// Copyright 2020 TiKV Project Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// See the License for the specific language governing permissions and
// limitations under the License.

package api

import (
	"net/http"

	"github.com/gorilla/mux"
	"github.com/tikv/pd/server"
	"github.com/tikv/pd/server/core"
	"github.com/unrolled/render"
)

type serviceGCSafepointHandler struct {
	svr *server.Server
	rd  *render.Render
}

func newServiceGCSafepointHandler(svr *server.Server, rd *render.Render) *serviceGCSafepointHandler {
	return &serviceGCSafepointHandler{
		svr: svr,
		rd:  rd,
	}
}

type listServiceGCSafepoint struct {
	ServiceGCSafepoints []*core.ServiceSafePoint `json:"service_gc_safe_points"`
	GCSafePoint         uint64                   `json:"gc_safe_point"`
}

// @Tags servicegcsafepoint
// @Summary Get all service GC safepoint.
// @Produce json
// @Success 200 {array} listServiceGCSafepoint
// @Failure 500 {string} string "PD server failed to proceed the request."
// @Router /gc/safepoint [get]
func (h *serviceGCSafepointHandler) List(w http.ResponseWriter, r *http.Request) {
	storage := h.svr.GetStorage()
	gcSafepoint, err := storage.LoadGCSafePoint()
	if err != nil {
		h.rd.JSON(w, http.StatusInternalServerError, err.Error())
		return
	}
	ssps, err := storage.GetAllServiceGCSafePoints()
	if err != nil {
		h.rd.JSON(w, http.StatusInternalServerError, err.Error())
		return
	}
	list := listServiceGCSafepoint{
		GCSafePoint:         gcSafepoint,
		ServiceGCSafepoints: ssps,
	}
	h.rd.JSON(w, http.StatusOK, list)
}

// @Tags servicegcsafepoint
// @Summary Delete a service GC safepoint.
// @Param service_id path string true "Service ID"
// @Produce json
// @Success 200 {string} string "Delete service GC safepoint successfully."
// @Failure 500 {string} string "PD server failed to proceed the request."
// @Router /gc/safepoint/{service_id} [delete]
// @Tags rule
func (h *serviceGCSafepointHandler) Delete(w http.ResponseWriter, r *http.Request) {
	storage := h.svr.GetStorage()
	serviceID := mux.Vars(r)["service_id"]
	err := storage.RemoveServiceGCSafePoint(serviceID)
	if err != nil {
		h.rd.JSON(w, http.StatusInternalServerError, err.Error())
		return
	}
	h.rd.JSON(w, http.StatusOK, "Delete service GC safepoint successfully.")
}