package handler

import (
	"net/http"

	"datarush/internal/gw/domain"
	"datarush/internal/gw/grpc_client"
	"datarush/internal/gw/utils"

	comppb "datarush/pkg/api/competition"
)

type CompetitionHandler struct {
	competitionClient *grpc_client.CompetitionClient
	userClient        *grpc_client.UserClient
}

func NewCompetitionHandler(
	competitionClient *grpc_client.CompetitionClient,
	userClient *grpc_client.UserClient,
) *CompetitionHandler {
	return &CompetitionHandler{
		competitionClient: competitionClient,
		userClient:        userClient,
	}
}

func (h *CompetitionHandler) CreateCompetition(w http.ResponseWriter, r *http.Request) {
	var req domain.CompetitionRequest
	if err := utils.DecodeJSON(r, &req); err != nil {
		utils.RespondError(w, err)
		return
	}

	competition := utils.CompetitionHTTPToProto(&req)
	resp, err := h.competitionClient.CreateCompetition(r.Context(), competition)
	if err != nil {
		utils.RespondError(w, domain.NewInternalServerError("failed to create competition"))
		return
	}

	utils.RespondJSON(w, http.StatusCreated, utils.CompetitionProtoToHTTP(resp))
}

func (h *CompetitionHandler) GetCompetition(w http.ResponseWriter, r *http.Request) {
	competitionID := getPathParam(r, "competition_id")

	competition, err := h.competitionClient.GetCompetition(r.Context(), competitionID)
	if err != nil {
		utils.RespondError(w, domain.NewNotFoundError("competition not found"))
		return
	}

	utils.RespondJSON(w, http.StatusOK, utils.CompetitionProtoToHTTP(competition))
}

func (h *CompetitionHandler) UpdateCompetition(w http.ResponseWriter, r *http.Request) {
	competitionID := getPathParam(r, "competition_id")

	var req domain.CompetitionRequest
	if err := utils.DecodeJSON(r, &req); err != nil {
		utils.RespondError(w, err)
		return
	}

	req.ID = competitionID
	competition := utils.CompetitionHTTPToProto(&req)
	resp, err := h.competitionClient.EditCompetition(r.Context(), competition)
	if err != nil {
		utils.RespondError(w, domain.NewInternalServerError("failed to update competition"))
		return
	}

	utils.RespondJSON(w, http.StatusOK, utils.CompetitionProtoToHTTP(resp))
}

func (h *CompetitionHandler) DeleteCompetition(w http.ResponseWriter, r *http.Request) {
	competitionID := getPathParam(r, "competition_id")

	if err := h.competitionClient.DeleteCompetition(r.Context(), competitionID); err != nil {
		utils.RespondError(w, domain.NewInternalServerError("failed to delete competition"))
		return
	}

	w.WriteHeader(http.StatusNoContent)
}
func (h *CompetitionHandler) ListCompetitions(w http.ResponseWriter, r *http.Request) {
	pageSize := getQueryParamInt32(r, "page_size", 20)
	pageToken := getQueryParamInt32(r, "page_token", 0)
	state := getQueryParam(r, "state")
	searchQuery := getQueryParam(r, "search_query")
	isParticipating := getQueryParamBool(r, "is_participating")

	req := &comppb.ListCompetitionsRequest{
		PageSize:  pageSize,
		PageToken: pageToken,
	}

	if state != "" {
		s := utils.StringToCompetitionState(state)
		req.State = &s
	}

	if searchQuery != "" {
		req.SearchQuery = &searchQuery
	}

	if isParticipating != nil {
		req.IsParticipating = isParticipating
	}

	resp, err := h.competitionClient.ListCompetitions(r.Context(), req)
	if err != nil {
		utils.RespondError(w, domain.NewInternalServerError("failed to list competitions"))
		return
	}

	competitions := make([]domain.CompetitionResponse, len(resp.Competitions))
	for i, comp := range resp.Competitions {
		competitions[i] = *utils.CompetitionProtoToHTTP(comp)
	}

	utils.RespondJSON(w, http.StatusOK, &domain.ListCompetitionsResponse{
		TotalCount:    resp.TotalCount,
		NextPageToken: resp.NextPageToken,
		Competitions:  competitions,
	})
}

func (h *CompetitionHandler) ChangeCompetitionState(w http.ResponseWriter, r *http.Request) {
	competitionID := getPathParam(r, "competition_id")

	var req domain.ChangeCompetitionStateRequest
	if err := utils.DecodeJSON(r, &req); err != nil {
		utils.RespondError(w, err)
		return
	}

	state := utils.StringToCompetitionState(req.State)
	competition, err := h.competitionClient.ChangeCompetitionState(r.Context(), competitionID, state)
	if err != nil {
		utils.RespondError(w, domain.NewInternalServerError("failed to change competition state"))
		return
	}

	utils.RespondJSON(w, http.StatusOK, utils.CompetitionProtoToHTTP(competition))
}

func (h *CompetitionHandler) JoinCompetition(w http.ResponseWriter, r *http.Request) {
	competitionID := getPathParam(r, "competition_id")

	if err := h.userClient.RegisterForCompetition(r.Context(), competitionID); err != nil {
		utils.RespondError(w, domain.NewInternalServerError("failed to join competition"))
		return
	}

	w.WriteHeader(http.StatusNoContent)
}