// client/src/input/microphone.rs

#![forbid(unsafe_code)]

use anyhow::{Context, Result};
use gstreamer as gst;
use gstreamer_app as gst_app;
use gst::prelude::*;
use lesavka_common::lesavka::AudioPacket;
use tracing::{debug, error, info, warn};

pub struct MicrophoneCapture {
    pipeline: gst::Pipeline,
    sink:     gst_app::AppSink,
}

impl MicrophoneCapture {
    pub fn new() -> Result<Self> {
        gst::init().ok();                        // idempotent

        /* pulsesrc (default mic) → AAC/ADTS → appsink  -------------------*/
        let desc = concat!(
            "pulsesrc do-timestamp=true ! ",
            "audio/x-raw,format=S16LE,channels=2,rate=48000 ! ",
            "audioconvert ! audioresample ! avenc_aac bitrate=128000 ! ",
            "aacparse ! capsfilter caps=audio/mpeg,stream-format=adts,rate=48000,channels=2 ! ",
            "appsink name=asink emit-signals=true max-buffers=50 drop=true"
        );

        let pipeline: gst::Pipeline = gst::parse::launch(desc)?
            .downcast()
            .expect("pipeline");
        let sink: gst_app::AppSink = pipeline
            .by_name("asink")
            .unwrap()
            .downcast()
            .unwrap();

        /* ─── bus for diagnostics ───────────────────────────────────────*/
        {
            let bus = pipeline.bus().unwrap();
            std::thread::spawn(move || {
                use gst::MessageView::*;
                for msg in bus.iter_timed(gst::ClockTime::NONE) {
                    match msg.view() {
                        StateChanged(s) if s.current() == gst::State::Playing
                            && msg.src().map(|s| s.is::<gst::Pipeline>()).unwrap_or(false) =>
                                info!("🎤 mic pipeline ▶️ (source=pulsesrc)"),
                        Error(e) =>
                            error!("🎤💥 mic: {} ({})", e.error(), e.debug().unwrap_or_default()),
                        Warning(w) =>
                            warn!("🎤⚠️ mic: {} ({})", w.error(), w.debug().unwrap_or_default()),
                        _ => {}
                    }
                }
            });
        }

        pipeline.set_state(gst::State::Playing)
            .context("start mic pipeline")?;

        Ok(Self { pipeline, sink })
    }

    /// Blocking pull; call from an async wrapper
    pub fn pull(&self) -> Option<AudioPacket> {
        match self.sink.pull_sample() {
            Ok(sample) => {
                let buf = sample.buffer().unwrap();
                let map = buf.map_readable().unwrap();
                let pts = buf.pts().unwrap_or(gst::ClockTime::ZERO).nseconds() / 1_000;
                Some(AudioPacket { id: 0, pts, data: map.as_slice().to_vec() })
            }
            Err(_) => None,
        }
    }
}