A request for a recipe the hub does not hold is refused

# Scenario 046: A request for a recipe the hub does not hold is refused
# A hub only cooks recipes it can fetch and hash. Ask for the catalog, then request a recipe id that is not in it and read the refusal.
# Run a hub first: python hub/cookwala_hub.py --recipes examples
import json, os
from cookwala.client import CookwalaClient, CookwalaProblem

def load(path):
    with open(path, encoding="utf-8") as f:
        return json.load(f)

def pick(obj, path):
    for part in path.replace("]", "").replace("[", ".").split("."):
        obj = obj[int(part)] if part.isdigit() else (len(obj) if part == "length" else obj.get(part))
    return obj

c = CookwalaClient(os.environ.get("COOKWALA_HUB", "http://localhost:7878"))


# Step 1: The runner's hub holds the nine example recipes.
recipes = c.list_recipes()
assert pick(recipes, "recipes.length") == 9, pick(recipes, "recipes.length")
print("ok", "recipes.length", "=", 9)
assert pick(recipes, "recipes[8]") == "shakshuka", pick(recipes, "recipes[8]")
print("ok", "recipes[8]", "=", "shakshuka")

# Step 2: Request a recipe reference the hub cannot resolve. The refusal reason is missing_capability and the detail says the recipe is not in the catalog.
try:
    refused = c.start_execution({"core": "0.2.0", "kind": "ExecuteRequest", "id": "ex-046-unknown", "recipe": "cw:cookwala.ai:example-nothing", "recipeHash": "sha256:2ea6fab93cc673fc6784f9bc9fe401d2387bb7779dc537df97286b73807c8841", "servings": 4, "requestedBy": "agent:planner-1", "idempotencyKey": "ex-046-unknown-a"}, "ex-046-unknown-key", True)
except CookwalaProblem as p:
    refused = p.body  # a refusal is a result, not a crash
    print("refused:", p.refusal)
assert pick(refused, "state") == "refused", pick(refused, "state")
print("ok", "state", "=", "refused")
assert pick(refused, "refusal.reason") == "missing_capability", pick(refused, "refusal.reason")
print("ok", "refusal.reason", "=", "missing_capability")
assert pick(refused, "refusal.detail") == "recipe not found in this hub's catalog", pick(refused, "refusal.detail")
print("ok", "refusal.detail", "=", "recipe not found in this hub's catalog")

print("scenario complete")