package internalhttp

import (
	"context"
	"encoding/json"
	"errors"
	"net/http"

	"galaxy/mail/internal/service/acceptauthdelivery"
)

// AcceptLoginCodeDeliveryUseCase accepts one auth login-code delivery request.
type AcceptLoginCodeDeliveryUseCase interface {
	// Execute durably accepts one normalized auth login-code delivery command.
	Execute(context.Context, acceptauthdelivery.Input) (acceptauthdelivery.Result, error)
}

func newAcceptLoginCodeDeliveryHandler(useCase AcceptLoginCodeDeliveryUseCase) http.HandlerFunc {
	return func(writer http.ResponseWriter, request *http.Request) {
		ctx := request.Context()

		command, err := DecodeLoginCodeDeliveryCommand(request)
		if err != nil {
			writeErrorResponse(writer, http.StatusBadRequest, ErrorCodeInvalidRequest, err.Error())
			return
		}

		result, err := useCase.Execute(ctx, acceptauthdelivery.Input{
			IdempotencyKey: command.IdempotencyKey,
			Email:          command.Email,
			Code:           command.Code,
			Locale:         command.Locale,
		})
		if err != nil {
			switch {
			case errors.Is(err, acceptauthdelivery.ErrConflict):
				writeErrorResponse(writer, http.StatusConflict, ErrorCodeConflict, "request conflicts with current state")
			case errors.Is(err, acceptauthdelivery.ErrServiceUnavailable):
				writeErrorResponse(writer, http.StatusServiceUnavailable, ErrorCodeServiceUnavailable, "service is unavailable")
			default:
				writeErrorResponse(writer, http.StatusInternalServerError, ErrorCodeInternalError, "internal server error")
			}
			return
		}

		if err := result.Validate(); err != nil {
			writeErrorResponse(writer, http.StatusInternalServerError, ErrorCodeInternalError, "internal server error")
			return
		}

		response := LoginCodeDeliveryResponse{
			Outcome: LoginCodeDeliveryOutcome(result.Outcome),
		}
		if err := response.Validate(); err != nil {
			writeErrorResponse(writer, http.StatusInternalServerError, ErrorCodeInternalError, "internal server error")
			return
		}

		writer.Header().Set("Content-Type", "application/json")
		writer.WriteHeader(http.StatusOK)
		_ = json.NewEncoder(writer).Encode(response)
	}
}