In(3)
	default:
		return nil
	}

	// are we dealing with a stream?
	switch rspType.Kind() {
	case reflect.Func, reflect.Interface:
		stream = true
	}

	request := extractValue(reqType, 0)
	response := extractValue(rspType, 0)

	return &registry.Endpoint{
		Name:     method.Name,
		Request:  request,
		Response: response,
		Metadata: map[string]string{
			"stream": fmt.Sprintf("%v", stream),
		},
	}
}

func extractSubValue(typ reflect.Type) *registry.Value {
	var reqType reflect.Type
	switch typ.NumIn() {
	case 1:
		reqType = typ.In(0)
	case 2:
		reqType = typ.In(1)
	case 3:
		reqType = typ.In(2)
	default:
		return nil
	}
	return extractValue(reqType, 0)
}
