#!/usr/bin/env python3
"""Initialize a project from the skill's knowledge-wiki boilerplate."""

from __future__ import annotations

import argparse
import filecmp
import re
import shutil
from datetime import date
from pathlib import Path

INITIALIZED_LOG_RE = re.compile(
    r"# Wiki Update Log\n\n"
    r"## \d{4}-\d{2}-\d{2}\n\n"
    r"\* \*\*Initialization\*\*: Wissensdatenbank nach OKF v0\.2 initialisiert\.\n?"
)


def parse_args() -> argparse.Namespace:
    parser = argparse.ArgumentParser(
        description="Copy the agent-managed wiki boilerplate into a project."
    )
    parser.add_argument("project_root", type=Path, help="Target project directory")
    parser.add_argument(
        "--force",
        action="store_true",
        help="Overwrite differing boilerplate files in the target project",
    )
    return parser.parse_args()


def template_files(template_root: Path) -> list[Path]:
    return sorted(path for path in template_root.rglob("*") if path.is_file())


def matches_template_or_initialized_log(
    source: Path, target: Path, relative: Path
) -> bool:
    if filecmp.cmp(source, target, shallow=False):
        return True
    return (
        relative == Path("wiki/log.md")
        and INITIALIZED_LOG_RE.fullmatch(target.read_text(encoding="utf-8")) is not None
    )


def main() -> int:
    args = parse_args()
    project_root = args.project_root.expanduser().resolve()
    template_root = Path(__file__).resolve().parent.parent / "assets" / "boilerplate"

    if not template_root.is_dir():
        raise SystemExit(f"Boilerplate not found: {template_root}")

    files = template_files(template_root)
    conflicts = []
    for source in files:
        relative = source.relative_to(template_root)
        target = project_root / relative
        if target.exists() and not matches_template_or_initialized_log(
            source, target, relative
        ):
            conflicts.append(relative)

    if conflicts and not args.force:
        rendered = "\n".join(f"  - {path}" for path in conflicts)
        raise SystemExit(
            "Refusing to overwrite differing files:\n"
            f"{rendered}\nRun again with --force only when replacement is intended."
        )

    created = 0
    unchanged = 0
    overwritten = 0
    for source in files:
        relative = source.relative_to(template_root)
        target = project_root / relative
        target.parent.mkdir(parents=True, exist_ok=True)
        if target.exists() and matches_template_or_initialized_log(
            source, target, relative
        ):
            unchanged += 1
            continue
        existed = target.exists()
        shutil.copy2(source, target)
        overwritten += int(existed)
        created += int(not existed)

    log_path = project_root / "wiki" / "log.md"
    if log_path.exists() and log_path.read_text(encoding="utf-8").strip() == "# Wiki Update Log":
        log_path.write_text(
            "# Wiki Update Log\n\n"
            f"## {date.today().isoformat()}\n\n"
            "* **Initialization**: Wissensdatenbank nach OKF v0.2 initialisiert.\n",
            encoding="utf-8",
        )

    print(
        f"Initialized {project_root}: "
        f"{created} created, {overwritten} overwritten, {unchanged} unchanged."
    )
    print(
        "\nKurzanleitung:\n"
        "- Originalquellen unter `sources/` ablegen; Entscheidungen verwaltet "
        "der Agent unter `sources/decisions/`.\n"
        "- Codex bitten, Quellen zu integrieren, das Wiki zu befragen oder "
        "Entscheidungen festzuhalten.\n"
        "- Der Skill pflegt `wiki/`, Provenienz, Index, Log und Quellenstatus."
    )
    return 0


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