package registry

import (
	"context"
	"path/filepath"
	"testing"
)

// 6b-N1: a claim transaction whose ROLLBACK (or NORMAL restore) fails
// discards its pooled connection. database/sql then opens a replacement, and
// that replacement must carry Open's pragmas: busy_timeout 5000, WAL and
// synchronous NORMAL, not SQLite's defaults (busy_timeout 0, synchronous
// FULL).
func TestClaimTransactionReplacementConnectionKeepsOpenPragmas(t *testing.T) {
	r, err := Open(filepath.Join(t.TempDir(), "registry.db"))
	if err != nil {
		t.Fatal(err)
	}
	defer r.Close()
	ctx := context.Background()
	// A connection-local marker: it survives only while the pool keeps the
	// same connection, so its loss proves the replacement happened.
	if _, err := r.sql.Exec("PRAGMA cache_size=-1234"); err != nil {
		t.Fatal(err)
	}
	tx, err := r.beginClaimTransaction(ctx, true)
	if err != nil {
		t.Fatal(err)
	}
	// End the transaction behind the wrapper so its ROLLBACK fails and the
	// connection is discarded with driver.ErrBadConn.
	if _, err := tx.ExecContext(ctx, "COMMIT"); err != nil {
		t.Fatal(err)
	}
	if err := tx.Rollback(); err == nil {
		t.Fatal("ROLLBACK after COMMIT succeeded; the discard path was not exercised")
	}
	var cache, busy, sync int
	var mode string
	if err := r.sql.QueryRow("PRAGMA cache_size").Scan(&cache); err != nil {
		t.Fatal(err)
	}
	if cache == -1234 {
		t.Fatal("the failed claim transaction's connection was kept; expected a replacement")
	}
	if err := r.sql.QueryRow("PRAGMA busy_timeout").Scan(&busy); err != nil {
		t.Fatal(err)
	}
	if err := r.sql.QueryRow("PRAGMA synchronous").Scan(&sync); err != nil {
		t.Fatal(err)
	}
	if err := r.sql.QueryRow("PRAGMA journal_mode").Scan(&mode); err != nil {
		t.Fatal(err)
	}
	if busy != 5000 || sync != 1 || mode != "wal" {
		t.Fatalf("replacement connection pragmas: busy_timeout=%d synchronous=%d journal_mode=%s, want 5000, 1 (NORMAL), wal", busy, sync, mode)
	}
}

// The first connection keeps exactly main's pragmas.
func TestOpenPragmasUnchangedOnFirstConnection(t *testing.T) {
	r, err := Open(filepath.Join(t.TempDir(), "registry.db"))
	if err != nil {
		t.Fatal(err)
	}
	defer r.Close()
	var busy, sync int
	var mode string
	if err := r.sql.QueryRow("PRAGMA busy_timeout").Scan(&busy); err != nil {
		t.Fatal(err)
	}
	if err := r.sql.QueryRow("PRAGMA synchronous").Scan(&sync); err != nil {
		t.Fatal(err)
	}
	if err := r.sql.QueryRow("PRAGMA journal_mode").Scan(&mode); err != nil {
		t.Fatal(err)
	}
	if busy != 5000 || sync != 1 || mode != "wal" {
		t.Fatalf("first connection pragmas: busy_timeout=%d synchronous=%d journal_mode=%s", busy, sync, mode)
	}
}