"""Append path-shaped char BIO focus examples.

This helper is intentionally small: it builds a handful of deterministic path
examples where leading directories are noise and the parseable entities appear
in later path segments.
"""

from __future__ import annotations

import argparse
import json
from pathlib import Path


def char_item(filename: str, spans: list[tuple[str, str]], source: str) -> dict[str, object]:
    tokens = list(filename)
    labels = ["O"] * len(tokens)
    cursor = 0
    for text, entity in spans:
        start = filename.find(text, cursor)
        if start < 0:
            start = filename.find(text)
        if start < 0:
            raise ValueError(f"span {text!r} not found in {filename!r}")
        labels[start] = f"B-{entity}"
        for index in range(start + 1, start + len(text)):
            labels[index] = f"I-{entity}"
        cursor = start + len(text)
    return {
        "filename": filename,
        "tokens": tokens,
        "labels": labels,
        "tokenizer_variant": "char",
        "source": source,
    }


def build_cases(source: str) -> list[dict[str, object]]:
    return [
        char_item(
            r"Z:\Library\Anime\Shinsekai Yori\Extras\NCED02 [Ma10p_1080p][x265_flac].mkv",
            [
                ("Shinsekai Yori", "TITLE"),
                ("NCED02", "SPECIAL"),
                ("1080p", "RESOLUTION"),
                ("x265_flac", "SOURCE"),
            ],
            source,
        ),
        char_item(
            r"O:\115open\Anime\Sousou no Frieren\Season 01\31 [1080P][Baha][WEB-DL].mkv",
            [
                ("Sousou no Frieren", "TITLE"),
                ("Season 01", "SEASON"),
                ("31", "EPISODE"),
                ("1080P", "RESOLUTION"),
                ("Baha", "SOURCE"),
                ("WEB-DL", "SOURCE"),
            ],
            source,
        ),
        char_item(
            r"/mnt/media/anime/Bangumi/One Piece/Season 21/1110 [1080p][WEB-DL].mkv",
            [
                ("One Piece", "TITLE"),
                ("Season 21", "SEASON"),
                ("1110", "EPISODE"),
                ("1080p", "RESOLUTION"),
                ("WEB-DL", "SOURCE"),
            ],
            source,
        ),
        char_item(
            r"D:\Media\Anime\completed\Witch Watch\S01\15 [1080p][CHS].mkv",
            [
                ("Witch Watch", "TITLE"),
                ("S01", "SEASON"),
                ("15", "EPISODE"),
                ("1080p", "RESOLUTION"),
                ("CHS", "SOURCE"),
            ],
            source,
        ),
        char_item(
            r"O:\115open\Anime\Kakuriyo no Yadomeshi\Season 02\12 [WebRip 1080p].mkv",
            [
                ("Kakuriyo no Yadomeshi", "TITLE"),
                ("Season 02", "SEASON"),
                ("12", "EPISODE"),
                ("WebRip", "SOURCE"),
                ("1080p", "RESOLUTION"),
            ],
            source,
        ),
        char_item(
            r"C:\Archive\old\misc\One Piece\Season 21\One.Piece.1110.1080p.WEB-DL.AAC2.0.H.264.mkv",
            [
                ("One Piece", "TITLE"),
                ("Season 21", "SEASON"),
                ("1110", "EPISODE"),
                ("1080p", "RESOLUTION"),
                ("WEB-DL", "SOURCE"),
            ],
            source,
        ),
    ]


def main() -> None:
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument("--output", required=True)
    parser.add_argument("--repeat", type=int, default=96)
    parser.add_argument("--source", default="manual_path_focus")
    parser.add_argument("--append", action="store_true")
    args = parser.parse_args()

    output = Path(args.output)
    output.parent.mkdir(parents=True, exist_ok=True)
    mode = "a" if args.append else "w"
    cases = build_cases(args.source)
    with output.open(mode, encoding="utf-8") as handle:
        for _ in range(args.repeat):
            for item in cases:
                handle.write(json.dumps(item, ensure_ascii=False, separators=(",", ":")) + "\n")

    print(
        json.dumps(
            {
                "output": str(output),
                "repeat": args.repeat,
                "case_count": len(cases),
                "written_rows": args.repeat * len(cases),
                "append": args.append,
            },
            ensure_ascii=False,
            indent=2,
        )
    )


if __name__ == "__main__":
    main()