feat: runtime config, Matomo analytics, chat accounts, DM history/search, and Prometheus retention

backend/chat/src/config/runtime.go

@@ -0,0 +1,221 @@
+package config
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/url"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"sync"
+)
+
+// Runtime configuration keys stored in the runtime config file.
+const (
+	keyMatomoURL     = "matomo_url"
+	keyMatomoSiteID  = "matomo_site_id"
+	keyHLSSegmentDur = "hls_segment_duration"
+	keyHLSWindowSize = "hls_window_size"
+)
+
+// Default HLS values used when neither env nor persisted config is set.
+const (
+	defaultHLSSegmentDuration = 6
+	defaultHLSWindowSize      = 24
+)
+
+var (
+	runtimeMu    sync.RWMutex
+	runtimeStore = map[string]string{}
+)
+
+// ConfigPath returns the runtime config JSON file path from env or default.
+// The default lives in the shared playlist volume so the playout service can
+// read the same file (chat has read-write, playout read-only).
+func ConfigPath() string {
+	p := strings.TrimSpace(os.Getenv("CONFIG_PATH"))
+	if p == "" {
+		return "/app/playlist/config.json"
+	}
+	return p
+}
+
+// GetRuntime returns a value from the runtime store and whether it is present.
+func GetRuntime(key string) (string, bool) {
+	runtimeMu.RLock()
+	defer runtimeMu.RUnlock()
+	v, ok := runtimeStore[key]
+	return v, ok
+}
+
+// SetRuntime stores a value in the runtime store (in-memory only).
+func SetRuntime(key, value string) {
+	runtimeMu.Lock()
+	defer runtimeMu.Unlock()
+	runtimeStore[key] = value
+}
+
+// LoadRuntimeConfig loads the persisted runtime config from disk. If the file does
+// not exist, it seeds the store from environment variables.
+func LoadRuntimeConfig() error {
+	data, err := os.ReadFile(ConfigPath())
+	if err != nil {
+		if os.IsNotExist(err) {
+			runtimeMu.Lock()
+			runtimeStore = map[string]string{}
+			runtimeMu.Unlock()
+			seedRuntimeDefaults()
+			return nil
+		}
+		return fmt.Errorf("read runtime config: %w", err)
+	}
+
+	values := map[string]string{}
+	if err := json.Unmarshal(data, &values); err != nil {
+		return fmt.Errorf("parse runtime config: %w", err)
+	}
+
+	runtimeMu.Lock()
+	defer runtimeMu.Unlock()
+	runtimeStore = values
+	return nil
+}
+
+// SaveRuntimeConfig persists the runtime store to disk as JSON.
+func SaveRuntimeConfig() error {
+	runtimeMu.RLock()
+	data, err := json.MarshalIndent(runtimeStore, "", "  ")
+	runtimeMu.RUnlock()
+	if err != nil {
+		return fmt.Errorf("marshal runtime config: %w", err)
+	}
+	if dir := filepath.Dir(ConfigPath()); dir != "" && dir != "." {
+		if err := os.MkdirAll(dir, 0o755); err != nil {
+			return fmt.Errorf("create runtime config dir: %w", err)
+		}
+	}
+	if err := os.WriteFile(ConfigPath(), append(data, '\n'), 0o644); err != nil {
+		return fmt.Errorf("write runtime config: %w", err)
+	}
+	return nil
+}
+
+// seedRuntimeDefaults populates the store from environment variables.
+func seedRuntimeDefaults() {
+	if v := strings.TrimSpace(os.Getenv("MATOMO_URL")); v != "" {
+		SetRuntime(keyMatomoURL, v)
+	}
+	if v := strings.TrimSpace(os.Getenv("MATOMO_SITE_ID")); v != "" {
+		SetRuntime(keyMatomoSiteID, v)
+	}
+	if v := strings.TrimSpace(os.Getenv("HLS_SEGMENT_DURATION")); v != "" {
+		SetRuntime(keyHLSSegmentDur, v)
+	}
+	if v := strings.TrimSpace(os.Getenv("HLS_WINDOW_SIZE")); v != "" {
+		SetRuntime(keyHLSWindowSize, v)
+	}
+}
+
+// MatomoURL returns the Matomo analytics URL.
+func MatomoURL() string {
+	if v, ok := GetRuntime(keyMatomoURL); ok && strings.TrimSpace(v) != "" {
+		return strings.TrimSpace(v)
+	}
+	return strings.TrimSpace(os.Getenv("MATOMO_URL"))
+}
+
+// MatomoSiteID returns the Matomo site ID.
+func MatomoSiteID() string {
+	if v, ok := GetRuntime(keyMatomoSiteID); ok && strings.TrimSpace(v) != "" {
+		return strings.TrimSpace(v)
+	}
+	return strings.TrimSpace(os.Getenv("MATOMO_SITE_ID"))
+}
+
+// HLSSegmentDuration returns the HLS segment duration in seconds.
+func HLSSegmentDuration() int {
+	raw := ""
+	if v, ok := GetRuntime(keyHLSSegmentDur); ok {
+		raw = strings.TrimSpace(v)
+	}
+	if raw == "" {
+		raw = strings.TrimSpace(os.Getenv("HLS_SEGMENT_DURATION"))
+	}
+	n, err := strconv.Atoi(raw)
+	if err != nil || n <= 0 {
+		return defaultHLSSegmentDuration
+	}
+	return n
+}
+
+// HLSWindowSize returns the HLS playlist window size in segments.
+func HLSWindowSize() int {
+	raw := ""
+	if v, ok := GetRuntime(keyHLSWindowSize); ok {
+		raw = strings.TrimSpace(v)
+	}
+	if raw == "" {
+		raw = strings.TrimSpace(os.Getenv("HLS_WINDOW_SIZE"))
+	}
+	n, err := strconv.Atoi(raw)
+	if err != nil || n <= 0 {
+		return defaultHLSWindowSize
+	}
+	return n
+}
+
+// SetMatomoURL validates and stores the Matomo URL.
+func SetMatomoURL(raw string) error {
+	raw = strings.TrimSpace(raw)
+	if raw == "" {
+		SetRuntime(keyMatomoURL, "")
+		return nil
+	}
+	u, err := url.Parse(raw)
+	if err != nil || (u.Scheme != "http" && u.Scheme != "https") || u.Host == "" {
+		return fmt.Errorf("matomo URL must be an absolute http(s) URL")
+	}
+	SetRuntime(keyMatomoURL, raw)
+	return nil
+}
+
+// SetMatomoSiteID validates and stores the Matomo site ID.
+func SetMatomoSiteID(raw string) error {
+	raw = strings.TrimSpace(raw)
+	if raw != "" {
+		if _, err := strconv.Atoi(raw); err != nil {
+			return fmt.Errorf("matomo site ID must be numeric")
+		}
+	}
+	SetRuntime(keyMatomoSiteID, raw)
+	return nil
+}
+
+// SetHLSSegmentDuration validates (2–15s) and stores the HLS segment duration.
+func SetHLSSegmentDuration(seconds int) error {
+	if seconds < 2 || seconds > 15 {
+		return fmt.Errorf("HLS segment duration must be between 2 and 15 seconds")
+	}
+	SetRuntime(keyHLSSegmentDur, strconv.Itoa(seconds))
+	return nil
+}
+
+// SetHLSWindowSize validates (3–100) and stores the HLS window size.
+func SetHLSWindowSize(size int) error {
+	if size < 3 || size > 100 {
+		return fmt.Errorf("HLS window size must be between 3 and 100 segments")
+	}
+	SetRuntime(keyHLSWindowSize, strconv.Itoa(size))
+	return nil
+}
+
+// RuntimeConfigSnapshot returns the resolved runtime configuration values.
+func RuntimeConfigSnapshot() map[string]any {
+	return map[string]any{
+		"matomoUrl":          MatomoURL(),
+		"matomoSiteId":       MatomoSiteID(),
+		"hlsSegmentDuration": HLSSegmentDuration(),
+		"hlsWindowSize":      HLSWindowSize(),
+	}
+}