"""Fast-forward a clean Git installation from the public O1Key release repo."""

import os
import subprocess
from pathlib import Path


PLUGIN_DIR = Path(__file__).resolve().parent.parent
RELEASE_REPOSITORY_URL = "https://git.o1key.com/publisher/comfyui_o1key.git"


class UpdateError(Exception):
    def __init__(self, code, message, suggestion, status=409):
        super().__init__(message)
        self.code = code
        self.suggestion = suggestion
        self.status = status

    def as_dict(self):
        return {
            "code": self.code,
            "error": str(self),
            "suggestion": self.suggestion,
        }


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(
            "git_missing", "未找到 Git。", "安装 Git 后重启 ComfyUI，再重新检查更新。", 503,
        ) from exc
    except subprocess.TimeoutExpired as exc:
        raise UpdateError(
            "timeout", "连接发布仓库超时。", "检查网络连接，稍后再试。", 504,
        ) from exc
    if check and result.returncode:
        raise UpdateError(
            "git_failed", "Git 操作未完成。", "检查插件目录的 Git 状态后重试。",
        )
    return result


def _check_release():
    """Inspect the release before considering any local file changes."""
    if not (PLUGIN_DIR / ".git").exists():
        raise UpdateError(
            "not_git", "当前插件不是 Git 安装。",
            "请从发布仓库重新以 Git 安装；现有配置文件先单独备份。",
        )

    branch = _git("symbolic-ref", "--quiet", "--short", "HEAD", check=False)
    if branch.returncode or branch.stdout.strip() != "main":
        raise UpdateError(
            "wrong_branch", "当前不在 main 分支。",
            "请先检查并切换分支；本地分支上的修改不会自动合并。",
        )

    old_commit = _git("rev-parse", "HEAD").stdout.strip()
    fetched = _git("fetch", "--no-tags", RELEASE_REPOSITORY_URL, "main", timeout=90, check=False)
    if fetched.returncode:
        raise UpdateError(
            "fetch_failed", "无法获取发布仓库的 main 分支。",
            "检查 git.o1key.com 的网络连接与仓库读取权限，稍后重试。", 503,
        )
    new_commit = _git("rev-parse", "FETCH_HEAD").stdout.strip()
    if old_commit == new_commit:
        return old_commit, new_commit

    if _git("merge-base", "--is-ancestor", "HEAD", "FETCH_HEAD", check=False).returncode:
        raise UpdateError(
            "diverged", "本地提交与发布仓库已分叉，无法自动快进。",
            "请手动比较两个分支并合并，不要强制重置本地文件。",
        )

    if _git("status", "--porcelain", "--untracked-files=no").stdout.strip():
        raise UpdateError(
            "local_changes", "插件目录有未提交的代码修改。",
            "请先保存、提交或暂存修改；更新不会覆盖这些文件。",
        )

    return old_commit, new_commit


def check_for_update():
    """Check whether the installed version can be updated without changing files."""
    old_commit, new_commit = _check_release()
    return {"update_available": old_commit != new_commit}


def update_package():
    """Fetch the release main branch and fast-forward only a clean local main."""
    old_commit, new_commit = _check_release()
    if old_commit == new_commit:
        return {"updated": False, "version": old_commit[:7], "requirements_changed": False}

    old_requirements = _git("show", "HEAD:requirements.txt", check=False).stdout
    new_requirements = _git("show", "FETCH_HEAD:requirements.txt", check=False).stdout
    merged = _git("merge", "--ff-only", "FETCH_HEAD", check=False)
    if merged.returncode:
        raise UpdateError(
            "merge_blocked", "更新被本地文件阻止。",
            "检查是否有与新版本重名的未跟踪文件，保留文件后手动处理。",
        )
    requirements_changed = old_requirements != new_requirements
    return {
        "updated": True,
        "version": new_commit[:7],
        "requirements_changed": requirements_changed,
    }