//! Example: render a song (JSON) to WAV using the sequencer.
//!
//! Song JSON format:
//! ```json
//! {
//!   "bpm": 120,
//!   "rows_per_beat": 4,
//!   "tracks": [
//!     { "type": "pulse", "duty": 50, "volume": 0.4 }
//!   ],
//!   "patterns": [
//!     { "rows": [ { "notes": [{"frequency": 440}] }, {"notes": [null]} ] }
//!   ],
//!   "pattern_order": [0]
//! }
//! ```

use soundgen_io::write_wav;
use soundgen_seq::{render_song, Song};

fn main() {
    // Build a simple chiptune melody programmatically
    let song_json = r#"{
        "bpm": 130,
        "rows_per_beat": 4,
        "sample_rate": 44100,
        "tracks": [
            {
                "type": "pulse", "duty": 50,
                "volume": 0.35, "pan": -0.2,
                "envelope": { "attack": 0.005, "decay": 0.03, "sustain": 0.6, "release": 0.05 }
            },
            {
                "type": "triangle",
                "volume": 0.4, "pan": 0.3,
                "envelope": { "attack": 0.01, "decay": 0.05, "sustain": 0.5, "release": 0.08 }
            },
            {
                "type": "noise", "mode": "white", "frequency": 8000,
                "volume": 0.15, "pan": 0.0,
                "envelope": { "attack": 0.0, "decay": 0.02, "sustain": 0.0, "release": 0.02 }
            }
        ],
        "patterns": [
            {
                "rows": [
                    { "notes": [
                        {"frequency": 523.25, "velocity": 1.0},
                        {"frequency": 261.63, "velocity": 1.0},
                        {"frequency": 8000, "velocity": 1.0}
                    ]},
                    { "notes": [null, null, null] },
                    { "notes": [
                        {"frequency": 659.25, "velocity": 1.0},
                        {"frequency": 261.63, "velocity": 1.0},
                        null
                    ]},
                    { "notes": [null, null, {"frequency": 8000, "velocity": 1.0}] },

                    { "notes": [
                        {"frequency": 783.99, "velocity": 1.0},
                        {"frequency": 329.63, "velocity": 1.0},
                        null
                    ]},
                    { "notes": [null, null, null] },
                    { "notes": [
                        {"frequency": 1046.50, "velocity": 1.0},
                        {"frequency": 329.63, "velocity": 1.0},
                        {"frequency": 8000, "velocity": 1.0}
                    ]},
                    { "notes": [null, null, null] },

                    { "notes": [
                        {"frequency": 659.25, "velocity": 1.0},
                        {"frequency": 196.00, "velocity": 1.0},
                        null
                    ]},
                    { "notes": [null, null, {"frequency": 8000, "velocity": 1.0}] },
                    { "notes": [
                        {"frequency": 587.33, "velocity": 1.0},
                        {"frequency": 196.00, "velocity": 1.0},
                        null
                    ]},
                    { "notes": [null, null, null] },

                    { "notes": [
                        {"frequency": 523.25, "velocity": 1.0},
                        {"frequency": 261.63, "velocity": 1.0},
                        {"frequency": 8000, "velocity": 1.0}
                    ]},
                    { "notes": [null, null, null] },
                    { "notes": [null, null, null] },
                    { "notes": [null, null, null] }
                ]
            }
        ],
        "pattern_order": [0, 0]
    }"#;

    let song: Song = serde_json::from_str(song_json).expect("parse song");
    let samples = render_song(&song);

    let out = std::path::Path::new("render_song.wav");
    write_wav(out, &samples, song.sample_rate).expect("write WAV");
    eprintln!(
        "Wrote {} ({:.1}s, {} patterns, {} tracks)",
        out.display(),
        song.duration(),
        song.pattern_order.len(),
        song.tracks.len()
    );
}