package server

import (
	"io"
	"net/http"
	"reflect"
	"runtime/debug"
	"strings"

	"repositories.action2quare.com/ayo/go-ayo/common"
	"repositories.action2quare.com/ayo/go-ayo/logger"
)

const (
	defaultMaxMemory = 32 << 10 // 32 KB
)

type HoustonServerWithHandler interface {
	HoustonServer
	RegisterHandlers(serveMux *http.ServeMux, prefix string) error
}

type houstonHandler struct {
	HoustonServer
	methods map[string]reflect.Method
}

func NewHoustonHandler() HoustonServerWithHandler {
	var tmp *houstonHandler

	methods := make(map[string]reflect.Method)
	tp := reflect.TypeOf(tmp)
	for i := 0; i < tp.NumMethod(); i++ {
		method := tp.Method(i)
		methods[strings.ToLower(method.Name)] = method
	}
	return &houstonHandler{
		HoustonServer: NewServer(),
		methods:       methods,
	}
}

func (h *houstonHandler) RegisterHandlers(serveMux *http.ServeMux, prefix string) error {
	serveMux.Handle(common.MakeHttpHandlerPattern(prefix, "houston"), h)

	return nil
}

func (h *houstonHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	defer func() {
		s := recover()
		if s != nil {
			logger.Println(s)
			debug.PrintStack()
		}
	}()

	defer func() {
		io.Copy(io.Discard, r.Body)
		r.Body.Close()
	}()

	operation := r.FormValue("operation")
	if len(operation) == 0 {
		w.WriteHeader(http.StatusBadRequest)
		return
	}

	method, ok := h.methods[strings.ToLower(operation)]
	if !ok {
		// 없는 operation
		logger.Println("fail to call api. operation is not valid :", operation)
		w.WriteHeader(http.StatusBadRequest)
		return
	}

	if r.PostForm == nil {
		r.ParseMultipartForm(defaultMaxMemory)
	}

	args := []reflect.Value{
		reflect.ValueOf(h),
		reflect.ValueOf(w),
		reflect.ValueOf(r),
	}

	method.Func.Call(args)
}