"""
Shared utilities for embedding extraction across all models.

Provides common audio loading, file collection, and save logic so that
each per-model extraction script only needs to define model initialization
and a single `model_fn(audio_path) -> np.ndarray` function.
"""

import sys
import numpy as np
from pathlib import Path

try:
    from tqdm import tqdm
except ImportError:
    def tqdm(iterable, desc=None, total=None):
        if desc:
            print(f"\nProcessing {desc}...")
        return iterable

import os

# Resolve the release root.
# Priority: VIPBENCH_ROOT env var > parent of this script's directory.
# Layout assumed:
#   <VIPBENCH_ROOT>/
#     code/extraction_utils.py    <- this file
#     data/audio/reference/*.wav
#     data/audio/comparison/*.wav
#     data/embeddings/<model>.npz <- output
def _resolve_root():
    env = os.environ.get("VIPBENCH_ROOT")
    if env:
        return Path(env).resolve()
    return Path(__file__).resolve().parent.parent

DEFAULT_BASE_DIR = _resolve_root()
DEFAULT_OUTPUT_DIR = DEFAULT_BASE_DIR / "data" / "embeddings"


def load_audio(file_path, target_sr=16000):
    """Load audio file as float32 mono at target_sr.

    Replicates the pattern from extract_rawnet3_embeddings.py.
    """
    try:
        import librosa
        audio, sr = librosa.load(file_path, sr=target_sr, mono=True)
        return audio.astype(np.float32)
    except ImportError:
        pass

    # Fallback to soundfile
    import soundfile as sf
    audio, sr = sf.read(file_path)
    if len(audio.shape) > 1:
        audio = np.mean(audio, axis=1)
    if sr != target_sr:
        import scipy.signal
        num_samples = int(len(audio) * target_sr / sr)
        audio = scipy.signal.resample(audio, num_samples)
    if audio.dtype != np.float32:
        if audio.dtype == np.int16:
            audio = audio.astype(np.float32) / 32768.0
        elif audio.dtype == np.int32:
            audio = audio.astype(np.float32) / 2147483648.0
        else:
            audio = audio.astype(np.float32)
    if np.max(np.abs(audio)) > 1.0:
        audio = audio / np.max(np.abs(audio))
    return audio.astype(np.float32)


def collect_audio_files(base_dir=None):
    """Collect reference and stimulus audio files.

    Returns
    -------
    ref_files : list[Path]
        100 reference clips from exp_2/*R.wav
    stim_files : list[Path]
        9,800 comparison clips from output/*.wav
    """
    base = Path(base_dir) if base_dir else DEFAULT_BASE_DIR
    ref_files = sorted((base / "data" / "audio" / "reference").glob("*R.wav"))
    stim_files = sorted((base / "data" / "audio" / "comparison").glob("*.wav"))
    return ref_files, stim_files


def save_embeddings(embeddings_dict, model_name, output_dir=None):
    """Save embeddings as compressed .npz with same format as rawnet3_embeddings.npz."""
    out = Path(output_dir) if output_dir else DEFAULT_OUTPUT_DIR
    out.mkdir(parents=True, exist_ok=True)
    path = out / f"{model_name}.npz"
    np.savez_compressed(path, **embeddings_dict)
    print(f"Saved {len(embeddings_dict)} embeddings to {path}")
    return path


def extract_all(model_fn, model_name, base_dir=None, output_dir=None):
    """Run extraction for all audio files using the provided model function.

    Parameters
    ----------
    model_fn : callable
        Takes a file path (str or Path) and returns a 1-D numpy array (the embedding).
    model_name : str
        Name used for the output file ({model_name}_embeddings.npz).
    base_dir : str or Path, optional
        Project root. Defaults to DEFAULT_BASE_DIR.
    output_dir : str or Path, optional
        Where to save the .npz. Defaults to DEFAULT_OUTPUT_DIR.
    """
    ref_files, stim_files = collect_audio_files(base_dir)
    total = len(ref_files) + len(stim_files)
    print(f"\n{'=' * 60}")
    print(f"{model_name} Embedding Extraction")
    print(f"{'=' * 60}")
    print(f"Reference files: {len(ref_files)}")
    print(f"Stimulus files:  {len(stim_files)}")
    print(f"Total:           {total}")

    embeddings_dict = {}
    failed = []

    print(f"\nProcessing reference files...")
    for path in tqdm(ref_files, desc="references"):
        key = path.stem
        try:
            emb = model_fn(path)
            if emb is not None:
                embeddings_dict[key] = emb
            else:
                failed.append(str(path))
        except Exception as e:
            print(f"\n  Error on {path.name}: {e}")
            failed.append(str(path))

    print(f"\nProcessing stimulus files...")
    for path in tqdm(stim_files, desc="stimuli"):
        key = path.stem
        try:
            emb = model_fn(path)
            if emb is not None:
                embeddings_dict[key] = emb
            else:
                failed.append(str(path))
        except Exception as e:
            print(f"\n  Error on {path.name}: {e}")
            failed.append(str(path))

    # Summary
    print(f"\n{'=' * 60}")
    print(f"Summary")
    print(f"{'=' * 60}")
    print(f"Extracted: {len(embeddings_dict)} / {total}")
    print(f"Failed:    {len(failed)}")
    if embeddings_dict:
        sample = next(iter(embeddings_dict.values()))
        print(f"Dimension: {sample.shape}")
    if failed:
        print(f"\nFailed files (first 10):")
        for f in failed[:10]:
            print(f"  {f}")

    save_embeddings(embeddings_dict, model_name, output_dir)
    return embeddings_dict