package apiTime

import (
	"encoding/json"
	"fmt"
	"log"
	"net/http"
	"strconv"
	"time"
)

type dateTimeResponse struct {
	Year         int    `json:"year,omitempty"`
	Month        int    `json:"month,omitempty"`
	Day          int    `json:"day,omitempty"`
	Hour         int    `json:"hour,omitempty"`
	Minute       int    `json:"minute,omitempty"`
	Seconds      int    `json:"seconds,omitempty"`
	MilliSeconds int    `json:"milliSeconds,omitempty"`
	DateTime     string `json:"dateTime,omitempty"`
	Date         string `json:"date,omitempty"`
	Time         string `json:"time,omitempty"`
	TimeZone     string `json:"timeZone,omitempty"`
	DayOfWeek    string `json:"dayOfWeek,omitempty"`
	DstActive    bool   `json:"dstActive,omitempty"`
}

func TimeCurrentZone(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-Language", "en")
	w.Header().Set("Content-Type", "application/json; charset=utf-8")

	timeZone := ""

	vals := r.URL.Query()
	parameters, ok := vals["timeZone"]
	if ok && len(parameters) == 1 {
		timeZone = parameters[0]
	}

	if timeZone == "" {
		w.WriteHeader(400)
		fmt.Fprint(w, "{\"error\": \"invalid value for timeZone\"}")
		return
	}

	loc, err := time.LoadLocation(timeZone)
	if err != nil {
		w.WriteHeader(400)
		fmt.Fprint(w, "{\"error\": \"invalid value for timeZone\"}")
		return
	}

	log.Printf("%q %q\n", loc.String(), r.RemoteAddr)

	w.WriteHeader(200)
	fmt.Fprint(w, getDateTimeResponseAsJSONString(loc))
}

func getDateTimeResponse(loc *time.Location) dateTimeResponse {
	t := time.Now().In(loc)
	return dateTimeResponse{
		Year:         t.Year(),
		Month:        int(t.Month()),
		Day:          t.Day(),
		Hour:         t.Hour(),
		Minute:       t.Minute(),
		Seconds:      t.Second(),
		MilliSeconds: func(i int64, err error) int { return int(i) }(strconv.ParseInt(strconv.Itoa(t.Nanosecond())[:3], 10, 0)),
		DateTime:     t.Format(time.RFC3339),
		Date:         fmt.Sprintf("%02d/%02d/%04d", t.Month(), t.Day(), t.Year()),
		Time:         fmt.Sprintf("%02d:%02d", t.Hour(), t.Minute()),
		TimeZone:     loc.String(),
		DayOfWeek:    t.Weekday().String(),
		DstActive:    t.IsDST(),
	}
}

func getDateTimeResponseAsJSONString(loc *time.Location) string {
	r, _ := json.Marshal(getDateTimeResponse(loc))
	return string(r)
}