From 6bc79e5ebf77e257d747092dabcf11360c7026ff Mon Sep 17 00:00:00 2001
From: 6543 <6543@obermui.de>
Date: Fri, 11 Nov 2022 19:03:17 +0100
Subject: [PATCH] wip

---
 server/handler.go | 11 ++++++-----
 server/try.go     | 43 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 49 insertions(+), 5 deletions(-)

diff --git a/server/handler.go b/server/handler.go
index 460875c..c25fa2a 100644
--- a/server/handler.go
+++ b/server/handler.go
@@ -93,7 +93,7 @@ func Handler(mainDomainSuffix, rawDomain string,
 		// tryBranch checks if a branch exists and populates the target variables. If canonicalLink is non-empty, it will
 		// also disallow search indexing and add a Link header to the canonical URL.
 		// TODO: move into external func to not alert vars indirectly
-		tryBranch := func(log zerolog.Logger, repo, branch string, _path []string, canonicalLink string) bool {
+		tryBranch1 := func(log zerolog.Logger, repo, branch string, _path []string, canonicalLink string) bool {
 			if repo == "" {
 				log.Debug().Msg("tryBranch: repo == ''")
 				return false
@@ -150,13 +150,14 @@ func Handler(mainDomainSuffix, rawDomain string,
 			// raw.codeberg.org/example/myrepo/@main/index.html
 			if len(pathElements) > 2 && strings.HasPrefix(pathElements[2], "@") {
 				log.Debug().Msg("raw domain preparations, now trying with specified branch")
-				if tryBranch(log,
-					targetRepo, pathElements[2][1:], pathElements[3:],
+				if newRepo, newPath, newBranch, newTimestamp, works := tryBranch2(log, ctx, giteaClient,
+					targetOwner, targetRepo, pathElements[2][1:], pathElements[3:],
 					giteaRoot+"/"+targetOwner+"/"+targetRepo+"/src/branch/%b/%p",
-				) {
+				); works {
+					targetOptions.BranchTimestamp = *newTimestamp
 					log.Debug().Msg("tryBranch, now trying upstream 1")
 					tryUpstream(ctx, giteaClient, mainDomainSuffix, trimmedHost,
-						targetOptions, targetOwner, targetRepo, targetBranch, targetPath,
+						targetOptions, targetOwner, newRepo, newBranch, newPath,
 						canonicalDomainCache)
 					return
 				}
diff --git a/server/try.go b/server/try.go
index 135c1e0..ccad226 100644
--- a/server/try.go
+++ b/server/try.go
@@ -2,13 +2,16 @@ package server
 
 import (
 	"net/http"
+	"path"
 	"strings"
+	"time"
 
 	"codeberg.org/codeberg/pages/html"
 	"codeberg.org/codeberg/pages/server/cache"
 	"codeberg.org/codeberg/pages/server/context"
 	"codeberg.org/codeberg/pages/server/gitea"
 	"codeberg.org/codeberg/pages/server/upstream"
+	"github.com/rs/zerolog"
 )
 
 // tryUpstream forwards the target request to the Gitea API, and shows an error page on failure.
@@ -47,3 +50,43 @@ func tryUpstream(ctx *context.Context, giteaClient *gitea.Client,
 		html.ReturnErrorPage(ctx, "", ctx.StatusCode)
 	}
 }
+
+func tryBranch2(log zerolog.Logger, ctx *context.Context, giteaClient *gitea.Client,
+	repoOwner, repoName, branch string, _path []string, canonicalLink string) (
+	targetRepo, targetPath, targetBranch string, branchTimestamp *time.Time,
+	works bool) {
+	if repoName == "" {
+		log.Debug().Msg("tryBranch: repo == ''")
+		return "", "", "", nil, false
+	}
+
+	// Replace "~" to "/" so we can access branch that contains slash character
+	// Branch name cannot contain "~" so doing this is okay
+	branch = strings.ReplaceAll(branch, "~", "/")
+
+	// Check if the branch exists, otherwise treat it as a file path
+	branchTimestampResult := upstream.GetBranchTimestamp(giteaClient, repoOwner, repoName, branch)
+	if branchTimestampResult == nil {
+		log.Debug().Msg("tryBranch: branch doesn't exist")
+		return "", "", "", nil, false
+	}
+
+	// Branch exists, use it
+	targetRepo = repoName
+	targetPath = path.Join(_path...)
+	targetBranch = branchTimestampResult.Branch
+
+	branchTimestamp = &branchTimestampResult.Timestamp
+
+	if canonicalLink != "" {
+		// Hide from search machines & add canonical link
+		ctx.RespWriter.Header().Set("X-Robots-Tag", "noarchive, noindex")
+		ctx.RespWriter.Header().Set("Link",
+			strings.NewReplacer("%b", targetBranch, "%p", targetPath).Replace(canonicalLink)+
+				"; rel=\"canonical\"",
+		)
+	}
+
+	log.Debug().Msg("tryBranch: true")
+	return
+}