package entities

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

	"github.com/google/uuid"
	"gorm.io/gorm"
)

type RewardType string

const (
	RewardTypeVoucher  RewardType = "VOUCHER"
	RewardTypePhysical RewardType = "PHYSICAL"
	RewardTypeDigital  RewardType = "DIGITAL"
	RewardTypeBalance  RewardType = "BALANCE"
)

// StringSlice is a custom type for []string that implements sql.Scanner and driver.Valuer
type StringSlice []string

// Scan implements the sql.Scanner interface for StringSlice
func (s *StringSlice) Scan(value interface{}) error {
	if value == nil {
		*s = StringSlice{}
		return nil
	}

	var bytes []byte
	switch v := value.(type) {
	case []byte:
		bytes = v
	case string:
		bytes = []byte(v)
	default:
		return fmt.Errorf("cannot scan %T into StringSlice", value)
	}

	return json.Unmarshal(bytes, s)
}

// Value implements the driver.Valuer interface for StringSlice
func (s StringSlice) Value() (driver.Value, error) {
	if s == nil {
		return nil, nil
	}
	return json.Marshal(s)
}

type TermsAndConditions struct {
	Sections   []TncSection `json:"sections"`
	ExpiryDays int          `json:"expiry_days"`
}

// Scan implements the sql.Scanner interface for TermsAndConditions
func (t *TermsAndConditions) Scan(value interface{}) error {
	if value == nil {
		*t = TermsAndConditions{}
		return nil
	}

	var bytes []byte
	switch v := value.(type) {
	case []byte:
		bytes = v
	case string:
		bytes = []byte(v)
	default:
		return fmt.Errorf("cannot scan %T into TermsAndConditions", value)
	}

	return json.Unmarshal(bytes, t)
}

// Value implements the driver.Valuer interface for TermsAndConditions
func (t TermsAndConditions) Value() (driver.Value, error) {
	return json.Marshal(t)
}

type TncSection struct {
	Title string   `json:"title"`
	Rules []string `json:"rules"`
}

type Reward struct {
	ID             uuid.UUID               `gorm:"type:uuid;primary_key;default:gen_random_uuid()" json:"id"`
	Name           string                  `gorm:"type:varchar(150);not null" json:"name"`
	RewardType     RewardType              `gorm:"type:varchar(50);not null" json:"reward_type"`
	CostPoints     int64                   `gorm:"type:bigint;not null" json:"cost_points"`
	Stock          *int                    `gorm:"type:int" json:"stock,omitempty"`
	MaxPerCustomer int                     `gorm:"type:int;default:1" json:"max_per_customer"`
	Tnc            *TermsAndConditions     `gorm:"type:jsonb" json:"tnc,omitempty"`
	Metadata       *map[string]interface{} `gorm:"type:jsonb" json:"metadata,omitempty"`
	Images         *StringSlice            `gorm:"type:jsonb" json:"images,omitempty"`
	CreatedAt      time.Time               `gorm:"type:timestamp;default:now()" json:"created_at"`
	UpdatedAt      time.Time               `gorm:"type:timestamp;default:now()" json:"updated_at"`
}

func (Reward) TableName() string {
	return "rewards"
}

func (r *Reward) BeforeCreate(tx *gorm.DB) error {
	if r.ID == uuid.Nil {
		r.ID = uuid.New()
	}
	return nil
}

func (r *Reward) BeforeUpdate(tx *gorm.DB) error {
	r.UpdatedAt = time.Now()
	return nil
}

type ListRewardsRequest struct {
	Page       int    `form:"page" binding:"min=1"`
	Limit      int    `form:"limit" binding:"min=1,max=100"`
	Search     string `form:"search"`
	RewardType string `form:"reward_type"`
	MinPoints  *int64 `form:"min_points"`
	MaxPoints  *int64 `form:"max_points"`
	HasStock   *bool  `form:"has_stock"`
}