Enforce fixture interaction policy

ampbrowser/interaction_policy.py

@@ -0,0 +1,96 @@
+from __future__ import annotations
+
+from dataclasses import dataclass
+
+
+TIER_ORDER = {
+    "static": 0,
+    "interactive-lite": 1,
+    "identity": 2,
+    "transactional": 3,
+    "realtime": 4,
+    "internal": 5,
+}
+
+
+@dataclass(frozen=True)
+class TransportInteractionPolicy:
+    transport: str
+    max_tier: str
+    identities: tuple[str, ...]
+    payments: tuple[str, ...]
+    realtime: str
+
+
+TRANSPORT_POLICIES = {
+    "clearnet": TransportInteractionPolicy(
+        "clearnet",
+        "realtime",
+        ("none", "http-session", "siwe"),
+        ("none", "server-invoice", "wallet-signature"),
+        "yes",
+    ),
+    "tor": TransportInteractionPolicy(
+        "tor",
+        "transactional",
+        ("none", "http-session", "siwe"),
+        ("none", "server-invoice", "wallet-signature"),
+        "private-only",
+    ),
+    "i2p": TransportInteractionPolicy(
+        "i2p",
+        "transactional",
+        ("none", "http-session", "siwe"),
+        ("none", "server-invoice", "wallet-signature"),
+        "private-only",
+    ),
+    "gemini": TransportInteractionPolicy(
+        "gemini",
+        "interactive-lite",
+        ("none", "signed-link"),
+        ("none", "static-instructions"),
+        "no",
+    ),
+    "ipfs": TransportInteractionPolicy(
+        "ipfs",
+        "static",
+        ("none",),
+        ("none", "static-instructions"),
+        "no",
+    ),
+    "reticulum": TransportInteractionPolicy(
+        "reticulum",
+        "interactive-lite",
+        ("none", "signed-link"),
+        ("none", "static-instructions"),
+        "research",
+    ),
+}
+
+
+def interaction_failures(
+    transport: str,
+    *,
+    tier: str,
+    identity: str,
+    payments: str,
+    realtime: bool,
+    public_allowed: bool,
+) -> list[str]:
+    failures: list[str] = []
+    policy = TRANSPORT_POLICIES.get(transport)
+    if not policy:
+        return [f"no interaction policy for transport {transport}"]
+    if not public_allowed:
+        failures.append("fixture is not public_allowed")
+    if tier not in TIER_ORDER:
+        failures.append(f"unknown tier {tier}")
+    elif TIER_ORDER[tier] > TIER_ORDER[policy.max_tier]:
+        failures.append(f"tier {tier} exceeds {transport} max {policy.max_tier}")
+    if identity not in policy.identities:
+        failures.append(f"identity {identity} not allowed on {transport}")
+    if payments not in policy.payments:
+        failures.append(f"payments {payments} not allowed on {transport}")
+    if realtime and policy.realtime not in {"yes", "private-only", "research"}:
+        failures.append(f"realtime not allowed on {transport}")
+    return failures