"""Safely fast-forward a Git installation of this node package."""

import ipaddress
import os
import subprocess
import sys
import tempfile
from pathlib import Path
from urllib.parse import urlsplit


PLUGIN_DIR = Path(__file__).resolve().parent.parent


class UpdateError(Exception):
    pass


def is_local_management_request(request):
    """Allow software management only from the local ComfyUI browser."""
    peer = request.transport.get_extra_info("peername") if request.transport else None
    if not peer:
        return False
    try:
        if not ipaddress.ip_address(peer[0]).is_loopback:
            return False
        host = request.headers.get("Host", "")
        host_url = urlsplit(f"http://{host}")
        hostname = host_url.hostname
        if host_url.username or host_url.password or host_url.path or host_url.query or host_url.fragment:
            return False
        if hostname != "localhost" and not ipaddress.ip_address(hostname).is_loopback:
            return False
        origin = request.headers.get("Origin", "")
        parsed_origin = urlsplit(origin)
    except (ValueError, TypeError):
        return False

    return (
        parsed_origin.scheme == request.scheme
        and parsed_origin.netloc.lower() == host.lower()
        and not parsed_origin.path
        and not parsed_origin.query
        and not parsed_origin.fragment
    )


def _git(*args, timeout=60, check=True):
    env = os.environ.copy()
    env["GIT_TERMINAL_PROMPT"] = "0"
    env["GCM_INTERACTIVE"] = "Never"
    try:
        result = subprocess.run(
            ["git", *args],
            cwd=PLUGIN_DIR,
            env=env,
            capture_output=True,
            text=True,
            encoding="utf-8",
            errors="replace",
            timeout=timeout,
        )
    except FileNotFoundError as exc:
        raise UpdateError("未找到 Git，请先安装 Git。") from exc
    except subprocess.TimeoutExpired as exc:
        raise UpdateError("Git 操作超时，请检查网络后重试。") from exc
    if check and result.returncode:
        detail = (result.stderr or result.stdout).strip().splitlines()
        raise UpdateError(detail[-1] if detail else "Git 操作失败。")
    return result


def _install_requirements(requirements):
    fd, filename = tempfile.mkstemp(prefix=".o1key-requirements-", suffix=".txt", dir=PLUGIN_DIR)
    try:
        with os.fdopen(fd, "w", encoding="utf-8") as req_file:
            req_file.write(requirements)
        try:
            result = subprocess.run(
                [sys.executable, "-m", "pip", "install", "-r", filename],
                cwd=PLUGIN_DIR,
                capture_output=True,
                text=True,
                encoding="utf-8",
                errors="replace",
                timeout=600,
            )
        except subprocess.TimeoutExpired as exc:
            raise UpdateError("依赖安装超时，节点代码尚未更新，请检查网络后重试。") from exc
        if result.returncode:
            raise UpdateError("依赖安装失败，节点代码尚未更新，请检查 ComfyUI 的 Python 环境后重试。")
    finally:
        Path(filename).unlink(missing_ok=True)


def update_package():
    """Update origin/main without discarding local changes or switching branches."""
    if not (PLUGIN_DIR / ".git").exists():
        raise UpdateError("当前节点包不是 Git 安装。请通过 Git 安装后再使用界面更新。")

    branch = _git("symbolic-ref", "--quiet", "--short", "HEAD", check=False)
    if branch.returncode or branch.stdout.strip() != "main":
        raise UpdateError("当前不在 main 分支，请手动检查分支后更新。")

    if _git("status", "--porcelain", "--untracked-files=no").stdout.strip():
        raise UpdateError("节点包有本地修改，请先保存或处理修改后再更新。")

    old_commit = _git("rev-parse", "HEAD").stdout.strip()
    old_requirements = _git("show", "HEAD:requirements.txt", check=False).stdout
    _git("fetch", "origin", "main")
    new_commit = _git("rev-parse", "FETCH_HEAD").stdout.strip()
    if old_commit == new_commit:
        return {"updated": False, "version": old_commit[:7], "requirements_changed": False}

    if _git("merge-base", "--is-ancestor", "HEAD", "FETCH_HEAD", check=False).returncode:
        raise UpdateError("本地与 origin/main 已分叉，无法安全快进。请手动处理。")

    new_requirements = _git("show", "FETCH_HEAD:requirements.txt", check=False).stdout
    requirements_changed = old_requirements != new_requirements
    if requirements_changed and new_requirements.strip():
        _install_requirements(new_requirements)
    _git("merge", "--ff-only", "FETCH_HEAD")
    return {
        "updated": True,
        "version": new_commit[:7],
        "requirements_changed": requirements_changed,
    }