afterhours-shift-manager/src/roster-api/app.py

"""HTTP API v2 handler — Bearer-authenticated roster PUT/DELETE.

PUT  /roster                 upsert name, extension, slack_user_id, optional email
DELETE /roster/{extension}   delete the row (204 even if it was already gone)

Auth is an app-level Bearer token stored in Secrets Manager. Do not log the
Authorization header, the token, or the request body.
"""

from __future__ import annotations

import base64
import json
import logging
from typing import Any

import shared.sentry_init  # noqa: F401
from shared.roster_http import (
    AuthError,
    SecretUnavailable,
    authorize_bearer,
    remove,
    upsert,
    validate_extension,
)

logger = logging.getLogger()
logger.setLevel(logging.INFO)


def _json_response(status: int, body: dict[str, Any] | None = None) -> dict:
    if status == 204:
        return {"statusCode": 204, "headers": {}, "body": ""}
    payload = {} if body is None else body
    return {
        "statusCode": status,
        "headers": {"Content-Type": "application/json"},
        "body": json.dumps(payload, separators=(",", ":")),
    }


def _header(event: dict, name: str) -> str:
    headers = event.get("headers") or {}
    if not isinstance(headers, dict):
        return ""
    target = name.lower()
    for key, value in headers.items():
        if str(key).lower() == target:
            return "" if value is None else str(value)
    return ""


def _route(event: dict) -> tuple[str, str]:
    request_context = event.get("requestContext") or {}
    http = request_context.get("http") or {}
    method = str(http.get("method") or event.get("httpMethod") or "").upper()
    path = str(event.get("rawPath") or http.get("path") or event.get("path") or "")
    route_key = event.get("routeKey")
    if isinstance(route_key, str) and " " in route_key:
        rk_method, rk_path = route_key.split(" ", 1)
        method = method or rk_method.upper()
        path = path or rk_path
    return method, path


def _raw_body(event: dict) -> bytes | None:
    body = event.get("body")
    if body is None:
        return b""
    try:
        if event.get("isBase64Encoded"):
            if isinstance(body, bytes):
                body = body.decode("ascii")
            return base64.b64decode(body, validate=True)
        if isinstance(body, bytes):
            return body
        return str(body).encode("utf-8")
    except (ValueError, UnicodeError):
        return None


def _delete_extension(event: dict) -> str:
    params = event.get("pathParameters") or {}
    if not isinstance(params, dict):
        raise TypeError("extension")
    raw = params.get("extension")
    if not isinstance(raw, str):
        raise TypeError("extension")
    return validate_extension(raw)


def handler(event, context):
    try:
        method, path = _route(event)
        logger.info("roster api %s %s", method, path)
        try:
            authorize_bearer(_header(event, "authorization"))
        except AuthError:
            return _json_response(401, {"error": "unauthorized"})
        except SecretUnavailable:
            return _json_response(503, {"error": "service unavailable"})

        if method == "PUT" and (path == "/roster" or path.rstrip("/") == "/roster"):
            raw = _raw_body(event)
            if raw is None:
                return _json_response(400, {"error": "invalid request"})
            try:
                upsert(raw)
            except (TypeError, ValueError):
                return _json_response(400, {"error": "invalid request"})
            return _json_response(200, {"ok": True})

        if method == "DELETE" and path.startswith("/roster/"):
            try:
                extension = _delete_extension(event)
            except (TypeError, ValueError):
                return _json_response(400, {"error": "invalid request"})
            remove(extension)
            return _json_response(204)

        return _json_response(405, {"error": "method not allowed"})
    except Exception:
        logger.exception("roster api unexpected failure")
        return _json_response(500, {"error": "internal error"})