"""Per-project state for os-status (deep module).

Owns the gitignored .cc-os/ directory contract: key=value config, per-check
once-per-day snooze stamps (snooze-<check>), and permanent suppress markers
(suppress-<check>). State only, never code; nothing here writes outside
.cc-os/. Fail-open throughout: unreadable state reads as unset.
"""
from __future__ import annotations

from datetime import date
from pathlib import Path
from typing import Optional


def find_project_root(cwd: Path) -> Optional[Path]:
    """Nearest ancestor (including cwd) containing .git, else None."""
    for candidate in [cwd, *cwd.parents]:
        if (candidate / ".git").exists():
            return candidate
    return None


def read_config(root: Path) -> dict:
    """Parse .cc-os/config as '#'-commented key = value lines."""
    config = {}
    try:
        text = (root / ".cc-os" / "config").read_text()
    except Exception:
        return config
    for line in text.splitlines():
        line = line.strip()
        if not line or line.startswith("#") or "=" not in line:
            continue
        key, value = line.split("=", 1)
        config[key.strip()] = value.strip()
    return config


def write_config_value(root: Path, key: str, value: str) -> None:
    """Set key=value in .cc-os/config, preserving every other line
    (comments included) and appending the key if absent. Used by
    /os-status:fix to stamp the config 'version' key."""
    config_path = root / ".cc-os" / "config"
    try:
        lines = config_path.read_text().splitlines()
    except Exception:
        lines = []
    found = False
    out = []
    for line in lines:
        stripped = line.strip()
        if stripped and not stripped.startswith("#") and "=" in stripped:
            existing_key = stripped.split("=", 1)[0].strip()
            if existing_key == key:
                out.append(f"{key} = {value}")
                found = True
                continue
        out.append(line)
    if not found:
        out.append(f"{key} = {value}")
    config_path.parent.mkdir(exist_ok=True)
    config_path.write_text("\n".join(out) + "\n")


class StateDir:
    """The gitignored per-project .cc-os/ state directory."""

    def __init__(self, root: Path) -> None:
        self._dir = root / ".cc-os"

    def suppressed(self, check: str) -> bool:
        return (self._dir / f"suppress-{check}").exists()

    def snoozed(self, check: str, today: date) -> bool:
        try:
            stamped = date.fromisoformat(
                (self._dir / f"snooze-{check}").read_text().strip()
            )
        except Exception:
            return False
        return stamped == today

    def stamp(self, check: str, today: date) -> None:
        self._dir.mkdir(exist_ok=True)
        (self._dir / f"snooze-{check}").write_text(today.isoformat())