package validator

import (
	"errors"
	"strings"

	"apskel-pos-be/internal/constants"
	"apskel-pos-be/internal/contract"

	"github.com/google/uuid"
)

type ExpenseValidator interface {
	ValidateCreateExpenseRequest(req *contract.CreateExpenseRequest) (error, string)
	ValidateUpdateExpenseRequest(req *contract.UpdateExpenseRequest) (error, string)
	ValidateListExpenseRequest(req *contract.ListExpenseRequest) (error, string)
}

type ExpenseValidatorImpl struct{}

func NewExpenseValidator() *ExpenseValidatorImpl {
	return &ExpenseValidatorImpl{}
}

func (v *ExpenseValidatorImpl) ValidateCreateExpenseRequest(req *contract.CreateExpenseRequest) (error, string) {
	if req == nil {
		return errors.New("request body is required"), constants.MissingFieldErrorCode
	}

	if strings.TrimSpace(req.Receiver) == "" {
		return errors.New("receiver is required"), constants.MissingFieldErrorCode
	}

	if strings.TrimSpace(req.TransactionDate) == "" {
		return errors.New("transaction_date is required"), constants.MissingFieldErrorCode
	}

	if strings.TrimSpace(req.CodeNumber) == "" {
		return errors.New("code_number is required"), constants.MissingFieldErrorCode
	}

	if strings.TrimSpace(req.ChartOfAccountID) == "" {
		return errors.New("chart_of_account_id is required"), constants.MissingFieldErrorCode
	}

	if _, err := uuid.Parse(req.ChartOfAccountID); err != nil {
		return errors.New("chart_of_account_id must be a valid UUID"), constants.MalformedFieldErrorCode
	}

	if strings.TrimSpace(req.OutletID) == "" {
		return errors.New("outlet_id is required"), constants.MissingFieldErrorCode
	}

	if _, err := uuid.Parse(req.OutletID); err != nil {
		return errors.New("outlet_id must be a valid UUID"), constants.MalformedFieldErrorCode
	}

	if req.Total <= 0 {
		return errors.New("total must be greater than 0"), constants.MalformedFieldErrorCode
	}

	if req.Tax < 0 {
		return errors.New("tax cannot be negative"), constants.MalformedFieldErrorCode
	}

	return nil, ""
}

func (v *ExpenseValidatorImpl) ValidateUpdateExpenseRequest(req *contract.UpdateExpenseRequest) (error, string) {
	if req == nil {
		return errors.New("request body is required"), constants.MissingFieldErrorCode
	}

	if req.Receiver != nil && strings.TrimSpace(*req.Receiver) == "" {
		return errors.New("receiver cannot be empty"), constants.MalformedFieldErrorCode
	}

	if req.CodeNumber != nil && strings.TrimSpace(*req.CodeNumber) == "" {
		return errors.New("code_number cannot be empty"), constants.MalformedFieldErrorCode
	}

	if req.ChartOfAccountID != nil {
		if strings.TrimSpace(*req.ChartOfAccountID) == "" {
			return errors.New("chart_of_account_id cannot be empty"), constants.MalformedFieldErrorCode
		}
		if _, err := uuid.Parse(*req.ChartOfAccountID); err != nil {
			return errors.New("chart_of_account_id must be a valid UUID"), constants.MalformedFieldErrorCode
		}
	}

	if req.OutletID != nil {
		if strings.TrimSpace(*req.OutletID) == "" {
			return errors.New("outlet_id cannot be empty"), constants.MalformedFieldErrorCode
		}
		if _, err := uuid.Parse(*req.OutletID); err != nil {
			return errors.New("outlet_id must be a valid UUID"), constants.MalformedFieldErrorCode
		}
	}

	if req.Total != nil && *req.Total <= 0 {
		return errors.New("total must be greater than 0"), constants.MalformedFieldErrorCode
	}

	if req.Tax != nil && *req.Tax < 0 {
		return errors.New("tax cannot be negative"), constants.MalformedFieldErrorCode
	}

	return nil, ""
}

func (v *ExpenseValidatorImpl) ValidateListExpenseRequest(req *contract.ListExpenseRequest) (error, string) {
	if req == nil {
		return errors.New("request body is required"), constants.MissingFieldErrorCode
	}

	if req.Page < 1 {
		return errors.New("page must be at least 1"), constants.MalformedFieldErrorCode
	}

	if req.Limit < 1 || req.Limit > 100 {
		return errors.New("limit must be between 1 and 100"), constants.MalformedFieldErrorCode
	}

	return nil, ""
}