// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
// See LICENSE.txt for license information.

package platform

import (
	"bytes"
	"encoding/json"
	"os"
	"path"
	"testing"

	"github.com/mattermost/mattermost/server/public/model"
	"github.com/mattermost/mattermost/server/public/shared/mlog"
	"github.com/mattermost/mattermost/server/v8/channels/testlib"
	"github.com/mattermost/mattermost/server/v8/config"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

func TestGetMattermostLog(t *testing.T) {
	mainHelper.Parallel(t)

	th := Setup(t)
	defer th.TearDown()

	// disable mattermost log file setting in config so we should get an warning
	th.Service.UpdateConfig(func(cfg *model.Config) {
		*cfg.LogSettings.EnableFile = false
	})

	fileData, err := th.Service.GetLogFile(th.Context)
	assert.Nil(t, fileData)
	assert.ErrorContains(t, err, "Unable to retrieve mattermost logs because LogSettings.EnableFile is set to false")

	dir, err := os.MkdirTemp("", "")
	require.NoError(t, err)
	t.Cleanup(func() {
		// MM-62438: Disable file target before cleaning up
		// to avoid a race between removing the directory and the file
		// getting written again.
		th.Service.UpdateConfig(func(cfg *model.Config) {
			*cfg.LogSettings.EnableFile = false
		})
		th.Service.Logger().Flush()

		err = os.RemoveAll(dir)
		assert.NoError(t, err)
	})

	// Enable log file but point to an empty directory to get an error trying to read the file
	th.Service.UpdateConfig(func(cfg *model.Config) {
		*cfg.LogSettings.EnableFile = true
		*cfg.LogSettings.FileLocation = dir
	})

	logLocation := config.GetLogFileLocation(dir)

	// There is no mattermost.log file yet, so this fails
	fileData, err = th.Service.GetLogFile(th.Context)
	assert.Nil(t, fileData)
	assert.ErrorContains(t, err, "failed read mattermost log file at path "+logLocation)

	// Happy path where we get a log file and no warning
	d1 := []byte("hello\ngo\n")
	err = os.WriteFile(logLocation, d1, 0777)
	require.NoError(t, err)

	fileData, err = th.Service.GetLogFile(th.Context)
	require.NoError(t, err)
	require.NotNil(t, fileData)
	assert.Equal(t, "mattermost.log", fileData.Filename)
	assert.Positive(t, len(fileData.Body))
}

func TestGetAdvancedLogs(t *testing.T) {
	mainHelper.Parallel(t)

	th := Setup(t)
	defer th.TearDown()

	t.Run("log messages from advanced logging settings get returned", func(t *testing.T) {
		dir, err := os.MkdirTemp("", "logs")
		require.NoError(t, err)
		t.Cleanup(func() {
			err = os.RemoveAll(dir)
			require.NoError(t, err)
		})

		// Setup log files for each setting
		optLDAP := map[string]string{
			"filename": path.Join(dir, "ldap.log"),
		}
		dataLDAP, err := json.Marshal(optLDAP)
		require.NoError(t, err)

		optStd := map[string]string{
			"filename": path.Join(dir, "std.log"),
		}
		dataStd, err := json.Marshal(optStd)
		require.NoError(t, err)

		// LogSettings config
		logCfg := mlog.LoggerConfiguration{
			"ldap-file": mlog.TargetCfg{
				Type:   "file",
				Format: "json",
				Levels: []mlog.Level{
					mlog.LvlLDAPError,
					mlog.LvlLDAPWarn,
					mlog.LvlLDAPInfo,
					mlog.LvlLDAPDebug,
				},
				Options: dataLDAP,
			},
			"std": mlog.TargetCfg{
				Type:   "file",
				Format: "json",
				Levels: []mlog.Level{
					mlog.LvlError,
				},
				Options: dataStd,
			},
		}
		logCfgData, err := json.Marshal(logCfg)
		require.NoError(t, err)

		th.Service.UpdateConfig(func(c *model.Config) {
			c.LogSettings.AdvancedLoggingJSON = logCfgData
			// Audit logs are not testiable as they as part of the server, not the platform
		})

		// Write some logs and ensure they're flushed
		logger := th.Service.Logger()

		logger.LogM([]mlog.Level{mlog.LvlLDAPInfo}, "Some LDAP info")
		logger.Error("Some Error")

		// Flush logger and wait a bit for filesystem
		err = logger.Flush()
		require.NoError(t, err)

		// Get and verify logs
		fileDatas, err := th.Service.GetAdvancedLogs(th.Context)
		require.NoError(t, err)
		for _, fd := range fileDatas {
			t.Log(fd.Filename)
		}
		require.Len(t, fileDatas, 2)

		// Helper to find file data by name
		findFile := func(name string) *model.FileData {
			for _, fd := range fileDatas {
				if fd.Filename == name {
					return fd
				}
			}
			return nil
		}

		// Check each log file
		ldapFile := findFile("ldap.log")
		require.NotNil(t, ldapFile)
		testlib.AssertLog(t, bytes.NewBuffer(ldapFile.Body), mlog.LvlLDAPInfo.Name, "Some LDAP info")

		stdFile := findFile("std.log")
		require.NotNil(t, stdFile)
		testlib.AssertLog(t, bytes.NewBuffer(stdFile.Body), mlog.LvlError.Name, "Some Error")
	})
	// Disable AdvancedLoggingJSON
	th.Service.UpdateConfig(func(c *model.Config) {
		c.LogSettings.AdvancedLoggingJSON = nil
	})
	t.Run("No logs returned when AdvancedLoggingJSON is empty", func(t *testing.T) {
		// Confirm no logs get returned
		fileDatas, err := th.Service.GetAdvancedLogs(th.Context)
		require.NoError(t, err)
		require.Len(t, fileDatas, 0)
	})
}