2 files changed, 198 insertions, 0 deletions
diff --git a/internal/daemon/daemon.go b/internal/daemon/daemon.go
new file mode 100644
index 0000000..4e2402f
--- /dev/null
+++ b/internal/daemon/daemon.go
@@ -0,0 +1,107 @@
+package daemon
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"net/http"
+	"time"
+
+	"codeberg.org/snonux/goprecords/internal/goprecords"
+)
+
+// Config holds daemon HTTP server settings.
+type Config struct {
+	StatsDir string
+	Addr     string
+}
+
+// Handler returns an HTTP handler that serves health checks and reports from statsDir.
+func Handler(statsDir string) http.Handler {
+	mux := http.NewServeMux()
+	mux.HandleFunc("/health", health)
+	mux.HandleFunc("/report", report(statsDir))
+	return mux
+}
+
+// Run starts a plain HTTP server until ctx is cancelled or ListenAndServe fails.
+func Run(ctx context.Context, cfg Config) error {
+	if cfg.StatsDir == "" {
+		return fmt.Errorf("stats directory is required")
+	}
+	if cfg.Addr == "" {
+		return fmt.Errorf("listen address is required")
+	}
+	srv := &http.Server{
+		Addr:    cfg.Addr,
+		Handler: Handler(cfg.StatsDir),
+	}
+	errCh := make(chan error, 1)
+	go func() { errCh <- srv.ListenAndServe() }()
+	select {
+	case <-ctx.Done():
+		shutCtx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
+		defer cancel()
+		_ = srv.Shutdown(shutCtx)
+		err := <-errCh
+		if err != nil && err != http.ErrServerClosed {
+			return fmt.Errorf("shutdown: %w", err)
+		}
+		return ctx.Err()
+	case err := <-errCh:
+		if err == http.ErrServerClosed {
+			return nil
+		}
+		if err != nil {
+			return fmt.Errorf("listen %s: %w", cfg.Addr, err)
+		}
+		return nil
+	}
+}
+
+func health(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodGet {
+		http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
+		return
+	}
+	w.Header().Set("Content-Type", "text/plain; charset=utf-8")
+	w.WriteHeader(http.StatusOK)
+	_, _ = w.Write([]byte("ok\n"))
+}
+
+func report(statsDir string) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != http.MethodGet {
+			http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
+			return
+		}
+		cfg, err := goprecords.ParseReportQuery(r.URL.Query())
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusBadRequest)
+			return
+		}
+		aggr := goprecords.NewAggregator(statsDir)
+		aggregates, err := aggr.Aggregate(r.Context())
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return
+		}
+		var buf bytes.Buffer
+		if err := goprecords.WriteReports(&buf, aggregates, cfg); err != nil {
+			http.Error(w, err.Error(), http.StatusBadRequest)
+			return
+		}
+		w.Header().Set("Content-Type", reportContentType(cfg.OutputFormat))
+		w.WriteHeader(http.StatusOK)
+		_, _ = w.Write(buf.Bytes())
+	}
+}
+
+func reportContentType(f goprecords.OutputFormat) string {
+	switch f {
+	case goprecords.FormatMarkdown:
+		return "text/markdown; charset=utf-8"
+	default:
+		return "text/plain; charset=utf-8"
+	}
+}
diff --git a/internal/daemon/daemon_test.go b/internal/daemon/daemon_test.go
new file mode 100644
index 0000000..38878fa
--- /dev/null
+++ b/internal/daemon/daemon_test.go
@@ -0,0 +1,91 @@
+package daemon
+
+import (
+	"context"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+func TestHealth(t *testing.T) {
+	srv := httptest.NewServer(Handler(t.TempDir()))
+	defer srv.Close()
+	res, err := http.Get(srv.URL + "/health")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer res.Body.Close()
+	if res.StatusCode != http.StatusOK {
+		t.Fatalf("status %d", res.StatusCode)
+	}
+	b, _ := io.ReadAll(res.Body)
+	if string(b) != "ok\n" {
+		t.Fatalf("body %q", b)
+	}
+}
+
+func TestHealthMethodNotAllowed(t *testing.T) {
+	srv := httptest.NewServer(Handler(t.TempDir()))
+	defer srv.Close()
+	req, _ := http.NewRequest(http.MethodPost, srv.URL+"/health", nil)
+	res, err := http.DefaultClient.Do(req)
+	if err != nil {
+		t.Fatal(err)
+	}
+	res.Body.Close()
+	if res.StatusCode != http.StatusMethodNotAllowed {
+		t.Fatalf("status %d", res.StatusCode)
+	}
+}
+
+func TestReport(t *testing.T) {
+	fixtures := filepath.Join("..", "..", "fixtures")
+	h := Handler(fixtures)
+	srv := httptest.NewServer(h)
+	defer srv.Close()
+	res, err := http.Get(srv.URL + "/report?category=Host&metric=Boots&limit=3&output-format=Plaintext")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer res.Body.Close()
+	if res.StatusCode != http.StatusOK {
+		t.Fatalf("status %d", res.StatusCode)
+	}
+	b, err := io.ReadAll(res.Body)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !strings.Contains(string(b), "Host") {
+		t.Fatalf("expected report body, got %q", b)
+	}
+}
+
+func TestReportBadQuery(t *testing.T) {
+	srv := httptest.NewServer(Handler(t.TempDir()))
+	defer srv.Close()
+	res, err := http.Get(srv.URL + "/report?category=Nope")
+	if err != nil {
+		t.Fatal(err)
+	}
+	res.Body.Close()
+	if res.StatusCode != http.StatusBadRequest {
+		t.Fatalf("status %d", res.StatusCode)
+	}
+}
+
+func TestRunEmptyStatsDir(t *testing.T) {
+	err := Run(context.Background(), Config{StatsDir: "", Addr: ":0"})
+	if err == nil {
+		t.Fatal("expected error")
+	}
+}
+
+func TestRunEmptyAddr(t *testing.T) {
+	err := Run(context.Background(), Config{StatsDir: t.TempDir(), Addr: ""})
+	if err == nil {
+		t.Fatal("expected error")
+	}
+}