Initial commit

internal/web/web.go

@@ -0,0 +1,131 @@
+package web
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"html/template"
+	"log/slog"
+	"net"
+	"net/http"
+	"os"
+	"os/signal"
+	"strconv"
+	"sync"
+	"syscall"
+	"time"
+
+	"gardomatic.kleiax.de/lib/client"
+	"gardomatic.kleiax.de/internal/vcs"
+	"github.com/go-playground/form/v4"
+)
+
+var (
+	version = vcs.Version()
+)
+
+// Config contains web listener, API endpoint, and browser cookie settings.
+type Config struct {
+	Host              string
+	Port              int
+	Env               string
+	APIBaseURL        string
+	SessionCookieName string
+	CookieSecure      bool
+}
+
+type application struct {
+	config        Config
+	logger        *slog.Logger
+	templateCache map[string]*template.Template
+	formDecoder   *form.Decoder
+	apiClient     *client.Client
+	wg            sync.WaitGroup
+}
+
+// New creates a web application configured to communicate with the Gardomatic API.
+func New(cfg Config) (*application, error) {
+	var handler slog.Handler = slog.NewTextHandler(os.Stdout, nil)
+	if cfg.Env == "production" {
+		handler = slog.NewJSONHandler(os.Stdout, nil)
+	}
+	logger := slog.New(handler)
+
+	templateCache, err := newTemplateCache()
+	if err != nil {
+		return nil, fmt.Errorf("create template cache: %w", err)
+	}
+
+	formDecoder := form.NewDecoder()
+	options := []client.Option{}
+	if cfg.SessionCookieName != "" {
+		options = append(options, client.WithSessionCookieName(cfg.SessionCookieName))
+	}
+	apiClient, err := client.New(cfg.APIBaseURL, options...)
+	if err != nil {
+		return nil, fmt.Errorf("create API client: %w", err)
+	}
+
+	app := &application{
+		templateCache: templateCache,
+		formDecoder:   formDecoder,
+		config:        cfg,
+		logger:        logger,
+		apiClient:     apiClient,
+	}
+
+	return app, nil
+}
+
+// Run starts the web server and blocks until it shuts down or encounters an error.
+func (app *application) Run() {
+	err := app.serve()
+	if err != nil {
+		app.logger.Error(err.Error())
+		os.Exit(1)
+	}
+}
+
+// Version returns the build version used by the web binary.
+func (app *application) Version() string {
+	return fmt.Sprintf("Version:\t%s\n", version)
+}
+
+func (app *application) serve() error {
+	srv := &http.Server{
+		Addr:              net.JoinHostPort(app.config.Host, strconv.Itoa(app.config.Port)),
+		Handler:           app.routes(),
+		IdleTimeout:       time.Minute,
+		ReadHeaderTimeout: 5 * time.Second,
+		ReadTimeout:       2 * time.Minute,
+		WriteTimeout:      2 * time.Minute,
+	}
+
+	shutdownError := make(chan error)
+
+	go func() {
+		quit := make(chan os.Signal, 1)
+		signal.Notify(quit, syscall.SIGINT, syscall.SIGTERM)
+		s := <-quit
+
+		app.logger.Info("stopping server", "addr", srv.Addr, "signal", s.String())
+		shutdownError <- srv.Shutdown(context.Background())
+	}()
+
+	app.logger.Info("starting server", "addr", srv.Addr, "env", app.config.Env)
+	err := srv.ListenAndServe()
+	if !errors.Is(err, http.ErrServerClosed) {
+		return err
+	}
+
+	err = <-shutdownError
+	if err != nil {
+		return err
+	}
+
+	app.logger.Info("waiting for background tasks")
+	app.wg.Wait()
+
+	app.logger.Info("shutdown complete")
+	return nil
+}