feat: enable reloading of law JSON files

1 files changed, 50 insertions, 24 deletions

diff --git a/lex-serve/main.go b/lex-serve/main.go
index ac67ad4..98cc403 100644
--- a/lex-serve/main.go
+++ b/lex-serve/main.go
@@ -10,7 +10,9 @@ import (
 	"net/http"
 	"net/url"
 	"os"
+	"path"
 	"strings"
+	"sync"
 
 	"github.com/BurntSushi/toml"
 )
@@ -33,7 +35,13 @@ func main() {
 		os.Exit(1)
 	}
 
-	var handler = handler{logger: log, domain: domain, lawsByCC: map[string]map[string]law{}}
+	lawsDir := os.Getenv("LAWS_DIR")
+	if lawsDir == "" {
+		log.Error("LAWS_DIR must be set")
+		os.Exit(1)
+	}
+
+	var handler = handler{logger: log, domain: domain, lawsDir: lawsDir, lawsByCC: map[string]map[string]law{}}
 	meta, err := toml.NewDecoder(bytes.NewReader(countriesTOML)).Decode(&handler.countries)
 	if err != nil {
 		log.Error("failed to parse countries.toml", Error(err))
@@ -44,30 +52,15 @@ func main() {
 		os.Exit(1)
 	}
 
-	lawFiles, err := os.ReadDir("laws")
-	if err != nil {
-		log.Error("failed to read laws/ directory", Error(err))
-		os.Exit(1)
-	}
-	for _, file := range lawFiles {
-		text, err := os.ReadFile("laws/" + file.Name())
-		if err != nil {
-			log.Error("failed to read file", Error(err), "path", "laws/"+file.Name())
-			os.Exit(1)
-		}
-		var laws []law
-		err = json.Unmarshal([]byte(text), &laws)
-		if err != nil {
-			log.Error("failed to parse file", Error(err), "path", file.Name())
-			os.Exit(1)
-		}
-		cc := strings.SplitN(file.Name(), ".", 2)[0]
-		handler.lawsByCC[cc] = map[string]law{}
-		for _, law := range laws {
-			if law.Redir != "" {
-				handler.lawsByCC[cc][law.Redir] = law
-			}
+	lawFiles, err := os.ReadDir(lawsDir)
+	if err == nil {
+		for _, file := range lawFiles {
+			cc := strings.SplitN(file.Name(), ".", 2)[0]
+			handler.loadLaws(cc)
 		}
+	} else if !os.IsNotExist(err) {
+		log.Error("failed to read laws directory", Error(err), "path", lawsDir)
+		os.Exit(1)
 	}
 	http.HandleFunc("/", handler.handle)
 	listener, err := net.Listen("unix", socketPath)
@@ -94,10 +87,16 @@ type handler struct {
 	logger    *slog.Logger
 	domain    string
 	countries map[string]country
+	lawsDir   string
 	lawsByCC  map[string]map[string]law
+	lawsMu    sync.RWMutex
 }
 
 func (h *handler) handle(w http.ResponseWriter, r *http.Request) {
+	if r.Host == "internal.invalid" {
+		h.loadLaws(r.URL.Query().Get("country"))
+		return
+	}
 	if r.Host == h.domain {
 		if r.URL.Path != "/" {
 			w.WriteHeader(http.StatusNotFound)
@@ -126,6 +125,8 @@ func (h *handler) handle(w http.ResponseWriter, r *http.Request) {
 	}
 	key := strings.TrimLeft(r.URL.Path, "/")
 	if len(key) > 0 {
+		h.lawsMu.RLock()
+		defer h.lawsMu.RUnlock()
 		val, ok := h.lawsByCC[cc][key]
 		if !ok {
 			w.WriteHeader(http.StatusNotFound)
@@ -149,6 +150,8 @@ func (h *handler) handle(w http.ResponseWriter, r *http.Request) {
 				w.WriteHeader(http.StatusBadRequest)
 			}
 		}
+		h.lawsMu.RLock()
+		defer h.lawsMu.RUnlock()
 		_, hasJSONLaws := h.lawsByCC[cc]
 		var html bytes.Buffer
 		err := tpl.ExecuteTemplate(&html, "search.html.tmpl", map[string]any{
@@ -166,6 +169,29 @@ func (h *handler) handle(w http.ResponseWriter, r *http.Request) {
 	}
 }
 
+func (h *handler) loadLaws(country string) {
+	filePath := path.Join(h.lawsDir, country+".json")
+	text, err := os.ReadFile(filePath)
+	if err != nil {
+		h.logger.Error("failed to read file", Error(err), "path", filePath)
+		return
+	}
+	var laws []law
+	err = json.Unmarshal([]byte(text), &laws)
+	if err != nil {
+		h.logger.Error("failed to parse file", Error(err), "path", filePath)
+		return
+	}
+	h.lawsMu.Lock()
+	defer h.lawsMu.Unlock()
+	h.lawsByCC[country] = map[string]law{}
+	for _, law := range laws {
+		if law.Redir != "" {
+			h.lawsByCC[country][law.Redir] = law
+		}
+	}
+}
+
 type law struct {
 	URL   string
 	Title string