Patient Match and CGM Demo

app/handlers/cgm.go

@@ -0,0 +1,125 @@
+// Package handlers — cgm.go implements the CGM preview proxy endpoint.
+//
+// GET /api/cgm-preview?patient_id=<fhir_id>
+//
+// This endpoint proxies requests to the Rimidi Provider CGM API to display
+// CGM data for a patient that has been matched between HRS and Rimidi.
+package handlers
+
+import (
+	"encoding/json"
+	"io"
+	"log"
+	"net/http"
+	"time"
+
+	"github.com/AmanTahiliani/FHIR-Sandbox/app/middleware"
+)
+
+// proxyTimeout is the HTTP client timeout for the outbound CGM API call.
+const cgmProxyTimeout = 15 * time.Second
+
+// HandleCGMPreview handles GET /api/cgm-preview requests.
+// It requires a valid session and looks up the confirmed match for the patient,
+// then proxies the request to the Rimidi Provider CGM API.
+func (h *Handler) HandleCGMPreview(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodGet {
+		http.Error(w, `{"error":"method not allowed"}`, http.StatusMethodNotAllowed)
+		return
+	}
+
+	sess := middleware.SessionFromContext(r.Context())
+	if sess == nil {
+		http.Error(w, `{"error":"unauthorized"}`, http.StatusUnauthorized)
+		return
+	}
+
+	// ── Resolve patient from query param or session ────────────────
+	patientFHIRID := r.URL.Query().Get("patient_id")
+	if patientFHIRID == "" {
+		patientFHIRID = sess.PatientFHIRID
+	}
+
+	if patientFHIRID == "" {
+		http.Error(w, `{"error":"no patient in context"}`, http.StatusBadRequest)
+		return
+	}
+
+	// ── Look up confirmed match for this patient ───────────────────
+	match, err := h.store.GetPatientMatchByFHIRID(patientFHIRID, sess.EHRURL)
+	if err != nil {
+		log.Printf("handlers: cgm-preview GetPatientMatchByFHIRID(%s, %s): %v", patientFHIRID, sess.EHRURL, err)
+		w.Header().Set("Content-Type", "application/json")
+		w.WriteHeader(http.StatusNotFound)
+		json.NewEncoder(w).Encode(map[string]string{
+			"error": "No confirmed patient match found. Please confirm a match first.",
+		})
+		return
+	}
+
+	// ── Build Rimidi CGM API URL ───────────────────────────────────
+	rimidiURL := h.cfg.RimidiCGMAPIURL
+	rimidiKey := h.cfg.RimidiInternalAPIKey
+
+	if rimidiURL == "" || rimidiKey == "" {
+		log.Printf("handlers: cgm-preview Rimidi CGM API not configured")
+		http.Error(w, `{"error":"CGM API not configured"}`, http.StatusServiceUnavailable)
+		return
+	}
+
+	// Construct the full URL: {base_url}/{patient_pk}/cgm-preview/
+	cgmURL := rimidiURL + "/" + match.RimidiPatientPK + "/cgm-preview/"
+
+	// ── Call Rimidi CGM API ────────────────────────────────────────
+	client := &http.Client{Timeout: cgmProxyTimeout}
+	req, err := http.NewRequest(http.MethodGet, cgmURL, nil)
+	if err != nil {
+		log.Printf("handlers: cgm-preview new request: %v", err)
+		http.Error(w, `{"error":"internal error"}`, http.StatusInternalServerError)
+		return
+	}
+	req.Header.Set("X-Api-Key", rimidiKey)
+	req.Header.Set("Accept", "application/json")
+
+	resp, err := client.Do(req)
+	if err != nil {
+		log.Printf("handlers: cgm-preview remote call failed: %v", err)
+		http.Error(w, `{"error":"could not reach Rimidi CGM API"}`, http.StatusBadGateway)
+		return
+	}
+	defer resp.Body.Close()
+
+	respBody, err := io.ReadAll(resp.Body)
+	if err != nil {
+		log.Printf("handlers: cgm-preview read response: %v", err)
+		http.Error(w, `{"error":"failed to read remote response"}`, http.StatusBadGateway)
+		return
+	}
+
+	if resp.StatusCode != http.StatusOK {
+		bodyLen := len(respBody)
+		if bodyLen > 500 {
+			bodyLen = 500
+		}
+		log.Printf("handlers: cgm-preview remote returned %d: %s", resp.StatusCode, string(respBody[:bodyLen]))
+		w.Header().Set("Content-Type", "application/json")
+		w.WriteHeader(resp.StatusCode)
+		w.Write(respBody)
+		return
+	}
+
+	// ── Parse and forward the response ──────────────────────────────
+	var cgmData map[string]interface{}
+	if err := json.Unmarshal(respBody, &cgmData); err != nil {
+		log.Printf("handlers: cgm-preview unmarshal response: %v", err)
+		http.Error(w, `{"error":"invalid response from Rimidi CGM API"}`, http.StatusBadGateway)
+		return
+	}
+
+	// Reports now come with presigned S3 URLs, no transformation needed
+
+	// Forward the response as-is
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(http.StatusOK)
+	json.NewEncoder(w).Encode(cgmData)
+}