#!/usr/bin/env python3
import re
from pathlib import Path
from typing import List


def prompt(message: str, default=None, input_type=str):
    """Prompt user with optional default value."""
    if default is not None:
        msg = f"{message} [{default}]: "
    else:
        msg = f"{message}: "

    while True:
        try:
            value = input(msg).strip()
            if not value:
                if default is not None:
                    return input_type(default)
                print("This field is required.")
                continue
            return input_type(value)
        except ValueError:
            print(f"Invalid input. Please enter a valid {input_type.__name__}.")


def prompt_bool(message: str, default=True):
    """Prompt user for yes/no."""
    default_str = "Y/n" if default else "y/N"
    while True:
        value = input(f"{message} [{default_str}]: ").strip().lower()
        if not value:
            return default
        if value in ("y", "yes"):
            return True
        if value in ("n", "no"):
            return False
        print("Please enter 'y' or 'n'.")


def get_config():
    """Interactively gather configuration."""
    print("\n" + "=" * 60)
    print("Audio File Tagger")
    print("=" * 60 + "\n")

    # Required: folder path
    while True:
        outdir = Path(prompt("Enter folder path containing audio files"))
        if outdir.is_dir():
            break
        print(f"Folder not found: {outdir}")

    print("\nOptional settings (press Enter for defaults):\n")

    album = prompt("Album name", default="The Bongo Cat Collection")

    artist = prompt("Artist name", default="Bongo Cat")

    album_artist = prompt("Album artist", default=artist)

    disc = prompt("Disc number", default="2")

    start_track = prompt(
        "Starting track number", default="15", input_type=int
    )

    cover_filename = prompt(
        "Cover filename (relative to folder)",
        default="cover.png",
    )

    return {
        "outdir": outdir,
        "album": album,
        "artist": artist,
        "album_artist": album_artist,
        "disc": disc,
        "start_track": start_track,
        "cover_filename": cover_filename,
    }


def list_audio_files(folder: Path) -> List[Path]:
    files = list(folder.glob("*.opus")) + list(folder.glob("*.ogg"))

    def sort_key(p: Path):
        m = re.match(r"^\s*(\d+)", p.stem)
        return (int(m.group(1)) if m else 10**9, p.name.lower())

    return sorted(files, key=sort_key)


def infer_clean_title(p: Path) -> str:
    name = p.stem
    name = re.sub(r"^\s*\d+\s*-\s*", "", name, count=1)
    return name.strip()


def tag_one(
    path: Path,
    title: str,
    track_number: int,
    cover_path: Path,
    artist: str,
    album: str,
    album_artist: str,
    disc: str,
):
    from mutagen.oggopus import OggOpus
    from mutagen.oggvorbis import OggVorbis
    from mutagen.flac import Picture
    import base64

    audio = None
    try:
        audio = OggOpus(path)
    except Exception:
        audio = OggVorbis(path)

    if audio.tags is None:
        audio.add_tags()

    audio["TITLE"] = [title]
    audio["ARTIST"] = [artist]
    audio["ALBUM"] = [album]
    audio["ALBUMARTIST"] = [album_artist]
    audio["DISCNUMBER"] = [disc]
    audio["TRACKNUMBER"] = [str(track_number)]

    if cover_path.is_file():
        data = cover_path.read_bytes()
        pic = Picture()
        pic.type = 3
        pic.mime = "image/png"
        pic.desc = "cover"
        pic.width = 0
        pic.height = 0
        pic.depth = 0
        pic.colors = 0
        pic.data = data
        b64 = base64.b64encode(pic.write()).decode("ascii")
        audio["METADATA_BLOCK_PICTURE"] = [b64]
        if "COVERART" in audio:
            del audio["COVERART"]
        if "COVERARTMIME" in audio:
            del audio["COVERARTMIME"]

    audio.save()


def main():
    config = get_config()

    cover_path = config["outdir"] / config["cover_filename"]
    if not cover_path.exists():
        print(
            f"\n⚠ Warning: cover not found at {cover_path}; "
            "will proceed without cover art.\n"
        )

    files = list_audio_files(config["outdir"])
    if not files:
        print("No .opus or .ogg files found.")
        return

    # Show summary
    print("\n" + "=" * 60)
    print("Configuration Summary:")
    print("=" * 60)
    print(f"Folder: {config['outdir']}")
    print(f"Files to tag: {len(files)}")
    print(f"Album: {config['album']}")
    print(f"Artist: {config['artist']}")
    print(f"Album Artist: {config['album_artist']}")
    print(f"Disc Number: {config['disc']}")
    print(f"Starting Track: {config['start_track']}")
    print(f"Cover file: {cover_path.name} "
          f"({'found' if cover_path.exists() else 'not found'})")
    print("=" * 60 + "\n")

    # Show first few files
    print("Sample files to be tagged:")
    for f in files[:5]:
        title = infer_clean_title(f)
        print(f"  - {f.name} → {title}")
    if len(files) > 5:
        print(f"  ... and {len(files) - 5} more")
    print()

    proceed = prompt_bool("Proceed with tagging?", default=True)
    if not proceed:
        print("Cancelled.")
        exit(0)

    print(f"\nTagging {len(files)} files...\n")
    for i, f in enumerate(files, start=1):
        title = infer_clean_title(f)
        track_no = config["start_track"] + (i - 1)
        try:
            tag_one(
                f,
                title,
                track_no,
                cover_path,
                config["artist"],
                config["album"],
                config["album_artist"],
                config["disc"],
            )
            print(f"[{i}/{len(files)}] ✓ {f.name} (track {track_no})")
        except Exception as e:
            print(f"[{i}/{len(files)}] ✗ {f.name} → {e}")

    print("\n✓ Done.")


if __name__ == "__main__":
    main()