feat(v2): add annotated evidence and alert dispatch

2026-07-22 21:17:50 +08:00
parent 3edda4fb62
commit d183170554
9 changed files with 424 additions and 5 deletions
@@ -0,0 +1,141 @@
+// Package alert owns durable, one-shot fall-event evidence.
+package alert
+
+import (
+	"encoding/json"
+	"fmt"
+	"image"
+	"image/png"
+	"os"
+	"path/filepath"
+	"regexp"
+	"sync"
+	"time"
+
+	"silverpose/v2/internal/fall"
+)
+
+var eventIDPattern = regexp.MustCompile(`^[A-Za-z0-9-]+$`)
+
+type Record struct {
+	Event          fall.Event
+	ScreenshotPath string
+	LogPath        string
+	CreatedAtUTC   time.Time
+	Written        bool
+}
+
+// Dispatcher de-duplicates events before writing to avoid screenshot overwrite,
+// duplicate JSONL records, duplicate sound, or duplicate popups downstream.
+type Dispatcher struct {
+	eventDirectory string
+	sourceID       string
+	mu             sync.Mutex
+	seen           map[string]struct{}
+}
+
+func NewDispatcher(eventDirectory, sourceID string) *Dispatcher {
+	return &Dispatcher{
+		eventDirectory: eventDirectory,
+		sourceID:       sourceID,
+		seen:           make(map[string]struct{}),
+	}
+}
+
+func (dispatcher *Dispatcher) Dispatch(event fall.Event, canvas image.Image, now time.Time) (Record, error) {
+	if event.State != fall.Confirmed {
+		return Record{}, fmt.Errorf("only confirmed events can be persisted")
+	}
+	if !eventIDPattern.MatchString(event.EventID) {
+		return Record{}, fmt.Errorf("event ID is invalid")
+	}
+	if canvas == nil {
+		return Record{}, fmt.Errorf("event screenshot is missing")
+	}
+	if now.IsZero() {
+		now = time.Now()
+	}
+	now = now.UTC()
+
+	dispatcher.mu.Lock()
+	if _, alreadyWritten := dispatcher.seen[event.EventID]; alreadyWritten {
+		dispatcher.mu.Unlock()
+		return Record{Event: event, Written: false}, nil
+	}
+	dispatcher.seen[event.EventID] = struct{}{}
+	dispatcher.mu.Unlock()
+
+	record, err := dispatcher.write(event, canvas, now)
+	if err != nil {
+		dispatcher.mu.Lock()
+		delete(dispatcher.seen, event.EventID)
+		dispatcher.mu.Unlock()
+		return Record{}, err
+	}
+	return record, nil
+}
+
+func (dispatcher *Dispatcher) write(event fall.Event, canvas image.Image, now time.Time) (Record, error) {
+	if dispatcher.eventDirectory == "" || dispatcher.sourceID == "" {
+		return Record{}, fmt.Errorf("event directory and source ID must be configured")
+	}
+	dayDirectory := filepath.Join(dispatcher.eventDirectory, now.Format("20060102"))
+	if err := os.MkdirAll(dayDirectory, 0o755); err != nil {
+		return Record{}, fmt.Errorf("create event directory: %w", err)
+	}
+	screenshotPath := filepath.Join(dayDirectory, event.EventID+".png")
+	file, err := os.Create(screenshotPath)
+	if err != nil {
+		return Record{}, fmt.Errorf("create screenshot: %w", err)
+	}
+	encodeErr := png.Encode(file, canvas)
+	closeErr := file.Close()
+	if encodeErr != nil || closeErr != nil {
+		_ = os.Remove(screenshotPath)
+		if encodeErr != nil {
+			return Record{}, fmt.Errorf("encode screenshot: %w", encodeErr)
+		}
+		return Record{}, fmt.Errorf("close screenshot: %w", closeErr)
+	}
+
+	logPath := filepath.Join(dayDirectory, "events.jsonl")
+	relativeScreenshot := filepath.ToSlash(filepath.Join(now.Format("20060102"), event.EventID+".png"))
+	line, err := json.Marshal(struct {
+		EventID              string     `json:"event_id"`
+		TrackID              string     `json:"track_id"`
+		ConfigVersion        string     `json:"config_version"`
+		SourceID             string     `json:"source_id"`
+		State                fall.State `json:"state"`
+		ConfirmedAtUTC       string     `json:"confirmed_at_utc"`
+		SuspectedAtMonotonic float64    `json:"suspected_at_monotonic"`
+		ConfirmedAtMonotonic float64    `json:"confirmed_at_monotonic"`
+		LatencySeconds       float64    `json:"latency_seconds"`
+		Screenshot           string     `json:"screenshot"`
+	}{
+		EventID: event.EventID, TrackID: event.TrackID, ConfigVersion: event.ConfigVersion,
+		SourceID: dispatcher.sourceID, State: event.State, ConfirmedAtUTC: now.Format(time.RFC3339Nano),
+		SuspectedAtMonotonic: event.SuspectedAtMonotonic,
+		ConfirmedAtMonotonic: event.ConfirmedAtMonotonic,
+		LatencySeconds:       event.LatencySeconds, Screenshot: relativeScreenshot,
+	})
+	if err != nil {
+		_ = os.Remove(screenshotPath)
+		return Record{}, fmt.Errorf("encode event record: %w", err)
+	}
+	log, err := os.OpenFile(logPath, os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0o600)
+	if err != nil {
+		_ = os.Remove(screenshotPath)
+		return Record{}, fmt.Errorf("open event log: %w", err)
+	}
+	if _, err := log.Write(append(line, '\n')); err != nil {
+		_ = log.Close()
+		_ = os.Remove(screenshotPath)
+		return Record{}, fmt.Errorf("write event log: %w", err)
+	}
+	if err := log.Close(); err != nil {
+		return Record{}, fmt.Errorf("close event log: %w", err)
+	}
+	return Record{
+		Event: event, ScreenshotPath: screenshotPath, LogPath: logPath, CreatedAtUTC: now, Written: true,
+	}, nil
+}