# jetstream: AT Protocol event firehose proxy for local development.
#
# Subscribes to a PDS's com.atproto.sync.subscribeRepos and re-broadcasts
# events over WebSocket in a simplified JSON format.
#
# Key env vars:
#   JETSTREAM_WS_URL        — upstream ATProto firehose URL
#   JETSTREAM_LISTEN_ADDR   — WebSocket listen address (default :6008)
#   JETSTREAM_DATA_DIR      — PebbleDB cursor storage directory
{
  lib,
  buildGoModule,
  fetchFromGitHub,
}:
buildGoModule {
  pname = "jetstream";
  version = "0-unstable-2024-06-18";

  src = fetchFromGitHub {
    owner = "bluesky-social";
    repo = "jetstream";
    rev = "a003f34cdb510c37d7245f0965814a6168243812";
    hash = "sha256-VMSOHTTLr+wFI0NQthGJvlj1oQkTlFSjWkfbRRLqM0A=";
  };

  vendorHash = "sha256-UvJQ27BZ9Pri8zhY+T40qvH+g5ZInENQqSby+Z+lReg=";

  proxyVendor = true;

  subPackages = ["cmd/jetstream"];

  # CGO is needed for PebbleDB's zstd compression (DataDog/czstd)
  env.CGO_ENABLED = 1;

  # Disable the 15-second liveness checker that kills Jetstream when idle.
  # It's designed for Docker (restart on crash) but we run natively.
  # In local dev there may be long periods with no events.
  postPatch = ''
    substituteInPlace cmd/jetstream/main.go \
      --replace-fail 'close(livenessKill)' '// disabled for local-dev: close(livenessKill)'
  '';

  # The go.sum needs updating for newer Go toolchains
  overrideModAttrs = _: {
    preBuild = ''
      go mod tidy
    '';
  };

  preBuild = ''
    go mod tidy
  '';

  meta = {
    description = "AT Protocol event firehose proxy";
    homepage = "https://github.com/bluesky-social/jetstream";
    license = lib.licenses.mit;
    platforms = lib.platforms.unix;
    mainProgram = "jetstream";
  };
}