package store

import (
	"context"
	"fmt"
)

// ResetAllSyncedData deletes every synced activity for userID (cascading to its laps,
// activity_samples, and kind_assignments via ON DELETE CASCADE) and rewinds
// the backfill watermark to its initial state, so a subsequent Backfill
// starts a genuinely fresh pull instead of thinking history is already
// covered. Workout kinds (the user's taxonomy) are left untouched.
func (db *DB) ResetAllSyncedData(ctx context.Context, userID int64) error {
	tx, err := db.BeginTx(ctx, nil)
	if err != nil {
		return fmt.Errorf("begin reset tx: %w", err)
	}
	defer tx.Rollback()

	if _, err := tx.ExecContext(ctx, `DELETE FROM activities WHERE user_id = ?`, userID); err != nil {
		return fmt.Errorf("delete activities for user %d: %w", userID, err)
	}
	if _, err := tx.ExecContext(ctx, `UPDATE sync_state SET earliest_synced_date = NULL, backfill_complete = 0 WHERE user_id = ?`, userID); err != nil {
		return fmt.Errorf("reset sync state for user %d: %w", userID, err)
	}
	return tx.Commit()
}