"""Download recordings from the S3 bucket and convert any .webm files to .wav.

Skips files that have already been downloaded (and, for .webm sources, already
converted to .wav), so re-running the script only fetches what's new.
"""

import os
import shutil
import subprocess
import sys
import boto3
from botocore.config import Config as BotoConfig
from pathlib import Path
from dotenv import load_dotenv

load_dotenv(Path.home() / ".config" / "otree" / ".env")

BUCKET  = 'ethz-otree-whisper'
REGION  = 'eu-north-1'
OUT_DIR = Path(__file__).parent.parent.parent / 'data' / 'recordings'

if not shutil.which('ffmpeg'):
    print('Error: ffmpeg not found. Install it with: brew install ffmpeg')
    sys.exit(1)

s3 = boto3.client(
    's3',
    aws_access_key_id=os.environ['S3_ACCESS_KEY'],
    aws_secret_access_key=os.environ['S3_SECRET_KEY'],
    region_name=REGION,
    config=BotoConfig(signature_version='s3v4'),
)

paginator = s3.get_paginator('list_objects_v2')
keys = [obj['Key'] for page in paginator.paginate(Bucket=BUCKET) for obj in page.get('Contents', [])]

if not keys:
    print('Bucket is empty.')
    sys.exit(0)

OUT_DIR.mkdir(exist_ok=True)


def local_target(key):
    """Path a key ends up at locally once fully processed (.webm -> .wav)."""
    dest = OUT_DIR / key
    return dest.with_suffix('.wav') if dest.suffix == '.webm' else dest


to_download = [k for k in keys if not local_target(k).exists()]
skipped = len(keys) - len(to_download)

print(f'Found {len(keys)} file(s) in bucket: {skipped} already downloaded, '
      f'{len(to_download)} to fetch. Saving to {OUT_DIR}/ ...')

converted = 0
for key in to_download:
    dest = OUT_DIR / key
    dest.parent.mkdir(parents=True, exist_ok=True)
    s3.download_file(BUCKET, key, str(dest))

    size_kb = dest.stat().st_size / 1024
    if dest.suffix == '.webm':
        wav_dest = dest.with_suffix('.wav')
        print(f'  {key}  ({size_kb:.1f} KB)  converting...', end=' ', flush=True)
        result = subprocess.run(
            ['ffmpeg', '-y', '-i', str(dest), '-ar', '44100', '-ac', '1',
             '-c:a', 'pcm_s16le', str(wav_dest)],
            capture_output=True,
        )
        if result.returncode == 0:
            dest.unlink()
            wav_kb = wav_dest.stat().st_size / 1024
            print(f'OK  →  {wav_dest.name} ({wav_kb:.1f} KB)')
            converted += 1
        else:
            print(f'FAILED')
            print(f'    ffmpeg stderr: {result.stderr.decode(errors="replace").strip()}')
    else:
        print(f'  {key}  ({size_kb:.1f} KB)')

webm_total = sum(1 for k in to_download if k.endswith('.webm'))
wav_total  = sum(1 for k in to_download if k.endswith('.wav'))
failed     = webm_total - converted

print(f'\n── Summary ───────────────────────────────')
print(f'  Files in bucket        : {len(keys)}')
print(f'  Already downloaded     : {skipped}')
print(f'  Newly downloaded       : {len(to_download)}')
print(f'  Already .wav (new)     : {wav_total}')
print(f'  .webm converted        : {converted}')
print(f'  Conversion failed      : {failed}')
print(f'  Saved to               : {OUT_DIR}/')
print(f'──────────────────────────────────────────')