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

SECRETS = json.loads(os.environ.get("INTEGRATION_SECRETS", "{}"))
INPUTS = json.loads(os.environ.get("INTEGRATION_INPUTS", "{}"))
BASE = SECRETS.get("base_url", "https://api.crowdstrike.com").rstrip("/")


def token():
    data = urllib.parse.urlencode({"client_id": SECRETS.get("client_id", ""), "client_secret": SECRETS.get("client_secret", "")}).encode()
    req = urllib.request.Request(BASE + "/oauth2/token", data=data, headers={"Content-Type": "application/x-www-form-urlencoded", "Accept": "application/json"}, method="POST")
    with urllib.request.urlopen(req, timeout=30) as r:
        return json.loads(r.read()).get("access_token", "")


def call(method, path, tok, params=None, body=None):
    url = BASE + path
    if params:
        # params is a list of (key, value) tuples to allow repeated keys (e.g. ids)
        url += "?" + urllib.parse.urlencode(params)
    data = json.dumps(body).encode() if body is not None else None
    headers = {"Authorization": "Bearer " + tok, "Accept": "application/json"}
    if data is not None:
        headers["Content-Type"] = "application/json"
    req = urllib.request.Request(url, data=data, headers=headers, method=method)
    with urllib.request.urlopen(req, timeout=90) as r:
        raw = r.read()
        return json.loads(raw) if raw else {}


def csv(v):
    return [x.strip() for x in str(v or "").split(",") if x.strip()]


def main():
    tok = token()
    # Next-Gen SIEM files its detections in the same unified Alerts API as the
    # EDR, under two products: 'thirdparty' for the alerts it raises from ingested
    # third-party logs (a FortiGate IPS hit, say) and 'ngsiem' for those of the
    # tenant's own correlation rules. The product clause is always kept, so a
    # filter narrows these detections and never widens past them.
    products = [p.strip().strip("'\"") for p in str(INPUTS.get("products") or "thirdparty,ngsiem").split(",") if p.strip()]
    # ',' is OR in FQL; parenthesised so the group binds before the '+' ANDs.
    fql = "(" + ",".join("product:'" + p.replace("'", "\\'") + "'" for p in products) + ")"
    extra = str(INPUTS.get("filter") or "").strip()
    if extra:
        fql += "+(" + extra + ")"
    # The alert rule's watermark lands in created_from, folded into the FQL as
    # created_timestamp (see search_detections for why it is not the filter input).
    since = str(INPUTS.get("created_from") or "").strip().strip("'\"")
    if since:
        fql += "+created_timestamp:>'" + since + "'"
    limit = INPUTS.get("limit", 50)
    params = [("filter", fql), ("limit", limit), ("sort", "created_timestamp.desc")]
    found = call("GET", "/alerts/queries/alerts/v2", tok, params=params)
    ids = found.get("resources", []) or []
    if ids:
        result = call("POST", "/alerts/entities/alerts/v2", tok, body={"composite_ids": ids})
    else:
        result = {"resources": []}
    # An empty page says nothing on its own: keep what the query answered — the
    # FQL actually sent, Falcon's total for it and any errors — so a run with no
    # alerts reads as "matched nothing" rather than as a silent failure.
    result["query"] = {
        "filter": fql,
        "total": ((found.get("meta") or {}).get("pagination") or {}).get("total"),
        "errors": found.get("errors") or [],
    }
    print(json.dumps(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)