package embeddedpostgres

import (
	"fmt"
	"io/ioutil"
	"os"
	"testing"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

type customLogger struct {
	logLines []byte
}

func (cl *customLogger) Write(p []byte) (n int, err error) {
	cl.logLines = append(cl.logLines, p...)
	return len(p), nil
}

func Test_SyncedLogger_CreateError(t *testing.T) {
	logger := customLogger{}
	_, err := newSyncedLogger("/not-exists-anywhere", &logger)

	assert.Error(t, err)
}

func Test_SyncedLogger_ErrorDuringFlush(t *testing.T) {
	logger := customLogger{}

	sl, slErr := newSyncedLogger("", &logger)

	assert.NoError(t, slErr)

	rmFileErr := os.Remove(sl.file.Name())

	assert.NoError(t, rmFileErr)

	err := sl.flush()

	assert.Error(t, err)
}

func Test_SyncedLogger_NoErrorDuringFlush(t *testing.T) {
	logger := customLogger{}

	sl, slErr := newSyncedLogger("", &logger)

	assert.NoError(t, slErr)

	err := os.WriteFile(sl.file.Name(), []byte("some logs\non a new line"), os.ModeAppend)

	assert.NoError(t, err)

	err = sl.flush()

	assert.NoError(t, err)

	assert.Equal(t, "some logs\non a new line", string(logger.logLines))
}

func Test_readLogsOrTimeout(t *testing.T) {
	logFile, err := ioutil.TempFile("", "prepare_database_test_log")
	if err != nil {
		panic(err)
	}

	logContent, err := readLogsOrTimeout(logFile)
	assert.NoError(t, err)
	assert.Equal(t, []byte(""), logContent)

	_, _ = logFile.Write([]byte("and here are the logs!"))

	logContent, err = readLogsOrTimeout(logFile)
	assert.NoError(t, err)
	assert.Equal(t, []byte("and here are the logs!"), logContent)

	require.NoError(t, os.Remove(logFile.Name()))
	logContent, err = readLogsOrTimeout(logFile)
	assert.Equal(t, []byte("logs could not be read"), logContent)
	assert.EqualError(t, err, fmt.Sprintf("open %s: no such file or directory", logFile.Name()))
}