"""
Extract audio-only tracks for the core-curriculum lectures of the ATM course.

No video ever touches disk: ffmpeg reads the CloudFront MP4 URL directly over
HTTP and writes only the audio track (mono, 16kHz -> what whisper wants
anyway) to disk. Manifest-free; resumable by checking file existence.
"""

import argparse
import logging
import os
import subprocess
import sys
from pathlib import Path

import requests
from dotenv import load_dotenv

from download import login, get_course_id, get_menu, get_lecture_video_url, slugify

# First-phase scope: core curriculum only, not the 147 "ANALIZĂ ZILNICĂ"
# recaps / Q&A / live-room recordings (confirmed with user 2026-09-11).
CORE_MODULES = {
    "MODUL 1", "MODUL 2", "MODUL 3", "MODUL 4", "MODUL 5", "MODUL 6",
    "CATALIZATORI", "ANALIZĂ FUNDAMENTALĂ",
    "MASTER ATM 1", "MASTER ATM 2", "MASTER ATM 3", "MASTER ATM 4",
}

logging.basicConfig(level=logging.INFO, format="%(asctime)s [%(levelname)s] %(message)s")
log = logging.getLogger(__name__)


def extract_audio(url: str, dest: Path) -> bool:
    dest.parent.mkdir(parents=True, exist_ok=True)
    tmp = dest.with_suffix(dest.suffix + ".tmp")
    cmd = [
        "ffmpeg", "-y", "-i", url,
        "-vn", "-acodec", "libmp3lame", "-ar", "16000", "-ac", "1", "-b:a", "64k",
        "-f", "mp3", str(tmp),
    ]
    result = subprocess.run(cmd, capture_output=True, text=True, timeout=3600)
    if result.returncode != 0 or not tmp.exists():
        log.error(f"  ffmpeg failed: {result.stderr[-1500:]}")
        return False
    tmp.rename(dest)
    return True


def main():
    p = argparse.ArgumentParser(description="Extract audio for ATM core-curriculum lectures")
    p.add_argument("--out", default="audio", help="Output directory")
    p.add_argument("--only", default=None, help="Limit to one module name (bypasses CORE_MODULES)")
    p.add_argument("--lectures", type=int, default=None, help="With --only: stop after lecture N of that module")
    p.add_argument("--skip", type=int, default=0, help="Skip the first N lectures (transa urmatoare)")
    args = p.parse_args()

    load_dotenv()
    email = os.getenv("ATM_EMAIL", "")
    password = os.getenv("ATM_PASSWORD", "")
    if not email or not password:
        log.error("Set ATM_EMAIL and ATM_PASSWORD in .env")
        sys.exit(1)

    out_dir = Path(args.out)
    session = requests.Session()
    session.headers.update({"User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64)"})

    log.info("Logging in...")
    login(session, email, password)
    course_id = get_course_id(session)
    modules = get_menu(session, course_id)

    done = skipped = failed = 0
    for mod_idx, mod in enumerate(modules, 1):
        if args.only:
            if mod["name"] != args.only:
                continue
        elif mod["name"] not in CORE_MODULES:
            continue

        mod_dir = out_dir / f"{mod_idx:02d}_{slugify(mod['name'])}"
        log.info(f"Module: {mod['name']} ({len(mod['lectures'])} lectures)")

        lectures = mod["lectures"][args.skip : args.lectures]
        for lec_idx, lec in enumerate(lectures, args.skip + 1):
            stem = f"{lec_idx:02d}_{slugify(lec['name'])}"
            dest = mod_dir / f"{stem}.mp3"
            if dest.exists() and dest.stat().st_size > 10_000:
                log.info(f"  Skipping (exists): {dest.name}")
                skipped += 1
                continue

            try:
                video_url = get_lecture_video_url(session, lec["id"])
            except requests.exceptions.HTTPError as e:
                if e.response is not None and e.response.status_code == 403:
                    log.info(f"  Skipping (not included in access): {lec['name']}")
                    continue
                raise
            if not video_url:
                log.info(f"  No video (text/quiz): {lec['name']}")
                continue

            log.info(f"  Extracting: {lec['name']}")
            if extract_audio(video_url, dest):
                done += 1
            else:
                failed += 1

    log.info("=" * 60)
    log.info(f"Extracted {done}, skipped {skipped}, failed {failed}.")
    if failed:
        sys.exit(1)


if __name__ == "__main__":
    main()