#include "AudioOut2PadMix.hpp"

#include <algorithm>
#include <cstddef>
#include <cstring>
#include <stdexcept>

AudioOut2Route AudioOut2RouteForPort(std::uint16_t type, std::uint32_t channels) {
    if (type == AUDIO_OUT2_PORT_TYPE_PAD_SPEAKER && (channels == 1 || channels == 2)) return AudioOut2Route::PadSpeaker;
    if (type == AUDIO_OUT2_PORT_TYPE_PAD_VIBRATION && (channels == 1 || channels == 2)) return AudioOut2Route::PadVibration;
    return AudioOut2Route::Main;
}

bool AudioOut2IsPadAudioDevice(const char* name) {
    if (name == nullptr) return false;
    constexpr char needle[] = "dualsense";
    constexpr std::size_t length = sizeof(needle) - 1;
    for (const char* start = name; *start != '\0'; start++) {
        std::size_t matched = 0;
        while (matched < length && start[matched] != '\0' && (start[matched] | 0x20) == needle[matched]) matched++;
        if (matched == length) return true;
    }
    return false;
}

void AudioOut2AccumulatePadFrame(AudioOut2Route route, const float* in, std::uint32_t channels, const float* volume, float* pad) {
    if (route == AudioOut2Route::Main || (channels != 1 && channels != 2)) throw std::invalid_argument("AudioOut2AccumulatePadFrame: the port does not play on the controller");
    const auto left = route == AudioOut2Route::PadSpeaker ? AUDIO_OUT2_PAD_SPEAKER_LEFT : AUDIO_OUT2_PAD_VIBRATION_LEFT;
    const auto right = route == AudioOut2Route::PadSpeaker ? AUDIO_OUT2_PAD_SPEAKER_RIGHT : AUDIO_OUT2_PAD_VIBRATION_RIGHT;
    const auto rightSource = channels == 2 ? 1u : 0u;
    pad[left] += in[0] * volume[0];
    pad[right] += in[rightSource] * volume[rightSource];
}

void AudioOut2FinishPadMix(float* out, std::uint32_t frames) {
    const auto samples = static_cast<std::size_t>(frames) * AUDIO_OUT2_PAD_CHANNELS;
    for (std::size_t index = 0; index < samples; index++) out[index] = std::clamp(out[index], -1.0f, 1.0f);
}

AudioOut2PadLayout AudioOut2PadLayoutForDriver(const char* driver) {
    AudioOut2PadLayout layout;
    if (driver != nullptr && std::strcmp(driver, "pulseaudio") == 0) {
        layout.channels = AUDIO_OUT2_PAD_DEVICE_CHANNELS_MAX;
        layout.position[AUDIO_OUT2_PAD_VIBRATION_LEFT] = 4;
        layout.position[AUDIO_OUT2_PAD_VIBRATION_RIGHT] = 5;
    }
    return layout;
}

void AudioOut2WritePadFrames(const float* pad, const AudioOut2PadLayout& layout, float* out, std::uint32_t frames) {
    std::fill(out, out + static_cast<std::size_t>(frames) * layout.channels, 0.0f);
    for (std::uint32_t frame = 0; frame < frames; frame++) {
        for (std::uint32_t channel = 0; channel < AUDIO_OUT2_PAD_CHANNELS; channel++) {
            out[static_cast<std::size_t>(frame) * layout.channels + layout.position[channel]] = pad[static_cast<std::size_t>(frame) * AUDIO_OUT2_PAD_CHANNELS + channel];
        }
    }
}