import datetime
from pathlib import Path

from pyra.memory import _MEMORY_ROOT
from pyra.memory.index import update_index, update_json_entry
from pyra.security.boundaries import assert_safe_path
from pyra.utils.paths import safe_chmod


def _resolve_and_validate(name: str) -> Path:
    if name.startswith("/") or name.startswith("~"):
        raise ValueError(f"Memory name must be relative, got: {name!r}")
    path = (_MEMORY_ROOT / name).resolve()
    assert_safe_path(path)
    try:
        path.relative_to(_MEMORY_ROOT.resolve())
    except ValueError:
        raise PermissionError(f"Path escapes memory directory: {name!r}")
    if path.suffix.lower() != ".md":
        path = path.with_suffix(".md")
    return path


def _upsert_to_db(path: Path, content: str, summary: str = "", keywords: list[str] | None = None) -> None:
    from pyra.memory import database
    if not database._DB_PATH.exists():
        return
    rel = path.relative_to(_MEMORY_ROOT).as_posix()
    category = rel.split("/")[0] if "/" in rel else "root"
    stat = path.stat()
    mtime = datetime.datetime.fromtimestamp(stat.st_mtime).isoformat(timespec="seconds")
    database.upsert(
        rel,
        content=content,
        category=category,
        size_bytes=stat.st_size,
        modified=mtime,
        summary=summary,
        keywords=keywords,
    )


def write_memory(
    name: str,
    content: str,
    summary: str = "",
    keywords: list[str] | None = None,
) -> Path:
    path = _resolve_and_validate(name)
    path.parent.mkdir(parents=True, exist_ok=True)
    path.write_text(content)
    safe_chmod(path, 0o600)
    update_index()
    if summary or keywords:
        rel_key = path.relative_to(_MEMORY_ROOT).as_posix()
        update_json_entry(rel_key, summary, keywords or [])
    _upsert_to_db(path, content, summary, keywords)
    return path


def append_memory(name: str, content: str) -> Path:
    path = _resolve_and_validate(name)
    path.parent.mkdir(parents=True, exist_ok=True)
    if path.exists():
        existing = path.read_text()
        new_content = existing.rstrip() + "\n\n" + content
        path.write_text(new_content)
    else:
        new_content = content
        path.write_text(new_content)
    safe_chmod(path, 0o600)
    update_index()
    _upsert_to_db(path, new_content)
    return path