package models

import (
	"time"

	"gorm.io/gorm"
)

// Language represents a supported language
type Language struct {
	ID         string    `gorm:"primaryKey;type:varchar(5)" json:"id"`
	Name       string    `gorm:"type:varchar(100);not null" json:"name"`
	NativeName string    `gorm:"type:varchar(100);not null" json:"native_name"`
	Code       string    `gorm:"type:varchar(10);not null;uniqueIndex" json:"code"`
	IsDefault  bool      `gorm:"default:false" json:"is_default"`
	IsActive   bool      `gorm:"default:true" json:"is_active"`
	SortOrder  int       `gorm:"default:0" json:"sort_order"`
	CreatedAt  time.Time `json:"created_at"`
	UpdatedAt  time.Time `json:"updated_at"`
}

// Translation represents a translatable string
type Translation struct {
	ID           uint      `gorm:"primaryKey" json:"id"`
	Key          string    `gorm:"type:varchar(200);not null;index" json:"key"`
	LanguageCode string    `gorm:"type:varchar(10);not null;index" json:"language_code"`
	Value        string    `gorm:"type:text;not null" json:"value"`
	Context      string    `gorm:"type:varchar(100)" json:"context"` // e.g., "navbar", "admin", "public"
	CreatedAt    time.Time `json:"created_at"`
	UpdatedAt    time.Time `json:"updated_at"`

	// Relationships
	Language Language `gorm:"foreignKey:LanguageCode;references:Code" json:"language,omitempty"`
}

// ContentTranslation represents translations for content like articles, activities, etc.
type ContentTranslation struct {
	ID              uint      `gorm:"primaryKey" json:"id"`
	ContentType     string    `gorm:"type:varchar(50);not null;index" json:"content_type"` // "article", "activity", "page", etc.
	ContentID       uint      `gorm:"not null;index" json:"content_id"`
	LanguageCode    string    `gorm:"type:varchar(10);not null;index" json:"language_code"`
	Title           string    `gorm:"type:varchar(500)" json:"title"`
	Content         string    `gorm:"type:text" json:"content"`
	Excerpt         string    `gorm:"type:text" json:"excerpt"`
	MetaTitle       string    `gorm:"type:varchar(200)" json:"meta_title"`
	MetaDescription string    `gorm:"type:varchar(500)" json:"meta_description"`
	CreatedAt       time.Time `json:"created_at"`
	UpdatedAt       time.Time `json:"updated_at"`

	// Relationships
	Language Language `gorm:"foreignKey:LanguageCode;references:Code" json:"language,omitempty"`
}

// UserLanguagePreference tracks user's preferred language
type UserLanguagePreference struct {
	ID           uint      `gorm:"primaryKey" json:"id"`
	UserID       uint      `gorm:"not null;uniqueIndex" json:"user_id"`
	LanguageCode string    `gorm:"type:varchar(10);not null" json:"language_code"`
	CreatedAt    time.Time `json:"created_at"`
	UpdatedAt    time.Time `json:"updated_at"`

	// Relationships
	User     User     `gorm:"foreignKey:UserID" json:"user,omitempty"`
	Language Language `gorm:"foreignKey:LanguageCode;references:Code" json:"language,omitempty"`
}

// TableName returns the table name for Language model
func (Language) TableName() string {
	return "languages"
}

// TableName returns the table name for Translation model
func (Translation) TableName() string {
	return "translations"
}

// TableName returns the table name for ContentTranslation model
func (ContentTranslation) TableName() string {
	return "content_translations"
}

// TableName returns the table name for UserLanguagePreference model
func (UserLanguagePreference) TableName() string {
	return "user_language_preferences"
}

// BeforeCreate sets default values
func (l *Language) BeforeCreate(tx *gorm.DB) error {
	if l.SortOrder == 0 {
		l.SortOrder = 100
	}
	return nil
}

// GetDefaultLanguage returns the default language
func GetDefaultLanguage(db *gorm.DB) (*Language, error) {
	var lang Language
	err := db.Where("is_default = ? AND is_active = ?", true, true).First(&lang).Error
	if err != nil {
		return nil, err
	}
	return &lang, nil
}

// GetActiveLanguages returns all active languages ordered by sort order
func GetActiveLanguages(db *gorm.DB) ([]Language, error) {
	var languages []Language
	err := db.Where("is_active = ?", true).Order("sort_order ASC, name ASC").Find(&languages).Error
	return languages, err
}

// GetTranslation returns a translation for a specific key and language
func GetTranslation(db *gorm.DB, key, languageCode string) (*Translation, error) {
	var translation Translation
	err := db.Where("key = ? AND language_code = ?", key, languageCode).First(&translation).Error
	if err != nil {
		return nil, err
	}
	return &translation, nil
}

// GetTranslationWithFallback returns a translation, falling back to default language if needed
func GetTranslationWithFallback(db *gorm.DB, key, languageCode string) (*Translation, error) {
	// Try requested language first
	translation, err := GetTranslation(db, key, languageCode)
	if err == nil {
		return translation, nil
	}

	// Fall back to default language
	defaultLang, err := GetDefaultLanguage(db)
	if err != nil {
		return nil, err
	}

	return GetTranslation(db, key, defaultLang.Code)
}