package fixes

import (
	"context"
	"database/sql"
	"fmt"
	errlog "mal/pkg"
)

func init() {
	Register(Fix{
		ID: "20260528_backfill_avatar_url",
		Apply: func(ctx context.Context, sqlDB *sql.DB, deps Dependencies) error {
			if deps.DefaultAvatarURL == nil {
				return fmt.Errorf("default avatar URL dependency is required")
			}

			rows, err := sqlDB.QueryContext(ctx, `SELECT id, username FROM user WHERE avatar_url = ''`)
			if err != nil {
				return fmt.Errorf("query users missing avatar_url: %w", err)
			}
			defer errlog.Close(rows, "failed to close avatar backfill rows")

			type userRow struct {
				id       string
				username string
			}
			toUpdate := make([]userRow, 0, 64)
			for rows.Next() {
				var r userRow
				if err := rows.Scan(&r.id, &r.username); err != nil {
					return fmt.Errorf("scan user missing avatar_url: %w", err)
				}
				toUpdate = append(toUpdate, r)
			}
			if err := rows.Err(); err != nil {
				return fmt.Errorf("iterate users missing avatar_url: %w", err)
			}

			for _, u := range toUpdate {
				avatarURL := deps.DefaultAvatarURL(u.username)
				if _, err := sqlDB.ExecContext(ctx, `UPDATE user SET avatar_url = ? WHERE id = ?`, avatarURL, u.id); err != nil {
					return fmt.Errorf("update avatar_url for user %s: %w", u.id, err)
				}
			}

			return nil
		},
	})
}