package handlers

import (
	"net/http"
	"time"

	"github.com/fiskerinc/cloud-services/pkg/cache"
	re "github.com/fiskerinc/cloud-services/pkg/redis"
	"github.com/fiskerinc/cloud-services/pkg/utils"
	"github.com/gomodule/redigo/redis"
	"github.com/pkg/errors"

	"otaupdate/services"

	"github.com/fiskerinc/cloud-services/pkg/common"
	orm "github.com/fiskerinc/cloud-services/pkg/db/queries"
	"github.com/fiskerinc/cloud-services/pkg/logger"
	"github.com/fiskerinc/cloud-services/pkg/loggerdataresp"
	"github.com/fiskerinc/cloud-services/pkg/utils/envtool"
	"github.com/fiskerinc/cloud-services/pkg/utils/urlhelper"
	"github.com/fiskerinc/cloud-services/pkg/validator"
	"github.com/fiskerinc/cloud-services/pkg/utils/elptr"
)

// HandleVehiclesGet godoc
// @Summary Search cars
// @Description Returns cars filtered by id, model, year, and vin
// @Accept  json
// @Produce  json
// @Param Authorization header string false "Bearer <ID token>"
// @Param Api-Key header string false "<API token>"
// @Param search query string false "Text search"
// @Param vins query []string false "csv of Car vin"
// @Param model query int false "Car model"
// @Param year query string false "Car year"
// @Param online query bool false "Car status"
// @Param online_hmi query bool false "HMI status"
// @Param limit query int false "Max number of records"
// @Param offset query int false "Records offset"
// @Param order query string false "Sort on column with asc or desc"
// @Success 200 {object} common.JSONDBQueryResult{data=[]common.Car}
// @Failure 400 {object} common.JSONError "Bad request"
// @Failure 401 {object} common.JSONError "Unauthorized"
// @Failure 503 {object} common.JSONError "Service unavailable"
// @Router /vehicles [get]
func HandleVehiclesGet(w http.ResponseWriter, r *http.Request) {
	var total int
	c := services.GetDB().GetCars()
	filter, err := parseCarsFilter(r)
	if loggerdataresp.BadDataErrorResp(w, err, http.StatusBadRequest) {
		return
	}

	options, err := orm.ParsePageQuery(r)
	if loggerdataresp.BadDataErrorResp(w, err, http.StatusBadRequest) {
		return
	}
	if options.Order == "" {
		options.Order = "vin"
	}

	err = fillOnline(filter)
	if loggerdataresp.BadDataErrorResp(w, err, http.StatusServiceUnavailable) {
		return
	}

	// Do not display EU vins in the list in NA prod UI
	if isNAProd() {
		filter.NoEU = true
	}

	cars, err := c.Search(filter, options)
	if loggerdataresp.BadDataErrorResp(w, err, http.StatusServiceUnavailable, loggerdataresp.PostgresNoRowsErrorCheck) {
		return
	}

	if options.Offset == 0 && filter.VIN == "" {
		total, err = c.SearchCount(filter)
		if loggerdataresp.BadDataErrorResp(w, err, http.StatusServiceUnavailable) {
			return
		}
	}

	utils.RespJSON(w, http.StatusOK, common.JSONDBQueryResult{
		Data:  cars,
		Total: total,
	})
}

var vehiclesCache cache.VehicleCacher

func SetVehiclesCache(c cache.VehicleCacher) {
	vehiclesCache = c
}

func GetVehiclesCache() cache.VehicleCacher {
	if vehiclesCache == nil {
		var err error
		vehiclesCache, err = cache.NewVehiclesCache(
			envtool.GetEnvDuration("VEHICLES_CACHE_TTL", 5*time.Minute),
			envtool.GetEnvInt("VEHICLES_CACHE_LIMIT", 1000))
		if err != nil {
			logger.Error().Err(err).Send()
		}
	}

	return vehiclesCache
}

func fillOnline(filter *common.CarSearch) error {
	if filter == nil || filter.Online == nil {
		return nil
	}

	var keys []string
	if filter.Online.Online != nil && *filter.Online.Online {
		keys = append(keys, re.CarSessionsKey())
	}

	if filter.Online.HMI != nil && *filter.Online.HMI {
		keys = append(keys, re.HMISessionsKey())
	}

	if len(keys) == 0 {
		return nil
	}

	vehicles, err := getOnline(keys)
	if err != nil {
		return errors.WithMessagef(err, "get online vehicles")
	}

	filter.Online.VINsOnline = vehicles

	return nil
}

func getOnline(sessionKeys []string) ([]string, error) {
	var onlineVehicles []string
	redisCli := services.RedisClientPool().GetFromPool()
	defer redisCli.Close()

	batch := re.NewRedisBatchCommands()

	for i := range sessionKeys {
		batch.Add("SMEMBERS", sessionKeys[i])
	}

	vinOfVins, err := redis.Values(redisCli.ExecuteBatch(batch))
	if err != nil {
		return nil, errors.WithMessagef(err, "redis get multi failed for keys: %v", sessionKeys)
	}

	onlineVehicles = make([]string, 0)

	for _, rvins := range vinOfVins {
		setVehicles, err := redis.Strings(rvins, nil)
		if err != nil {
			return nil, errors.WithMessagef(err, "redis cast to string failed: %v", sessionKeys)
		}

		onlineVehicles = append(onlineVehicles, setVehicles...)
	}

	return onlineVehicles, nil
}

func parseCarsFilter(r *http.Request) (*common.CarSearch, error) {
	qs := r.URL.Query()

	filter := common.CarSearch{
		Search: qs.Get("search"),
		VINs:   qs.Get("vins"),
		Car: common.Car{
			VIN:   qs.Get("vin"),
			Model: qs.Get("model"),
			Year:  urlhelper.GetQueryInt(qs, "year"),
		},
	}

	var o *common.CarOnlineFilter

	online, ok := urlhelper.GetQueryBool(qs, "online")
	if ok {
		if o == nil {
			o = &common.CarOnlineFilter{}
		}

		o.Online = elptr.ElPtr(online)
	}

	onlineHMI, ok := urlhelper.GetQueryBool(qs, "online_hmi")
	if ok {
		if o == nil {
			o = &common.CarOnlineFilter{}
		}

		o.HMI = elptr.ElPtr(onlineHMI)
	}

	filter.Online = o

	err := validator.ValidateNonRequired(filter)

	return &filter, err
}

func isNAProd() bool {
	return envtool.GetEnv("IS_NA_PROD", "") != ""
}