package sqlite

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

func TestNewConnectionReadsWhileWriteIsOpen(t *testing.T) {
	db, err := Open(filepath.Join(t.TempDir(), "t.db"))
	if err != nil {
		t.Fatal(err)
	}
	defer db.Close()
	if _, err := db.Exec(`create table t (x integer)`); err != nil {
		t.Fatal(err)
	}

	tx, err := db.Begin()
	if err != nil {
		t.Fatal(err)
	}
	defer tx.Rollback()
	if _, err := tx.Exec(`insert into t values (1)`); err != nil {
		t.Fatal(err)
	}

	start := time.Now()
	var n int
	if err := db.QueryRow(`select count(*) from t`).Scan(&n); err != nil {
		t.Fatalf("read on a fresh connection while a write is open: %v", err)
	}
	if took := time.Since(start); took > time.Second {
		t.Fatalf("read on a fresh connection waited %v behind the open write", took)
	}
}

func TestOpenPopulatedFileWhileWriteIsOpen(t *testing.T) {
	path := filepath.Join(t.TempDir(), "t.db")
	writer, err := Open(path)
	if err != nil {
		t.Fatal(err)
	}
	defer writer.Close()
	if _, err := writer.Exec(`create table t (x integer)`); err != nil {
		t.Fatal(err)
	}
	tx, err := writer.Begin()
	if err != nil {
		t.Fatal(err)
	}
	defer tx.Rollback()
	if _, err := tx.Exec(`insert into t values (1)`); err != nil {
		t.Fatal(err)
	}

	start := time.Now()
	other, err := Open(path)
	if err != nil {
		t.Fatalf("opening a populated file while a write is open: %v", err)
	}
	defer other.Close()
	if took := time.Since(start); took > time.Second {
		t.Fatalf("opening a populated file waited %v behind the open write", took)
	}
}

func TestFreshFileGetsIncrementalAutoVacuum(t *testing.T) {
	db, err := Open(filepath.Join(t.TempDir(), "t.db"))
	if err != nil {
		t.Fatal(err)
	}
	defer db.Close()
	if _, err := db.Exec(`create table t (x integer)`); err != nil {
		t.Fatal(err)
	}

	var mode int
	if err := db.QueryRow(`pragma auto_vacuum`).Scan(&mode); err != nil {
		t.Fatal(err)
	}
	if mode != 2 {
		t.Fatalf("auto_vacuum = %d, want 2 (incremental)", mode)
	}
}