[MM-28422] Enable processing of import files through API (#16062)

* Implement unzip function

* Implement FileSize method

* Implement path rewriting for bulk import

* Small improvements

* Add ImportSettings to config

* Implement ListImports API endpoint

* Enable uploading import files

* Implement import process job

* Add missing license headers

* Address reviews

* Make path sanitization a bit smarter

* Clean path before calculating Dir

* [MM-30008] Add mmctl support for file imports (#16301)

* Add mmctl support for import files

* Improve test

* Remove unnecessary handlers

* Use th.TestForSystemAdminAndLocal

* Make nouser id a constant

api4/import_test.go

@@ -0,0 +1,106 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package api4
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/mattermost/mattermost-server/v5/model"
+	"github.com/mattermost/mattermost-server/v5/utils/fileutils"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestListImports(t *testing.T) {
+	th := Setup(t)
+	defer th.TearDown()
+
+	testsDir, _ := fileutils.FindDir("tests")
+	require.NotEmpty(t, testsDir)
+
+	uploadNewImport := func(c *model.Client4, t *testing.T) string {
+		file, err := os.Open(testsDir + "/import_test.zip")
+		require.Nil(t, err)
+
+		info, err := file.Stat()
+		require.Nil(t, err)
+
+		us := &model.UploadSession{
+			Filename: info.Name(),
+			FileSize: info.Size(),
+			Type:     model.UploadTypeImport,
+		}
+
+		if c == th.LocalClient {
+			us.UserId = model.UploadNoUserID
+		}
+
+		u, resp := c.CreateUpload(us)
+		require.Nil(t, resp.Error)
+		require.NotNil(t, u)
+
+		finfo, resp := c.UploadData(u.Id, file)
+		require.Nil(t, resp.Error)
+		require.NotNil(t, finfo)
+
+		return u.Id
+	}
+
+	t.Run("no permissions", func(t *testing.T) {
+		imports, resp := th.Client.ListImports()
+		require.Error(t, resp.Error)
+		require.Equal(t, "api.context.permissions.app_error", resp.Error.Id)
+		require.Nil(t, imports)
+	})
+
+	dataDir, found := fileutils.FindDir("data")
+	require.True(t, found)
+
+	th.TestForSystemAdminAndLocal(t, func(t *testing.T, c *model.Client4) {
+		imports, resp := c.ListImports()
+		require.Nil(t, resp.Error)
+		require.Empty(t, imports)
+	}, "no imports")
+
+	th.TestForSystemAdminAndLocal(t, func(t *testing.T, c *model.Client4) {
+		id := uploadNewImport(c, t)
+		id2 := uploadNewImport(c, t)
+
+		importDir := filepath.Join(dataDir, "import")
+		f, err := os.Create(filepath.Join(importDir, "import.zip.tmp"))
+		require.Nil(t, err)
+		f.Close()
+
+		imports, resp := c.ListImports()
+		require.Nil(t, resp.Error)
+		require.NotEmpty(t, imports)
+		require.Len(t, imports, 2)
+		require.Contains(t, imports, id+"_import_test.zip")
+		require.Contains(t, imports, id2+"_import_test.zip")
+
+		require.Nil(t, os.RemoveAll(importDir))
+	}, "expected imports")
+
+	th.TestForSystemAdminAndLocal(t, func(t *testing.T, c *model.Client4) {
+		th.App.UpdateConfig(func(cfg *model.Config) { *cfg.ImportSettings.Directory = "import_new" })
+		defer th.App.UpdateConfig(func(cfg *model.Config) { *cfg.ImportSettings.Directory = "import" })
+
+		importDir := filepath.Join(dataDir, "import_new")
+
+		imports, resp := c.ListImports()
+		require.Nil(t, resp.Error)
+		require.Empty(t, imports)
+
+		id := uploadNewImport(c, t)
+		imports, resp = c.ListImports()
+		require.Nil(t, resp.Error)
+		require.NotEmpty(t, imports)
+		require.Len(t, imports, 1)
+		require.Equal(t, id+"_import_test.zip", imports[0])
+
+		require.Nil(t, os.RemoveAll(importDir))
+	}, "change import directory")
+}