register and sign in pages

backend/users/sms.py

@@ -0,0 +1,73 @@
+"""SMS delivery via the SAR Link SMS gateway.
+
+    POST {SMS_API_URL}
+    X-API-Key: {SMS_API_KEY}
+    {"to": "+9607712345", "text": "..."}
+
+With `SMS_API_URL`/`SMS_API_KEY` unset (dev) nothing is sent and the message is
+logged instead, so the OTP flows stay usable without the gateway.
+"""
+
+import logging
+
+import requests
+from django.conf import settings
+
+logger = logging.getLogger(__name__)
+
+TIMEOUT_SECONDS = 10
+
+
+def send_sms(mobile: str, text: str) -> bool:
+    if not settings.SMS_API_URL or not settings.SMS_API_KEY:
+        logger.warning("SMS not configured; would send to %s: %s", mobile, text)
+        return False
+
+    try:
+        response = requests.post(
+            settings.SMS_API_URL,
+            json={"to": mobile, "text": text},
+            headers={
+                "X-API-Key": settings.SMS_API_KEY,
+                "Content-Type": "application/json",
+            },
+            timeout=TIMEOUT_SECONDS,
+        )
+        response.raise_for_status()
+    except requests.RequestException:
+        logger.exception("Failed to send SMS to %s", mobile)
+        return False
+
+    logger.info("Sent SMS to %s", mobile)
+    return True
+
+
+def send_otp(mobile: str, code: str, purpose: str) -> bool:
+    minutes = max(1, settings.OTP_TTL_SECONDS // 60)
+    what = "registration" if purpose == "registration" else "login"
+    return send_sms(
+        mobile,
+        f"{code} is your SAR Link {what} code. It expires in {minutes} minutes.",
+    )
+
+
+def send_registration_submitted(mobile: str) -> bool:
+    return send_sms(
+        mobile,
+        "Thanks for registering with SAR Link. Your application is being "
+        "reviewed and we'll text you once it's approved.",
+    )
+
+
+def send_registration_approved(mobile: str) -> bool:
+    return send_sms(
+        mobile,
+        f"Your SAR Link registration is approved. Sign in at {settings.FRONTEND_URL}",
+    )
+
+
+def send_registration_rejected(mobile: str, reason: str = "") -> bool:
+    tail = f" Reason: {reason}" if reason else ""
+    return send_sms(
+        mobile, f"Your SAR Link registration could not be approved.{tail}"
+    )