unrandomize randomness

go.mod

@@ -8,6 +8,7 @@ require (
 	github.com/go-ini/ini v1.67.0
 	github.com/gorilla/feeds v1.2.0
 	github.com/gorilla/mux v1.8.1
+	github.com/hashicorp/golang-lru/v2 v2.0.7
 	github.com/rivo/uniseg v0.4.7
 	golang.org/x/crypto v0.31.0
 	golang.org/x/term v0.27.0

go.sum

@@ -10,6 +10,8 @@ github.com/gorilla/feeds v1.2.0 h1:O6pBiXJ5JHhPvqy53NsjKOThq+dNFm8+DFrxBEdzSCc=
 github.com/gorilla/feeds v1.2.0/go.mod h1:WMib8uJP3BbY+X8Szd1rA5Pzhdfh+HCCAYT2z7Fza6Y=
 github.com/gorilla/mux v1.8.1 h1:TuBL49tXwgrFYWhqrNgrUNEY92u81SPhu7sTdzQEiWY=
 github.com/gorilla/mux v1.8.1/go.mod h1:AKf9I4AEqPTmMytcMc0KkNouC66V3BtZ4qD5fmWSiMQ=
+github.com/hashicorp/golang-lru/v2 v2.0.7 h1:a+bsQ5rvGLjzHuww6tVxozPZFVghXaHOwFs4luLUK2k=
+github.com/hashicorp/golang-lru/v2 v2.0.7/go.mod h1:QeFd9opnmA6QUJc5vARoKUSoFhyfM2/ZepoAG6RGpeM=
 github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
 github.com/kr/pretty v0.3.1/go.mod h1:hoEshYVHaxMs3cyo3Yncou5ZscifuDolrwPKZanG3xk=
 github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=

internal/cfg/config.go

@@ -50,6 +50,8 @@ var (
 	Motds []string
 
 	OverrideLogin string
+
+	UserModelBackendURL string
 )
 
 // WikiDir is a full path to the wiki storage directory, which also must be a
@@ -59,17 +61,18 @@ var WikiDir string
 // Config represents a Mycorrhiza wiki configuration file. This type is used
 // only when reading configs.
 type Config struct {
-	WikiName      string `comment:"This name appears in the header and on various pages."`
-	NaviTitleIcon string `comment:"This icon is used in the breadcrumbs bar."`
+	WikiName             string `comment:"This name appears in the header and on various pages."`
+	NaviTitleIcon        string `comment:"This icon is used in the breadcrumbs bar."`
 	Hyphae
 	Network
 	Authorization
-	CustomScripts `comment:"You can specify additional scripts to load on different kinds of pages, delimited by a comma ',' sign."`
-	Telegram      `comment:"You can enable Telegram authorization. Follow these instructions: https://core.telegram.org/widgets/login#setting-up-a-bot"`
-	ReplaceFrom   []string
-	ReplaceTo     []string
-	Motds         []string
-	OverrideLogin string
+	CustomScripts       `comment:"You can specify additional scripts to load on different kinds of pages, delimited by a comma ',' sign."`
+	Telegram            `comment:"You can enable Telegram authorization. Follow these instructions: https://core.telegram.org/widgets/login#setting-up-a-bot"`
+	ReplaceFrom         []string
+	ReplaceTo           []string
+	Motds               []string
+	OverrideLogin       string
+	UserModelBackendURL string
 }
 
 // Hyphae is a section of Config which has fields related to special hyphae.
@@ -206,6 +209,7 @@ func ReadConfigFile(path string) error {
 	ReplaceTo = cfg.ReplaceTo
 	Motds = cfg.Motds
 	OverrideLogin = cfg.OverrideLogin
+	UserModelBackendURL = cfg.UserModelBackendURL
 
 	// This URL makes much more sense. If no URL is set or the protocol is forgotten, assume HTTP.
 	if URL == "" {

internal/hyphae/iterators.go

@@ -26,6 +26,14 @@ func YieldExistingHyphae() chan ExistingHypha {
 	return ch
 }
 
+func GetAll() []ExistingHypha {
+	out := []ExistingHypha{}
+	for _, h := range byNames {
+		out = append(out, h)
+	}
+	return out
+}
+
 // FilterHyphaeWithText filters the source channel and yields only those hyphae than have text parts.
 func FilterHyphaeWithText(src chan ExistingHypha) chan ExistingHypha {
 	// TODO: reimplement as a function with a callback?

misc/handlers.go

@@ -2,12 +2,15 @@
 package misc
 
 import (
+	"bytes"
+	"encoding/json"
 	"io"
 	"log/slog"
 	"math/rand"
 	"mime"
 	"net/http"
 	"path/filepath"
+	"time"
 
 	"github.com/gorilla/mux"
 
@@ -98,9 +101,49 @@ func handlerUpdateHeaderLinks(w http.ResponseWriter, rq *http.Request) {
 	http.Redirect(w, rq, "/", http.StatusSeeOther)
 }
 
+var hclient http.Client = http.Client{
+	Timeout: 1 * time.Second,
+}
+
+type ModelReq struct {
+	Trace    []string `json:"trace"`
+	AllNames []string `json:"all_names"`
+}
+
+func accessModelBackend(trace []string, allNames []string) (*string, error) {
+	jsonData, err := json.Marshal(ModelReq {
+		Trace: trace,
+		AllNames: allNames,
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	r, err := hclient.Post(cfg.UserModelBackendURL, "application/json", bytes.NewBuffer(jsonData))
+	if err != nil {
+		return nil, err
+	}
+
+	reqBody, err := io.ReadAll(r.Body)
+	if err != nil {
+		return nil, err
+	}
+
+	var output string
+	err = json.Unmarshal(reqBody, &output)
+	if err != nil {
+		return nil, err
+	}
+
+	return &output, nil
+}
+
 // handlerRandom redirects to a random hypha.
 func handlerRandom(w http.ResponseWriter, rq *http.Request) {
 	util.PrepareRq(rq)
+
+	trace := util.ReadTrace(rq)
+
 	var (
 		randomHyphaName string
 		amountOfHyphae  = hyphae.Count()
@@ -110,13 +153,28 @@ func handlerRandom(w http.ResponseWriter, rq *http.Request) {
 		viewutil.HttpErr(viewutil.MetaFrom(w, rq), http.StatusNotFound, cfg.HomeHypha, lc.Get("ui.random_no_hyphae_tip"))
 		return
 	}
-	i := rand.Intn(amountOfHyphae)
-	for h := range hyphae.YieldExistingHyphae() {
-		if i == 0 {
-			randomHyphaName = h.CanonicalName()
-		}
-		i--
+
+	hyphae := hyphae.GetAll()
+
+	allNames := []string{}
+
+	for _, h := range hyphae {
+		allNames = append(allNames, h.CanonicalName())
 	}
+
+	var res *string
+	var err error
+	if cfg.UserModelBackendURL != "" {
+		res, err = accessModelBackend(trace, allNames)
+	}
+
+	if err != nil || res == nil || (res != nil && *res == "") {
+		i := rand.Intn(amountOfHyphae)
+		randomHyphaName = hyphae[i].CanonicalName()
+	} else {
+		randomHyphaName = *res
+	}
+
 	http.Redirect(w, rq, "/hypha/"+randomHyphaName, http.StatusSeeOther)
 }
 

util/util.go

@@ -3,10 +3,14 @@ package util
 import (
 	"crypto/rand"
 	"encoding/hex"
+	"hash/fnv"
 	"log/slog"
 	"net/http"
 	"strings"
 	"time"
+	insecureRand "math/rand"
+
+	"github.com/hashicorp/golang-lru/v2"
 
 	"github.com/bouncepaw/mycorrhiza/internal/cfg"
 	"github.com/bouncepaw/mycorrhiza/internal/files"
@@ -164,3 +168,99 @@ func GetMotd() string {
 	dayIndex := now / 86400
 	return cfg.Motds[dayIndex%int64(len(cfg.Motds))]
 }
+
+func RequestHeaderFingerprint(rq *http.Request) uint64 {
+	fprintHeaders := []string{"accept", "accept-encoding", "accept-language", "dnt", "host", "user-agent", "x-tls-fp"}
+	hasher := fnv.New64()
+
+	for _, hdr := range fprintHeaders {
+		if value := rq.Header.Get(hdr); value != "" {
+			hasher.Write([]byte(hdr))
+			hasher.Write([]byte(value))
+		}
+	}
+
+	return hasher.Sum64()
+}
+
+var ipLookup *lru.Cache[string, uint64]
+var fprintLookup *lru.Cache[uint64, uint64]
+
+func EstimateTrackingIdentifier(rq *http.Request) uint64 {
+	if ipLookup == nil || fprintLookup == nil {
+		var err error
+		ipLookup, err = lru.New[string, uint64](1<<20)
+		if err != nil {
+			slog.Error("cache create failed?", "error", err)
+		}
+		// golang...
+		fprintLookup, err = lru.New[uint64, uint64](1<<20)
+		if err != nil {
+			slog.Error("cache create failed?", "error", err)
+		}
+	}
+
+	ip := strings.Split(rq.RemoteAddr, ":")[0]
+	if val := rq.Header.Get("x-forwarded-for"); val != "" {
+		ip = val
+	}
+
+	fp := RequestHeaderFingerprint(rq)
+
+	// Try to look up by IP address. If that fails, look up by fingerprint, and update the record for that IP address.
+	// If that also fails, assign a random identifier to both.
+	id := insecureRand.Uint64()
+	if cid, ok := ipLookup.Get(ip); ok {
+		id = cid
+	} else {
+		if cid, ok := fprintLookup.Get(fp); ok {
+			id = cid
+			ipLookup.Add(ip, cid)
+		} else {
+			ipLookup.Add(ip, id)
+			fprintLookup.Add(fp, id)
+		}
+	}
+
+	return id
+}
+
+var visitHistory *lru.Cache[uint64, []string]
+const maxTraceLen int = 64
+
+func EnsureVisitHistoryExists() {
+	if visitHistory == nil {
+		var err error
+		visitHistory, err = lru.New[uint64, []string](1<<18)
+		if err != nil {
+			slog.Error("cache create failed?", "error", err)
+		}
+	}
+}
+
+func WriteTrace(rq *http.Request, hyphaName string) {
+	EnsureVisitHistoryExists()
+
+	trk := EstimateTrackingIdentifier(rq)
+	trace := []string{}
+	if htrace, ok := visitHistory.Get(trk); ok {
+		trace = htrace
+	}
+	trace = append(trace, hyphaName)
+	if len(trace) > maxTraceLen {
+		trace = trace[1:]
+	}
+	visitHistory.Add(trk, trace)
+}
+
+func ReadTrace(rq *http.Request) []string {
+	EnsureVisitHistoryExists()
+
+	trk := EstimateTrackingIdentifier(rq)
+	trace := []string{}
+	if htrace, ok := visitHistory.Get(trk); ok {
+		trace = htrace
+	}
+
+	return trace
+}

web/readers.go

@@ -218,6 +218,7 @@ func handlerBinary(w http.ResponseWriter, rq *http.Request) {
 // handlerHypha is the main hypha action that displays the hypha and the binary upload form along with some navigation.
 func handlerHypha(w http.ResponseWriter, rq *http.Request) {
 	util.PrepareRq(rq)
+
 	var (
 		hyphaName                               = util.HyphaNameFromRq(rq, "page", "hypha")
 		h                                       = hyphae.ByName(hyphaName)
@@ -243,6 +244,9 @@ func handlerHypha(w http.ResponseWriter, rq *http.Request) {
 			"IsMediaHypha":            false,
 		}
 	)
+
+	util.WriteTrace(rq, hyphaName)
+
 	slog.Info("reading hypha", "name", h.CanonicalName(), "can edit", data["GivenPermissionToModify"])
 	meta.BodyAttributes = map[string]string{
 		"cats": category_list,