package validator

import (
	"apskel-pos-be/internal/contract"
	"errors"
	"strings"

	"github.com/go-playground/validator/v10"
)

type GamificationValidator interface {
	// Tiers
	ValidateCreateTierRequest(req *contract.CreateTierRequest) (error, string)
	ValidateUpdateTierRequest(req *contract.UpdateTierRequest) (error, string)
	ValidateListTiersRequest(req *contract.ListTiersRequest) (error, string)

	// Omset Tracker
	ValidateCreateOmsetTrackerRequest(req *contract.CreateOmsetTrackerRequest) (error, string)
	ValidateUpdateOmsetTrackerRequest(req *contract.UpdateOmsetTrackerRequest) (error, string)
	ValidateListOmsetTrackerRequest(req *contract.ListOmsetTrackerRequest) (error, string)
	ValidateAddOmsetRequest(req *contract.AddOmsetRequest) (error, string)
}

type GamificationValidatorImpl struct {
	validate *validator.Validate
}

func NewGamificationValidator() *GamificationValidatorImpl {
	return &GamificationValidatorImpl{
		validate: validator.New(),
	}
}

// Tier Validators
func (v *GamificationValidatorImpl) ValidateCreateTierRequest(req *contract.CreateTierRequest) (error, string) {
	if err := v.validate.Struct(req); err != nil {
		return err, "VALIDATION_ERROR"
	}

	if req.Name != "" {
		req.Name = strings.TrimSpace(req.Name)
		if req.Name == "" {
			return errors.New("name cannot be empty or whitespace only"), "INVALID_NAME"
		}
		if len(req.Name) > 100 {
			return errors.New("name cannot exceed 100 characters"), "INVALID_NAME"
		}
	}

	if req.MinPoints < 0 {
		return errors.New("min points cannot be negative"), "INVALID_MIN_POINTS"
	}

	return nil, ""
}

func (v *GamificationValidatorImpl) ValidateUpdateTierRequest(req *contract.UpdateTierRequest) (error, string) {
	if err := v.validate.Struct(req); err != nil {
		return err, "VALIDATION_ERROR"
	}

	if req.Name != nil && *req.Name != "" {
		*req.Name = strings.TrimSpace(*req.Name)
		if *req.Name == "" {
			return errors.New("name cannot be empty or whitespace only"), "INVALID_NAME"
		}
		if len(*req.Name) > 100 {
			return errors.New("name cannot exceed 100 characters"), "INVALID_NAME"
		}
	}

	if req.MinPoints != nil && *req.MinPoints < 0 {
		return errors.New("min points cannot be negative"), "INVALID_MIN_POINTS"
	}

	return nil, ""
}

func (v *GamificationValidatorImpl) ValidateListTiersRequest(req *contract.ListTiersRequest) (error, string) {
	if err := v.validate.Struct(req); err != nil {
		return err, "VALIDATION_ERROR"
	}

	if req.Page <= 0 {
		req.Page = 1
	}
	if req.Limit <= 0 {
		req.Limit = 10
	}
	if req.Limit > 100 {
		req.Limit = 100
	}

	return nil, ""
}

// Omset Tracker Validators
func (v *GamificationValidatorImpl) ValidateCreateOmsetTrackerRequest(req *contract.CreateOmsetTrackerRequest) (error, string) {
	if err := v.validate.Struct(req); err != nil {
		return err, "VALIDATION_ERROR"
	}

	validPeriodTypes := []string{"DAILY", "WEEKLY", "MONTHLY", "TOTAL"}
	if !contains(validPeriodTypes, req.PeriodType) {
		return errors.New("invalid period type"), "INVALID_PERIOD_TYPE"
	}

	if req.Total < 0 {
		return errors.New("total cannot be negative"), "INVALID_TOTAL"
	}

	if req.PeriodEnd.Before(req.PeriodStart) {
		return errors.New("period end must be after period start"), "INVALID_PERIOD"
	}

	return nil, ""
}

func (v *GamificationValidatorImpl) ValidateUpdateOmsetTrackerRequest(req *contract.UpdateOmsetTrackerRequest) (error, string) {
	if err := v.validate.Struct(req); err != nil {
		return err, "VALIDATION_ERROR"
	}

	if req.PeriodType != nil {
		validPeriodTypes := []string{"DAILY", "WEEKLY", "MONTHLY", "TOTAL"}
		if !contains(validPeriodTypes, *req.PeriodType) {
			return errors.New("invalid period type"), "INVALID_PERIOD_TYPE"
		}
	}

	if req.Total != nil && *req.Total < 0 {
		return errors.New("total cannot be negative"), "INVALID_TOTAL"
	}

	if req.PeriodStart != nil && req.PeriodEnd != nil && req.PeriodEnd.Before(*req.PeriodStart) {
		return errors.New("period end must be after period start"), "INVALID_PERIOD"
	}

	return nil, ""
}

func (v *GamificationValidatorImpl) ValidateListOmsetTrackerRequest(req *contract.ListOmsetTrackerRequest) (error, string) {
	if err := v.validate.Struct(req); err != nil {
		return err, "VALIDATION_ERROR"
	}

	if req.Page <= 0 {
		req.Page = 1
	}
	if req.Limit <= 0 {
		req.Limit = 10
	}
	if req.Limit > 100 {
		req.Limit = 100
	}

	if req.PeriodType != "" {
		validPeriodTypes := []string{"DAILY", "WEEKLY", "MONTHLY", "TOTAL"}
		if !contains(validPeriodTypes, req.PeriodType) {
			return errors.New("invalid period type"), "INVALID_PERIOD_TYPE"
		}
	}

	return nil, ""
}

func (v *GamificationValidatorImpl) ValidateAddOmsetRequest(req *contract.AddOmsetRequest) (error, string) {
	if err := v.validate.Struct(req); err != nil {
		return err, "VALIDATION_ERROR"
	}

	if req.Amount <= 0 {
		return errors.New("amount must be greater than 0"), "INVALID_AMOUNT"
	}

	return nil, ""
}