Implement GCP Cloud Function

README.md

@@ -0,0 +1,20 @@
+# Puzzle Solver
+
+Match patterns and solve anagrams - handy for crossword fanatics.
+
+## Standalone Server
+
+```bash
+go run main.go
+```
+
+## Cloud Function
+
+To test using the Cloud Functions Framework:
+
+```bash
+env FUNCTION_TARGET=WordSearch WORDLIST_BUCKET=word-search-1729-assets \
+  WORDLIST_PATH=data/wordlist.txt LOCAL_ONLY=true go run cmd/main.go
+
+curl 'http://localhost:8080?mode=anagrams&pattern=idea'
+```

anagram/anagram.go

@@ -10,6 +10,18 @@ import (
 
 type DB interface {
 	FindAnagrams(s string) []string
+	Add(s string)
+}
+
+type HashDBImpl map[string][]string
+
+func New() HashDBImpl {
+	return make(HashDBImpl)
+}
+
+func (db HashDBImpl) Add(s string) {
+	k := toKey(s)
+	db[k] = append(db[k], s)
 }
 
 func toKey(s string) string {
@@ -18,15 +30,11 @@ func toKey(s string) string {
 	return string(xs)
 }
 
-type HashDBImpl map[string][]string
-
 func Load(r io.Reader) (DB, error) {
-	db := make(HashDBImpl)
+	db := New()
 	sc := bufio.NewScanner(r)
 	for sc.Scan() {
-		s := sc.Text()
+		db.Add(sc.Text())
-		k := toKey(s)
-		db[k] = append(db[k], s)
 
 	}
 	if err := sc.Err(); err != nil {

assets/custom.css

@@ -3,10 +3,11 @@ div.center {
 }
 
 div#results {
-    overflow-y: auto;
+    height: 60dvh;
-    max-height: 70dvh;
 }
 
 div#results > ul {
     list-style-type: none;
+    overflow-y: auto;
+    height: 100%;
 }

cloudfn/cloudfn.go

@@ -0,0 +1,141 @@
+package cloudfn
+
+import (
+	"bufio"
+	"context"
+	"fmt"
+	"log"
+	"net/http"
+	"os"
+	"sort"
+	"text/template"
+
+	"cloud.google.com/go/storage"
+	"github.com/GoogleCloudPlatform/functions-framework-go/functions"
+	"github.com/ray1729/puzzle-solver/anagram"
+	"github.com/ray1729/puzzle-solver/match"
+	"github.com/rs/cors"
+)
+
+var anagramDB anagram.DB
+var matchDB match.DB
+
+func initializeDB(ctx context.Context, bucketName, objectName string) error {
+	client, err := storage.NewClient(ctx)
+	if err != nil {
+		return fmt.Errorf("error creating storage client: %v", err)
+	}
+	r, err := client.Bucket(bucketName).Object(objectName).NewReader(ctx)
+	if err != nil {
+		return fmt.Errorf("error opening gs://%s/%s: %v", bucketName, objectName, err)
+	}
+	defer r.Close()
+	anagramDB = anagram.New()
+	matchDB = match.New()
+	sc := bufio.NewScanner(r)
+	for sc.Scan() {
+		s := sc.Text()
+		anagramDB.Add(s)
+		matchDB.Add(s)
+	}
+	if err := sc.Err(); err != nil {
+		return fmt.Errorf("error reading gs://%s/%s: %v", bucketName, objectName, err)
+	}
+	return nil
+}
+
+func init() {
+	ctx := context.Background()
+	bucketName := mustGetenv("WORDLIST_BUCKET")
+	objectName := mustGetenv("WORDLIST_PATH")
+	log.Println("Initializing databases")
+	if err := initializeDB(ctx, bucketName, objectName); err != nil {
+		panic(err)
+	}
+	var corsHandler = cors.Default()
+	log.Println("Registering HTTP function with the Functions Framework")
+	functions.HTTP("WordSearch", func(w http.ResponseWriter, r *http.Request) {
+		corsHandler.ServeHTTP(w, r, handleFormSubmission)
+	})
+}
+
+func mustGetenv(s string) string {
+	v := os.Getenv(s)
+	if len(v) == 0 {
+		panic(fmt.Sprintf("environment variable %s not set", s))
+	}
+	return v
+}
+
+func handleFormSubmission(w http.ResponseWriter, r *http.Request) {
+	if err := r.ParseForm(); err != nil {
+		log.Printf("error parsing form: %v", err)
+		http.Error(w, "error parsing form", http.StatusBadRequest)
+		return
+	}
+	mode := r.Form.Get("mode")
+	pattern := r.Form.Get("pattern")
+	if len(pattern) == 0 {
+		http.Error(w, "Missing pattern", http.StatusBadRequest)
+		return
+	}
+	switch mode {
+	case "match":
+		results := matchResults(matchDB, pattern)
+		renderTemplate(w, resultsTmpl, results)
+	case "anagrams":
+		results := anagramResults(anagramDB, pattern)
+		renderTemplate(w, resultsTmpl, results)
+	default:
+		log.Printf("invalid mode: %s", mode)
+		http.Error(w, fmt.Sprintf("Invalid mode: %s", mode), http.StatusBadRequest)
+	}
+}
+
+func anagramResults(db anagram.DB, pattern string) ResultParams {
+	var params ResultParams
+	params.Results = db.FindAnagrams(pattern)
+	if len(params.Results) > 0 {
+		params.Preamble = fmt.Sprintf("Anagrams of %q:", pattern)
+	} else {
+		params.Preamble = fmt.Sprintf("Found no anagrams of %q", pattern)
+	}
+	sort.Slice(params.Results, func(i, j int) bool { return params.Results[i] < params.Results[j] })
+	return params
+}
+
+func matchResults(db match.DB, pattern string) ResultParams {
+	var params ResultParams
+	params.Results = db.FindMatches(pattern)
+	if len(params.Results) > 0 {
+		params.Preamble = fmt.Sprintf("Matches for %q:", pattern)
+	} else {
+		params.Preamble = fmt.Sprintf("Found no matches for %q", pattern)
+	}
+	sort.Slice(params.Results, func(i, j int) bool { return params.Results[i] < params.Results[j] })
+	return params
+}
+
+func renderTemplate(w http.ResponseWriter, t *template.Template, params any) {
+	err := t.Execute(w, params)
+	if err != nil {
+		log.Printf("Error rendering template %s: %v", t.Name(), err)
+		http.Error(w, "Internal server error", http.StatusInternalServerError)
+	}
+}
+
+type ResultParams struct {
+	Preamble string
+	Results  []string
+}
+
+var resultsTmpl = template.Must(template.New("results").Parse(`
+{{ with .Preamble }}
+<p>{{ . }}</p>
+{{ end }}
+<ul>
+{{ range .Results }}
+  <li>{{.}}</li>
+{{ end }}
+</ul>
+`))

cmd/main.go

@@ -0,0 +1,29 @@
+package main
+
+import (
+	"log"
+	"os"
+
+	// Blank-import the function package so the init() runs
+	"github.com/GoogleCloudPlatform/functions-framework-go/funcframework"
+	_ "github.com/ray1729/puzzle-solver/cloudfn"
+)
+
+func main() {
+	// Use PORT environment variable, or default to 8080.
+	port := "8080"
+	if envPort := os.Getenv("PORT"); envPort != "" {
+		port = envPort
+	}
+
+	// By default, listen on all interfaces. If testing locally, run with
+	// LOCAL_ONLY=true to avoid triggering firewall warnings and
+	// exposing the server outside of your own machine.
+	hostname := ""
+	if localOnly := os.Getenv("LOCAL_ONLY"); localOnly == "true" {
+		hostname = "127.0.0.1"
+	}
+	if err := funcframework.StartHostPort(hostname, port); err != nil {
+		log.Fatalf("funcframework.StartHostPort: %v\n", err)
+	}
+}

fix-wordlist/main.go

@@ -0,0 +1,25 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"log"
+	"os"
+	"strings"
+
+	"golang.org/x/text/encoding/charmap"
+)
+
+func main() {
+	dec := charmap.ISO8859_1.NewDecoder()
+	sc := bufio.NewScanner(dec.Reader(os.Stdin))
+	for sc.Scan() {
+		s := strings.TrimSpace(sc.Text())
+		if len(s) > 0 {
+			fmt.Println(s)
+		}
+	}
+	if err := sc.Err(); err != nil {
+		log.Fatal(err)
+	}
+}

go.mod

@@ -2,4 +2,44 @@ module github.com/ray1729/puzzle-solver
 
 go 1.21.1
 
-require golang.org/x/text v0.13.0 // indirect
+require (
+	cloud.google.com/go/storage v1.33.0
+	github.com/GoogleCloudPlatform/functions-framework-go v1.8.0
+	github.com/rs/cors v1.10.1
+	golang.org/x/text v0.13.0
+)
+
+require (
+	cloud.google.com/go v0.110.4 // indirect
+	cloud.google.com/go/compute v1.20.1 // indirect
+	cloud.google.com/go/compute/metadata v0.2.3 // indirect
+	cloud.google.com/go/functions v1.15.1 // indirect
+	cloud.google.com/go/iam v1.1.0 // indirect
+	github.com/cloudevents/sdk-go/v2 v2.14.0 // indirect
+	github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da // indirect
+	github.com/golang/protobuf v1.5.3 // indirect
+	github.com/google/go-cmp v0.5.9 // indirect
+	github.com/google/s2a-go v0.1.4 // indirect
+	github.com/google/uuid v1.3.0 // indirect
+	github.com/googleapis/enterprise-certificate-proxy v0.2.5 // indirect
+	github.com/googleapis/gax-go/v2 v2.12.0 // indirect
+	github.com/json-iterator/go v1.1.10 // indirect
+	github.com/modern-go/concurrent v0.0.0-20180228061459-e0a39a4cb421 // indirect
+	github.com/modern-go/reflect2 v0.0.0-20180701023420-4b7aa43c6742 // indirect
+	go.opencensus.io v0.24.0 // indirect
+	go.uber.org/atomic v1.4.0 // indirect
+	go.uber.org/multierr v1.1.0 // indirect
+	go.uber.org/zap v1.10.0 // indirect
+	golang.org/x/crypto v0.11.0 // indirect
+	golang.org/x/net v0.12.0 // indirect
+	golang.org/x/oauth2 v0.10.0 // indirect
+	golang.org/x/sys v0.10.0 // indirect
+	golang.org/x/xerrors v0.0.0-20220907171357-04be3eba64a2 // indirect
+	google.golang.org/api v0.132.0 // indirect
+	google.golang.org/appengine v1.6.7 // indirect
+	google.golang.org/genproto v0.0.0-20230706204954-ccb25ca9f130 // indirect
+	google.golang.org/genproto/googleapis/api v0.0.0-20230706204954-ccb25ca9f130 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20230711160842-782d3b101e98 // indirect
+	google.golang.org/grpc v1.56.2 // indirect
+	google.golang.org/protobuf v1.31.0 // indirect
+)

main.go

@@ -1,37 +1,40 @@
 package main
 
 import (
+	"bufio"
 	"log"
 	"net/http"
 	"os"
 
 	"github.com/ray1729/puzzle-solver/anagram"
-	"github.com/ray1729/puzzle-solver/grep"
+	"github.com/ray1729/puzzle-solver/match"
 	"github.com/ray1729/puzzle-solver/server"
 )
 
-var grepDB grep.DB
+var matchDB match.DB
 var anagramDB anagram.DB
 
 func init() {
-	f, err := os.Open("/usr/share/dict/british-english-huge")
+	f, err := os.Open("wordlist.txt")
 	if err != nil {
 		log.Fatalf("Error opening word list: %v", err)
 	}
 	defer f.Close()
-	grepDB, err = grep.Load(f)
+	matchDB = match.New()
-	if err != nil {
+	anagramDB = anagram.New()
-		log.Fatalf("Error loading grep database:  %v", err)
+	sc := bufio.NewScanner(f)
+	for sc.Scan() {
+		s := sc.Text()
+		matchDB.Add(s)
+		anagramDB.Add(s)
 	}
-	f.Seek(0, 0)
+	if err := sc.Err(); err != nil {
-	anagramDB, err = anagram.Load(f)
+		log.Fatalf("Error loading databases: %v", err)
-	if err != nil {
-		log.Fatalf("Error loading anagram database: %v", err)
 	}
 }
 
 func main() {
-	s := server.New("./assets", grepDB, anagramDB)
+	s := server.New("./assets", matchDB, anagramDB)
 	address := ":8000"
 	log.Printf("Listening on %s", address)
 	if err := http.ListenAndServe(address, s); err != nil {

match/match.go

@@ -1,4 +1,4 @@
-package grep
+package match
 
 import (
 	"bufio"
@@ -9,6 +9,20 @@ import (
 
 type DB interface {
 	FindMatches(s string) []string
+	Add(s string)
+}
+
+type PrefixTreeImpl struct {
+	Root *Node
+}
+
+func New() PrefixTreeImpl {
+	return PrefixTreeImpl{Root: &Node{}}
+}
+
+func (db PrefixTreeImpl) Add(s string) {
+	xs := util.LowerCaseAlpha(s)
+	db.Root.add(xs, s)
 }
 
 type Node struct {
@@ -17,7 +31,7 @@ type Node struct {
 	Results  []string
 }
 
-func (n *Node) Add(xs []byte, s string) {
+func (n *Node) add(xs []byte, s string) {
 	if len(xs) == 0 {
 		n.Results = append(n.Results, s)
 		return
@@ -34,16 +48,14 @@ func (n *Node) Add(xs []byte, s string) {
 		child = &Node{Value: x}
 		n.Children = append(n.Children, child)
 	}
-	child.Add(xs[1:], s)
+	child.add(xs[1:], s)
 }
 
 func Load(r io.Reader) (DB, error) {
-	db := &Node{}
+	db := New()
 	sc := bufio.NewScanner(r)
 	for sc.Scan() {
-		s := sc.Text()
+		db.Add(sc.Text())
-		xs := util.LowerCaseAlpha(s)
-		db.Add(xs, s)
 	}
 	if err := sc.Err(); err != nil {
 		return nil, err
@@ -51,8 +63,8 @@ func Load(r io.Reader) (DB, error) {
 	return db, nil
 }
 
-func (n *Node) FindMatches(s string) []string {
+func (db PrefixTreeImpl) FindMatches(s string) []string {
-	return n.find(util.LowerCaseAlphaOrDot(s))
+	return db.Root.find(util.LowerCaseAlphaOrDot(s))
 }
 
 func (n *Node) find(xs []byte) []string {

server/server.go

@@ -8,13 +8,16 @@ import (
 	"sort"
 
 	"github.com/ray1729/puzzle-solver/anagram"
-	"github.com/ray1729/puzzle-solver/grep"
+	"github.com/ray1729/puzzle-solver/match"
 )
 
-func New(assetsPath string, grepDB grep.DB, anagramDB anagram.DB) http.Handler {
+func New(assetsPath string, matchDB match.DB, anagramDB anagram.DB) http.Handler {
 	mux := http.NewServeMux()
 	mux.Handle("/assets/", http.StripPrefix("/assets/", http.FileServer(http.Dir(assetsPath))))
-	mux.HandleFunc("/", handler(grepDB, anagramDB))
+	mux.HandleFunc("/search", searchHandler(matchDB, anagramDB))
+	mux.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
+		renderTemplate(w, home, nil)
+	})
 	return withRequestLogger(mux)
 }
 
@@ -25,7 +28,7 @@ func withRequestLogger(h http.Handler) http.Handler {
 	})
 }
 
-func handler(grepDB grep.DB, anagramDB anagram.DB) func(w http.ResponseWriter, r *http.Request) {
+func searchHandler(matchDB match.DB, anagramDB anagram.DB) func(w http.ResponseWriter, r *http.Request) {
 	return func(w http.ResponseWriter, r *http.Request) {
 		if err := r.ParseForm(); err != nil {
 			log.Printf("error parsing form: %v", err)
@@ -34,13 +37,13 @@ func handler(grepDB grep.DB, anagramDB anagram.DB) func(w http.ResponseWriter, r
 		}
 		switch r.Form.Get("mode") {
 		case "match":
-			params := matchResults(grepDB, r.Form.Get("pattern"))
+			params := matchResults(matchDB, r.Form.Get("pattern"))
 			renderTemplate(w, results, params)
 		case "anagrams":
 			params := anagramResults(anagramDB, r.Form.Get("pattern"))
 			renderTemplate(w, results, params)
 		default:
-			renderTemplate(w, home, nil)
+			renderTemplate(w, results, ResultParams{})
 		}
 	}
 }
@@ -57,7 +60,7 @@ func anagramResults(db anagram.DB, pattern string) ResultParams {
 	return params
 }
 
-func matchResults(db grep.DB, pattern string) ResultParams {
+func matchResults(db match.DB, pattern string) ResultParams {
 	var params ResultParams
 	params.Results = db.FindMatches(pattern)
 	if len(params.Results) > 0 {

server/templates.go

@@ -19,11 +19,12 @@ var home = template.Must(template.New("home").Parse(`
   </header>
 
   <main>
-	<form action="/" method="get" hx-boost="true" hx-target="#results" hx-replace="innerHTML" hx-on::after-request="this.reset()">
+	<form action="/search" method="post" hx-boost="true" hx-target="#results">
 	  <div class="center">
 	    <input type="text" name="pattern" required></input>
 	    <button name="mode" value="match">Match</button>
 	    <button name="mode" value="anagrams">Anagrams</button>
+		<button type="reset">Clear</button>
 	  </div>
     </form>
 	<div id="results">