package models

import (
	"gorm.io/gorm"
	"time"
)

// Translation represents a polymorphic translation for any entity
type Translation struct {
	BaseModel
	Title       string            `gorm:"size:255;not null"`
	Content     string            `gorm:"type:text"` // Markdown formatted content
	Description string            `gorm:"type:text"`
	Language    string            `gorm:"size:50;not null"`
	Status      TranslationStatus `gorm:"size:50;default:'draft'"`
	PublishedAt *time.Time

	// Polymorphic relationship
	TranslatableID   uint   `gorm:"not null"`
	TranslatableType string `gorm:"size:50;not null"` // "Work", "Author", "Book", "Country", etc.

	// Translator information
	TranslatorID *uint
	Translator   *User `gorm:"foreignKey:TranslatorID"`

	// Additional metadata
	IsOriginalLanguage bool   `gorm:"default:false"`
	AudioURL           string `gorm:"size:512"`
	DateTranslated     *time.Time
}

// TranslationField represents a specific translatable field
type TranslationField struct {
	BaseModel
	TranslationID uint
	Translation   *Translation `gorm:"foreignKey:TranslationID"`
	FieldName     string       `gorm:"size:100;not null"` // e.g., "title", "description", "biography"
	FieldValue    string       `gorm:"type:text;not null"`
	Language      string       `gorm:"size:50;not null"`
}

// TranslatableEntity interface for entities that can have translations
type TranslatableEntity interface {
	GetID() uint
	GetType() string
	GetDefaultLanguage() string
}

// Persistence is owned by repositories; models remain persistence-agnostic

// GetTranslatableFields returns the fields that can be translated for an entity type
func GetTranslatableFields(entityType string) []string {
	fieldMappings := map[string][]string{
		"Work":      {"title", "content", "description"},
		"Author":    {"name", "biography"},
		"Book":      {"title", "description"},
		"Country":   {"name"},
		"Publisher": {"name", "description"},
		"Source":    {"name", "description"},
	}

	if fields, exists := fieldMappings[entityType]; exists {
		return fields
	}
	return []string{}
}

// BeforeSave hook for Translation to ensure title is set
func (t *Translation) BeforeSave(tx *gorm.DB) error {
	if t.Title == "" {
		t.Title = "Untitled Translation"
	}
	return nil
}

// Interface implementations for existing models

// Work implements TranslatableEntity
func (w *Work) GetID() uint                { return w.ID }
func (w *Work) GetType() string            { return "Work" }
func (w *Work) GetDefaultLanguage() string { return w.Language }

// Author implements TranslatableEntity
func (a *Author) GetID() uint                { return a.ID }
func (a *Author) GetType() string            { return "Author" }
func (a *Author) GetDefaultLanguage() string { return a.Language }

// Book implements TranslatableEntity
func (b *Book) GetID() uint                { return b.ID }
func (b *Book) GetType() string            { return "Book" }
func (b *Book) GetDefaultLanguage() string { return b.Language }

// Country implements TranslatableEntity
func (c *Country) GetID() uint                { return c.ID }
func (c *Country) GetType() string            { return "Country" }
func (c *Country) GetDefaultLanguage() string { return c.Language }

// Publisher implements TranslatableEntity
func (p *Publisher) GetID() uint                { return p.ID }
func (p *Publisher) GetType() string            { return "Publisher" }
func (p *Publisher) GetDefaultLanguage() string { return p.Language }

// Source implements TranslatableEntity
func (s *Source) GetID() uint                { return s.ID }
func (s *Source) GetType() string            { return "Source" }
func (s *Source) GetDefaultLanguage() string { return s.Language }