use parking_lot::Mutex;
use serde::{Deserialize, Serialize};
/// Codec AAC pour compatibilité universelle
///
/// AAC est optimal pour :
/// - Compatibilité iOS/Safari/mobile
/// - Streaming adaptatif (HLS/DASH)
/// - Qualité élevée à bitrates moyens
/// - Support multi-canal
use std::sync::Arc;
use std::time::Instant;
// Note: Use tracing::debug! macro directly instead of importing

use super::{
    AudioDecoder, AudioEncoder, AudioSampleFormat, DecodedAudio, DecoderConfig, DecoderInfo,
    EncoderConfig, EncoderInfo, EncoderMetrics,
};
use crate::error::AppError;

/// Implémentation de l'encodeur AAC
#[derive(Debug)]
pub struct AacEncoderImpl {
    config: AacEncoderConfig,
    encoder_state: Arc<Mutex<AacEncoderState>>,
    metrics: EncoderMetrics,
    sample_buffer: Vec<f32>,
    frame_size: usize,
}

/// Implémentation du décodeur AAC
#[derive(Debug)]
pub struct AacDecoderImpl {
    config: AacDecoderConfig,
    decoder_state: Arc<Mutex<AacDecoderState>>,
    output_buffer: Vec<f32>,
}

/// Configuration spécifique à AAC pour l'encodeur
#[derive(Debug, Clone)]
pub struct AacEncoderConfig {
    pub sample_rate: u32,
    pub channels: u8,
    pub bitrate: u32,
    pub profile: AacProfile,
    pub object_type: AacObjectType,
    pub vbr_mode: AacVbrMode,
    pub bandwidth_mode: AacBandwidthMode,
    pub afterburner: bool, // Qualité améliorée (plus lent)
    pub sbr_enabled: bool, // Spectral Band Replication
    pub ps_enabled: bool,  // Parametric Stereo
}

/// Configuration spécifique à AAC pour le décodeur
#[derive(Debug, Clone)]
pub struct AacDecoderConfig {
    pub sample_rate: u32,
    pub channels: u8,
    pub drc_mode: AacDrcMode, // Dynamic Range Control
    pub conceal_method: AacConcealMethod,
}

/// Profils AAC
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
pub enum AacProfile {
    /// Low Complexity - standard, compatible
    LC,
    /// High Efficiency - pour bas débits
    HE,
    /// High Efficiency v2 - stéréo optimisé
    HEv2,
    /// Low Delay - latence réduite
    LD,
    /// Enhanced Low Delay - meilleure qualité low delay
    ELD,
}

/// Types d'objets AAC
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
pub enum AacObjectType {
    Main,
    LC,
    SSR,
    LTP,
    HE,
    HEv2,
    LD,
    ELD,
}

/// Mode Variable Bit Rate pour AAC
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
pub enum AacVbrMode {
    CBR,  // Constant Bit Rate
    VBR1, // Variable Bit Rate très bas
    VBR2, // Variable Bit Rate bas
    VBR3, // Variable Bit Rate moyen
    VBR4, // Variable Bit Rate élevé
    VBR5, // Variable Bit Rate très élevé
}

/// Mode de bande passante
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
pub enum AacBandwidthMode {
    Auto,
    Full,
    Limited,
    Custom(u32), // Hz
}

/// Mode de contrôle de dynamique
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
pub enum AacDrcMode {
    Off,
    Light,
    Heavy,
    Auto,
}

/// Méthode de dissimulation d'erreur
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
pub enum AacConcealMethod {
    SpectralMuting,
    NoiseSubstitution,
    EnergyInterpolation,
}

/// État interne de l'encodeur AAC
#[derive(Debug)]
struct AacEncoderState {
    initialized: bool,
    last_frame_time: Option<Instant>,
    total_frames: u64,
    total_bytes: u64,
    psychoacoustic_model: PsychoacousticModel,
    bandwidth_extension: BandwidthExtension,
}

/// État interne du décodeur AAC
#[derive(Debug)]
struct AacDecoderState {
    initialized: bool,
    last_decode_time: Option<Instant>,
    total_frames: u64,
    error_concealment: ErrorConcealmentState,
    spectral_data: SpectralData,
}

/// Modèle psychoacoustique simplifié
#[derive(Debug)]
struct PsychoacousticModel {
    masking_threshold: Vec<f32>,
    perceptual_entropy: f32,
    tonal_components: Vec<TonalComponent>,
}

/// Extension de bande passante (SBR/PS)
#[derive(Debug)]
struct BandwidthExtension {
    sbr_active: bool,
    ps_active: bool,
    high_freq_reconstruction: Vec<f32>,
}

/// État de dissimulation d'erreur
#[derive(Debug)]
struct ErrorConcealmentState {
    last_good_spectrum: Option<Vec<f32>>,
    concealment_method: AacConcealMethod,
    error_count: u32,
}

/// Données spectrales
#[derive(Debug)]
struct SpectralData {
    mdct_coefficients: Vec<f32>,
    scale_factors: Vec<u8>,
    quantized_spectrum: Vec<i16>,
}

/// Composante tonale pour modèle psychoacoustique
#[derive(Debug)]
struct TonalComponent {
    frequency: f32,
    amplitude: f32,
    phase: f32,
}

impl Default for AacEncoderConfig {
    fn default() -> Self {
        Self {
            sample_rate: 44100,
            channels: 2,
            bitrate: 128_000,
            profile: AacProfile::LC,
            object_type: AacObjectType::LC,
            vbr_mode: AacVbrMode::VBR3,
            bandwidth_mode: AacBandwidthMode::Auto,
            afterburner: true,
            sbr_enabled: false,
            ps_enabled: false,
        }
    }
}

impl Default for AacDecoderConfig {
    fn default() -> Self {
        Self {
            sample_rate: 44100,
            channels: 2,
            drc_mode: AacDrcMode::Off,
            conceal_method: AacConcealMethod::EnergyInterpolation,
        }
    }
}

impl AacEncoderImpl {
    pub fn new(config: EncoderConfig) -> Result<Self, AppError> {
        let aac_config = AacEncoderConfig {
            sample_rate: config.sample_rate,
            channels: config.channels,
            bitrate: config.bitrate,
            profile: match config.bitrate {
                0..=64_000 => AacProfile::HE,
                64_001..=128_000 => AacProfile::LC,
                _ => AacProfile::LC,
            },
            object_type: AacObjectType::LC,
            vbr_mode: if config.enable_vbr {
                AacVbrMode::VBR3
            } else {
                AacVbrMode::CBR
            },
            bandwidth_mode: AacBandwidthMode::Auto,
            afterburner: true,
            sbr_enabled: config.bitrate <= 128_000,
            ps_enabled: config.bitrate <= 64_000 && config.channels == 2,
        };

        // AAC utilise des frames de 1024 échantillons
        let frame_size = 1024 * aac_config.channels as usize;

        let encoder_state = AacEncoderState {
            initialized: false,
            last_frame_time: None,
            total_frames: 0,
            total_bytes: 0,
            psychoacoustic_model: PsychoacousticModel {
                masking_threshold: vec![0.0; 512],
                perceptual_entropy: 0.0,
                tonal_components: Vec::new(),
            },
            bandwidth_extension: BandwidthExtension {
                sbr_active: aac_config.sbr_enabled,
                ps_active: aac_config.ps_enabled,
                high_freq_reconstruction: Vec::new(),
            },
        };

        let mut encoder = Self {
            config: aac_config,
            encoder_state: Arc::new(Mutex::new(encoder_state)),
            metrics: EncoderMetrics::default(),
            sample_buffer: Vec::with_capacity(frame_size * 2),
            frame_size,
        };

        encoder.initialize()?;
        Ok(encoder)
    }

    fn initialize(&mut self) -> Result<(), AppError> {
        self.validate_config()?;

        {
            let mut state = self.encoder_state.lock();
            state.initialized = true;
        }

        tracing::debug!(
            "Encodeur AAC initialisé: {}Hz, {} ch, profile {:?}",
            self.config.sample_rate,
            self.config.channels,
            self.config.profile
        );
        Ok(())
    }

    fn validate_config(&self) -> Result<(), AppError> {
        // AAC supporte de nombreux sample rates
        let valid_rates = [
            8000, 11025, 12000, 16000, 22050, 24000, 32000, 44100, 48000, 88200, 96000,
        ];
        if !valid_rates.contains(&self.config.sample_rate) {
            return Err(AppError::InvalidSampleRate {
                rate: self.config.sample_rate,
                supported: valid_rates.to_vec(),
            });
        }

        // Jusqu'à 8 canaux
        if self.config.channels == 0 || self.config.channels > 8 {
            return Err(AppError::InvalidChannelCount {
                channels: self.config.channels,
            });
        }

        // Bitrate : 8kbps à 800kbps
        if self.config.bitrate < 8_000 || self.config.bitrate > 800_000 {
            return Err(AppError::InvalidBitrate {
                codec: "aac".to_string(),
                bitrate: self.config.bitrate,
                min: 8_000,
                max: 800_000,
            });
        }

        Ok(())
    }

    fn encode_aac_frame(&mut self, samples: &[f32]) -> Result<Vec<u8>, AppError> {
        let start_time = Instant::now();

        // Simulation d'encodage AAC avec modèle psychoacoustique
        let estimated_size = self.estimate_aac_frame_size(samples);
        let mut encoded_data = vec![0u8; estimated_size];

        // Simulation des étapes AAC
        self.simulate_mdct_transform(samples)?;
        self.simulate_psychoacoustic_modeling(samples)?;
        self.simulate_quantization_and_coding(&mut encoded_data)?;

        let encoding_time = start_time.elapsed();
        self.update_metrics(samples.len(), encoded_data.len(), encoding_time);

        Ok(encoded_data)
    }

    fn estimate_aac_frame_size(&self, samples: &[f32]) -> usize {
        let bits_per_sample = self.config.bitrate as f32 / self.config.sample_rate as f32;
        let estimated_bits = samples.len() as f32 * bits_per_sample;
        (estimated_bits / 8.0) as usize
    }

    fn simulate_mdct_transform(&self, _samples: &[f32]) -> Result<(), AppError> {
        // Simulation de la transformée MDCT
        tracing::debug!("MDCT transform simulé");
        Ok(())
    }

    fn simulate_psychoacoustic_modeling(&self, samples: &[f32]) -> Result<(), AppError> {
        // Calcul simplifié du masquage
        let _energy = samples.iter().map(|&s| s * s).sum::<f32>() / samples.len() as f32;
        tracing::debug!("Modèle psychoacoustique appliqué");
        Ok(())
    }

    fn simulate_quantization_and_coding(&self, output: &mut [u8]) -> Result<(), AppError> {
        // Simulation de quantification et codage entropique
        for (i, byte) in output.iter_mut().enumerate() {
            *byte = (i % 256) as u8; // Données simulées
        }
        Ok(())
    }

    fn update_metrics(
        &mut self,
        input_samples: usize,
        output_bytes: usize,
        encoding_time: std::time::Duration,
    ) {
        self.metrics.frames_encoded += 1;
        self.metrics.bytes_output += output_bytes as u64;
        self.metrics.encoding_time_ms += encoding_time.as_millis() as u64;

        let input_bytes = input_samples * 4;
        self.metrics.compression_ratio = input_bytes as f32 / output_bytes as f32;

        {
            let mut state = self.encoder_state.lock();
            state.total_frames += 1;
            state.total_bytes += output_bytes as u64;
            state.last_frame_time = Some(Instant::now());
        }
    }
}

impl AudioEncoder for AacEncoderImpl {
    fn encode(
        &mut self,
        samples: &[f32],
        sample_rate: u32,
        channels: u8,
    ) -> Result<Vec<u8>, AppError> {
        if sample_rate != self.config.sample_rate || channels != self.config.channels {
            return Err(AppError::ParameterMismatch {
                expected: format!("{}Hz, {} ch", self.config.sample_rate, self.config.channels),
                received: format!("{}Hz, {} ch", sample_rate, channels),
            });
        }

        self.sample_buffer.extend_from_slice(samples);
        let mut encoded_frames = Vec::new();

        while self.sample_buffer.len() >= self.frame_size {
            let frame_samples: Vec<f32> = self.sample_buffer.drain(..self.frame_size).collect();
            let encoded_frame = self.encode_aac_frame(&frame_samples)?;
            encoded_frames.extend(encoded_frame);
        }

        Ok(encoded_frames)
    }

    fn finalize(&mut self) -> Result<Vec<u8>, AppError> {
        if !self.sample_buffer.is_empty() {
            while self.sample_buffer.len() < self.frame_size {
                self.sample_buffer.push(0.0);
            }
            let final_frame: Vec<f32> = self.sample_buffer.drain(..).collect();
            return self.encode_aac_frame(&final_frame);
        }
        Ok(Vec::new())
    }

    fn reset(&mut self) -> Result<(), AppError> {
        self.sample_buffer.clear();
        self.metrics = EncoderMetrics::default();

        {
            let mut state = self.encoder_state.lock();
            state.total_frames = 0;
            state.total_bytes = 0;
            state.last_frame_time = None;
        }

        Ok(())
    }

    fn set_bitrate(&mut self, bitrate: u32) -> Result<(), AppError> {
        if bitrate < 8_000 || bitrate > 800_000 {
            return Err(AppError::InvalidBitrate {
                codec: "aac".to_string(),
                bitrate,
                min: 8_000,
                max: 800_000,
            });
        }

        self.config.bitrate = bitrate;
        Ok(())
    }

    fn info(&self) -> EncoderInfo {
        EncoderInfo {
            codec_name: "AAC".to_string(),
            version: "2.0".to_string(),
            bitrate: self.config.bitrate,
            sample_rate: self.config.sample_rate,
            channels: self.config.channels,
            bit_depth: 16,
            frame_size: self.frame_size,
            latency_ms: 23.2, // 1024 samples à 44.1kHz
            quality_mode: format!("{:?}", self.config.profile),
        }
    }

    fn metrics(&self) -> EncoderMetrics {
        self.metrics.clone()
    }
}

impl AacDecoderImpl {
    pub fn new(config: DecoderConfig) -> Result<Self, AppError> {
        let aac_config = AacDecoderConfig {
            sample_rate: config.sample_rate,
            channels: config.channels,
            drc_mode: AacDrcMode::Off,
            conceal_method: AacConcealMethod::EnergyInterpolation,
        };

        let decoder_state = AacDecoderState {
            initialized: false,
            last_decode_time: None,
            total_frames: 0,
            error_concealment: ErrorConcealmentState {
                last_good_spectrum: None,
                concealment_method: aac_config.conceal_method.clone(),
                error_count: 0,
            },
            spectral_data: SpectralData {
                mdct_coefficients: Vec::new(),
                scale_factors: Vec::new(),
                quantized_spectrum: Vec::new(),
            },
        };

        let mut decoder = Self {
            config: aac_config,
            decoder_state: Arc::new(Mutex::new(decoder_state)),
            output_buffer: Vec::new(),
        };

        decoder.initialize()?;
        Ok(decoder)
    }

    fn initialize(&mut self) -> Result<(), AppError> {
        {
            let mut state = self.decoder_state.lock();
            state.initialized = true;
        }
        Ok(())
    }
}

impl AudioDecoder for AacDecoderImpl {
    fn decode(&mut self, data: &[u8]) -> Result<DecodedAudio, AppError> {
        let frame_size = 1024 * self.config.channels as usize;
        let mut samples = Vec::with_capacity(frame_size);

        // Simulation simple de décodage AAC
        for (_i, &byte) in data.iter().enumerate() {
            if samples.len() < frame_size {
                let sample = (byte as f32 - 128.0) / 128.0;
                samples.push(sample);

                // Interpolation
                for _ in 0..3 {
                    if samples.len() < frame_size {
                        samples.push(sample * 0.9);
                    }
                }
            }
        }

        while samples.len() < frame_size {
            samples.push(0.0);
        }

        {
            let mut state = self.decoder_state.lock();
            state.total_frames += 1;
            state.last_decode_time = Some(Instant::now());
        }

        Ok(DecodedAudio {
            samples,
            sample_rate: self.config.sample_rate,
            channels: self.config.channels,
            duration_ms: 23, // ~23ms pour 1024 samples à 44.1kHz
            format: AudioSampleFormat::F32,
        })
    }

    fn reset(&mut self) -> Result<(), AppError> {
        self.output_buffer.clear();

        {
            let mut state = self.decoder_state.lock();
            state.total_frames = 0;
            state.last_decode_time = None;
            state.error_concealment.last_good_spectrum = None;
            state.error_concealment.error_count = 0;
        }

        Ok(())
    }

    fn info(&self) -> DecoderInfo {
        DecoderInfo {
            codec_name: "AAC".to_string(),
            version: "2.0".to_string(),
            sample_rate: self.config.sample_rate,
            channels: self.config.channels,
            bit_depth: 16,
            frame_size: 1024 * self.config.channels as usize,
        }
    }
}
