import json, os, sys, time, urllib.request, urllib.parse, urllib.error

# Assignment rides the same alertTriggerActions mutation as the status and
# verdict updates, with the assignUser payload. The action id is the console's,
# and can be overridden for a tenant that names it differently.
#
# The variable types are the console's, not a guess: the action id is an ID!
# and assignUser.value a Long. Declared String! and ID!, the console rejected
# the mutation at validation (VariableTypeMismatch) before assigning anything.
DEFAULT_ACTION_ID = "S1/alert/assignUser"

MUTATION = """mutation AlertTriggerActions($id: String!, $actionId: ID!, $user: Long) {
  alertTriggerActions(
    filter: { or: [ { and: [ { fieldId: "id", stringEqual: { value: $id } } ] } ] },
    actions: [ { id: $actionId, payload: { assignUser: { value: $user } } } ]
  ) {
    __typename
    ... on ActionsTriggered {
      actions { actionId alertCount
        success { id }
        failure { id errorType errorMessage }
        skip { id } }
    }
  }
}"""

# What the alert says afterwards. The mutation answering "success" only means
# the console accepted the action: a run reported the alert under success while
# the console still showed its previous assignee. Reading the alert back is the
# only way the playbook learns the assignment did not happen.
READ_BACK = """query AlertAssignee($id: ID!) {
  alert(id: $id) { assignee { userId fullName email } }
}"""

# The action is triggered, not necessarily applied, when the mutation returns;
# give the console a few seconds before calling it a no-op.
READ_BACK_DELAYS = (0, 1, 2, 4)


def request(method, url, headers, body=None):
    data = json.dumps(body).encode("utf-8") if body is not None else None
    req = urllib.request.Request(url, data=data, headers=headers, method=method)
    with urllib.request.urlopen(req, timeout=30) as resp:
        raw = resp.read()
        return json.loads(raw) if raw else {}


def main():
    secrets = json.loads(os.environ.get("INTEGRATION_SECRETS", "{}"))
    inputs = json.loads(os.environ.get("INTEGRATION_INPUTS", "{}"))
    base = secrets.get("url", "").rstrip("/") + "/web/api/v2.1"
    headers = {
        "Authorization": "ApiToken " + secrets.get("api_token", ""),
        "Accept": "application/json",
        "Content-Type": "application/json",
    }
    alert_id = str(inputs.get("alert_id") or "").strip()
    user_id = str(inputs.get("assignee_user_id") or "").strip()
    if not alert_id or not user_id:
        raise ValueError("alert_id and assignee_user_id are required")

    # A Long is a number: an email or a display name would only be refused by
    # the console with a type error that does not say which input was wrong.
    if not user_id.isdigit():
        raise ValueError("assignee_user_id must be the console's numeric user id "
                         "(assignee.userId, or the id from list users), got " + repr(user_id))

    variables = {
        "id": alert_id,
        "actionId": str(inputs.get("action_id") or "").strip() or DEFAULT_ACTION_ID,
        # Sent as a JSON number. Python's int keeps the 19 digits of a console
        # id exactly; it fits the Long the console declares.
        "user": int(user_id),
    }
    url = base + "/unifiedalerts/graphql"
    resp = request("POST", url, headers, {"query": MUTATION, "variables": variables})
    if resp.get("errors"):
        print(json.dumps({"error": "GraphQL error", "detail": resp["errors"]}))
        sys.exit(1)
    result = resp.get("data") or {}

    # A refused alert comes back in the payload, not in errors. A skipped one is
    # what the console answers for an alert already assigned to that user — a
    # second run of the same playbook — so it is settled by the read-back below
    # rather than failed outright.
    triggered = (result.get("alertTriggerActions") or {}).get("actions") or []
    failures = [f for a in triggered for f in (a.get("failure") or [])]
    skipped = [s for a in triggered for s in (a.get("skip") or [])]
    succeeded = any(a.get("success") for a in triggered)
    if failures or not (succeeded or skipped):
        print(json.dumps({"error": "The console did not assign the alert",
                          "failure": failures, "skip": skipped, "result": result}))
        sys.exit(1)

    assignee = None
    for delay in READ_BACK_DELAYS:
        time.sleep(delay)
        back = request("POST", url, headers, {"query": READ_BACK, "variables": {"id": alert_id}})
        if back.get("errors"):
            # The assignment went through as far as the console says; failing
            # here on a read we could not make would report a false negative.
            assignee = {"unverified": back["errors"]}
            break
        assignee = ((back.get("data") or {}).get("alert") or {}).get("assignee")
        if str((assignee or {}).get("userId") or "") == user_id:
            break
    else:
        said = "reported success" if succeeded else "skipped the alert"
        print(json.dumps({
            "error": "The console " + said + " but the alert is not assigned to "
                     + user_id + " — check that this id is the console user's (assignee.userId)",
            "assignee_now": assignee, "result": result}))
        sys.exit(1)

    print(json.dumps({"alert_id": alert_id, "assignee_user_id": user_id,
                      "already_assigned": not succeeded,
                      "assignee": assignee, "result": result}))


try:
    main()
except urllib.error.HTTPError as e:
    print(json.dumps({"error": "HTTP " + str(e.code), "detail": e.read().decode("utf-8", "replace")}))
    sys.exit(1)
except Exception as e:
    print(json.dumps({"error": str(e)}))
    sys.exit(1)