/// Audio pipeline constants.
pub const WHISPER_SAMPLE_RATE: u32 = 16_000;
pub const WHISPER_CHANNELS: u16 = 1;

/// Parakeet mel spectrogram constants.
pub const PARAKEET_N_FFT: usize = 512;
pub const PARAKEET_HOP_LENGTH: usize = 160;
pub const PARAKEET_WIN_LENGTH: usize = 400;
pub const PARAKEET_N_MELS: usize = 80;
pub const PARAKEET_PRE_EMPHASIS: f32 = 0.97;
pub const PARAKEET_BLANK_TOKEN: usize = 1024;
pub const PARAKEET_LOG_GUARD: f32 = 5.960_464_5e-8; // 2^-24

/// Chunk timing for live transcription.
pub const CHUNK_INTERVAL_MS: u64 = 3000;
pub const MIN_CHUNK_SAMPLES: usize = 8000;

/// Post-processing thresholds.
pub const SMART_PARAGRAPH_GAP_SECS: f64 = 2.0;

/// History limits.
pub const HISTORY_MAX_ENTRIES: usize = 100;

/// RAM thresholds for model recommendations (in GB).
pub const RAM_MINIMUM_FOR_LOCAL_STT: f64 = 2.0;
pub const RAM_THRESHOLD_LIGHTWEIGHT: f64 = 4.0;
pub const RAM_THRESHOLD_STANDARD: f64 = 8.0;
pub const RAM_THRESHOLD_COMFORTABLE: f64 = 16.0;

/// VAD configuration defaults.
pub const VAD_SPEECH_THRESHOLD: f64 = 0.5;
pub const VAD_MIN_SPEECH_DURATION_MS: u32 = 250;
pub const VAD_MAX_SPEECH_DURATION_S: u32 = 30;
pub const VAD_MIN_SILENCE_DURATION_MS: u32 = 300;
pub const VAD_SPEECH_PAD_MS: u32 = 100;

/// Model download chunk size for progress reporting.
pub const DOWNLOAD_CHUNK_BYTES: usize = 65_536;