from __future__ import annotations

from pathlib import Path


class LogReader:
    def __init__(self, root_dir: Path | None = None):
        self.root_dir = (root_dir or Path(__file__).resolve().parents[3]).resolve()
        self.log_dirs = [
            self.root_dir / "logs",
            self.root_dir / "runtime" / "logs",
            self.root_dir / "data" / "workspace" / "logs",
        ]

    def _allowed_log_files(self) -> dict[str, Path]:
        items: dict[str, Path] = {}
        for log_dir in self.log_dirs:
            if not log_dir.exists():
                continue
            for path in sorted(p for p in log_dir.rglob("*.log") if p.is_file()):
                items.setdefault(path.name, path.resolve())
        return items

    def list_logs(self) -> dict[str, object]:
        allowed_log_files = self._allowed_log_files()
        return {
            "items": [
                {
                    "name": name,
                    "path": str(path),
                    "exists": path.exists(),
                }
                for name, path in sorted(allowed_log_files.items())
            ]
        }

    def tail(self, name: str, lines: int = 200, contains: str | None = None) -> dict[str, object]:
        allowed_log_files = self._allowed_log_files()
        if name not in allowed_log_files:
            raise ValueError(f"unsupported log: {name}")
        path = allowed_log_files[name]
        if not path.exists():
            return {"name": name, "path": str(path), "exists": False, "content": ""}
        content = path.read_text(encoding="utf-8", errors="replace").splitlines()
        if contains:
            content = [line for line in content if contains in line]
        return {
            "name": name,
            "path": str(path),
            "exists": True,
            "content": "\n".join(content[-max(1, min(lines, 1000)):]),
        }