use std::os::windows::ffi::OsStrExt;
use std::{env, mem::size_of, path::Path, ptr::null_mut};

use std::ffi::{OsStr, OsString};
use tracing::error;
use windows_sys::Win32::UI::Shell::{SHELLEXECUTEINFOW, ShellExecuteExW};

use windows_sys::Win32::Foundation::CloseHandle;
use windows_sys::{
    Win32::{
        Foundation::{FALSE, TRUE},
        System::{
            Com::{COINIT_APARTMENTTHREADED, COINIT_DISABLE_OLE1DDE, CoInitializeEx},
            Console::{
                CTRL_BREAK_EVENT, CTRL_C_EVENT, CTRL_CLOSE_EVENT, CTRL_LOGOFF_EVENT,
                CTRL_SHUTDOWN_EVENT, SetConsoleCtrlHandler,
            },
            Threading::{GetExitCodeProcess, INFINITE, WaitForSingleObject},
        },
        UI::{
            Shell::{SEE_MASK_NOASYNC, SEE_MASK_NOCLOSEPROCESS},
            WindowsAndMessaging::SW_NORMAL,
        },
    },
    core::BOOL,
};

pub const EXIT_FAILED_LOAD_SHIM: i32 = 1;
pub const EXIT_FAILED_SPAWN_PROG: i32 = 2;
pub const EXIT_FAILED_WAIT_PROG: i32 = 3;
pub const EXIT_PROG_TERMINATED: i32 = 4;

pub const ERROR_ELEVATION_REQUIRED: i32 = 740;

unsafe extern "system" fn console_ctrl_handler(evt: u32) -> BOOL {
    match evt {
        CTRL_C_EVENT => TRUE,        //eprintln!("ctrl_c handled!"),
        CTRL_BREAK_EVENT => TRUE,    //eprintln!("ctrl_break handled!"),
        CTRL_CLOSE_EVENT => TRUE,    //eprintln!("ctrl_close handled!"),
        CTRL_LOGOFF_EVENT => TRUE,   //eprintln!("ctrl_logoff handled!"),
        CTRL_SHUTDOWN_EVENT => TRUE, //eprintln!("ctrl_shutdown handled!"),
        other => {
            error!("未知的系统事件编号: {}，未处理！", other);
            FALSE
        }
    }
}

pub fn set_console_ctrl_handler() {
    let res: BOOL = unsafe { SetConsoleCtrlHandler(Some(console_ctrl_handler), TRUE) };
    if res == FALSE {
        error!("警告: 注册控制台中断事件处理器失败。");
    }
}

fn to_wide_null(s: impl AsRef<OsStr>) -> Vec<u16> {
    s.as_ref().encode_wide().chain(std::iter::once(0)).collect()
}

pub fn execute_elevated(
    program: &Path,
    args: &[OsString],
    env_vars: Option<&std::collections::HashMap<String, OsString>>,
) -> i32 {
    // 若提权启动，在此处将环境变量设置给当前进程（即将弹窗 UAC 的进程，随后会被子进程继承）
    if let Some(env_map) = env_vars {
        for (k, v) in env_map {
            unsafe {
                env::set_var(k, v);
            }
        }
    }
    // 2. 将参数列表按 Windows 命令行规则拼装为单个命令行字符串
    let mut arguments_os = OsString::new();
    for (i, arg) in args.iter().enumerate() {
        if i > 0 {
            arguments_os.push(" ");
        }
        let arg_str = arg.to_string_lossy();
        if arg_str.is_empty() {
            arguments_os.push("\"\"");
        } else if !arg_str.contains([' ', '\t', '"']) {
            arguments_os.push(arg);
        } else {
            // 包含空格或引号时进行标准转义包裹
            arguments_os.push("\"");
            for c in arg_str.chars() {
                match c {
                    '\\' => arguments_os.push("\\\\"),
                    '"' => arguments_os.push("\\\""),
                    _ => arguments_os.push(c.to_string()),
                }
            }
            arguments_os.push("\"");
        }
    }

    // 3. 准备 Windows 宽字符参数
    let runas = to_wide_null("runas");
    let program_wide = to_wide_null(program.as_os_str());
    let arguments_wide = to_wide_null(&arguments_os);

    let mut info = SHELLEXECUTEINFOW {
        cbSize: size_of::<SHELLEXECUTEINFOW>() as u32,
        fMask: SEE_MASK_NOASYNC | SEE_MASK_NOCLOSEPROCESS,
        hwnd: null_mut(),
        lpVerb: runas.as_ptr(),
        lpFile: program_wide.as_ptr(),
        lpParameters: arguments_wide.as_ptr(),
        lpDirectory: null_mut(),
        nShow: SW_NORMAL as i32,
        hInstApp: null_mut(),
        lpIDList: null_mut(),
        lpClass: null_mut(),
        hkeyClass: null_mut(),
        dwHotKey: 0,
        Anonymous: unsafe { std::mem::zeroed() },
        hProcess: null_mut(),
    };
    // let arguments = CString::new(&arguments[..]).unwrap();
    // let mut info = SHELLEXECUTEINFOA::default();
    // info.cbSize = size_of::<SHELLEXECUTEINFOA>() as u32;
    // info.fMask = SEE_MASK_NOASYNC | SEE_MASK_NOCLOSEPROCESS;
    // info.lpVerb = runas.as_ptr().cast::<u8>();
    // info.lpFile = program.as_ptr().cast::<u8>();
    // info.lpParameters = arguments.as_ptr().cast::<u8>();
    // info.nShow = SW_NORMAL;
    let res = unsafe {
        CoInitializeEx(
            null_mut(),
            (COINIT_APARTMENTTHREADED | COINIT_DISABLE_OLE1DDE) as u32,
        );
        // ShellExecuteExA(&mut info as *mut _)
        ShellExecuteExW(&mut info)
    };
    if res == FALSE || info.hProcess == null_mut() {
        return EXIT_FAILED_SPAWN_PROG;
    }
    // 5. 等待提权子进程执行结束并获取退出状态码
    let mut exit_code: u32 = 0;
    unsafe {
        WaitForSingleObject(info.hProcess, INFINITE);
        let ok = GetExitCodeProcess(info.hProcess, &mut exit_code);
        CloseHandle(info.hProcess); // 释放进程句柄，防止资源泄露

        if ok == FALSE {
            return EXIT_FAILED_WAIT_PROG;
        }
    }

    exit_code as i32
}