Gitea 2 Gitea migration (#12657)

* first draft

* update gitea sdk to 9e280adb4da

* adapt feat of updated sdk

* releases now works

* break the Reactions loop

* use convertGiteaLabel

* fix endless loop because paggination is not supported there !!!

* rename gitea local uploader files

* pagination can bite you in the ass

* Version Checks

* lint

* docs

* rename gitea sdk import to miss future conficts

* go-swagger: dont scan the sdk structs

* make sure gitea can shutdown gracefully

* make GetPullRequests and GetIssues similar

* rm useles

* Add Test: started ...

* ... add tests ...

* Add tests and Fixing things

* Workaround missing SHA

* Adapt: Ensure that all migration requests are cancellable
(714ab71ddc)

* LINT: fix misspells in test set

* adapt ListMergeRequestAwardEmoji

* update sdk

* Return error when creating giteadownloader failed

* update sdk

* adapt new sdk

* adopt new features

* check version before err

* adapt: 'migrate service type switch page'

* optimize

* Fix DefaultBranch

* impruve

* handle subPath

* fix test

* Fix ReviewCommentPosition

* test GetReviews

* add DefaultBranch int test set

* rm unused

* Update SDK to v0.13.0

* addopt sdk changes

* found better link

* format template

* Update Docs

* Update Gitea SDK (v0.13.1)

vendor/code.gitea.io/sdk/gitea/version.go

@@ -0,0 +1,58 @@
+// Copyright 2020 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package gitea
+
+import (
+	"fmt"
+
+	"github.com/hashicorp/go-version"
+)
+
+// ServerVersion returns the version of the server
+func (c *Client) ServerVersion() (string, *Response, error) {
+	var v = struct {
+		Version string `json:"version"`
+	}{}
+	resp, err := c.getParsedResponse("GET", "/version", nil, nil, &v)
+	return v.Version, resp, err
+}
+
+// CheckServerVersionConstraint validates that the login's server satisfies a
+// given version constraint such as ">= 1.11.0+dev"
+func (c *Client) CheckServerVersionConstraint(constraint string) error {
+	c.versionLock.RLock()
+	if c.serverVersion == nil {
+		c.versionLock.RUnlock()
+		if err := c.loadClientServerVersion(); err != nil {
+			return err
+		}
+	} else {
+		c.versionLock.RUnlock()
+	}
+
+	check, err := version.NewConstraint(constraint)
+	if err != nil {
+		return err
+	}
+	if !check.Check(c.serverVersion) {
+		return fmt.Errorf("gitea server at %s does not satisfy version constraint %s", c.url, constraint)
+	}
+	return nil
+}
+
+// loadClientServerVersion init the serverVersion variable
+func (c *Client) loadClientServerVersion() error {
+	c.versionLock.Lock()
+	defer c.versionLock.Unlock()
+
+	raw, _, err := c.ServerVersion()
+	if err != nil {
+		return err
+	}
+	if c.serverVersion, err = version.NewVersion(raw); err != nil {
+		return err
+	}
+	return nil
+}