# Warp Pipe

Warp Pipe is a C++20 static library wrapping libpipewire for virtual audio node management, link routing, and per-app routing policy.

## Features

- **Virtual sinks/sources** — create Audio/Sink and Audio/Source nodes with configurable sample rate and channels
- **Link management** — connect and disconnect ports by node+port name or ID, with passive and linger options
- **Per-app routing rules** — match applications by name, process binary, or media role and auto-route to target sinks
- **Persistence** — JSON config with atomic writes, auto-save on change, auto-load on startup
- **Volume control** — set per-node volume and mute state
- **Audio metering** — per-node and master peak meters
- **Metadata integration** — read and set default audio sink/source via PipeWire metadata
- **Policy-only mode** — observe and set metadata without creating links (avoids fighting WirePlumber)
- **Thread-safe** — dedicated PipeWire thread loop; all public methods callable from any thread

## Build

Requirements:
- CMake 3.20+
- pkg-config
- libpipewire-0.3 development files
- C++20 compiler
- Qt6 6.2+ (for the GUI target; disable with `-DWARPPIPE_BUILD_GUI=OFF`)
- Catch2 v3 (for tests; required when `-DWARPPIPE_BUILD_TESTS=ON`)

```sh
cmake -S . -B build
cmake --build build
```

Targets: `warppipe` (library), `warppipe_example`, `warppipe_cli`, `warppipe_tests`, `warppipe_perf`, `warppipe-gui`, `warppipe-gui-tests`

### Dependencies

- [libpipewire-0.3](https://pipewire.org/) — system package
- [nlohmann/json](https://github.com/nlohmann/json) — fetched automatically if not installed
- [Catch2 v3](https://github.com/catchorg/Catch2) — required for tests (via `find_package`)
- [Qt6](https://www.qt.io/) — required for `warppipe-gui` (default on)
- [QtNodes](https://github.com/paceholder/nodeeditor) — fetched automatically when GUI is enabled

## Quick Start

```cpp
#include <warppipe/warppipe.hpp>

warppipe::ConnectionOptions opts;
opts.application_name = "my-app";
opts.config_path = "/home/user/.config/warppipe/config.json";

auto result = warppipe::Client::Create(opts);
auto& client = result.value;

// Create a virtual sink
auto sink = client->CreateVirtualSink("my-sink");

// Route Firefox audio to it
warppipe::RouteRule rule;
rule.match.application_name = "Firefox";
rule.target_node = "my-sink";
client->AddRouteRule(rule);

// The policy engine auto-links Firefox when it starts playing
```

## CLI

`warppipe_cli` provides full access to the library for manual testing and scripting:

```
warppipe_cli list-nodes
warppipe_cli list-ports <node-id>
warppipe_cli list-links
warppipe_cli list-rules
warppipe_cli create-sink <name> [--rate N] [--channels N]
warppipe_cli create-source <name> [--rate N] [--channels N]
warppipe_cli link <out-node> <out-port> <in-node> <in-port> [--passive] [--linger]
warppipe_cli unlink <link-id>
warppipe_cli add-rule --app <name> --target <node> [--process <bin>] [--role <role>]
warppipe_cli remove-rule <rule-id>
warppipe_cli save-config <path>
warppipe_cli load-config <path>
warppipe_cli defaults
```

`link` uses node and port names (not IDs). `--passive` sets `PW_KEY_LINK_PASSIVE`, and `--linger` sets `PW_KEY_OBJECT_LINGER` so links persist after the client exits. `defaults` prints the current and configured default sink/source names.

`create-sink` and `create-source` block until interrupted with Ctrl-C.

## Configuration

Config is JSON. Set `ConnectionOptions::config_path` to enable auto-save/load, or use `SaveConfig`/`LoadConfig` manually. The config persists virtual nodes, routing rules, saved links, and per-node volume/mute state.

```json
{
  "version": 1,
  "virtual_nodes": [
    {
      "name": "warppipe-gaming-sink",
      "is_source": false,
      "rate": 48000,
      "channels": 2,
      "loopback": false,
      "target_node": "",
      "volume": 1.0,
      "mute": false
    }
  ],
  "route_rules": [
    {
      "match": {
        "application_name": "Firefox",
        "process_binary": "",
        "media_role": ""
      },
      "target_node": "warppipe-gaming-sink"
    }
  ],
  "links": [
    {
      "out_node": "Firefox",
      "out_port": "output_FL",
      "in_node": "warppipe-gaming-sink",
      "in_port": "input_FL"
    }
  ]
}
```

See [docs/config-schema.md](docs/config-schema.md) for full schema documentation.

## Policy-Only Mode

When running alongside WirePlumber, enable `policy_only` to prevent Warp Pipe from creating links that conflict with the session manager:

```cpp
warppipe::ConnectionOptions opts;
opts.policy_only = true;
```

In this mode the policy engine still evaluates rules but does not create links. Metadata defaults can still be read and set.

## Documentation

- [API Reference](docs/api.md) — full API, threading model, error model, performance notes
- [Config Schema](docs/config-schema.md) — JSON configuration format and persistence behavior
- [GUI Usage](docs/gui-usage.md) — how to run the Qt GUI and capture screenshots
- [Examples](docs/examples.md) — common patterns and usage recipes

## Tests

```sh
./build/warppipe_tests
```

31 test cases covering connection, registry, virtual nodes, links, route rules, policy engine, persistence, and metadata.

## Performance

```sh
./build/warppipe_perf --mode <create-destroy|registry|links|policy|e2e>
```

| Mode | Workload | Typical Result |
|------|----------|----------------|
| create-destroy | 200 sink create/destroy | < 1s |
| registry | 1000 object ingest + 100 events | < 1s |
| links | 200 link create/destroy | < 1s |
| policy | 200 ephemeral sources routed | ~370ms |
| e2e | 200 full iterations (sink + rule + source + teardown) | median ~3ms, p95 ~4ms |