libflo_audio/

lib.rs

#![cfg_attr(not(test), no_std)]
#![allow(clippy::needless_range_loop)]

extern crate alloc;

#[cfg(feature = "wasm")]
use alloc::format;
#[cfg(feature = "wasm")]
use alloc::string::String;
#[cfg(feature = "wasm")]
use alloc::string::ToString;
#[cfg(feature = "wasm")]
use alloc::vec;
use alloc::vec::Vec;
#[cfg(feature = "wasm")]
use messagepack_serde::{from_slice, to_vec};
#[cfg(feature = "wasm")]
use wasm_bindgen::prelude::*;

pub mod core;
pub mod dsp;
pub mod lossless;
pub mod lossy;
pub mod streaming;

mod reader;
pub mod seeking;
mod writer;

pub use core::{
    compute_crc32, compute_ebu_r128_loudness, extract_spectral_fingerprint, extract_waveform_peaks,
    metadata::*, rice, ChannelData, FloError, FloErrorExt, FloErrorKind, FloFile, FloResult,
    FrameType, LoudnessMetrics, ResidualEncoding, HEADER_SIZE, MAGIC, VERSION_MAJOR, VERSION_MINOR,
};
pub use lossless::{lpc, Decoder, Encoder};
pub use lossy::{
    deserialize_frame, serialize_frame, BlockSize, Mdct, PsychoacousticModel, QualityPreset,
    TransformDecoder as LossyDecoder, TransformEncoder as LossyEncoder, TransformFrame, WindowType,
    FRAME_COEFFICIENTS, LONG_BLOCK_SIZE, SHORTS_PER_GROUP, SHORT_BLOCK_SIZE, SHORT_GROUP_OFFSET,
};
pub use reader::Reader;
pub use streaming::{
    DecoderState, EncodedFrame, StreamingAudioInfo, StreamingDecoder, StreamingEncoder,
};
pub use writer::Writer;

// audio info for the info() function

/// info about a flo file
#[cfg(feature = "wasm")]
#[wasm_bindgen]
#[derive(Debug, Clone)]
pub struct AudioInfo {
    /// version string like "1.2"
    #[wasm_bindgen(skip)]
    pub version: String,
    /// Sample rate in Hz
    pub sample_rate: u32,
    /// Number of channels
    pub channels: u8,
    /// Bits per sample
    pub bit_depth: u8,
    /// Total sample-frames (samples per channel). This is the number of sample
    /// instants per channel (not interleaved samples). Use metadata.length_ms
    /// for a quick duration lookup.
    pub total_samples: u64,
    /// Duration in seconds
    pub duration_secs: f64,
    /// File size in bytes
    pub file_size: usize,
    /// Compression ratio (original / compressed)
    pub compression_ratio: f64,
    /// Is CRC valid?
    pub crc_valid: bool,
    /// Is lossy compression mode?
    pub is_lossy: bool,
    /// Lossy quality 0-4 (only valid if is_lossy)
    pub lossy_quality: u8,
}

#[cfg(feature = "wasm")]
#[wasm_bindgen]
impl AudioInfo {
    #[wasm_bindgen(getter)]
    pub fn version(&self) -> String {
        self.version.clone()
    }
}

// result helpers

/// turn an error into js
#[cfg(feature = "wasm")]
fn to_js_err(e: impl ::core::fmt::Display) -> JsValue {
    JsValue::from_str(&e.to_string())
}

// api functions

/// encode samples to flo lossless
///
/// # Arguments
/// * `samples` - Interleaved audio samples (f32, -1.0 to 1.0)
/// * `sample_rate` - Sample rate in Hz (e.g., 44100)
/// * `channels` - Number of channels (1 or 2)
/// * `bit_depth` - Bits per sample (16, 24, or 32)
/// * `metadata` - Optional MessagePack metadata
///
/// # Returns
/// flo file as byte array
///
/// # Note
/// For advanced usage with custom compression levels (0-9),
/// use the `Encoder` builder pattern directly.
#[cfg(feature = "wasm")]
#[wasm_bindgen]
pub fn encode(
    samples: &[f32],
    sample_rate: u32,
    channels: u8,
    bit_depth: u8,
    metadata: Option<Vec<u8>>,
) -> Result<Vec<u8>, JsValue> {
    validate_audio_format(samples, sample_rate, channels, bit_depth).map_err(to_js_err)?;

    // Auto-add analysis data if missing
    let metadata_with_waveform = add_analysis_data_if_missing(
        &metadata.unwrap_or_default(),
        samples,
        sample_rate,
        channels,
        50, // 50 peaks per second default
    )
    .map_err(to_js_err)?;

    let encoder = Encoder::new(sample_rate, channels, bit_depth);
    encoder
        .encode(samples, &metadata_with_waveform)
        .map_err(to_js_err)
}

/// encode samples to flo lossy
///
/// # Arguments
/// * `samples` - Interleaved audio samples (f32, -1.0 to 1.0)
/// * `sample_rate` - Sample rate in Hz (e.g., 44100)
/// * `channels` - Number of audio channels (1 or 2)
/// * `bit_depth` - Bits per sample (typically 16)
/// * `quality` - Quality level 0-4 (0=low/~64kbps, 4=transparent/~320kbps)
/// * `metadata` - Optional MessagePack metadata
///
/// # Returns
/// flo file as byte array
///
/// # Note
/// For advanced usage with continuous quality control (0.0-1.0) or custom settings,
/// use the `LossyEncoder` builder pattern directly.
#[cfg(feature = "wasm")]
#[wasm_bindgen]
pub fn encode_lossy(
    samples: &[f32],
    sample_rate: u32,
    channels: u8,
    _bit_depth: u8,
    quality: u8,
    metadata: Option<Vec<u8>>,
) -> Result<Vec<u8>, JsValue> {
    validate_audio_format(samples, sample_rate, channels, _bit_depth).map_err(to_js_err)?;

    // quality levels to 0.0-1.0
    let quality_f32 = match quality {
        0 => 0.0,
        1 => 0.35,
        2 => 0.55,
        3 => 0.75,
        _ => 1.0,
    };

    // Auto-add analysis data if missing
    let metadata_with_waveform = add_analysis_data_if_missing(
        &metadata.unwrap_or_default(),
        samples,
        sample_rate,
        channels,
        50, // 50 peaks per second default
    )
    .map_err(to_js_err)?;

    let mut encoder = lossy::TransformEncoder::new(sample_rate, channels, quality_f32);
    encoder
        .encode_to_flo(samples, &metadata_with_waveform)
        .map_err(to_js_err)
}

/// encode to flo lossy with target bitrate
///
/// # Arguments
/// * `samples` - Interleaved audio samples (f32, -1.0 to 1.0)
/// * `sample_rate` - Sample rate in Hz (e.g., 44100)
/// * `channels` - Number of audio channels
/// * `bit_depth` - Bits per sample (16, 24, or 32)
/// * `target_bitrate_kbps` - Target bitrate in kbps (e.g., 128, 192, 256, 320)
/// * `metadata` - Optional MessagePack metadata
///
/// # Returns
/// flo file as byte array
#[cfg(feature = "wasm")]
#[wasm_bindgen]
pub fn encode_with_bitrate(
    samples: &[f32],
    sample_rate: u32,
    channels: u8,
    _bit_depth: u8,
    target_bitrate_kbps: u32,
    metadata: Option<Vec<u8>>,
) -> Result<Vec<u8>, JsValue> {
    validate_audio_format(samples, sample_rate, channels, _bit_depth).map_err(to_js_err)?;

    // bitrate to quality
    let quality =
        lossy::QualityPreset::from_bitrate(target_bitrate_kbps, sample_rate, channels).as_f32();

    // Auto-add analysis data if missing
    let metadata_with_waveform = add_analysis_data_if_missing(
        &metadata.unwrap_or_default(),
        samples,
        sample_rate,
        channels,
        50, // 50 peaks per second default
    )
    .map_err(to_js_err)?;

    let mut encoder = lossy::TransformEncoder::new(sample_rate, channels, quality);
    encoder
        .encode_to_flo(samples, &metadata_with_waveform)
        .map_err(to_js_err)
}

/// Add analysis data to metadata if not present
///
/// # Arguments
/// * `metadata` - MessagePack metadata bytes
/// * `samples` - Audio samples (interleaved)
/// * `sample_rate` - Sample rate in Hz
/// * `channels` - Number of audio channels
/// * `peaks_per_second` - Number of peaks per second (default: 50)
///
/// # Returns
/// Updated metadata with analysis data (waveform, spectrum, loudness)
#[cfg(feature = "wasm")]
fn validate_audio_format(
    samples: &[f32],
    sample_rate: u32,
    channels: u8,
    bit_depth: u8,
) -> Result<(), String> {
    if sample_rate == 0 {
        return Err("Sample rate must be greater than zero".to_string());
    }
    if channels == 0 {
        return Err("Channel count must be greater than zero".to_string());
    }
    if !matches!(bit_depth, 8 | 16 | 24 | 32) {
        return Err("Bit depth must be 8, 16, 24, or 32".to_string());
    }
    if !samples.len().is_multiple_of(channels as usize) {
        return Err("Interleaved samples must contain a complete final frame".to_string());
    }
    Ok(())
}

#[cfg(feature = "wasm")]
fn add_analysis_data_if_missing(
    metadata: &[u8],
    samples: &[f32],
    sample_rate: u32,
    channels: u8,
    peaks_per_second: u32,
) -> Result<Vec<u8>, String> {
    // Try to parse existing metadata
    let mut flo_metadata: FloMetadata = if !metadata.is_empty() {
        from_slice(metadata).map_err(|e| format!("Invalid metadata: {}", e))?
    } else {
        FloMetadata::default()
    };

    // Add waveform data if not present
    if flo_metadata.waveform_data.is_none() {
        let waveform = core::analysis::extract_waveform_peaks(
            samples,
            channels,
            sample_rate,
            peaks_per_second,
        );
        flo_metadata.waveform_data = Some(waveform);
    }

    // Add spectral fingerprint if not present
    if flo_metadata.spectrum_fingerprint.is_none() {
        let spectral_fingerprint = core::analysis::extract_spectral_fingerprint(
            samples,
            channels,
            sample_rate,
            Some(2048), // Default FFT size
            Some(1024), // Default hop size for 50% overlap
        );

        // Convert spectral data to bytes for storage
        if let Ok(spectral_bytes) = messagepack_serde::to_vec(&spectral_fingerprint) {
            flo_metadata.spectrum_fingerprint = Some(spectral_bytes);
        }
    }

    // Add loudness metrics if not present
    if flo_metadata.loudness_profile.is_empty() {
        let loudness_metrics =
            core::ebu_r128::compute_ebu_r128_loudness(samples, channels, sample_rate);

        // Convert loudness metrics to LoudnessPoint format
        let loudness_point = core::metadata::LoudnessPoint {
            timestamp_ms: 0,
            lufs: loudness_metrics.integrated_lufs as f32,
        };

        flo_metadata.loudness_profile = vec![loudness_point];
    }

    // Always set length_ms (duration in milliseconds).
    // `samples` is interleaved (L,R,L,R...)
    let interleaved_len = samples.len() as u64;
    let samples_per_channel = interleaved_len / (channels as u64);
    let length_ms = (((samples_per_channel as f64) / (sample_rate as f64)) * 1000.0) as u64;
    flo_metadata.length_ms = Some(length_ms);

    // Serialize back to bytes
    to_vec(&flo_metadata).map_err(|e| format!("Failed to serialize metadata: {}", e))
}

/// decode flo file to samples
///
/// This automatically detects whether the file uses lossless or lossy encoding
/// and dispatches to the appropriate decoder.
///
/// # Arguments
/// * `data` - flo file bytes
///
/// # Returns
/// Interleaved audio samples (f32, -1.0 to 1.0)
#[cfg(feature = "wasm")]
#[wasm_bindgen]
pub fn decode(data: &[u8]) -> Result<Vec<f32>, JsValue> {
    // figure out if its transform/lossy
    let reader = Reader::new();
    let file = reader.read(data).map_err(to_js_err)?;

    // any transform frames means lossy
    let is_transform = file
        .frames
        .iter()
        .any(|f| f.frame_type == (FrameType::Transform as u8));

    if is_transform {
        // lossy
        decode_transform_file(&file).map_err(to_js_err)
    } else {
        // lossless
        let decoder = Decoder::new();
        decoder.decode_file(&file).map_err(to_js_err)
    }
}

/// Decode a lossy flo file that uses transform-based compression
///
/// # Arguments
/// * `file` - Parsed flo file
///
/// # Returns
/// Interleaved audio samples (f32, -1.0 to 1.0)
/// Decode a transform-based lossy file
#[cfg(feature = "wasm")]
fn decode_transform_file(file: &FloFile) -> FloResult<Vec<f32>> {
    let mut decoder = lossy::TransformDecoder::new(file.header.sample_rate, file.header.channels);
    let mut all_samples = Vec::new();
    let mut frame_count = 0;

    for frame in &file.frames {
        if frame.channels.is_empty() {
            continue;
        }

        // transform data is in first channels residuals
        let frame_data = &frame.channels[0].residuals;

        if let Some(transform_frame) = lossy::deserialize_frame(frame_data) {
            let samples = decoder.decode_frame(&transform_frame);

            // skip first frame (pre-roll for overlap-add)
            if frame_count > 0 {
                all_samples.extend(samples);
            }
            frame_count += 1;
        } else {
            return Err(crate::core::FloError::from(
                "Failed to deserialize transform frame",
            ));
        }
    }

    Ok(all_samples)
}

/// Validate flo file integrity
///
/// # Arguments
/// * `data` - flo file bytes
///
/// # Returns
/// true if file is valid and CRC matches
#[cfg(feature = "wasm")]
#[wasm_bindgen]
pub fn validate(data: &[u8]) -> Result<bool, JsValue> {
    let reader = Reader::new();
    match reader.read(data) {
        Ok(file) => {
            let start = (4 + file.header.header_size + file.header.toc_size) as usize;
            let end = start + (file.header.data_size as usize);
            if end <= data.len() {
                let computed = core::crc32::compute(&data[start..end]);
                Ok(computed == file.header.data_crc32)
            } else {
                Ok(false)
            }
        }
        Err(_) => Ok(false),
    }
}

/// Get information about a flo file
///
/// # Arguments
/// * `data` - flo file bytes
///
/// # Returns
/// AudioInfo struct with file details
#[cfg(feature = "wasm")]
#[wasm_bindgen]
pub fn info(data: &[u8]) -> Result<AudioInfo, JsValue> {
    let reader = Reader::new();
    let file = reader.read(data).map_err(to_js_err)?;

    // Use length_ms from metadata for duration
    let metadata = FloMetadata::from_msgpack(&file.metadata).unwrap_or_default();
    let duration_secs = metadata
        .length_ms
        .map(|ms| (ms as f64) / 1000.0)
        .unwrap_or_else(|| {
            // Fallback: calculate from total_samples / sample_rate
            (file.header.total_samples as f64) / (file.header.sample_rate as f64)
        });

    // Calculate original size from total_samples (actual sample count in header)
    let original_size = ((file.header.total_samples as f64)
        * (file.header.channels as f64)
        * ((file.header.bit_depth as f64) / 8.0)) as usize;
    let compression_ratio = if !data.is_empty() {
        (original_size as f64) / (data.len() as f64)
    } else {
        0.0
    };

    // check crc
    let start = (4 + file.header.header_size + file.header.toc_size) as usize;
    let end = start + (file.header.data_size as usize);
    let crc_valid = if end <= data.len() {
        core::crc32::compute(&data[start..end]) == file.header.data_crc32
    } else {
        false
    };

    // lossy mode from flags
    let is_lossy = (file.header.flags & 0x01) != 0;
    let lossy_quality = ((file.header.flags >> 8) & 0x0f) as u8;

    Ok(AudioInfo {
        version: format!(
            "{}.{}",
            file.header.version_major, file.header.version_minor
        ),
        sample_rate: file.header.sample_rate,
        channels: file.header.channels,
        bit_depth: file.header.bit_depth,
        total_samples: file.header.total_samples,
        duration_secs,
        file_size: data.len(),
        compression_ratio,
        crc_valid,
        is_lossy,
        lossy_quality,
    })
}

/// get lib version
#[cfg(feature = "wasm")]
#[wasm_bindgen]
pub fn version() -> String {
    format!("{}.{}", VERSION_MAJOR, VERSION_MINOR)
}

/// Format time in seconds to MM:SS or H:MM:SS string
#[cfg(feature = "wasm")]
#[wasm_bindgen]
pub fn format_time(seconds: f64) -> String {
    if !seconds.is_finite() || seconds < 0.0 {
        return "0:00".to_string();
    }

    let total_secs = seconds.floor() as u64;
    let hours = total_secs / 3600;
    let mins = (total_secs % 3600) / 60;
    let secs = total_secs % 60;

    if hours > 0 {
        format!("{}:{:02}:{:02}", hours, mins, secs)
    } else {
        format!("{}:{:02}", mins, secs)
    }
}

/// Format time in milliseconds to MM:SS or H:MM:SS string
#[cfg(feature = "wasm")]
#[wasm_bindgen]
pub fn format_time_ms(milliseconds: f64) -> String {
    format_time(milliseconds / 1000.0)
}

/// Extract TOC (Table of Contents) entries from a flo file
///
/// # Returns
/// Array of TOC entries with frame indices, byte offsets, and timestamps
#[cfg(feature = "wasm")]
#[wasm_bindgen]
pub fn get_toc(flo_data: &[u8]) -> Result<Vec<JsValue>, JsValue> {
    let toc = seeking::get_toc(flo_data).map_err(to_js_err)?;
    let result = toc
        .into_iter()
        .map(|entry| {
            let obj = js_sys::Object::new();
            js_sys::Reflect::set(&obj, &"frame_index".into(), &entry.frame_index.into()).ok();
            js_sys::Reflect::set(
                &obj,
                &"byte_offset".into(),
                &(entry.byte_offset as f64).into(),
            )
            .ok();
            js_sys::Reflect::set(&obj, &"frame_size".into(), &entry.frame_size.into()).ok();
            js_sys::Reflect::set(&obj, &"timestamp_ms".into(), &entry.timestamp_ms.into()).ok();
            obj.into()
        })
        .collect();
    Ok(result)
}

/// Decode a single frame by index without decoding the entire file
///
/// # Arguments
/// * `flo_data` - Complete flo file bytes
/// * `frame_index` - Zero-based frame index
///
/// # Returns
/// Interleaved audio samples for that frame (f32, -1.0 to 1.0)
#[cfg(feature = "wasm")]
#[wasm_bindgen]
pub fn decode_frame_at(flo_data: &[u8], frame_index: u32) -> Result<Vec<f32>, JsValue> {
    seeking::decode_frame_at(flo_data, frame_index).map_err(to_js_err)
}

/// Seek to a specific time in milliseconds
///
/// # Arguments
/// * `flo_data` - Complete flo file bytes
/// * `time_ms` - Target time in milliseconds
///
/// # Returns
/// Seek result object containing frame index, byte offset, timestamp, sample offset, and next timestamp.
#[cfg(feature = "wasm")]
#[wasm_bindgen]
pub fn seek_to_time(flo_data: &[u8], time_ms: u32) -> Result<JsValue, JsValue> {
    let result = seeking::seek_to_time(flo_data, time_ms).map_err(to_js_err)?;

    let obj = js_sys::Object::new();
    js_sys::Reflect::set(&obj, &"frame_index".into(), &result.frame_index.into())?;
    js_sys::Reflect::set(
        &obj,
        &"byte_offset".into(),
        &(result.byte_offset as f64).into(),
    )?;
    js_sys::Reflect::set(&obj, &"timestamp_ms".into(), &result.timestamp_ms.into())?;
    js_sys::Reflect::set(&obj, &"sample_offset".into(), &result.sample_offset.into())?;
    js_sys::Reflect::set(
        &obj,
        &"next_timestamp_ms".into(),
        &result.next_timestamp_ms.into(),
    )?;

    Ok(obj.into())
}

// streaming decoder wasm api

#[cfg(feature = "wasm")]
#[wasm_bindgen]
pub struct WasmStreamingDecoder {
    inner: StreamingDecoder,
}

#[cfg(feature = "wasm")]
#[wasm_bindgen]
impl WasmStreamingDecoder {
    /// new streaming decoder
    #[wasm_bindgen(constructor)]
    pub fn new() -> Self {
        Self {
            inner: StreamingDecoder::new(),
        }
    }

    /// feed data to the decoder, call as bytes come in from network
    #[cfg(feature = "wasm")]
    #[wasm_bindgen]
    pub fn feed(&mut self, data: &[u8]) -> Result<bool, JsValue> {
        self.inner.feed(data).map_err(to_js_err)
    }

    /// Check if the decoder is ready to produce audio
    #[cfg(feature = "wasm")]
    #[wasm_bindgen]
    pub fn is_ready(&self) -> bool {
        self.inner.state() == DecoderState::Ready
    }

    /// stream done?
    #[cfg(feature = "wasm")]
    #[wasm_bindgen]
    pub fn is_finished(&self) -> bool {
        self.inner.state() == DecoderState::Finished
    }

    /// Check if there was an error
    #[cfg(feature = "wasm")]
    #[wasm_bindgen]
    pub fn has_error(&self) -> bool {
        self.inner.state() == DecoderState::Error
    }

    /// Get the current state as a string
    #[cfg(feature = "wasm")]
    #[wasm_bindgen]
    pub fn state(&self) -> String {
        match self.inner.state() {
            DecoderState::WaitingForHeader => "waiting_for_header".into(),
            DecoderState::WaitingForToc => "waiting_for_toc".into(),
            DecoderState::Ready => "ready".into(),
            DecoderState::Finished => "finished".into(),
            DecoderState::Error => "error".into(),
        }
    }

    /// Get audio information (available after header is parsed)
    ///
    /// Returns null if header hasn't been parsed yet.
    #[cfg(feature = "wasm")]
    #[wasm_bindgen]
    pub fn get_info(&self) -> Result<JsValue, JsValue> {
        match self.inner.info() {
            Some(info) => {
                let obj = js_sys::Object::new();
                js_sys::Reflect::set(&obj, &"sample_rate".into(), &info.sample_rate.into())?;
                js_sys::Reflect::set(&obj, &"channels".into(), &info.channels.into())?;
                js_sys::Reflect::set(&obj, &"bit_depth".into(), &info.bit_depth.into())?;
                js_sys::Reflect::set(
                    &obj,
                    &"total_samples".into(),
                    &(info.total_samples as f64).into(),
                )?;
                js_sys::Reflect::set(&obj, &"is_lossy".into(), &info.is_lossy.into())?;
                Ok(obj.into())
            }
            None => Ok(JsValue::NULL),
        }
    }

    /// decode all currently available samples
    #[cfg(feature = "wasm")]
    #[wasm_bindgen]
    pub fn decode_available(&mut self) -> Result<Vec<f32>, JsValue> {
        self.inner.decode_available().map_err(to_js_err)
    }

    /// Decode the next available frame
    ///
    /// Returns interleaved f32 samples for one frame, or null if no frame is ready.
    /// This enables true streaming: decode and play frames as they arrive.
    ///
    /// Usage pattern:
    /// ```js
    /// while (true) {
    ///     const samples = decoder.next_frame();
    ///     if (samples === null) break; // No more frames ready
    ///     playAudio(samples);
    /// }
    /// ```
    #[cfg(feature = "wasm")]
    #[wasm_bindgen]
    pub fn next_frame(&mut self) -> Result<JsValue, JsValue> {
        match self.inner.next_frame() {
            Ok(Some(samples)) => {
                let array = js_sys::Float32Array::new_with_length(samples.len() as u32);
                array.copy_from(&samples);
                Ok(array.into())
            }
            Ok(None) => Ok(JsValue::NULL),
            Err(e) => Err(to_js_err(e)),
        }
    }

    /// how many frames ready to decode
    #[cfg(feature = "wasm")]
    #[wasm_bindgen]
    pub fn available_frames(&self) -> usize {
        self.inner.available_frames()
    }

    /// current frame index
    #[cfg(feature = "wasm")]
    #[wasm_bindgen]
    pub fn current_frame_index(&self) -> usize {
        self.inner.current_frame_index()
    }

    /// Reset the decoder to initial state
    ///
    /// Use this to start decoding a new stream.
    #[cfg(feature = "wasm")]
    #[wasm_bindgen]
    pub fn reset(&mut self) {
        self.inner.reset();
    }

    /// bytes currently buffered
    #[cfg(feature = "wasm")]
    #[wasm_bindgen]
    pub fn buffered_bytes(&self) -> usize {
        self.inner.buffered_bytes()
    }
}

#[cfg(feature = "wasm")]
impl Default for WasmStreamingDecoder {
    fn default() -> Self {
        Self::new()
    }
}

/// Encodes samples frame-by-frame as they arrive, returning encoded frames ready for transmission.
/// Use this for low-latency streaming encoding where you push samples and pull frames.
#[cfg(feature = "wasm")]
#[wasm_bindgen]
pub struct WasmStreamingEncoder {
    inner: StreamingEncoder,
}

#[cfg(feature = "wasm")]
#[wasm_bindgen]
impl WasmStreamingEncoder {
    /// Create a new streaming encoder
    ///
    /// # Arguments
    /// * `sample_rate` - Sample rate in Hz (e.g., 44100)
    /// * `channels` - Number of channels (1 or 2)
    /// * `bit_depth` - Bits per sample (16, 24, or 32)
    ///
    /// # Returns
    /// New encoder instance
    #[wasm_bindgen(constructor)]
    pub fn new(sample_rate: u32, channels: u8, bit_depth: u8) -> Self {
        Self {
            inner: StreamingEncoder::new(sample_rate, channels, bit_depth),
        }
    }

    /// Set compression level (0-9)
    ///
    /// # Arguments
    /// * `level` - Compression level (0=fast/large, 9=slow/small)
    ///
    /// # Returns
    /// Self for method chaining
    #[cfg(feature = "wasm")]
    #[wasm_bindgen]
    pub fn with_compression(mut self, level: u8) -> Self {
        self.inner = self.inner.with_compression(level);
        self
    }

    /// Push audio samples to the encoder
    ///
    /// Samples should be interleaved if multi-channel (e.g., [L0, R0, L1, R1, ...] for stereo).
    /// Frames are encoded automatically when enough samples accumulate.
    ///
    /// # Arguments
    /// * `samples` - Interleaved f32 audio samples (-1.0 to 1.0)
    ///
    /// # Returns
    /// Error if encoding fails
    #[cfg(feature = "wasm")]
    #[wasm_bindgen]
    pub fn push_samples(&mut self, samples: &[f32]) -> Result<(), JsValue> {
        self.inner.push_samples(samples).map_err(to_js_err)
    }

    /// Get the next encoded frame if available
    ///
    /// Returns an object with: index, timestamp_ms, data (Uint8Array), samples
    /// Returns null if no frames are ready yet.
    ///
    /// # Returns
    /// Encoded frame object or null
    #[cfg(feature = "wasm")]
    #[wasm_bindgen]
    pub fn next_frame(&mut self) -> JsValue {
        match self.inner.next_frame() {
            Some(frame) => {
                let obj = js_sys::Object::new();
                let _ = js_sys::Reflect::set(&obj, &"index".into(), &frame.index.into());
                let _ =
                    js_sys::Reflect::set(&obj, &"timestamp_ms".into(), &frame.timestamp_ms.into());
                let _ = js_sys::Reflect::set(
                    &obj,
                    &"data".into(),
                    &js_sys::Uint8Array::from(&frame.data[..]).into(),
                );
                let _ = js_sys::Reflect::set(&obj, &"samples".into(), &frame.samples.into());
                obj.into()
            }
            None => JsValue::NULL,
        }
    }

    /// Get number of samples currently buffered
    ///
    /// # Returns
    /// Number of sample frames in buffer
    #[cfg(feature = "wasm")]
    #[wasm_bindgen]
    pub fn pending_samples(&self) -> usize {
        self.inner.pending_samples()
    }

    /// Get number of encoded frames ready for transmission
    ///
    /// # Returns
    /// Number of ready frames
    #[cfg(feature = "wasm")]
    #[wasm_bindgen]
    pub fn pending_frames(&self) -> usize {
        self.inner.pending_frames()
    }

    /// Flush remaining samples and finalize encoding
    ///
    /// Call this when done pushing samples. Encodes any remaining partial frame.
    /// After this, call finalize() to get the complete flo file.
    ///
    /// # Returns
    /// Error if encoding fails
    #[cfg(feature = "wasm")]
    #[wasm_bindgen]
    pub fn flush(&mut self) -> Result<(), JsValue> {
        self.inner.flush_into_frames().map_err(to_js_err)?;
        Ok(())
    }

    /// Build a complete flo file from all accumulated frames
    ///
    /// Call flush() first, then this method to generate the complete file.
    /// The file will contain all encoded frames with proper table-of-contents.
    ///
    /// # Arguments
    /// * `metadata` - Optional metadata bytes (MessagePack encoded, use create_metadata())
    ///
    /// # Returns
    /// Complete flo file as byte array
    #[cfg(feature = "wasm")]
    #[wasm_bindgen]
    pub fn finalize(&mut self, metadata: Option<Vec<u8>>) -> Result<Vec<u8>, JsValue> {
        let meta = metadata.unwrap_or_default();
        self.inner.finalize(&meta).map_err(to_js_err)
    }
}

#[cfg(feature = "wasm")]
impl Default for WasmStreamingEncoder {
    fn default() -> Self {
        Self {
            inner: StreamingEncoder::new(44100, 2, 16),
        }
    }
}

/// Create metadata from basic fields and serialize to MessagePack
///
/// # Arguments
/// * `title` - Optional title
/// * `artist` - Optional artist
/// * `album` - Optional album
///
/// # Returns
/// MessagePack bytes containing metadata
#[cfg(feature = "wasm")]
#[wasm_bindgen]
pub fn create_metadata(
    title: Option<String>,
    artist: Option<String>,
    album: Option<String>,
) -> Result<Vec<u8>, JsValue> {
    let meta = FloMetadata::with_basic(title, artist, album);
    meta.to_msgpack()
        .map_err(|e| JsValue::from_str(&e.to_string()))
}

/// Create metadata from a JavaScript object
///
/// Accepts an object with any of the supported metadata fields.
/// See FloMetadata for available fields.
///
/// # Returns
/// MessagePack bytes containing metadata
#[cfg(feature = "wasm")]
#[wasm_bindgen]
pub fn create_metadata_from_object(obj: JsValue) -> Result<Vec<u8>, JsValue> {
    let meta: FloMetadata = serde_wasm_bindgen::from_value(obj)
        .map_err(|e| JsValue::from_str(&format!("Invalid metadata: {}", e)))?;
    meta.to_msgpack()
        .map_err(|e| JsValue::from_str(&e.to_string()))
}

/// Extract metadata from a flo file
///
/// # Arguments
/// * `data` - flo file bytes
///
/// # Returns
/// JavaScript object with metadata fields (or null if no metadata)
#[cfg(feature = "wasm")]
#[wasm_bindgen]
pub fn get_metadata(data: &[u8]) -> Result<JsValue, JsValue> {
    let reader = Reader::new();
    let file = reader.read(data).map_err(to_js_err)?;

    if file.metadata.is_empty() {
        return Ok(JsValue::NULL);
    }

    let meta = FloMetadata::from_msgpack(&file.metadata)
        .map_err(|e| JsValue::from_str(&format!("Invalid metadata: {}", e)))?;

    serde_wasm_bindgen::to_value(&meta)
        .map_err(|e| JsValue::from_str(&format!("Serialization error: {}", e)))
}

/// Get cover art from a flo file
///
/// # Arguments
/// * `data` - flo file bytes
///
/// # Returns
/// Object with `mime_type` and `data` (Uint8Array) or null if no cover
#[cfg(feature = "wasm")]
#[wasm_bindgen]
pub fn get_cover_art(data: &[u8]) -> Result<JsValue, JsValue> {
    let reader = Reader::new();
    let file = reader.read(data).map_err(to_js_err)?;

    if file.metadata.is_empty() {
        return Ok(JsValue::NULL);
    }

    let meta = FloMetadata::from_msgpack(&file.metadata)
        .map_err(|e| JsValue::from_str(&format!("Invalid metadata: {}", e)))?;

    // try front cover first
    if let Some(pic) = meta.front_cover().or_else(|| meta.any_picture()) {
        let obj = js_sys::Object::new();
        js_sys::Reflect::set(&obj, &"mime_type".into(), &pic.mime_type.clone().into())?;
        js_sys::Reflect::set(
            &obj,
            &"data".into(),
            &js_sys::Uint8Array::from(&pic.data[..]).into(),
        )?;
        if let Some(ref desc) = pic.description {
            js_sys::Reflect::set(&obj, &"description".into(), &desc.clone().into())?;
        }
        Ok(obj.into())
    } else {
        Ok(JsValue::NULL)
    }
}

/// Set a single field in existing metadata bytes
///
/// Uses serde to dynamically set fields - field names match FloMetadata struct.
/// For complex fields (pictures, synced_lyrics, etc.) use create_metadata_from_object.
///
/// # Arguments
/// * `metadata` - Existing MessagePack metadata bytes (or empty for new)
/// * `field` - Field name (e.g., "title", "artist", "bpm")
/// * `value` - Field value (string, number, or null)
///
/// # Returns
/// Updated MessagePack metadata bytes
#[cfg(feature = "wasm")]
#[wasm_bindgen]
pub fn set_metadata_field(
    metadata: Option<Vec<u8>>,
    field: &str,
    value: JsValue,
) -> Result<Vec<u8>, JsValue> {
    // parse or create new
    let meta = match &metadata {
        Some(data) if !data.is_empty() => FloMetadata::from_msgpack(data)
            .map_err(|e| JsValue::from_str(&format!("Invalid metadata: {}", e)))?,
        _ => FloMetadata::new(),
    };

    // modify via serde
    let mut obj: serde_json::Value = serde_json::to_value(&meta)
        .map_err(|e| JsValue::from_str(&format!("Serialization error: {}", e)))?;

    // jsvalue to serde
    let json_value = if value.is_null() || value.is_undefined() {
        serde_json::Value::Null
    } else if let Some(s) = value.as_string() {
        serde_json::Value::String(s)
    } else if let Some(n) = value.as_f64() {
        serde_json::json!(n)
    } else if let Some(b) = value.as_bool() {
        serde_json::Value::Bool(b)
    } else {
        // try json for complex stuff
        let js_json = js_sys::JSON::stringify(&value)
            .map_err(|_| JsValue::from_str("Cannot serialize value"))?;
        serde_json::from_str(&js_json.as_string().unwrap_or_default())
            .map_err(|e| JsValue::from_str(&format!("Invalid JSON: {}", e)))?
    };

    // do it
    if let serde_json::Value::Object(ref mut map) = obj {
        map.insert(field.to_string(), json_value);
    } else {
        return Err(JsValue::from_str("Internal error: metadata not an object"));
    }

    // back to struct
    let updated: FloMetadata = serde_json::from_value(obj)
        .map_err(|e| JsValue::from_str(&format!("Invalid field '{}': {}", field, e)))?;

    updated
        .to_msgpack()
        .map_err(|e| JsValue::from_str(&e.to_string()))
}

/// Get synced lyrics from a flo file
///
/// # Returns
/// Array of synced lyrics objects or null if none
#[cfg(feature = "wasm")]
#[wasm_bindgen]
pub fn get_synced_lyrics(data: &[u8]) -> Result<JsValue, JsValue> {
    let reader = Reader::new();
    let file = reader.read(data).map_err(to_js_err)?;

    if file.metadata.is_empty() {
        return Ok(JsValue::NULL);
    }

    let meta = FloMetadata::from_msgpack(&file.metadata)
        .map_err(|e| JsValue::from_str(&format!("Invalid metadata: {}", e)))?;

    if meta.synced_lyrics.is_empty() {
        return Ok(JsValue::NULL);
    }

    serde_wasm_bindgen::to_value(&meta.synced_lyrics)
        .map_err(|e| JsValue::from_str(&format!("Serialization error: {}", e)))
}

/// Get waveform data from a flo file for instant visualization
///
/// # Returns
/// WaveformData object or null if not present
#[cfg(feature = "wasm")]
#[wasm_bindgen]
pub fn get_waveform_data(data: &[u8]) -> Result<JsValue, JsValue> {
    let reader = Reader::new();
    let file = reader.read(data).map_err(to_js_err)?;

    if file.metadata.is_empty() {
        return Ok(JsValue::NULL);
    }

    let meta = FloMetadata::from_msgpack(&file.metadata)
        .map_err(|e| JsValue::from_str(&format!("Invalid metadata: {}", e)))?;

    match meta.waveform_data {
        Some(ref waveform) => serde_wasm_bindgen::to_value(waveform)
            .map_err(|e| JsValue::from_str(&format!("Serialization error: {}", e))),
        None => Ok(JsValue::NULL),
    }
}

/// Get section markers from a flo file
///
/// # Returns
/// Array of section markers or null if none
#[cfg(feature = "wasm")]
#[wasm_bindgen]
pub fn get_section_markers(data: &[u8]) -> Result<JsValue, JsValue> {
    let reader = Reader::new();
    let file = reader.read(data).map_err(to_js_err)?;

    if file.metadata.is_empty() {
        return Ok(JsValue::NULL);
    }

    let meta = FloMetadata::from_msgpack(&file.metadata)
        .map_err(|e| JsValue::from_str(&format!("Invalid metadata: {}", e)))?;

    if meta.section_markers.is_empty() {
        return Ok(JsValue::NULL);
    }

    serde_wasm_bindgen::to_value(&meta.section_markers)
        .map_err(|e| JsValue::from_str(&format!("Serialization error: {}", e)))
}

// zero-copy metadata editing

/// update metadata without re-encoding audio
///
/// # Arguments
/// * `flo_data` - Original flo file bytes
/// * `new_metadata` - New MessagePack metadata bytes (use create_metadata_*)
///
/// # Returns
/// New flo file with updated metadata
#[cfg(feature = "wasm")]
#[wasm_bindgen]
pub fn update_metadata(flo_data: &[u8], new_metadata: &[u8]) -> Result<Vec<u8>, JsValue> {
    update_metadata_bytes(flo_data, new_metadata).map_err(to_js_err)
}

/// update metadata without re-encoding (native)
pub fn update_metadata_bytes(flo_data: &[u8], new_metadata: &[u8]) -> FloResult<Vec<u8>> {
    // basic checks
    if flo_data.len() < (HEADER_SIZE as usize) {
        return Err(crate::core::FloError::from(
            "File too small to be valid flo",
        ));
    }

    // check magic
    if flo_data[0..4] != MAGIC {
        return Err(crate::core::FloError::from("Invalid flo file: bad magic"));
    }

    // read header for chunk sizes
    let reader = Reader::new();
    let file = reader.read(flo_data)?;

    // find where metadata starts
    // layout: magic(4) + header + toc + data + extra + metadata
    let meta_offset = 4
        + (file.header.header_size as usize)
        + (file.header.toc_size as usize)
        + (file.header.data_size as usize)
        + (file.header.extra_size as usize);

    // copy up to metadata
    let mut result = Vec::with_capacity(meta_offset + new_metadata.len());
    result.extend_from_slice(&flo_data[..meta_offset]);

    // add new metadata
    result.extend_from_slice(new_metadata);

    // fix meta_size in header
    // header layout: version(2) + flags(2) + sample_rate(4) + ...
    // meta_size is at offset: 4 + 58 = 62
    let meta_size_offset = 4 + 2 + 2 + 4 + 1 + 1 + 8 + 1 + 3 + 4 + 8 + 8 + 8 + 8;
    let new_meta_size = new_metadata.len() as u64;
    result[meta_size_offset..meta_size_offset + 8].copy_from_slice(&new_meta_size.to_le_bytes());

    Ok(result)
}

/// Replace just the metadata in a flo file (convenience function)
///
/// Takes a metadata object directly instead of MessagePack bytes.
///
/// # Arguments
/// * `flo_data` - Original flo file bytes
/// * `metadata` - JavaScript metadata object
///
/// # Returns
/// New flo file with updated metadata
#[cfg(feature = "wasm")]
#[wasm_bindgen]
pub fn set_metadata(flo_data: &[u8], metadata: JsValue) -> Result<Vec<u8>, JsValue> {
    let new_meta_bytes = create_metadata_from_object(metadata)?;
    update_metadata(flo_data, &new_meta_bytes)
}

/// Remove all metadata from a flo file
///
/// # Arguments
/// * `flo_data` - Original flo file bytes
///
/// # Returns
/// New flo file with no metadata
pub fn strip_metadata_bytes(flo_data: &[u8]) -> FloResult<Vec<u8>> {
    update_metadata_bytes(flo_data, &[])
}

/// Remove all metadata from a flo file
///
/// # Arguments
/// * `flo_data` - Original flo file bytes
///
/// # Returns
/// New flo file with no metadata
#[cfg(feature = "wasm")]
#[wasm_bindgen]
pub fn strip_metadata(flo_data: &[u8]) -> Result<Vec<u8>, JsValue> {
    strip_metadata_bytes(flo_data).map_err(to_js_err)
}

/// Get just the metadata bytes from a flo file
///
/// # Arguments
/// * `flo_data` - flo file bytes
///
/// # Returns
/// Raw MessagePack metadata bytes (or empty array)
#[cfg(feature = "wasm")]
#[wasm_bindgen]
pub fn get_metadata_bytes(flo_data: &[u8]) -> Result<Vec<u8>, JsValue> {
    get_metadata_bytes_native(flo_data).map_err(to_js_err)
}

/// Get just the metadata bytes from a flo file
///
/// # Arguments
/// * `flo_data` - flo file bytes
///
/// # Returns
/// Raw MessagePack metadata bytes (or empty array)
pub fn get_metadata_bytes_native(flo_data: &[u8]) -> FloResult<Vec<u8>> {
    if flo_data.len() < (HEADER_SIZE as usize) {
        return Err(crate::core::FloError::from("File too small"));
    }

    // just read header for metadata location
    let reader = Reader::new();
    let file = reader.read(flo_data)?;

    Ok(file.metadata)
}

/// does the file have metadata? (wasm binding)
#[cfg(feature = "wasm")]
#[wasm_bindgen(js_name = has_metadata)]
pub fn has_metadata_wasm(flo_data: &[u8]) -> bool {
    has_metadata(flo_data)
}

/// does the file have metadata? (native)
pub fn has_metadata(flo_data: &[u8]) -> bool {
    if flo_data.len() < (HEADER_SIZE as usize) {
        return false;
    }

    // fast path, just read meta_size from header
    let meta_size_offset = 4 + 2 + 2 + 4 + 1 + 1 + 8 + 1 + 3 + 4 + 8 + 8 + 8 + 8;
    if flo_data.len() < meta_size_offset + 8 {
        return false;
    }

    let meta_size = u64::from_le_bytes(
        flo_data[meta_size_offset..meta_size_offset + 8]
            .try_into()
            .unwrap_or([0; 8]),
    );

    meta_size > 0
}

/// Extract waveform peaks from audio samples (native version)
///
/// # Arguments
/// * `samples` - Interleaved audio samples (f32, -1.0 to 1.0)
/// * `sample_rate` - Sample rate in Hz (e.g., 44100)
/// * `channels` - Number of audio channels (1 or 2)
/// * `peaks_per_second` - Number of peak values per second (default: 50)
///
/// # Returns
/// WaveformData struct containing extracted peaks
pub fn extract_waveform_peaks_to_struct(
    samples: &[f32],
    sample_rate: u32,
    channels: u8,
    peaks_per_second: Option<u32>,
) -> core::metadata::WaveformData {
    let peaks_per_second = peaks_per_second.unwrap_or(50);
    core::analysis::extract_waveform_peaks(samples, channels, sample_rate, peaks_per_second)
}

/// Extract waveform RMS from audio samples
///
/// # Arguments
/// * `samples` - Interleaved audio samples (f32, -1.0 to 1.0)
/// * `sample_rate` - Sample rate in Hz (e.g., 44100)
/// * `channels` - Number of audio channels (1 or 2)
/// * `peaks_per_second` - Number of RMS values per second (default: 50)
///
/// # Returns
/// WaveformData struct containing extracted RMS values
pub fn extract_waveform_rms_to_struct(
    samples: &[f32],
    sample_rate: u32,
    channels: u8,
    peaks_per_second: Option<u32>,
) -> core::metadata::WaveformData {
    let peaks_per_second = peaks_per_second.unwrap_or(50);
    core::analysis::extract_waveform_rms(samples, channels, sample_rate, peaks_per_second)
}

/// Extract spectral fingerprint from audio samples
///
/// # Arguments
/// * `samples` - Audio samples (interleaved if multi-channel)
/// * `channels` - Number of audio channels
/// * `sample_rate` - Sample rate in Hz
/// * `fft_size` - FFT window size (must be power of 2)
/// * `hop_size` - Hop size between consecutive frames
///
/// # Returns
/// SpectralFingerprint object with frequency analysis
#[cfg(target_arch = "wasm32")]
#[cfg(feature = "wasm")]
#[wasm_bindgen]
pub fn extract_spectral_fingerprint_wasm(
    samples: &[f32],
    channels: u32,
    sample_rate: u32,
    fft_size: Option<usize>,
    hop_size: Option<usize>,
) -> Result<JsValue, JsValue> {
    use crate::core::extract_spectral_fingerprint;
    let fingerprint =
        extract_spectral_fingerprint(samples, channels as u8, sample_rate, fft_size, hop_size);
    serde_wasm_bindgen::to_value(&fingerprint)
        .map_err(|e| JsValue::from_str(&format!("Serialization error: {}", e)))
}

/// Extract dominant frequencies from spectral fingerprint
#[cfg(target_arch = "wasm32")]
#[cfg(feature = "wasm")]
#[wasm_bindgen]
pub fn extract_dominant_frequencies_wasm(
    fingerprint_js: JsValue,
    num_frequencies: usize,
) -> Result<JsValue, JsValue> {
    use crate::core::analysis::{extract_dominant_frequencies, SpectralFingerprint};

    let fingerprint: SpectralFingerprint = serde_wasm_bindgen::from_value(fingerprint_js)
        .map_err(|e| JsValue::from_str(&format!("Deserialization error: {}", e)))?;

    let dominant_freqs = extract_dominant_frequencies(&fingerprint, num_frequencies);
    serde_wasm_bindgen::to_value(&dominant_freqs)
        .map_err(|e| JsValue::from_str(&format!("Serialization error: {}", e)))
}

/// Extract dominant frequencies from spectral fingerprint
///
/// # Arguments
/// * `fingerprint` - SpectralFingerprint struct
/// * `num_frequencies` - Number of dominant frequencies to extract per frame
///
/// # Returns
/// Vector of vectors containing dominant frequencies (Hz) for each frame
pub fn extract_dominant_frequencies_to_vec(
    fingerprint: &core::analysis::SpectralFingerprint,
    num_frequencies: usize,
) -> Vec<Vec<f64>> {
    core::analysis::extract_dominant_frequencies(fingerprint, num_frequencies)
}

/// Extract dominant frequencies from audio samples (convenience function)
///
/// # Arguments
/// * `samples` - Audio samples (interleaved if multi-channel)
/// * `sample_rate` - Sample rate in Hz
/// * `channels` - Number of audio channels
/// * `num_frequencies` - Number of dominant frequencies to extract per frame
/// * `fft_size` - FFT window size (optional, will auto-select if None)
/// * `hop_size` - Hop size between frames (optional, will auto-select if None)
///
/// # Returns
/// JavaScript array of arrays containing dominant frequencies (Hz) for each frame
#[cfg(target_arch = "wasm32")]
#[cfg(feature = "wasm")]
#[wasm_bindgen]
pub fn extract_dominant_frequencies_from_samples_wasm(
    samples: &[f32],
    sample_rate: u32,
    channels: u8,
    num_frequencies: usize,
    fft_size: Option<usize>,
    hop_size: Option<usize>,
) -> Result<JsValue, JsValue> {
    let fingerprint =
        extract_spectral_fingerprint(samples, channels, sample_rate, fft_size, hop_size);
    let dominant_freqs = extract_dominant_frequencies_to_vec(&fingerprint, num_frequencies);

    // Convert to JavaScript arrays
    let js_result = js_sys::Array::new();
    for frame_freqs in &dominant_freqs {
        let frame_array = js_sys::Float64Array::from(&frame_freqs[..]);
        js_result.push(&frame_array);
    }

    Ok(js_result.into())
}

/// Extract dominant frequencies from spectral fingerprint
///
/// # Arguments
/// * `fingerprint_js` - SpectralFingerprint JavaScript object
/// * `num_frequencies` - Number of dominant frequencies to extract per frame
///
/// # Returns
/// JavaScript array of arrays containing dominant frequencies (Hz) for each frame
#[cfg(target_arch = "wasm32")]
#[cfg(feature = "wasm")]
#[wasm_bindgen]
pub fn extract_dominant_frequencies_from_fingerprint_wasm(
    fingerprint_js: JsValue,
    num_frequencies: usize,
) -> Result<JsValue, JsValue> {
    use crate::core::analysis::{extract_dominant_frequencies, SpectralFingerprint};

    let fingerprint: SpectralFingerprint = serde_wasm_bindgen::from_value(fingerprint_js)
        .map_err(|e| JsValue::from_str(&format!("Deserialization error: {}", e)))?;

    let dominant_freqs = extract_dominant_frequencies(&fingerprint, num_frequencies);
    serde_wasm_bindgen::to_value(&dominant_freqs)
        .map_err(|e| JsValue::from_str(&format!("Serialization error: {}", e)))
}

/// Compute spectral similarity between two fingerprints
///
/// # Arguments
/// * `fingerprint1` - First spectral fingerprint
/// * `fingerprint2` - Second spectral fingerprint
///
/// # Returns
/// Similarity score between 0.0 (completely different) and 1.0 (identical)
pub fn spectral_similarity_score(
    fingerprint1: &core::analysis::SpectralFingerprint,
    fingerprint2: &core::analysis::SpectralFingerprint,
) -> f32 {
    core::analysis::spectral_similarity(fingerprint1, fingerprint2)
}

/// Compute spectral similarity between two fingerprints
///
/// # Arguments
/// * `samples1` - First audio samples
/// * `samples2` - Second audio samples
/// * `sample_rate` - Sample rate in Hz
/// * `channels` - Number of audio channels (1 or 2)
/// * `fft_size` - FFT window size (default: 2048)
/// * `hop_size` - Hop size between frames (default: fft_size/2)
///
/// # Returns
/// Similarity score between 0.0 (completely different) and 1.0 (identical)
#[cfg(target_arch = "wasm32")]
#[cfg(feature = "wasm")]
#[wasm_bindgen]
pub fn spectral_similarity(
    samples1: &[f32],
    samples2: &[f32],
    sample_rate: u32,
    channels: u8,
    fft_size: Option<usize>,
    hop_size: Option<usize>,
) -> Result<JsValue, JsValue> {
    let fingerprint1 =
        extract_spectral_fingerprint(samples1, channels, sample_rate, fft_size, hop_size);
    let fingerprint2 =
        extract_spectral_fingerprint(samples2, channels, sample_rate, fft_size, hop_size);

    let similarity = spectral_similarity_score(&fingerprint1, &fingerprint2);
    Ok(JsValue::from_f64(similarity as f64))
}

/// Compute EBU R128 loudness metrics from audio samples
///
/// # Arguments
/// * `samples` - Audio samples (interleaved if multi-channel)
/// * `channels` - Number of audio channels
/// * `sample_rate` - Sample rate in Hz
///
/// # Returns
/// LoudnessMetrics object with integrated LUFS, loudness range LU, and true peak dBTP
#[cfg(target_arch = "wasm32")]
#[cfg(feature = "wasm")]
#[wasm_bindgen]
pub fn compute_loudness_metrics(
    samples: &[f32],
    channels: u32,
    sample_rate: u32,
) -> Result<JsValue, JsValue> {
    use crate::core::compute_ebu_r128_loudness;
    let metrics = compute_ebu_r128_loudness(samples, channels as u8, sample_rate);
    serde_wasm_bindgen::to_value(&metrics)
        .map_err(|e| JsValue::from_str(&format!("Serialization error: {}", e)))
}

/// Extract waveform peaks from audio samples
///
/// # Arguments
/// * `samples` - Audio samples (interleaved if multi-channel)
/// * `channels` - Number of audio channels
/// * `sample_rate` - Sample rate in Hz
/// * `peaks_per_second` - Number of peak values to extract per second
///
/// # Returns
/// WaveformData object with extracted peaks
#[cfg(target_arch = "wasm32")]
#[cfg(feature = "wasm")]
#[wasm_bindgen]
pub fn extract_waveform_peaks_wasm(
    samples: &[f32],
    channels: u32,
    sample_rate: u32,
    peaks_per_second: Option<u32>,
) -> Result<JsValue, JsValue> {
    use crate::core::extract_waveform_peaks;
    let waveform = extract_waveform_peaks(
        samples,
        channels as u8,
        sample_rate,
        peaks_per_second.unwrap_or(50),
    );
    serde_wasm_bindgen::to_value(&waveform)
        .map_err(|e| JsValue::from_str(&format!("Serialization error: {}", e)))
}

// tests
#[cfg(test)]
mod tests {
    use super::*;
    use alloc::vec;
    use alloc::vec::Vec;

    #[test]
    fn test_frame_type_conversion() {
        assert_eq!(FrameType::from(0), FrameType::Silence);
        assert_eq!(FrameType::from(8), FrameType::Alpc8);
        assert_eq!(FrameType::from(254), FrameType::Raw);
        assert!(FrameType::Alpc8.is_alpc());
        assert!(!FrameType::Silence.is_alpc());
        assert_eq!(FrameType::Alpc8.lpc_order(), Some(8));
    }

    #[test]
    #[cfg(feature = "wasm")]
    fn test_version() {
        assert_eq!(version(), "1.2");
    }

    #[test]
    fn test_update_metadata_preserves_audio() {
        // Create a simple flo file with metadata
        let samples: Vec<f32> = (0..4410).map(|i| ((i as f32) * 0.01).sin() * 0.5).collect();
        let encoder = Encoder::new(44100, 1, 16);
        let original_meta = b"original metadata";
        let flo_data = encoder.encode(&samples, original_meta).unwrap();

        // Update metadata
        let new_meta = b"new metadata that is longer!";
        let updated = update_metadata_bytes(&flo_data, new_meta).unwrap();

        // Verify the new file is valid
        let reader = Reader::new();
        let file = reader.read(&updated).unwrap();

        // Check metadata was updated
        assert_eq!(file.metadata, new_meta);
        assert_eq!(file.header.meta_size, new_meta.len() as u64);

        // Check audio data CRC is unchanged (proves audio wasn't touched)
        let original_file = reader.read(&flo_data).unwrap();
        assert_eq!(file.header.data_crc32, original_file.header.data_crc32);

        // Decode and verify audio is identical
        let decoder = Decoder::new();
        let original_samples = decoder.decode(&flo_data).unwrap();
        let updated_samples = decoder.decode(&updated).unwrap();
        assert_eq!(original_samples, updated_samples);
    }

    #[test]
    fn test_strip_metadata() {
        let samples: Vec<f32> = vec![0.5; 1000];
        let encoder = Encoder::new(44100, 1, 16);
        let flo_with_meta = encoder.encode(&samples, b"some metadata here").unwrap();

        // Strip metadata using empty bytes (simulates strip)
        let stripped = update_metadata_bytes(&flo_with_meta, &[]).unwrap();

        // Verify
        let reader = Reader::new();
        let file = reader.read(&stripped).unwrap();
        assert!(file.metadata.is_empty());
        assert_eq!(file.header.meta_size, 0);

        // File should be smaller
        assert!(stripped.len() < flo_with_meta.len());
    }

    #[test]
    fn test_has_metadata() {
        let samples: Vec<f32> = vec![0.5; 1000];
        let encoder = Encoder::new(44100, 1, 16);

        let with_meta = encoder.encode(&samples, b"metadata").unwrap();
        let without_meta = encoder.encode(&samples, &[]).unwrap();

        assert!(has_metadata(&with_meta));
        assert!(!has_metadata(&without_meta));
    }
}