from __future__ import annotations

import logging
import shutil
import subprocess
import sys
from pathlib import Path
from typing import Any

from .dependency_validator import DependencyValidator
from .discovery import ChannelPluginDiscovery
from .manifest import ChannelPluginManifest

logger = logging.getLogger(__name__)


class SecurityError(Exception):
    """安全校验错误 —— 阻断不安全的插件安装。"""


def install_channel_plugin(
    manifest: ChannelPluginManifest,
    validator: DependencyValidator | None = None,
) -> None:
    """安装一个渠道插件：
    1. 安装依赖 (pip install) —— 带白名单校验
    2. 复制/链接插件代码到目标目录
    3. 发现并注册插件类

    Args:
        manifest: 插件清单
        validator: 依赖校验器，为 None 时使用默认校验器
    """
    logger.info("Installing channel plugin: %s", manifest.id)

    if manifest.dependencies:
        logger.info("Installing dependencies for %s: %s", manifest.id, manifest.dependencies)
        _install_dependencies_with_validation(manifest.dependencies, validator)

    if manifest.source_path:
        try:
            source = ChannelPluginDiscovery.validate_plugin_path(manifest.source_path, purpose="source copy")
        except PermissionError as e:
            raise SecurityError(str(e)) from e
        target = Path(manifest.target_path or f"yuxi/channels/{manifest.id}")
        if source.exists():
            if target.exists():
                shutil.rmtree(target)
            if source.is_dir():
                shutil.copytree(source, target)
            else:
                target.parent.mkdir(parents=True, exist_ok=True)
                shutil.copy2(source, target)
            logger.info("Copied plugin source from %s to %s", source, target)

    if manifest.entry_point:
        try:
            entry_path = ChannelPluginDiscovery.validate_plugin_path(manifest.entry_point, purpose="entry point")
        except PermissionError as e:
            raise SecurityError(str(e)) from e
        ChannelPluginDiscovery.discover_from_path(entry_path)

    logger.info("Channel plugin '%s' installed successfully", manifest.id)


def _install_dependencies_with_validation(
    dependencies: list[str],
    validator: DependencyValidator | None = None,
) -> None:
    """带白名单校验的依赖安装。

    校验流程：
    1. 使用 DependencyValidator 校验每个依赖
    2. 收集所有校验错误
    3. 如有错误，抛出 SecurityError 阻断安装
    4. 校验通过后执行 pip install
    """
    validator = validator or DependencyValidator.default_validator()
    results = validator.validate_all(dependencies)

    errors = [err for r in results for err in r.errors]
    if errors:
        for err in errors:
            logger.error("Dependency validation failed: %s", err)
        raise SecurityError(f"Dependency validation failed: {'; '.join(errors)}")

    allowed_deps = [r.requested_spec for r in results if r.is_valid]
    if not allowed_deps:
        logger.info("No valid dependencies to install after validation")
        return

    logger.info("Installing validated dependencies: %s", allowed_deps)
    try:
        pip_cmd = [
            sys.executable, "-m", "pip", "install",
            "--no-build-isolation",
            *allowed_deps,
        ]
        subprocess.check_output(
            pip_cmd,
            stderr=subprocess.STDOUT,
            text=True,
        )
    except subprocess.CalledProcessError as e:
        logger.error("pip install failed: %s", e.output)
        raise SecurityError(f"Failed to install dependencies: {e.output}") from e


def uninstall_channel_plugin(
    plugin_id: str,
    target_dir: str | Path | None = None,
    dependencies: list[str] | None = None,
) -> bool:
    """卸载一个渠道插件：

    1. 从 Registry 中注销
    2. 清理文件系统中的插件文件
    3. 卸载 pip 安装的依赖（尽力而为，不阻断卸载流程）

    Args:
        plugin_id: 插件 ID
        target_dir: 插件文件所在目录（从 manifest.target_path 提取）
        dependencies: 插件依赖列表（从 manifest.dependencies 提取）
    """
    from .registry import ChannelPluginRegistry

    ChannelPluginRegistry.unregister(plugin_id)

    if target_dir:
        target = Path(target_dir)
        if target.exists():
            shutil.rmtree(target)
            logger.info("Removed plugin directory: %s", target)

    if dependencies:
        _uninstall_dependencies(plugin_id, dependencies)

    logger.info("Channel plugin '%s' fully uninstalled", plugin_id)
    return True


def _uninstall_dependencies(plugin_id: str, dependencies: list[str]) -> None:
    """卸载插件依赖（尽力而为：失败仅记录告警，不抛异常）。"""
    if not dependencies:
        return

    package_names = []
    for dep in dependencies:
        name = dep.strip().split("=")[0].split(">")[0].split("<")[0].split("~")[0].split("!")[0].strip()
        name = name.split("[")[0].split(";")[0].strip()
        if name:
            package_names.append(name)

    if not package_names:
        return

    logger.info("Uninstalling dependencies for '%s': %s", plugin_id, package_names)
    try:
        subprocess.check_output(
            [sys.executable, "-m", "pip", "uninstall", "-y", *package_names],
            stderr=subprocess.STDOUT,
            text=True,
        )
        logger.info("Successfully uninstalled dependencies for '%s'", plugin_id)
    except subprocess.CalledProcessError as e:
        logger.warning(
            "Failed to uninstall dependencies for '%s': %s (plugin already unregistered)",
            plugin_id, e.output.strip() if e.output else str(e),
        )