Tile Update Event Pipelines

def quadkey(zoom: int, x: int, y: int) -> str:
    """Convert z/x/y to a Bing-style quadkey string."""
    key = []
    for i in range(zoom, 0, -1):
        digit = 0
        mask = 1 << (i - 1)
        if x & mask:
            digit += 1
        if y & mask:
            digit += 2
        key.append(str(digit))
    return "".join(key)

def partition_key(event: TileUpdateEvent) -> str:
    qk = quadkey(event.zoom, event.x, event.y)
    return f"{event.zoom}:{qk}"

import asyncio
import hashlib
import logging
from pydantic import ValidationError

# Stubs — replace with your Redis, tile renderer, and broker bindings
async def idempotency_guard_check(key: str) -> bool: ...
async def idempotency_guard_set(key: str) -> None: ...
async def regenerate_tile(zoom: int, x: int, y: int) -> str: ...  # returns content hash
async def broadcast_tile_updated(event: TileUpdateEvent, content_hash: str) -> None: ...
async def write_to_dlq(raw: dict, reason: str) -> None: ...

async def process_tile_event(raw_payload: dict) -> None:
    try:
        event = TileUpdateEvent(**raw_payload)
    except ValidationError as exc:
        logging.error("Schema validation failed: %s", exc)
        await write_to_dlq(raw_payload, str(exc))
        return

    ok, reason = validate_geometry(raw_payload.get("geometry", {})) if "geometry" in raw_payload else (True, None)
    if not ok:
        await write_to_dlq(raw_payload, f"invalid geometry: {reason}")
        return

    idem_key = hashlib.sha256(event.event_id.encode()).hexdigest()
    if await idempotency_guard_check(idem_key):
        logging.info("Duplicate skipped: event_id=%s", event.event_id)
        return

    content_hash = await regenerate_tile(event.zoom, event.x, event.y)
    await broadcast_tile_updated(event, content_hash)
    await idempotency_guard_set(idem_key)

async def run_consumer(broker_topic: str, concurrency: int = 10) -> None:
    dlq: asyncio.Queue[dict] = asyncio.Queue()
    semaphore = asyncio.Semaphore(concurrency)

    async def bounded_process(payload: dict) -> None:
        async with semaphore:
            await process_tile_event(payload)

    # Replace with your actual broker polling loop
    async for raw in poll_broker(broker_topic):  # type: ignore[name-defined]
        asyncio.create_task(bounded_process(raw))

import random
import asyncio

async def regenerate_with_backoff(
    zoom: int,
    x: int,
    y: int,
    max_attempts: int = 5,
    base_delay: float = 0.5,
) -> str:
    for attempt in range(max_attempts):
        try:
            return await regenerate_tile(zoom, x, y)
        except Exception as exc:
            if attempt == max_attempts - 1:
                raise
            delay = base_delay * (2 ** attempt) * random.uniform(0.5, 1.5)
            logging.warning(
                "Tile regeneration failed (attempt %d/%d), retrying in %.2fs: %s",
                attempt + 1, max_attempts, delay, exc,
            )
            await asyncio.sleep(delay)
    raise RuntimeError("unreachable")  # satisfies type checker

import asyncio
import pytest

@pytest.mark.asyncio
async def test_valid_event_triggers_broadcast(monkeypatch):
    processed: list[TileUpdateEvent] = []
    broadcast_calls: list[str] = []

    async def mock_regenerate(zoom, x, y):
        return "abc123"

    async def mock_broadcast(event, content_hash):
        processed.append(event)
        broadcast_calls.append(content_hash)

    async def mock_idem_check(key):
        return False  # not yet processed

    async def mock_idem_set(key):
        pass

    monkeypatch.setattr("your_module.regenerate_tile", mock_regenerate)
    monkeypatch.setattr("your_module.broadcast_tile_updated", mock_broadcast)
    monkeypatch.setattr("your_module.idempotency_guard_check", mock_idem_check)
    monkeypatch.setattr("your_module.idempotency_guard_set", mock_idem_set)

    payload = {
        "event_id": "evt-001",
        "zoom": 12,
        "x": 2048,
        "y": 1024,
        "bbox": (-74.01, 40.70, -73.97, 40.73),
        "crs": "EPSG:4326",
        "version": 1,
        "source": "parcel-edit-service",
    }
    await process_tile_event(payload)

    assert len(processed) == 1
    assert broadcast_calls == ["abc123"]

@pytest.mark.asyncio
async def test_duplicate_event_is_skipped(monkeypatch):
    regenerate_calls: list = []

    async def mock_regenerate(zoom, x, y):
        regenerate_calls.append((zoom, x, y))
        return "abc123"

    async def mock_idem_check(key):
        return True  # already processed

    monkeypatch.setattr("your_module.regenerate_tile", mock_regenerate)
    monkeypatch.setattr("your_module.idempotency_guard_check", mock_idem_check)

    payload = {
        "event_id": "evt-002",
        "zoom": 10,
        "x": 512,
        "y": 256,
        "bbox": (-74.01, 40.70, -73.97, 40.73),
        "crs": "EPSG:4326",
        "version": 3,
        "source": "parcel-edit-service",
    }
    await process_tile_event(payload)
    assert regenerate_calls == []