// ExternalPcmTests — Swift wrapper smoke tests for vc_stream_feed_pcm / vc_set_pcm_sink.
//
// These tests verify that the Swift API surface compiles, is callable, and returns expected
// results at the C-ABI boundary — without requiring a live server or audio hardware.
// Full end-to-end relay / decode verification is covered by tests/test_external_pcm.cpp
// (C++ ctest), which runs headlessly on all platforms.

import XCTest
@testable import VoiceCatCore

final class ExternalPcmTests: XCTestCase {

    // MARK: - feedPcm: API surface smoke

    /// Calling feedPcm without a connected client or active stream must return .invalidArg
    /// (not crash). Proves the Swift→C bridge compiles and handles the error path.
    func testFeedPcm_noActiveStream_returnsInvalidArg() {
        let client = VoiceCatClient(config: VoiceCatConfig(
            clientName: "ext-pcm-test",
            clientVersion: "0.1",
            logLevel: .off
        ))
        let sine = [Int16](repeating: 0, count: 960)
        // Stream 0 doesn't exist — the core must return invalidArg, not crash.
        let result = client.feedPcm(streamId: 0, pcm: sine, samplesPerChannel: 960, channels: 1)
        XCTAssertEqual(result, .invalidArg)
    }

    /// Calling feedPcm with channels=3 (invalid) must return .invalidArg.
    func testFeedPcm_invalidChannels_returnsInvalidArg() {
        let client = VoiceCatClient(config: VoiceCatConfig(
            clientName: "ext-pcm-test",
            clientVersion: "0.1",
            logLevel: .off
        ))
        let pcm = [Int16](repeating: 0, count: 960 * 3)
        let result = client.feedPcm(streamId: 0, pcm: pcm, samplesPerChannel: 960, channels: 3)
        XCTAssertEqual(result, .invalidArg)
    }

    // MARK: - setPcmSink: API surface smoke

    /// setPcmSink(nil) on a freshly-created client must succeed (nil = disable, which is the
    /// default state — a no-op that must still return .ok).
    func testSetPcmSink_nil_returnsOk() {
        let client = VoiceCatClient(config: VoiceCatConfig(
            clientName: "ext-pcm-test",
            clientVersion: "0.1",
            logLevel: .off
        ))
        let result = client.setPcmSink(nil, user: nil)
        XCTAssertEqual(result, .ok)
    }

    /// Calling setPcmSink with a @convention(c) function and then immediately disabling it
    /// with nil must both succeed. Verifies the C-ABI function-pointer round-trip.
    func testSetPcmSink_enableThenDisable_bothSucceed() {
        let client = VoiceCatClient(config: VoiceCatConfig(
            clientName: "ext-pcm-test",
            clientVersion: "0.1",
            logLevel: .off
        ))

        let mySink: VoiceCatPcmSinkCallback = { _, _, _, _, _, _, _ in }
        XCTAssertEqual(client.setPcmSink(mySink, user: nil), .ok)
        XCTAssertEqual(client.setPcmSink(nil, user: nil), .ok)
    }
}
