package api

import (
	"crypto/sha256"
	"crypto/subtle"
	"encoding/json"
	"net/http"
	"strings"
	"time"
)

const maxOnecEventBody = 8 << 10

func (a *API) WithOneCWebhook(key string)  { a.onecHook = strings.TrimSpace(key) }
func (a *API) onecAutonomousEnabled() bool { return a.onecHook != "" }

type onecEvent struct {
	Event         string     `json:"event"`
	DoctorID      string     `json:"doctor_id"`
	AppointmentID string     `json:"appointment_id"`
	Status        string     `json:"status"`
	BranchID      string     `json:"branch_id"`
	Start         *time.Time `json:"start"`
	End           *time.Time `json:"end"`
}

func sameKey(got, want string) bool {
	g, w := sha256.Sum256([]byte(got)), sha256.Sum256([]byte(want))
	return subtle.ConstantTimeCompare(g[:], w[:]) == 1
}
func (a *API) onecEvents(w http.ResponseWriter, r *http.Request) {
	if !a.onecAutonomousEnabled() {
		fail(w, 404, "not_found", "Не найдено")
		return
	}
	ip := clientIP(r)
	if a.tooMany(w, "onec-ev:"+ip, 300, time.Minute) {
		return
	}
	if !a.checkOnecKey(r) {
		if a.tooMany(w, "onec-bad:"+ip, 20, 10*time.Minute) {
			return
		}
		fail(w, 401, "unauthorized", "Неверный ключ")
		return
	}
	var ev onecEvent
	if err := json.NewDecoder(http.MaxBytesReader(w, r.Body, maxOnecEventBody)).Decode(&ev); err != nil {
		fail(w, 400, "bad_json", "Не удалось разобрать событие")
		return
	}
	switch ev.Event {
	case "schedule_changed", "directory_changed":
		if err := a.store.RequestOnecSnapshot(r.Context()); err != nil {
			handleErr(w, err)
			return
		}
		writeJSON(w, http.StatusAccepted, envelope{Data: map[string]any{"ok": true, "queued": "push"}})
	case "appointment_status":
		if ev.AppointmentID == "" || (ev.Status != "booked" && ev.Status != "arrived" && ev.Status != "cancelled") {
			fail(w, 400, "validation", "Нужны appointment_id и status: booked, arrived или cancelled")
			return
		}
		if (ev.Start == nil) != (ev.End == nil) || (ev.Start != nil && !ev.Start.Before(*ev.End)) {
			fail(w, 400, "validation", "Некорректный интервал события")
			return
		}
		_, _, known, err := a.store.ApplyOnecAppointmentEvent(r.Context(), ev.AppointmentID, ev.Status, ev.DoctorID, ev.BranchID, ev.Start, ev.End)
		if err != nil {
			handleErr(w, err)
			return
		}
		if err = a.store.RequestOnecSnapshot(r.Context()); err != nil {
			handleErr(w, err)
			return
		}
		ok(w, map[string]any{"ok": true, "known": known}, nil)
	default:
		fail(w, 400, "validation", "Неизвестное событие: допустимы schedule_changed, directory_changed, appointment_status")
	}
}