package api

import (
	"encoding/json"
	"log"
	"net/http"
	"strconv"

	"go.mongodb.org/mongo-driver/bson"

	"github.com/gorilla/mux"
	"github.com/leandrofars/oktopus/internal/db"
	usp_msg "github.com/leandrofars/oktopus/internal/usp_message"
	"github.com/leandrofars/oktopus/internal/utils"
	"go.mongodb.org/mongo-driver/mongo"
)

func (a *Api) deviceGetSupportedParametersMsg(w http.ResponseWriter, r *http.Request) {
	vars := mux.Vars(r)
	sn := vars["sn"]
	device := a.deviceExists(sn, w)

	var receiver usp_msg.GetSupportedDM

	err := json.NewDecoder(r.Body).Decode(&receiver)
	if err != nil {
		log.Println(err)
		w.WriteHeader(http.StatusBadRequest)
		return
	}

	msg := utils.NewGetSupportedParametersMsg(receiver)
	a.uspCall(msg, sn, w, device)
}

func (a *Api) retrieveDevices(w http.ResponseWriter, r *http.Request) {
	const PAGE_SIZE_LIMIT = 50
	const PAGE_SIZE_DEFAULT = 20

	// Get specific device
	id := r.URL.Query().Get("id")
	if id != "" {
		device, err := a.Db.RetrieveDevice(id)
		if err != nil {
			if err == mongo.ErrNoDocuments {
				json.NewEncoder(w).Encode("Device id: " + id + " not found")
				return
			}
			json.NewEncoder(w).Encode(err)
			w.WriteHeader(http.StatusInternalServerError)
			return
		}
		err = json.NewEncoder(w).Encode(device)
		if err != nil {
			log.Println(err)
		}
		return
	}

	// Get devices with pagination
	page_n := r.URL.Query().Get("page_number")
	page_s := r.URL.Query().Get("page_size")
	var err error

	var page_number int64
	if page_n == "" {
		page_number = 1
	} else {
		page_number, err = strconv.ParseInt(page_n, 10, 64)
		if err != nil {
			w.WriteHeader(http.StatusBadRequest)
			json.NewEncoder(w).Encode("Page number must be an integer")
			return
		}
	}

	var page_size int64
	if page_s != "" {
		page_size, err = strconv.ParseInt(page_s, 10, 64)

		if err != nil {
			w.WriteHeader(http.StatusBadRequest)
			json.NewEncoder(w).Encode("Page size must be an integer")
			return
		}

		if page_size > PAGE_SIZE_LIMIT {
			w.WriteHeader(http.StatusBadRequest)
			json.NewEncoder(w).Encode("Page size must not exceed " + strconv.Itoa(PAGE_SIZE_LIMIT))
			return
		}

	} else {
		page_size = PAGE_SIZE_DEFAULT
	}

	total, err := a.Db.RetrieveDevicesCount(bson.M{})
	if err != nil {
		w.WriteHeader(http.StatusInternalServerError)
		json.NewEncoder(w).Encode("Unable to get devices count from database")
		return
	}

	skip := page_number * (page_size - 1)
	if total < page_size {
		skip = 0
	}

	//TODO: Create filters
	//TODO: Create sorting

	filter := bson.A{
		//bson.M{"$match": filter},
		//bson.M{"$sort": sort},
		bson.M{"$skip": skip},
		bson.M{"$limit": page_size},
	}

	devices, err := a.Db.RetrieveDevices(filter)
	if err != nil {
		w.WriteHeader(http.StatusInternalServerError)
		json.NewEncoder(w).Encode("Unable to aggregate database devices info")
		return
	}

	err = json.NewEncoder(w).Encode(map[string]interface{}{
		"pages":   total / page_size,
		"page":    page_number,
		"size":    page_size,
		"devices": devices,
	})
	if err != nil {
		log.Println(err)
	}
}

func (a *Api) deviceCreateMsg(w http.ResponseWriter, r *http.Request) {
	vars := mux.Vars(r)
	sn := vars["sn"]
	device := a.deviceExists(sn, w)

	var receiver usp_msg.Add

	err := json.NewDecoder(r.Body).Decode(&receiver)
	if err != nil {
		log.Println(err)
		w.WriteHeader(http.StatusBadRequest)
		return
	}

	msg := utils.NewCreateMsg(receiver)
	a.uspCall(msg, sn, w, device)
}

func (a *Api) deviceGetMsg(w http.ResponseWriter, r *http.Request) {
	vars := mux.Vars(r)
	sn := vars["sn"]

	device := a.deviceExists(sn, w)

	var receiver usp_msg.Get

	err := json.NewDecoder(r.Body).Decode(&receiver)
	if err != nil {
		log.Println(err)
		w.WriteHeader(http.StatusBadRequest)
		return
	}

	msg := utils.NewGetMsg(receiver)
	a.uspCall(msg, sn, w, device)
}

func (a *Api) deviceOperateMsg(w http.ResponseWriter, r *http.Request) {
	vars := mux.Vars(r)
	sn := vars["sn"]

	device := a.deviceExists(sn, w)

	var receiver usp_msg.Operate

	err := json.NewDecoder(r.Body).Decode(&receiver)
	if err != nil {
		log.Println(err)
		w.WriteHeader(http.StatusBadRequest)
		return
	}

	msg := utils.NewOperateMsg(receiver)
	a.uspCall(msg, sn, w, device)
}

func (a *Api) deviceDeleteMsg(w http.ResponseWriter, r *http.Request) {
	vars := mux.Vars(r)
	sn := vars["sn"]
	device := a.deviceExists(sn, w)

	var receiver usp_msg.Delete

	err := json.NewDecoder(r.Body).Decode(&receiver)
	if err != nil {
		log.Println(err)
		w.WriteHeader(http.StatusBadRequest)
		return
	}

	msg := utils.NewDelMsg(receiver)
	a.uspCall(msg, sn, w, device)

	//a.Broker.Request(tr369Message, usp_msg.Header_GET, "oktopus/v1/agent/"+sn, "oktopus/v1/get/"+sn)

}

func (a *Api) deviceUpdateMsg(w http.ResponseWriter, r *http.Request) {
	vars := mux.Vars(r)
	sn := vars["sn"]
	device := a.deviceExists(sn, w)

	var receiver usp_msg.Set

	err := json.NewDecoder(r.Body).Decode(&receiver)
	if err != nil {
		log.Println(err)
		w.WriteHeader(http.StatusBadRequest)
		return
	}

	msg := utils.NewSetMsg(receiver)
	a.uspCall(msg, sn, w, device)
}

func (a *Api) deviceExists(sn string, w http.ResponseWriter) db.Device {
	device, err := a.Db.RetrieveDevice(sn)
	if err != nil {
		if err == mongo.ErrNoDocuments {
			w.WriteHeader(http.StatusBadRequest)
			json.NewEncoder(w).Encode("No device with serial number " + sn + " was found")
		}
		w.WriteHeader(http.StatusInternalServerError)
		return device
	}
	return device
}

func (a *Api) deviceGetParameterInstances(w http.ResponseWriter, r *http.Request) {
	vars := mux.Vars(r)
	sn := vars["sn"]
	device := a.deviceExists(sn, w)

	var receiver usp_msg.GetInstances

	err := json.NewDecoder(r.Body).Decode(&receiver)
	if err != nil {
		log.Println(err)
		w.WriteHeader(http.StatusBadRequest)
		return
	}

	msg := utils.NewGetParametersInstancesMsg(receiver)
	a.uspCall(msg, sn, w, device)
}