config: add config package and wire it into server and handlers

Replace the hardcoded server.Config with an ini-backed config package
that reads /etc/openstore/openstore.conf then the user's config file, so
user settings override system ones and both override the built-in
defaults. Missing files are ignored rather than fatal.

Move route registration into a handlers package that owns the templates
and builds a Page view model, which removes the server -> handlers
import cycle along with the setter-based context injection.

6 files changed, 155 insertions, 31 deletions

diff --git a/internal/config/config.go b/internal/config/config.go
new file mode 100644
index 0000000..2be9dd6
--- /dev/null
+++ b/internal/config/config.go
@@ -0,0 +1,73 @@
+package config
+
+import (
+	"fmt"
+	"net/url"
+	"os"
+	"path/filepath"
+
+	"gopkg.in/ini.v1"
+)
+
+type Serve struct {
+	Addr string `ini:"addr"`
+}
+
+type Instance struct {
+	Name         string `ini:"name"`
+	ContactEmail string `ini:"contact-email"`
+	BaseURL      string `ini:"base-url"`
+}
+
+type Config struct {
+	Serve    Serve    `ini:"serve"`
+	Instance Instance `ini:"instance"`
+}
+
+var systemConfigPath = "/etc/openstore/openstore.conf"
+
+func DefaultPath() (string, error) {
+	dir, err := os.UserConfigDir()
+	if err != nil {
+		return "", err
+	}
+
+	return filepath.Join(dir, "openstore", "openstore.conf"), nil
+}
+
+func Load(filename string) (*Config, error) {
+	cfg, err := ini.LoadSources(ini.LoadOptions{
+		Loose:              true,
+		KeyValueDelimiters: "=",
+	}, systemConfigPath, filename)
+
+	if err != nil {
+		return nil, err
+	}
+
+	config := &Config{
+		Serve: Serve{
+			Addr: ":3000",
+		},
+		Instance: Instance{
+			Name:         "Openstore",
+			ContactEmail: "jane@doe.com",
+			BaseURL:      "https://www.example.com",
+		},
+	}
+
+	err = cfg.MapTo(config)
+	if err != nil {
+		return nil, err
+	}
+
+	u, err := url.Parse(config.Instance.BaseURL)
+	if err != nil || u.Host == "" || u.Scheme == "" {
+		return nil, fmt.Errorf(
+			"config: base-url must be an absolute url, got %s",
+			config.Instance.BaseURL,
+		)
+	}
+
+	return config, nil
+}
diff --git a/internal/server/handlers/handlers.go b/internal/server/handlers/handlers.go
new file mode 100644
index 0000000..958ca30
--- /dev/null
+++ b/internal/server/handlers/handlers.go
@@ -0,0 +1,25 @@
+package handlers
+
+import (
+	"html/template"
+	"net/http"
+
+	"codeberg.org/mihna123/openstore/internal/config"
+	"codeberg.org/mihna123/openstore/internal/web"
+)
+
+type Handler struct {
+	tmpl *template.Template
+	cfg  *config.Config
+}
+
+func Routes(conf *config.Config) *http.ServeMux {
+	handler := Handler{
+		tmpl: template.Must(template.ParseFS(web.Files, "templates/*.html")),
+		cfg:  conf,
+	}
+	mux := http.NewServeMux()
+	mux.HandleFunc("GET /{$}", handler.home)
+
+	return mux
+}
diff --git a/internal/server/handlers/pages.go b/internal/server/handlers/pages.go
new file mode 100644
index 0000000..8c5bfb5
--- /dev/null
+++ b/internal/server/handlers/pages.go
@@ -0,0 +1,24 @@
+package handlers
+
+import (
+	"log/slog"
+	"net/http"
+
+	"codeberg.org/mihna123/openstore/internal/config"
+)
+
+type Page struct {
+	Lang     string
+	Instance config.Instance
+	Data     any
+}
+
+func (h *Handler) home(w http.ResponseWriter, r *http.Request) {
+	page := Page{Lang: "en", Instance: h.cfg.Instance}
+	err := h.tmpl.ExecuteTemplate(w, "index.html", page)
+
+	if err != nil {
+		slog.Error("render template", "err", err.Error())
+		return
+	}
+}
diff --git a/internal/server/server.go b/internal/server/server.go
index a444958..a2f2d45 100644
--- a/internal/server/server.go
+++ b/internal/server/server.go
@@ -5,55 +5,39 @@ import (
 	"net"
 	"time"
 
-	"html/template"
 	"net/http"
 
-	"codeberg.org/mihna123/openstore/internal/web"
+	"codeberg.org/mihna123/openstore/internal/config"
+	"codeberg.org/mihna123/openstore/internal/server/handlers"
 )
 
-type Config struct {
-	Name string
-}
-
 type Server struct {
-	config *Config
-	tmpl   *template.Template
+	config *config.Config
 	mux    *http.ServeMux
 }
 
-func (s *Server) routes() {
-	s.mux.HandleFunc("GET /{$}", func(w http.ResponseWriter, r *http.Request) {
-		err := s.tmpl.ExecuteTemplate(w, "index.html", s.config)
-
-		if err != nil {
-			slog.Error("render template", "err", err.Error())
-			return
-		}
-	})
-}
-
-func (s *Server) Serve(addr string) error {
+func (s *Server) Serve() error {
 	httpSrv := &http.Server{
 		Handler:           logRequests(s.mux),
 		ReadHeaderTimeout: 5 * time.Second,
 		WriteTimeout:      10 * time.Second,
 	}
 
-	ln, err := net.Listen("tcp", addr)
+	ln, err := net.Listen("tcp", s.config.Serve.Addr)
 	if err != nil {
 		return err
 	}
 
-	slog.Info("listening", "name", s.config.Name, "addr", addr)
+	slog.Info("listening", "name", s.config.Instance.Name, "addr", s.config.Serve.Addr)
 	return httpSrv.Serve(ln)
 }
 
-func New(c *Config) *Server {
+func New(c *config.Config) *Server {
+	mux := handlers.Routes(c)
 	s := &Server{
 		config: c,
-		mux:    http.NewServeMux(),
-		tmpl:   template.Must(template.ParseFS(web.Files, "templates/*.html")),
+		mux:    mux,
 	}
-	s.routes()
+
 	return s
 }
diff --git a/internal/server/server_test.go b/internal/server/server_test.go
index 7e6a748..aea434f 100644
--- a/internal/server/server_test.go
+++ b/internal/server/server_test.go
@@ -7,6 +7,8 @@ import (
 	"os"
 	"strings"
 	"testing"
+
+	"codeberg.org/mihna123/openstore/internal/config"
 )
 
 func TestMain(m *testing.M) {
@@ -14,9 +16,23 @@ func TestMain(m *testing.M) {
 	os.Exit(m.Run())
 }
 
+func newTestConfig(t *testing.T) *config.Config {
+	t.Helper()
+	return &config.Config{
+		Serve: config.Serve{
+			Addr: ":3000",
+		},
+		Instance: config.Instance{
+			Name:         "TestStore",
+			ContactEmail: "test@email.com",
+			BaseURL:      "https://example.com",
+		},
+	}
+}
+
 func newTestServer(t *testing.T) *Server {
 	t.Helper()
-	return New(&Config{Name: "test"})
+	return New(newTestConfig(t))
 }
 
 func TestRoutes(t *testing.T) {
@@ -47,7 +63,9 @@ func TestRoutes(t *testing.T) {
 }
 
 func TestIndexRendersTemplate(t *testing.T) {
-	s := New(&Config{Name: "testname123"})
+	cfg := newTestConfig(t)
+	cfg.Instance.Name = "testname123"
+	s := New(cfg)
 
 	rec := httptest.NewRecorder()
 	s.mux.ServeHTTP(rec, httptest.NewRequest(http.MethodGet, "/", nil))
diff --git a/internal/web/templates/index.html b/internal/web/templates/index.html
index 54630e7..16ca1fe 100644
--- a/internal/web/templates/index.html
+++ b/internal/web/templates/index.html
@@ -3,11 +3,11 @@
   <head>
     <meta charset="UTF-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1" />
-    <title>{{ .Name }}</title>
-    <link href="css/style.css" rel="stylesheet" />
+    <title>{{ .Instance.Name }}</title>
+    <link href="/css/style.css" rel="stylesheet" />
   </head>
   <body>
-    <h1>Welcome to {{ .Name }}!</h1>
+    <h1>Welcome to {{ .Instance.Name }}!</h1>
     <p>Work in progress...</p>
   </body>
 </html>