from __future__ import annotations

import re
import shlex
from typing import Any

from app.core.permission_service import PermissionService


class CommandAnalyzer:
    """Deterministic shell action analyzer for structured critic evidence."""

    _SPLIT_RE = re.compile(r"\s*(?:&&|;)\s*")

    def __init__(self, permission_service: PermissionService) -> None:
        self._permission_service = permission_service

    def analyze(self, command: str, task_id: str, session_id: str) -> dict[str, Any]:
        segments = [segment.strip() for segment in self._SPLIT_RE.split(command) if segment.strip()]
        root_required: list[str] = []
        elevated: list[str] = []
        unelevated_root: list[str] = []

        for segment in segments:
            normalized, is_elevated = self._strip_sudo(segment)
            check = self._permission_service.check_shell_command(
                task_id=task_id,
                session_id=session_id,
                command=normalized,
            )
            if check.get("requires_sudo"):
                root_required.append(normalized)
                if is_elevated:
                    elevated.append(normalized)
                else:
                    unelevated_root.append(normalized)

        diagnosis_type = "privilege_scope_error" if unelevated_root else "ok"
        return {
            "type": diagnosis_type,
            "command": command,
            "segments": segments,
            "root_required_segments": root_required,
            "elevated_segments": elevated,
            "unelevated_root_segments": unelevated_root,
        }

    def _strip_sudo(self, segment: str) -> tuple[str, bool]:
        try:
            parts = shlex.split(segment)
        except ValueError:
            return segment, segment.strip().startswith("sudo ")
        if not parts or parts[0] != "sudo":
            return segment, False
        index = 1
        while index < len(parts) and parts[index].startswith("-"):
            index += 1
            if index < len(parts) and parts[index - 1] in {"-p", "--prompt"}:
                index += 1
        return " ".join(shlex.quote(part) for part in parts[index:]), True