package syncstore

import (
	"fmt"
	"math/rand"
	"regexp"
	"strconv"
	"sync"
	"testing"
	"time"
)

func testStoreHelper(t *testing.T, drv StoreDriver) {
	store := NewStore(drv)

	v1 := "0.1.2"
	time10 := time.Now().UTC()
	t1, e1 := store.Create(v1)
	time11 := time.Now().UTC()
	if e1 != nil {
		t.Errorf("Create() failed (%v)", e1)
	}
	if t1 == nil {
		t.Fatal("Create() returned nil result")
	}
	idOk, err := regexp.MatchString("^[[:xdigit:]]{32}$", t1.ID)
	if err != nil {
		t.Errorf("Matching ID failed (%v)", err)
	}
	if idOk != true {
		t.Errorf("Create() returned an invalid ID: %s", t1.ID)
	}
	if t1.Version != v1 {
		t.Errorf(
			"Create() returned a mismatched version: \"%s\" (expected \"%s\")",
			t1.Version, v1)
	}
	if t1.LastUpdated.Before(time10) || t1.LastUpdated.After(time11) {
		t.Errorf(
			"Create() returned an incorrect lastUpdated timestamp: %v (should be between %v and %v)",
			t1.LastUpdated, time10, time11)
	}
	t2, e2 := store.Get(t1.ID)
	if e2 != nil {
		t.Errorf("Get() failed (%v)", e2)
	}
	if t2.Bookmarks != "" {
		t.Errorf("Expected empty bookmarks after Create(), got \"%s\" instead", t2.Bookmarks)
	}
	if t2.LastUpdated != t1.LastUpdated {
		t.Errorf("lastUpdate changed from %v to %v", t1.LastUpdated, t2.LastUpdated)
	}
	if t2.Version != t1.Version {
		t.Errorf("version changed from \"%s\" to \"%s\"", t1.Version, t2.Version)
	}
	testBookmark := "This is a test"
	time30 := time.Now().UTC()
	t3, e3 := store.Update(t1.ID, testBookmark, time.Time{})
	time31 := time.Now().UTC()
	if e3 != nil {
		t.Errorf("Update() with zero lastUpdated failed (%v)", e3)
	}
	if t3.Before(time30) || t3.After(time31) {
		t.Errorf(
			"Update() returned an incorrect lastUpdated timestamp: %v (should be between %v and %v)",
			t3, time30, time31)
	}
	t4, e4 := store.Get(t1.ID)
	if e4 != nil {
		t.Errorf("Get() failed with error (%v)", e4)
	}
	if t4.Bookmarks != testBookmark {
		t.Errorf("Get() did not return updated bookmarks (expected %v, got %v)",
			testBookmark, t4.Bookmarks)
	}
	testBookmark2 := "This is another test"
	_, e5 := store.Update(t1.ID, testBookmark2, t3.Add(time.Duration(-10000000)))
	if e5 != SyncConflictError {
		t.Errorf("Expected SyncConflictError on Update() with incorrect lastUpdated, got %v instead", e5)
	}
}

func TestStore_Mem(t *testing.T) {
	drv, _ := NewMemStore()
	testStoreHelper(t, drv)
}

func TestStore_FS(t *testing.T) {
	drv, _ := NewFSStore(t.TempDir())
	testStoreHelper(t, drv)
}

func testStoreConcurrencyWorker(wg *sync.WaitGroup, t *testing.T, store *Store, sid string, rounds int) {
	defer wg.Done()
	for i := 0; i < rounds; i++ {
		for {
			s, err := store.Get(sid)
			if err != nil {
				t.Error("Get() failed", err)
			}
			n := 0
			if s.Bookmarks != "" {
				n, err = strconv.Atoi(s.Bookmarks)
				if err != nil {
					t.Error("string to int conversion failed", err)
				}
			}
			_, err = store.Update(sid, fmt.Sprintf("%d", n+1), s.LastUpdated)
			if err == nil {
				break
			} else {
				time.Sleep(time.Duration(10000 * (rand.Int31()%300 + 10)))
			}
		}
	}
}

func testStoreConcurrencyHelper(t *testing.T, drv StoreDriver, workers, rounds int) {
	var wg sync.WaitGroup
	store := NewStore(drv)

	s, err := store.Create("0.1.2")
	if err != nil {
		t.Error("Create() failed")
		return
	}
	wg.Add(workers)
	for i := 0; i < workers; i++ {
		go testStoreConcurrencyWorker(&wg, t, &store, s.ID, rounds)
	}
	wg.Wait()
	data, err := store.Get(s.ID)
	if err != nil {
		t.Error("Get() failed: ", err)
	}
	n, err := strconv.Atoi(data.Bookmarks)
	if err != nil {
		t.Error("failed to parse an integer: ", err)
	}
	expected := workers * rounds
	if n != expected {
		t.Errorf("inconsistent result: expected %d, got %d", expected, n)
	}
}

func TestStore_Concurrency_Mem(t *testing.T) {
	drv, _ := NewMemStore()
	testStoreConcurrencyHelper(t, drv, 5, 50000)
}

func TestStore_Concurrency_FS(t *testing.T) {
	drv, _ := NewFSStore(t.TempDir())
	testStoreConcurrencyHelper(t, drv, 5, 1000)
}

func benchCreateHelper(b *testing.B, drv StoreDriver) {
	store := NewStore(drv)

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		_, _ = store.Create("0.1.2")
	}
}

func BenchmarkStore_Create_Mem(b *testing.B) {
	drv, _ := NewMemStore()
	benchCreateHelper(b, drv)
}

func BenchmarkStore_Create_FS(b *testing.B) {
	drv, _ := NewFSStore(b.TempDir())
	benchCreateHelper(b, drv)
}