from __future__ import annotations

import base64
import locale
import os
import subprocess
import webbrowser
from pathlib import Path
from typing import Any, Literal

import psutil
from fastapi import HTTPException


MouseAction = Literal["move_to", "move_rel", "click", "double_click", "right_click", "drag_to", "scroll"]
KeyboardAction = Literal["press", "hotkey", "write", "key_down", "key_up"]

KEY_ALIASES = {
    "arrowup": "up",
    "↑": "up",
    "arrowdown": "down",
    "↓": "down",
    "arrowleft": "left",
    "←": "left",
    "arrowright": "right",
    "→": "right",
    "control": "ctrl",
    "cmd": "win",
    "command": "win",
    "meta": "win",
    "windows": "win",
    "esc": "escape",
    "del": "delete",
    "pgup": "pageup",
    "pgdn": "pagedown",
    " ": "space",
}


def hidden_creationflags() -> int:
    """返回 Windows 下隐藏控制台窗口所需的启动标志。"""
    if os.name != "nt":
        return 0
    return subprocess.CREATE_NO_WINDOW


def command_encoding() -> str:
    """获取当前系统命令行输出编码，避免中文 Windows 输出乱码。"""
    return locale.getpreferredencoding(False) or "utf-8"


def ensure_windows() -> None:
    """确认当前运行环境是 Windows，系统电源操作只允许在 Windows 上执行。"""
    if os.name != "nt":
        raise HTTPException(status_code=400, detail="Windows automation is only available on Windows")


def load_pyautogui():
    """按需加载 pyautogui，避免未安装依赖时影响后端其他接口启动。"""
    try:
        import pyautogui
    except ImportError as exc:
        raise HTTPException(
            status_code=500,
            detail="pyautogui is not installed. Run pip install -r backend/requirements.txt",
        ) from exc
    pyautogui.FAILSAFE = True
    return pyautogui


def raise_if_pyautogui_failsafe(pyautogui: Any, exc: Exception, action: str, extra: dict[str, Any] | None = None) -> None:
    """把 PyAutoGUI 安全保护异常转换为带坐标上下文的接口错误。"""
    if exc.__class__.__name__ != "FailSafeException":
        raise exc
    position: dict[str, Any] = {"x": None, "y": None}
    try:
        current = pyautogui.position()
        position = {"x": current.x, "y": current.y}
    except Exception:
        pass
    raise HTTPException(
        status_code=500,
        detail={
            "message": str(exc),
            "action": action,
            "mouse_position": position,
            "extra": extra or {},
        },
    ) from exc


def normalize_key_name(key: str) -> str:
    """把浏览器或用户输入的按键名转换为 pyautogui 兼容名称。"""
    normalized = str(key).strip().lower()
    return KEY_ALIASES.get(normalized, normalized)


def normalize_key_list(keys: list[str] | None) -> list[str]:
    """规范化组合键列表，并去掉空值。"""
    return [normalize_key_name(key) for key in keys or [] if str(key).strip()]


def run_shutdown_command(args: list[str], timeout: int = 10) -> dict[str, Any]:
    """执行 shutdown.exe 命令，并统一返回命令输出。"""
    ensure_windows()
    result = subprocess.run(
        ["shutdown.exe", *args],
        capture_output=True,
        text=True,
        encoding=command_encoding(),
        errors="replace",
        timeout=timeout,
        creationflags=hidden_creationflags(),
        check=False,
    )
    output = "\n".join(part for part in [result.stdout.strip(), result.stderr.strip()] if part)
    if result.returncode != 0:
        raise HTTPException(status_code=500, detail=output or f"shutdown.exe exited with {result.returncode}")
    return {"returncode": result.returncode, "output": output}


def shutdown_windows(delay_seconds: int = 0, force: bool = False, reason: str | None = None) -> dict[str, Any]:
    """关闭 Windows 系统，支持延迟秒数和强制关闭正在运行的程序。"""
    args = ["/s", "/t", str(delay_seconds)]
    if force:
        args.append("/f")
    if reason:
        args.extend(["/c", reason[:512]])
    result = run_shutdown_command(args)
    return {"action": "shutdown", "delay_seconds": delay_seconds, "force": force, **result}


def restart_windows(delay_seconds: int = 0, force: bool = False, reason: str | None = None) -> dict[str, Any]:
    """重启 Windows 系统，支持延迟秒数和强制关闭正在运行的程序。"""
    args = ["/r", "/t", str(delay_seconds)]
    if force:
        args.append("/f")
    if reason:
        args.extend(["/c", reason[:512]])
    result = run_shutdown_command(args)
    return {"action": "restart", "delay_seconds": delay_seconds, "force": force, **result}


def cancel_power_action() -> dict[str, Any]:
    """取消已经排程但尚未执行的关机或重启操作。"""
    result = run_shutdown_command(["/a"])
    return {"action": "cancel_power_action", **result}


def start_program(command: str, cwd: str | None = None, shell: bool = True) -> dict[str, Any]:
    """启动一个程序或命令，返回新进程 PID 供后续自动化流程追踪。"""
    working_dir = cwd if cwd and os.path.isdir(cwd) else None
    try:
        proc = subprocess.Popen(
            command,
            cwd=working_dir,
            shell=shell,
            creationflags=hidden_creationflags(),
        )
    except OSError as exc:
        raise HTTPException(status_code=500, detail=str(exc)) from exc
    return {"action": "start_program", "pid": proc.pid, "command": command, "cwd": working_dir}


def open_url(url: str, browser: str | None = None, new_window: bool = True) -> dict[str, Any]:
    """打开网页 URL。优先使用 Windows shell/浏览器注册表，避免 shell 命令静默失败。"""
    target = str(url).strip()
    if not target:
        raise HTTPException(status_code=400, detail="url is required")

    browser_name = (browser or "").strip().lower()
    if browser_name in {"edge", "msedge"}:
        args = ["cmd.exe", "/c", "start", "", "msedge"]
        if new_window:
            args.append("--new-window")
        args.append(target)
        proc = subprocess.Popen(args, creationflags=hidden_creationflags())
        return {"action": "open_url", "browser": "msedge", "url": target, "pid": proc.pid}

    if os.name == "nt":
        try:
            os.startfile(target)  # type: ignore[attr-defined]
            return {"action": "open_url", "browser": "default", "url": target}
        except OSError as exc:
            raise HTTPException(status_code=500, detail=str(exc)) from exc

    opened = webbrowser.open(target, new=1 if new_window else 0)
    if not opened:
        raise HTTPException(status_code=500, detail="Failed to open url")
    return {"action": "open_url", "browser": "default", "url": target}


def stop_program(pid: int | None = None, name: str | None = None, timeout_seconds: float = 8, kill_after_timeout: bool = True) -> dict[str, Any]:
    """按 PID 或进程名关闭程序；优先温和终止，超时后可选择强制结束。"""
    processes = find_processes(pid=pid, name=name)
    if not processes:
        raise HTTPException(status_code=404, detail="No matching process found")

    stopped: list[dict[str, Any]] = []
    for proc in processes:
        item: dict[str, Any] = {"pid": proc.pid, "name": safe_proc_name(proc)}
        try:
            proc.terminate()
            proc.wait(timeout=timeout_seconds)
            item["stopped_by"] = "terminate"
        except psutil.TimeoutExpired:
            if not kill_after_timeout:
                item["stopped_by"] = None
                item["error"] = "terminate timeout"
            else:
                proc.kill()
                proc.wait(timeout=5)
                item["stopped_by"] = "kill"
        except psutil.NoSuchProcess:
            item["already_stopped"] = True
        except psutil.AccessDenied as exc:
            item["error"] = f"access denied: {exc}"
        stopped.append(item)
    return {"action": "stop_program", "matched": len(processes), "items": stopped}


def find_processes(pid: int | None = None, name: str | None = None) -> list[psutil.Process]:
    """根据 PID 或进程名查找进程，供关闭程序等动作复用。"""
    if pid is None and not name:
        raise HTTPException(status_code=400, detail="pid or name is required")
    if pid is not None:
        try:
            return [psutil.Process(pid)]
        except psutil.NoSuchProcess:
            return []
        except psutil.AccessDenied as exc:
            raise HTTPException(status_code=403, detail=f"Access denied: {exc}") from exc

    target = (name or "").lower()
    matched = []
    for proc in psutil.process_iter(["name"]):
        proc_name = (proc.info.get("name") or "").lower()
        if proc_name == target:
            matched.append(proc)
    return matched


def safe_proc_name(proc: psutil.Process) -> str | None:
    """安全读取进程名，避免进程消失或权限不足导致自动化流程中断。"""
    try:
        return proc.name()
    except (psutil.Error, OSError):
        return None


def take_screenshot(save_path: str | None = None, include_base64: bool = True) -> dict[str, Any]:
    """截取当前屏幕；可保存为 PNG 文件，也可返回 base64 供接口直接预览。"""
    pyautogui = load_pyautogui()
    try:
        image = pyautogui.screenshot()
    except Exception as exc:
        raise_if_pyautogui_failsafe(pyautogui, exc, "screenshot")
        raise
    width, height = image.size

    result: dict[str, Any] = {"action": "screenshot", "width": width, "height": height}
    if save_path:
        path = Path(save_path).expanduser().resolve()
        path.parent.mkdir(parents=True, exist_ok=True)
        image.save(path, format="PNG")
        result["path"] = str(path)

    if include_base64:
        from io import BytesIO

        buffer = BytesIO()
        image.save(buffer, format="PNG")
        result["image_base64"] = base64.b64encode(buffer.getvalue()).decode("ascii")
        result["mime_type"] = "image/png"
    return result


def active_window_bounds() -> dict[str, Any]:
    """返回当前活动窗口的位置和尺寸，用于把点击限制在浏览器窗口内部。"""
    pyautogui = load_pyautogui()
    window = pyautogui.getActiveWindow()
    if window is None:
        raise HTTPException(status_code=500, detail="No active window found")
    return {
        "left": int(window.left),
        "top": int(window.top),
        "width": int(window.width),
        "height": int(window.height),
        "title": str(getattr(window, "title", "") or ""),
    }


def maximize_active_window() -> dict[str, Any]:
    """最大化当前活动窗口；失败时退回 Windows 快捷键。"""
    pyautogui = load_pyautogui()
    window = pyautogui.getActiveWindow()
    if window is not None:
        try:
            window.maximize()
            return {"action": "maximize_window", "method": "window.maximize", "title": str(window.title or "")}
        except Exception:
            pass
    pyautogui.hotkey("win", "up")
    return {"action": "maximize_window", "method": "hotkey", "keys": ["win", "up"]}


def mouse_action(
    action: MouseAction,
    x: int | None = None,
    y: int | None = None,
    duration: float = 0,
    button: str = "left",
    clicks: int = 1,
    amount: int = 0,
) -> dict[str, Any]:
    """执行鼠标动作，包括移动、点击、拖拽和滚轮操作。"""
    pyautogui = load_pyautogui()
    if action in {"move_to", "drag_to"} and (x is None or y is None):
        raise HTTPException(status_code=400, detail="x and y are required for this mouse action")

    try:
        if action == "move_to":
            pyautogui.moveTo(x, y, duration=duration)
        elif action == "move_rel":
            pyautogui.moveRel(x or 0, y or 0, duration=duration)
        elif action == "click":
            pyautogui.click(x=x, y=y, clicks=clicks, button=button)
        elif action == "double_click":
            pyautogui.doubleClick(x=x, y=y, button=button)
        elif action == "right_click":
            pyautogui.rightClick(x=x, y=y)
        elif action == "drag_to":
            pyautogui.dragTo(x, y, duration=duration, button=button)
        elif action == "scroll":
            pyautogui.scroll(amount)
        else:
            raise HTTPException(status_code=400, detail="Unsupported mouse action")
    except Exception as exc:
        raise_if_pyautogui_failsafe(
            pyautogui,
            exc,
            f"mouse_{action}",
            {"x": x, "y": y, "button": button, "clicks": clicks, "amount": amount},
        )
        raise

    position = pyautogui.position()
    return {"action": f"mouse_{action}", "x": position.x, "y": position.y}


def keyboard_action(
    action: KeyboardAction,
    key: str | None = None,
    keys: list[str] | None = None,
    text: str | None = None,
    interval: float = 0,
) -> dict[str, Any]:
    """执行键盘动作，包括单键、组合键、输入文本、按下和释放。"""
    pyautogui = load_pyautogui()
    normalized_key = normalize_key_name(key) if key else None
    normalized_keys = normalize_key_list(keys)
    try:
        if action == "press":
            if not normalized_key:
                raise HTTPException(status_code=400, detail="key is required")
            pyautogui.press(normalized_key, interval=interval)
        elif action == "hotkey":
            if not normalized_keys:
                raise HTTPException(status_code=400, detail="keys are required")
            pyautogui.hotkey(*normalized_keys, interval=interval)
        elif action == "write":
            if text is None:
                raise HTTPException(status_code=400, detail="text is required")
            pyautogui.write(text, interval=interval)
        elif action == "key_down":
            if not normalized_key:
                raise HTTPException(status_code=400, detail="key is required")
            pyautogui.keyDown(normalized_key)
        elif action == "key_up":
            if not normalized_key:
                raise HTTPException(status_code=400, detail="key is required")
            pyautogui.keyUp(normalized_key)
        else:
            raise HTTPException(status_code=400, detail="Unsupported keyboard action")
    except Exception as exc:
        raise_if_pyautogui_failsafe(
            pyautogui,
            exc,
            f"keyboard_{action}",
            {"key": normalized_key, "keys": normalized_keys},
        )
        raise
    return {"action": f"keyboard_{action}", "key": normalized_key, "keys": normalized_keys}