package history

import (
	"context"
	"fmt"
	"log"
	"math"

	"go.uber.org/zap"
	"penahub.gitlab.yandexcloud.net/pena-services/customer/internal/dto"
	"penahub.gitlab.yandexcloud.net/pena-services/customer/internal/errors"
	"penahub.gitlab.yandexcloud.net/pena-services/customer/internal/models"
)

type historyRepository interface {
	CountAll(context.Context, *dto.GetHistories) (int64, errors.Error)
	FindMany(context.Context, *dto.GetHistories) ([]models.History, errors.Error)
	Insert(context.Context, *models.History) (*models.History, errors.Error)
	GetRecentTariffs(context.Context, string) ([]models.TariffID, errors.Error) // new
}

type Deps struct {
	Logger     *zap.Logger
	Repository historyRepository
}

type Service struct {
	logger     *zap.Logger
	repository historyRepository
}

func New(deps Deps) *Service {
	if deps.Logger == nil {
		log.Panicln("logger is nil on <New (history service)>")
	}

	if deps.Repository == nil {
		log.Panicln("repository is nil on <New (history service)>")
	}

	return &Service{
		logger:     deps.Logger,
		repository: deps.Repository,
	}
}

func (receiver *Service) GetHistoryList(ctx context.Context, dto *dto.GetHistories) (*models.PaginationResponse[models.History], errors.Error) {
	if dto == nil {
		return nil, errors.New(
			fmt.Errorf("pagination is nil on <GetHistoryList> of <HistoryService>: %w", errors.ErrInternalError),
			errors.ErrInternalError,
		)
	}

	count, err := receiver.repository.CountAll(ctx, dto)
	if err != nil {
		receiver.logger.Error("failed to count histories on <GetHistoryList> of <HistoryService>",
			zap.Error(err),
		)

		return nil, err
	}

	if count == 0 {
		return &models.PaginationResponse[models.History]{TotalPages: 0, Records: []models.History{}}, nil
	}

	totalPages := int64(math.Ceil(float64(count) / float64(dto.Pagination.Limit)))

	histories, err := receiver.repository.FindMany(ctx, dto)
	if err != nil {
		receiver.logger.Error("failed to get historiy list on <GetHistoryList> of <HistoryService>",
			zap.Error(err),
		)

		return nil, err
	}

	return &models.PaginationResponse[models.History]{
		TotalPages: totalPages,
		Records:    histories,
	}, nil
}

func (receiver *Service) CreateHistory(ctx context.Context, history *models.History) (*models.History, errors.Error) {
	createdHistory, err := receiver.repository.Insert(ctx, history)
	if err != nil {
		receiver.logger.Error("failed to create history on <CreateHistory> of <HistoryService>", zap.Error(err))
		return nil, err
	}

	return createdHistory, nil
}

// TODO:tests.
func (receiver *Service) GetRecentTariffs(ctx context.Context, userID string) ([]models.TariffID, errors.Error) {
	if userID == "" {
		receiver.logger.Error("user id is missing in <GetRecentTariffs> of <HistoryService>")
		return nil, errors.New(
			fmt.Errorf("user id is missing: %w", errors.ErrInvalidArgs),
			errors.ErrInvalidArgs,
		)
	}

	tariffs, err := receiver.repository.GetRecentTariffs(ctx, userID)
	if err != nil {
		receiver.logger.Error(
			"failed to get recent tariffs in <GetRecentTariffs> of <HistoryService>",
			zap.String("userId", userID),
			zap.Error(err),
		)
		return nil, err
	}

	return tariffs, nil
}