Decouple the different contexts from each other (#24786)

Replace #16455

Close #21803

Mixing different Gitea contexts together causes some problems:

1. Unable to respond proper content when error occurs, eg: Web should
respond HTML while API should respond JSON
2. Unclear dependency, eg: it's unclear when Context is used in
APIContext, which fields should be initialized, which methods are
necessary.


To make things clear, this PR introduces a Base context, it only
provides basic Req/Resp/Data features.

This PR mainly moves code. There are still many legacy problems and
TODOs in code, leave unrelated changes to future PRs.

1 files changed, 9 insertions, 7 deletions

diff --git a/services/context/user.go b/services/context/user.go
index c713667bca..4e74aa50bd 100644
--- a/services/context/user.go
+++ b/services/context/user.go
@@ -15,7 +15,7 @@ import (
 // UserAssignmentWeb returns a middleware to handle context-user assignment for web routes
 func UserAssignmentWeb() func(ctx *context.Context) {
 	return func(ctx *context.Context) {
-		userAssignment(ctx, func(status int, title string, obj interface{}) {
+		errorFn := func(status int, title string, obj interface{}) {
 			err, ok := obj.(error)
 			if !ok {
 				err = fmt.Errorf("%s", obj)
@@ -25,7 +25,8 @@ func UserAssignmentWeb() func(ctx *context.Context) {
 			} else {
 				ctx.ServerError(title, err)
 			}
-		})
+		}
+		ctx.ContextUser = userAssignment(ctx.Base, ctx.Doer, errorFn)
 	}
 }
 
@@ -53,18 +54,18 @@ func UserIDAssignmentAPI() func(ctx *context.APIContext) {
 // UserAssignmentAPI returns a middleware to handle context-user assignment for api routes
 func UserAssignmentAPI() func(ctx *context.APIContext) {
 	return func(ctx *context.APIContext) {
-		userAssignment(ctx.Context, ctx.Error)
+		ctx.ContextUser = userAssignment(ctx.Base, ctx.Doer, ctx.Error)
 	}
 }
 
-func userAssignment(ctx *context.Context, errCb func(int, string, interface{})) {
+func userAssignment(ctx *context.Base, doer *user_model.User, errCb func(int, string, interface{})) (contextUser *user_model.User) {
 	username := ctx.Params(":username")
 
-	if ctx.IsSigned && ctx.Doer.LowerName == strings.ToLower(username) {
-		ctx.ContextUser = ctx.Doer
+	if doer != nil && doer.LowerName == strings.ToLower(username) {
+		contextUser = doer
 	} else {
 		var err error
-		ctx.ContextUser, err = user_model.GetUserByName(ctx, username)
+		contextUser, err = user_model.GetUserByName(ctx, username)
 		if err != nil {
 			if user_model.IsErrUserNotExist(err) {
 				if redirectUserID, err := user_model.LookupUserRedirect(username); err == nil {
@@ -79,4 +80,5 @@ func userAssignment(ctx *context.Context, errCb func(int, string, interface{}))
 			}
 		}
 	}
+	return contextUser
 }