From cff7dafceaea50d3a533bdac7cd57f0a8fd692a4 Mon Sep 17 00:00:00 2001
From: Timur Ismagilov <bouncepaw2@ya.ru>
Date: Fri, 1 Jul 2022 20:51:22 +0500
Subject: [PATCH] Implement redirection hyphae #152

---
 categories/categories.go |  5 +++--
 categories/handlers.go   |  2 +-
 cfg/config.go            | 22 +++++++++++++---------
 hypview/hypview.go       |  3 ++-
 hypview/view_rename.html |  5 ++++-
 shroom/rename.go         | 33 +++++++++++++++++++++++++++++++--
 web/mutators.go          |  9 +++++----
 7 files changed, 59 insertions(+), 20 deletions(-)

diff --git a/categories/categories.go b/categories/categories.go
index 61d1345..b004e18 100644
--- a/categories/categories.go
+++ b/categories/categories.go
@@ -57,8 +57,8 @@ func hyphaeInCategory(catName string) (hyphaList []string) {
 
 var mutex sync.RWMutex
 
-// addHyphaToCategory adds the hypha to the category and updates the records on the disk. If the hypha is already in the category, nothing happens. Pass canonical names.
-func addHyphaToCategory(hyphaName, catName string) {
+// AddHyphaToCategory adds the hypha to the category and updates the records on the disk. If the hypha is already in the category, nothing happens. Pass canonical names.
+func AddHyphaToCategory(hyphaName, catName string) {
 	mutex.Lock()
 	if node, ok := hyphaToCategories[hyphaName]; ok {
 		node.storeCategory(catName)
@@ -109,4 +109,5 @@ func RenameHyphaInAllCategories(oldName, newName string) {
 			}
 		}
 	}
+	go saveToDisk()
 }
diff --git a/categories/handlers.go b/categories/handlers.go
index 3c30319..625ce66 100644
--- a/categories/handlers.go
+++ b/categories/handlers.go
@@ -74,6 +74,6 @@ func handlerAddToCategory(w http.ResponseWriter, rq *http.Request) {
 		return
 	}
 	log.Println(user.FromRequest(rq).Name, "added", hyphaName, "to", catName)
-	addHyphaToCategory(hyphaName, catName)
+	AddHyphaToCategory(hyphaName, catName)
 	http.Redirect(w, rq, redirectTo, http.StatusSeeOther)
 }
diff --git a/cfg/config.go b/cfg/config.go
index af1f071..e12f775 100644
--- a/cfg/config.go
+++ b/cfg/config.go
@@ -21,9 +21,10 @@ var (
 	NaviTitleIcon           string
 	UseSiblingHyphaeSidebar bool
 
-	HomeHypha        string
-	UserHypha        string
-	HeaderLinksHypha string
+	HomeHypha           string
+	UserHypha           string
+	HeaderLinksHypha    string
+	RedirectionCategory string
 
 	ListenAddr string
 	URL        string
@@ -64,9 +65,10 @@ type Config struct {
 
 // Hyphae is a section of Config which has fields related to special hyphae.
 type Hyphae struct {
-	HomeHypha        string `comment:"This hypha will be the main (index) page of your wiki, served on /."`
-	UserHypha        string `comment:"This hypha is used as a prefix for user hyphae."`
-	HeaderLinksHypha string `comment:"You can also specify a hypha to populate your own custom header links from."`
+	HomeHypha           string `comment:"This hypha will be the main (index) page of your wiki, served on /."`
+	UserHypha           string `comment:"This hypha is used as a prefix for user hyphae."`
+	HeaderLinksHypha    string `comment:"You can also specify a hypha to populate your own custom header links from."`
+	RedirectionCategory string `comment:"Redirection hyphae will be added to this category. Default: redirection."`
 }
 
 // Network is a section of Config that has fields related to network stuff.
@@ -113,9 +115,10 @@ func ReadConfigFile(path string) error {
 		NaviTitleIcon:           "🍄",
 		UseSiblingHyphaeSidebar: false,
 		Hyphae: Hyphae{
-			HomeHypha:        "home",
-			UserHypha:        "u",
-			HeaderLinksHypha: "",
+			HomeHypha:           "home",
+			UserHypha:           "u",
+			HeaderLinksHypha:    "",
+			RedirectionCategory: "redirection",
 		},
 		Network: Network{
 			ListenAddr: "127.0.0.1:1737",
@@ -175,6 +178,7 @@ func ReadConfigFile(path string) error {
 	HomeHypha = cfg.HomeHypha
 	UserHypha = cfg.UserHypha
 	HeaderLinksHypha = cfg.HeaderLinksHypha
+	RedirectionCategory = cfg.RedirectionCategory
 	if ListenAddr == "" {
 		ListenAddr = cfg.ListenAddr
 	}
diff --git a/hypview/hypview.go b/hypview/hypview.go
index 1e10598..216aebc 100644
--- a/hypview/hypview.go
+++ b/hypview/hypview.go
@@ -33,7 +33,8 @@ var (
 {{define "rename [[hypha]]?"}}Переименовать <a href="/hypha/{{.}}">{{beautifulName .}}</a>?{{end}}
 {{define "new name"}}Новое название:{{end}}
 {{define "rename recursively"}}Также переименовать подгифы{{end}}
-{{define "rename tip"}}Если вы переименуете эту гифу, сломаются все ссылки, ведущие на неё, а также исходящие относительные ссылки. Также вы потеряете всю текущую историю для нового названия. Переименовывайте аккуратно.{{end}}
+{{define "rename tip"}}Переименовывайте аккуратно. <a href="/help/en/rename">Документация на английском.</a>{{end}}
+{{define "leave redirections"}}Оставить перенаправления{{end}}
 `
 	chainNaviTitle   viewutil.Chain
 	chainEmptyHypha  viewutil.Chain
diff --git a/hypview/view_rename.html b/hypview/view_rename.html
index 11c5b55..8a49dd1 100644
--- a/hypview/view_rename.html
+++ b/hypview/view_rename.html
@@ -12,8 +12,11 @@
 
 			<input type="checkbox" id="recursive" name="recursive" value="true" checked/>
 			<label for="recursive">{{block "rename recursively" .}}Rename subhyphae too{{end}}</label>
+			<br>
+			<input type="checkbox" id="redirection" name="redirection" value="true" checked/>
+			<label for="redirection">{{block "leave redirections" .}}Leave redirections{{end}}</label>
 
-			<p>{{block "rename tip" .}}If you rename this hypha, all incoming links and all relative outcoming links will break. You will also lose all history for the new name. Rename carefully.{{end}}</p>
+			<p>{{block "rename tip" .}}Rename carefully. <a href="/help/en/rename">Documentation.</a>{{end}}</p>
 			<button type="submit" value="Confirm" class="btn">
 				{{template "confirm"}}
 			</button>
diff --git a/shroom/rename.go b/shroom/rename.go
index fc22fe6..24fb5bd 100644
--- a/shroom/rename.go
+++ b/shroom/rename.go
@@ -5,6 +5,9 @@ import (
 	"fmt"
 	"github.com/bouncepaw/mycorrhiza/backlinks"
 	"github.com/bouncepaw/mycorrhiza/categories"
+	"github.com/bouncepaw/mycorrhiza/cfg"
+	"github.com/bouncepaw/mycorrhiza/files"
+	"path/filepath"
 	"regexp"
 
 	"github.com/bouncepaw/mycorrhiza/history"
@@ -14,7 +17,8 @@ import (
 )
 
 // Rename renames the old hypha to the new name and makes a history record about that. Call if and only if the user has the permission to rename.
-func Rename(oldHypha hyphae.ExistingHypha, newName string, recursive bool, u *user.User) error {
+func Rename(oldHypha hyphae.ExistingHypha, newName string, recursive bool, leaveRedirections bool, u *user.User) error {
+	// * bouncepaw hates this function and related renaming functions
 	if newName == "" {
 		rejectRenameLog(oldHypha, u, "no new name given")
 		return errors.New("ui.rename_noname_tip")
@@ -62,7 +66,7 @@ func Rename(oldHypha hyphae.ExistingHypha, newName string, recursive bool, u *us
 			newName))
 	}
 
-	hop.WithFilesRenamed(renameMap).Apply()
+	hop.WithFilesRenamed(renameMap)
 
 	if len(hop.Errs) != 0 {
 		return hop.Errs[0]
@@ -76,11 +80,36 @@ func Rename(oldHypha hyphae.ExistingHypha, newName string, recursive bool, u *us
 		hyphae.RenameHyphaTo(h, newName, replaceName)
 		backlinks.UpdateBacklinksAfterRename(h, oldName)
 		categories.RenameHyphaInAllCategories(oldName, newName)
+		if leaveRedirections {
+			if err := leaveRedirection(oldName, newName, hop); err != nil {
+				hop.WithErrAbort(err)
+				return err
+			}
+		}
 	}
 
+	hop.Apply()
+
 	return nil
 }
 
+func leaveRedirection(oldName, newName string, hop *history.Op) error {
+	var (
+		text       = fmt.Sprintf("=> %s | ✏️ %s\n", newName, util.BeautifulName(newName))
+		emptyHypha = hyphae.ByName(oldName)
+	)
+	switch emptyHypha := emptyHypha.(type) {
+	case *hyphae.EmptyHypha:
+		h := hyphae.ExtendEmptyToTextual(emptyHypha, filepath.Join(files.HyphaeDir(), oldName+".myco"))
+		hyphae.Insert(h)
+		categories.AddHyphaToCategory(oldName, cfg.RedirectionCategory)
+		defer backlinks.UpdateBacklinksAfterEdit(h, "")
+		return writeTextToDisk(h, []byte(text), hop)
+	default:
+		return errors.New("invalid state for hypha " + oldName + " renamed to " + newName)
+	}
+}
+
 func findHyphaeToRename(superhypha hyphae.ExistingHypha, recursive bool) []hyphae.ExistingHypha {
 	hyphaList := []hyphae.ExistingHypha{superhypha}
 	if recursive {
diff --git a/web/mutators.go b/web/mutators.go
index 43c846f..d1632b7 100644
--- a/web/mutators.go
+++ b/web/mutators.go
@@ -124,9 +124,10 @@ func handlerRename(w http.ResponseWriter, rq *http.Request) {
 	}
 
 	var (
-		oldHypha  = h.(hyphae.ExistingHypha)
-		newName   = util.CanonicalName(rq.PostFormValue("new-name"))
-		recursive = rq.PostFormValue("recursive") == "true"
+		oldHypha          = h.(hyphae.ExistingHypha)
+		newName           = util.CanonicalName(rq.PostFormValue("new-name"))
+		recursive         = rq.PostFormValue("recursive") == "true"
+		leaveRedirections = rq.PostFormValue("redirection") == "true"
 	)
 
 	if rq.Method == "GET" {
@@ -134,7 +135,7 @@ func handlerRename(w http.ResponseWriter, rq *http.Request) {
 		return
 	}
 
-	if err := shroom.Rename(oldHypha, newName, recursive, u); err != nil {
+	if err := shroom.Rename(oldHypha, newName, recursive, leaveRedirections, u); err != nil {
 		log.Printf("%s tries to rename ‘%s’: %s", u.Name, oldHypha.CanonicalName(), err.Error())
 		viewutil.HttpErr(meta, http.StatusForbidden, oldHypha.CanonicalName(), lc.Get(err.Error())) // TODO: localize
 		return