// Copyright (c) 2020 Proton Technologies AG
//
// This file is part of ProtonMail Bridge.
//
// ProtonMail Bridge is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// ProtonMail Bridge is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with ProtonMail Bridge.  If not, see <https://www.gnu.org/licenses/>.

package cache

import (
	"bytes"
	"fmt"
	"testing"
	"time"

	bckMsg "github.com/ProtonMail/proton-bridge/pkg/message"
	"github.com/stretchr/testify/require"
)

var bs = &bckMsg.BodyStructure{} //nolint[gochecknoglobals]
const testUID = "testmsg"

func TestSaveAndLoad(t *testing.T) {
	msg := []byte("Test message")

	SaveMail(testUID, msg, bs)
	require.Equal(t, mailCache[testUID].data, msg)

	reader, _ := LoadMail(testUID)
	require.Equal(t, reader.Len(), len(msg))
	stored := make([]byte, len(msg))
	_, _ = reader.Read(stored)
	require.Equal(t, stored, msg)
}

func TestMissing(t *testing.T) {
	reader, _ := LoadMail("non-existing")
	require.Equal(t, reader.Len(), 0)
}

func TestClearOld(t *testing.T) {
	cacheTimeLimit = 10
	msg := []byte("Test message")
	SaveMail(testUID, msg, bs)
	time.Sleep(100 * time.Millisecond)

	reader, _ := LoadMail(testUID)
	require.Equal(t, reader.Len(), 0)
}

func TestClearBig(t *testing.T) {
	msg := []byte("Test message")

	nSize := 3
	cacheSizeLimit = nSize*len(msg) + 1
	cacheTimeLimit = int64(nSize * nSize * 2) // be sure the message will survive

	// It should have more than nSize items.
	for i := 0; i < nSize*nSize; i++ {
		time.Sleep(1 * time.Millisecond)
		SaveMail(fmt.Sprintf("%s%d", testUID, i), msg, bs)
		if len(mailCache) > nSize {
			t.Error("Number of items in cache should not be more than", nSize)
		}
	}

	// Check that the oldest are deleted first.
	for i := 0; i < nSize*nSize; i++ {
		iUID := fmt.Sprintf("%s%d", testUID, i)
		reader, _ := LoadMail(iUID)
		if i < nSize*(nSize-1) && reader.Len() != 0 {
			mail := mailCache[iUID]
			t.Error("LoadMail should return empty but have:", mail.data, iUID, mail.key.Timestamp)
		}
		stored := make([]byte, len(msg))
		_, _ = reader.Read(stored)

		if i >= nSize*(nSize-1) && !bytes.Equal(stored, msg) {
			t.Error("LoadMail returned wrong message:", stored, iUID)
		}
	}
}

func TestConcurency(t *testing.T) {
	msg := []byte("Test message")
	for i := 0; i < 10; i++ {
		go SaveMail(fmt.Sprintf("%s%d", testUID, i), msg, bs)
	}
}