package models

import (
	"database/sql"
	"database/sql/driver"
	"encoding/json"
	"time"
)

// NullableInt32 is a custom type to replace sql.NullInt32 for swagger compatibility
type NullableInt32 struct {
	Int32 int32 `json:"int32,omitempty"`
	Valid bool  `json:"valid"`
}

// Scan implements the sql.Scanner interface for NullableInt32
func (n *NullableInt32) Scan(value interface{}) error {
	var ni sql.NullInt32
	if err := ni.Scan(value); err != nil {
		return err
	}
	n.Int32 = ni.Int32
	n.Valid = ni.Valid
	return nil
}

// Value implements the driver.Valuer interface for NullableInt32
func (n NullableInt32) Value() (driver.Value, error) {
	if !n.Valid {
		return nil, nil
	}
	return n.Int32, nil
}

// Product represents the data structure for the product table
type Product struct {
	ID          string         `json:"id" db:"id"`
	Status      string         `json:"status" db:"status"`
	Sort        NullableInt32  `json:"sort,omitempty" db:"sort"`
	UserCreated sql.NullString `json:"user_created,omitempty" db:"user_created"`
	DateCreated sql.NullTime   `json:"date_created,omitempty" db:"date_created"`
	UserUpdated sql.NullString `json:"user_updated,omitempty" db:"user_updated"`
	DateUpdated sql.NullTime   `json:"date_updated,omitempty" db:"date_updated"`
	Name        sql.NullString `json:"name,omitempty" db:"name"`
}

// Custom JSON marshaling for Product
func (r Product) MarshalJSON() ([]byte, error) {
	type Alias Product
	aux := &struct {
		Sort        *int       `json:"sort,omitempty"`
		UserCreated *string    `json:"user_created,omitempty"`
		DateCreated *time.Time `json:"date_created,omitempty"`
		UserUpdated *string    `json:"user_updated,omitempty"`
		DateUpdated *time.Time `json:"date_updated,omitempty"`
		Name        *string    `json:"name,omitempty"`
		*Alias
	}{
		Alias: (*Alias)(&r),
	}

	if r.Sort.Valid {
		sort := int(r.Sort.Int32)
		aux.Sort = &sort
	}
	if r.UserCreated.Valid {
		aux.UserCreated = &r.UserCreated.String
	}
	if r.DateCreated.Valid {
		aux.DateCreated = &r.DateCreated.Time
	}
	if r.UserUpdated.Valid {
		aux.UserUpdated = &r.UserUpdated.String
	}
	if r.DateUpdated.Valid {
		aux.DateUpdated = &r.DateUpdated.Time
	}
	if r.Name.Valid {
		aux.Name = &r.Name.String
	}

	return json.Marshal(aux)
}

// Helper methods
func (r *Product) GetName() string {
	if r.Name.Valid {
		return r.Name.String
	}
	return ""
}

// Response struct for GET by ID
type ProductGetByIDResponse struct {
	Message string `json:"message"`
	Data    *Product   `json:"data"`
}

// Enhanced GET response with pagination and aggregation
type ProductGetResponse struct {
	Message string        `json:"message"`
	Data    []Product          `json:"data"`
	Meta    MetaResponse  `json:"meta"`
	Summary *AggregateData `json:"summary,omitempty"`
}

// Request struct for create
type ProductCreateRequest struct {
	Status string  `json:"status" validate:"required,oneof=draft active inactive"`
	Name   *string `json:"name,omitempty" validate:"omitempty,min=1,max=255"`
}

// Response struct for create
type ProductCreateResponse struct {
	Message string `json:"message"`
	Data    *Product   `json:"data"`
}

// Update request
type ProductUpdateRequest struct {
	ID     string  `json:"-" validate:"required,uuid4"` // ID dari URL path
	Status string  `json:"status" validate:"required,oneof=draft active inactive"`
	Name   *string `json:"name,omitempty" validate:"omitempty,min=1,max=255"`
}

// Response struct for update
type ProductUpdateResponse struct {
	Message string `json:"message"`
	Data    *Product   `json:"data"`
}

// Response struct for delete
type ProductDeleteResponse struct {
	Message string `json:"message"`
	ID      string `json:"id"`
}

// Metadata for pagination
type MetaResponse struct {
	Limit       int  `json:"limit"`
	Offset      int  `json:"offset"`
	Total       int  `json:"total"`
	TotalPages  int  `json:"total_pages"`
	CurrentPage int  `json:"current_page"`
	HasNext     bool `json:"has_next"`
	HasPrev     bool `json:"has_prev"`
}

// Aggregate data for summary
type AggregateData struct {
	TotalActive   int            `json:"total_active"`
	TotalDraft    int            `json:"total_draft"`
	TotalInactive int            `json:"total_inactive"`
	ByStatus      map[string]int `json:"by_status"`
	LastUpdated   *time.Time     `json:"last_updated,omitempty"`
	CreatedToday  int            `json:"created_today"`
	UpdatedToday  int            `json:"updated_today"`
}

// Error response
type ErrorResponse struct {
	Error     string    `json:"error"`
	Code      int       `json:"code"`
	Message   string    `json:"message"`
	Timestamp time.Time `json:"timestamp"`
}

// Filter struct for query parameters
type ProductFilter struct {
	Status   *string    `json:"status,omitempty" form:"status"`
	Search   *string    `json:"search,omitempty" form:"search"`
	DateFrom *time.Time `json:"date_from,omitempty" form:"date_from"`
	DateTo   *time.Time `json:"date_to,omitempty" form:"date_to"`
}

// Validation constants
const (
	StatusDraft    = "draft"
	StatusActive   = "active"
	StatusInactive = "inactive"
	StatusDeleted  = "deleted"
)

// ValidStatuses for validation
var ValidStatuses = []string{StatusDraft, StatusActive, StatusInactive}

// IsValidStatus helper function
func IsValidStatus(status string) bool {
	for _, validStatus := range ValidStatuses {
		if status == validStatus {
			return true
		}
	}
	return false
}