package repository

import (
	"enaklo-pos-be/internal/common/mycontext"
	"enaklo-pos-be/internal/entity"
	"enaklo-pos-be/internal/repository/models"
	"github.com/pkg/errors"
	"gorm.io/gorm"
	"time"
)

type CashierSessionRepository interface {
	CreateSession(ctx mycontext.Context, session *entity.CashierSession) (*entity.CashierSession, error)
	CloseSession(ctx mycontext.Context, sessionID int64, closingAmount, expectedAmount float64) error
	GetOpenSessionByCashierID(ctx mycontext.Context, cashierID int64) (*entity.CashierSession, error)
	GetSessionByID(ctx mycontext.Context, sessionID int64) (*entity.CashierSession, error)
	GetPaymentSummaryBySessionID(ctx mycontext.Context, sessionID int64) ([]entity.PaymentSummary, error)
}

type cashierSessionRepository struct {
	db *gorm.DB
}

func NewCashierSessionRepository(db *gorm.DB) CashierSessionRepository {
	return &cashierSessionRepository{db: db}
}

func (r *cashierSessionRepository) CreateSession(ctx mycontext.Context, session *entity.CashierSession) (*entity.CashierSession, error) {
	dbModel := models.CashierSessionDB{
		CashierID:     session.CashierID,
		OpenedAt:      time.Now(),
		OpeningAmount: session.OpeningAmount,
		Status:        "open",
		CreatedAt:     time.Now(),
	}

	if err := r.db.Create(&dbModel).Error; err != nil {
		return nil, errors.Wrap(err, "failed to create cashier session")
	}

	session.ID = dbModel.ID
	session.Status = dbModel.Status
	session.OpenedAt = dbModel.OpenedAt

	return session, nil
}

func (r *cashierSessionRepository) CloseSession(ctx mycontext.Context, sessionID int64, closingAmount, expectedAmount float64) error {
	result := r.db.Model(&models.CashierSessionDB{}).
		Where("id = ?", sessionID).
		Updates(map[string]interface{}{
			"closed_at":       time.Now(),
			"closing_amount":  closingAmount,
			"expected_amount": expectedAmount,
			"status":          "closed",
		})

	if result.Error != nil {
		return errors.Wrap(result.Error, "failed to close session")
	}

	if result.RowsAffected == 0 {
		return errors.New("no session updated")
	}

	return nil
}

func (r *cashierSessionRepository) GetOpenSessionByCashierID(ctx mycontext.Context, cashierID int64) (*entity.CashierSession, error) {
	var dbModel models.CashierSessionDB
	if err := r.db.Where("cashier_id = ? AND status = 'open'", cashierID).
		Order("opened_at DESC").First(&dbModel).Error; err != nil {
		if errors.Is(err, gorm.ErrRecordNotFound) {
			return nil, nil
		}
		return nil, errors.Wrap(err, "failed to get open session")
	}

	return r.toEntity(&dbModel), nil
}

func (r *cashierSessionRepository) GetSessionByID(ctx mycontext.Context, sessionID int64) (*entity.CashierSession, error) {
	var dbModel models.CashierSessionDB
	if err := r.db.First(&dbModel, sessionID).Error; err != nil {
		if errors.Is(err, gorm.ErrRecordNotFound) {
			return nil, nil
		}
		return nil, errors.Wrap(err, "failed to get session by ID")
	}

	return r.toEntity(&dbModel), nil
}

func (r *cashierSessionRepository) toEntity(db *models.CashierSessionDB) *entity.CashierSession {
	return &entity.CashierSession{
		ID:             db.ID,
		CashierID:      db.CashierID,
		OpenedAt:       db.OpenedAt,
		ClosedAt:       db.ClosedAt,
		OpeningAmount:  db.OpeningAmount,
		ClosingAmount:  db.ClosingAmount,
		ExpectedAmount: db.ExpectedAmount,
		Status:         db.Status,
	}
}

func (r *cashierSessionRepository) GetPaymentSummaryBySessionID(ctx mycontext.Context, sessionID int64) ([]entity.PaymentSummary, error) {
	type result struct {
		PaymentType     string
		PaymentProvider string
		TotalAmount     float64
	}

	var rows []result

	err := r.db.WithContext(ctx).
		Table("orders").
		Select("payment_type, payment_provider, SUM(total) AS total_amount").
		Where("cashier_session_id = ?", sessionID).
		Group("payment_type, payment_provider").
		Scan(&rows).Error

	if err != nil {
		return nil, errors.Wrap(err, "failed to summarize payments from orders")
	}

	summary := make([]entity.PaymentSummary, len(rows))
	for i, row := range rows {
		summary[i] = entity.PaymentSummary{
			PaymentType:     row.PaymentType,
			PaymentProvider: row.PaymentProvider,
			TotalAmount:     row.TotalAmount,
		}
	}

	return summary, nil
}