fix(gemini): implement official hook contract

elydora/plugins/gemini_command.py

@@ -0,0 +1,206 @@
+"""Gemini CLI hook command construction and exact runtime ownership."""
+
+from __future__ import annotations
+
+import base64
+from dataclasses import dataclass
+import ntpath
+import os
+import re
+import sys
+from typing import Optional, Tuple
+
+
+@dataclass(frozen=True)
+class GeminiRuntimeReference:
+    agent_id: str
+    script_path: str
+
+
+def same_gemini_path(left: str, right: str) -> bool:
+    return os.path.normcase(os.path.abspath(left)) == os.path.normcase(
+        os.path.abspath(right)
+    )
+
+
+def same_gemini_agent_id(left: str, right: str) -> bool:
+    return os.path.normcase(left) == os.path.normcase(right)
+
+
+def _quote_posix(value: str) -> str:
+    return "'" + value.replace("'", "'\"'\"'") + "'"
+
+
+def _quote_powershell(value: str) -> str:
+    return "'" + value.replace("'", "''") + "'"
+
+
+def _windows_powershell_path() -> str:
+    configured = os.environ.get("SystemRoot")
+    system_root = (
+        configured
+        if configured
+        and ntpath.isabs(configured)
+        and re.search(r'["%\r\n]', configured) is None
+        else r"C:\Windows"
+    )
+    return ntpath.join(
+        system_root,
+        "System32",
+        "WindowsPowerShell",
+        "v1.0",
+        "powershell.exe",
+    )
+
+
+def _windows_command(script_path: str) -> str:
+    source = (
+        f"& {_quote_powershell(sys.executable)} "
+        f"{_quote_powershell(script_path)}; exit $LASTEXITCODE"
+    )
+    encoded = base64.b64encode(source.encode("utf-16le")).decode("ascii")
+    return (
+        f"& {_quote_powershell(_windows_powershell_path())} "
+        "-NoLogo -NoProfile -NonInteractive -EncodedCommand "
+        f"{encoded}"
+    )
+
+
+def build_gemini_command(script_path: str) -> str:
+    if not os.path.isabs(sys.executable) or not os.path.isabs(script_path):
+        raise ValueError(
+            "Gemini CLI hook commands require absolute executable and script paths"
+        )
+    if os.name == "nt":
+        return _windows_command(script_path)
+    return f"{_quote_posix(sys.executable)} {_quote_posix(script_path)}"
+
+
+def _read_posix_argument(command: str, start: int) -> Optional[Tuple[str, int]]:
+    if start >= len(command) or command[start] != "'":
+        return None
+    apostrophe = "'\"'\"'"
+    value = ""
+    index = start + 1
+    while index < len(command):
+        if command.startswith(apostrophe, index):
+            value += "'"
+            index += len(apostrophe)
+            continue
+        if command[index] == "'":
+            return value, index + 1
+        value += command[index]
+        index += 1
+    return None
+
+
+def _parse_posix_command(command: str) -> Optional[Tuple[str, str]]:
+    executable = _read_posix_argument(command, 0)
+    if executable is None or executable[1] >= len(command):
+        return None
+    if command[executable[1]] != " ":
+        return None
+    script = _read_posix_argument(command, executable[1] + 1)
+    if script is None or script[1] != len(command):
+        return None
+    return executable[0], script[0]
+
+
+def _read_powershell_argument(
+    command: str, start: int
+) -> Optional[Tuple[str, int]]:
+    if start >= len(command) or command[start] != "'":
+        return None
+    value = ""
+    index = start + 1
+    while index < len(command):
+        if command[index] != "'":
+            value += command[index]
+            index += 1
+            continue
+        if index + 1 < len(command) and command[index + 1] == "'":
+            value += "'"
+            index += 2
+            continue
+        return value, index + 1
+    return None
+
+
+def _parse_powershell_source(source: str) -> Optional[Tuple[str, str]]:
+    if not source.startswith("& "):
+        return None
+    executable = _read_powershell_argument(source, 2)
+    if executable is None or executable[1] >= len(source):
+        return None
+    if source[executable[1]] != " ":
+        return None
+    script = _read_powershell_argument(source, executable[1] + 1)
+    if script is None or source[script[1] :] != "; exit $LASTEXITCODE":
+        return None
+    return executable[0], script[0]
+
+
+def _parse_windows_command(command: str) -> Optional[Tuple[str, str]]:
+    if not command.startswith("& "):
+        return None
+    powershell = _read_powershell_argument(command, 2)
+    if (
+        powershell is None
+        or not ntpath.isabs(powershell[0])
+        or ntpath.basename(powershell[0]).lower() != "powershell.exe"
+    ):
+        return None
+    prefix = " -NoLogo -NoProfile -NonInteractive -EncodedCommand "
+    if not command.startswith(prefix, powershell[1]):
+        return None
+    encoded = command[powershell[1] + len(prefix) :]
+    if re.fullmatch(r"[A-Za-z0-9+/]+={0,2}", encoded) is None:
+        return None
+    try:
+        payload = base64.b64decode(encoded, validate=True)
+        if base64.b64encode(payload).decode("ascii") != encoded:
+            return None
+        if len(payload) % 2:
+            return None
+        source = payload.decode("utf-16le")
+    except (ValueError, UnicodeDecodeError):
+        return None
+    return _parse_powershell_source(source)
+
+
+def _parse_legacy_command(
+    command: str, script_name: str
+) -> Optional[Tuple[str, str]]:
+    if script_name == "guard.py":
+        match = re.fullmatch(r'"([^"\r\n]+)" ([^\r\n]+)', command)
+        if match is None or not same_gemini_path(match.group(1), sys.executable):
+            return None
+        return match.group(1), match.group(2)
+    if "\r" in command or "\n" in command:
+        return None
+    return sys.executable, command
+
+
+def gemini_runtime_reference(
+    command: str,
+    script_name: str,
+    include_legacy: bool = False,
+) -> Optional[GeminiRuntimeReference]:
+    parsed = _parse_posix_command(command) or _parse_windows_command(command)
+    if parsed is None and include_legacy:
+        parsed = _parse_legacy_command(command, script_name)
+    if (
+        parsed is None
+        or not same_gemini_path(parsed[0], sys.executable)
+        or not os.path.isabs(parsed[1])
+        or os.path.basename(parsed[1]) != script_name
+    ):
+        return None
+    agent_directory = os.path.dirname(parsed[1])
+    runtime_root = os.path.join(os.path.expanduser("~"), ".elydora")
+    if not same_gemini_path(os.path.dirname(agent_directory), runtime_root):
+        return None
+    agent_id = os.path.basename(agent_directory)
+    if agent_id in {"", ".", ".."}:
+        return None
+    return GeminiRuntimeReference(agent_id, parsed[1])