package entity

import (
	"errors"
	"time"

	"github.com/gocql/gocql"
)

// Like represents a like entity for posts or comments.
// Uses composite primary key: (target_id, user_uid) for uniqueness.
type Like struct {
	ID         gocql.UUID `db:"id" partition_key:"true"`         // Like unique identifier
	TargetID   gocql.UUID `db:"target_id" clustering_key:"true"` // Target ID (post_id or comment_id)
	UserUID    string     `db:"user_uid" clustering_key:"true"`  // User UID who liked
	TargetType string     `db:"target_type"`                     // Target type: "post" or "comment"
	CreatedAt  int64      `db:"created_at"`                      // Creation timestamp
}

// TableName returns the Cassandra table name for Like entities.
func (l *Like) TableName() string {
	return "likes"
}

// Validate validates the Like entity
func (l *Like) Validate() error {
	var zeroUUID gocql.UUID
	if l.TargetID == zeroUUID {
		return errors.New("target_id is required")
	}
	if l.UserUID == "" {
		return errors.New("user_uid is required")
	}
	if l.TargetType != "post" && l.TargetType != "comment" {
		return errors.New("target_type must be 'post' or 'comment'")
	}
	return nil
}

// SetTimestamps sets the create timestamp
func (l *Like) SetTimestamps() {
	if l.CreatedAt == 0 {
		l.CreatedAt = time.Now().UTC().UnixNano() / 1e6 // milliseconds
	}
}

// IsNew returns true if this is a new like (no ID set)
func (l *Like) IsNew() bool {
	var zeroUUID gocql.UUID
	return l.ID == zeroUUID
}

// IsPostLike returns true if this like is for a post
func (l *Like) IsPostLike() bool {
	return l.TargetType == "post"
}

// IsCommentLike returns true if this like is for a comment
func (l *Like) IsCommentLike() bool {
	return l.TargetType == "comment"
}