95 lines
2.1 KiB
Go
95 lines
2.1 KiB
Go
package main
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import (
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"encoding/json"
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"fmt"
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"log"
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"net/http"
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"os"
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"sync"
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)
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// Define the DroneEvent struct as JSON
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type DroneEvent struct {
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DroneID string `json:"drone_id"`
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Latitude float64 `json:"latitude"`
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Longitude float64 `json:"longitude"`
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Timestamp string `json:"timestamp"`
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}
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// Shared state type alias
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type Server struct {
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// This is a shared state between handlers
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// It is protected by a mutex to prevent concurrent access
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mu sync.RWMutex
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history []DroneEvent
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}
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// Ingest handler
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func (s *Server) ingestHandler(w http.ResponseWriter, r *http.Request) {
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var event DroneEvent
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if err := json.NewDecoder(r.Body).Decode(&event); err != nil {
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http.Error(w, err.Error(), http.StatusBadRequest)
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return
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}
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fmt.Printf("Data ingested: %+v\n", event)
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s.mu.Lock()
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s.history = append(s.history, event)
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s.mu.Unlock()
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w.WriteHeader(http.StatusCreated)
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}
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// Snapshot handler
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func (s *Server) snapshotHandler(w http.ResponseWriter, r *http.Request) {
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timeParam := r.URL.Query().Get("time")
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if timeParam == "" {
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http.Error(w, "Missing 'time' query parameter", http.StatusBadRequest)
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return
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}
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s.mu.RLock()
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defer s.mu.RUnlock()
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latestStates := make(map[string]DroneEvent)
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for _, event := range s.history {
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if event.Timestamp <= timeParam {
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latestStates[event.DroneID] = event
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}
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}
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result := make([]DroneEvent, 0, len(latestStates))
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for _, event := range latestStates {
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result = append(result, event)
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}
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w.Header().Set("Content-Type", "application/json")
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if err := json.NewEncoder(w).Encode(result); err != nil {
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log.Printf("Error encoding response: %v", err)
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}
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}
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func main() {
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// By default, listen on port 3000
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port := os.Getenv("BLACKBOX_PORT")
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if port == "" {
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port = "3000"
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}
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server := &Server{
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history: make([]DroneEvent, 0),
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}
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mux := http.NewServeMux()
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mux.HandleFunc("POST /ingest", server.ingestHandler)
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mux.HandleFunc("GET /snapshot", server.snapshotHandler)
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fmt.Printf("Black Box Service is running on port %s...\n", port)
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if err := http.ListenAndServe(":"+port, mux); err != nil {
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log.Fatal(err)
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os.Exit(1)
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}
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}
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