#!/usr/bin/env python3
# Copyright (c) 2026 Krzysztof Rudnicki. MIT licence.
"""Write a synthetic photo pack for the offline end-to-end run.

The real album is private and lives outside this repository, so the e2e
script cannot use it -- and must not need to. This builds a pack of three
invented people, one "both of them" combination and one video, which is
enough to exercise every path the real one uses.

    python tool/e2e_pack.py --dir /tmp/pack --group 'group.abc='
"""

from __future__ import annotations

import argparse
import base64
import json
import sys
from pathlib import Path
from typing import Final

# A 1x1 PNG, inline so that no binary file enters the repository.
PIXEL: Final = base64.b64decode(
    "iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mP8z8BQDwAEhQGAhKmMIQAAAABJRU5ErkJggg=="
)
# Not playable, and it does not have to be: nothing decodes it, the point is
# that it leaves as video/mp4 rather than as a photo.
CLIP: Final = b"\x00\x00\x00\x18ftypmp42fake"

PEOPLE: Final = [
    {"key": "p1", "triggers": ["!alfa"]},
    {"key": "p2", "triggers": ["!beta"]},
    {"key": "p3", "triggers": ["!gamma"]},
    {"key": "p4", "triggers": ["!wideo"]},
]
COMBOS: Final = [{"key": "c1", "triggers": ["!oboje"], "all_of": ["p1", "p2"]}]
TAGS: Final = {
    "alfa.png": ["p1"],
    "both.png": ["p1", "p2"],
    "gamma.png": ["p3"],
    "clip.mp4": ["p4"],
}


def write(directory: Path, group: str, extra: str | None = None) -> None:
    """Write the manifest, the tags and the files themselves.

    ``extra`` adds one more person, ``!<extra>`` with one photo, on top of
    the fixed four -- run a second time over the same directory, that is
    what "somebody tagged a new person while the bot was up" looks like,
    and what POST /_reload has to pick up without a restart.
    """
    people, tags = list(PEOPLE), dict(TAGS)
    if extra is not None:
        people.append({"key": "p5", "triggers": [f"!{extra}"]})
        tags[f"{extra}.png"] = ["p5"]
    album = directory / "media"
    album.mkdir(parents=True, exist_ok=True)
    for name in tags:
        (album / name).write_bytes(CLIP if name.endswith(".mp4") else PIXEL)
    manifest = {"groups": [group], "people": people, "combos": COMBOS}
    (directory / "people.json").write_text(json.dumps(manifest, indent=2), encoding="utf-8")
    (directory / "tags.json").write_text(json.dumps(tags, indent=2), encoding="utf-8")


def main() -> int:
    """Build the pack asked for on the command line."""
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument("--dir", required=True, type=Path, help="where to write the pack")
    parser.add_argument("--group", required=True, help="the group id the pack belongs to")
    parser.add_argument("--extra", help="one more person to add, by trigger word")
    arguments = parser.parse_args()
    write(arguments.dir, arguments.group, arguments.extra)
    sys.stdout.write(f"== wrote a synthetic pack to {arguments.dir}\n")
    return 0


if __name__ == "__main__":
    raise SystemExit(main())