//! 3b 桌面验收：相对鼠标（协议 v4）的像素级闭环。
//!
//! 为什么必须单独写一个 proof：V-B1 的判据是「位移**恰好**等于请求值」，
//! 而 Android 侧的真机脚本只能看到 UI 文本，看不到远端指针实际走了多少像素。
//! 这里直接走完整链路：viewer-core 发 `MouseMoveRel` → QUIC → agent 注入 →
//! `GetCursorPos` 读回，逐项比对。
//!
//! 覆盖判据：
//! - V-B1a 方向与量值：dx=+50 → +50px，dx=-50 → -50px（误差 ≤1px）
//! - V-B1b 慢速不丢位移：连发 20 次 dx=+1 → 累计 +20px（误差 ≤2px）
//! - V-B1c 撞边不积债：右边界 +200 后 -50 → 立即 -50
//!
//! 用法（agent 需已启动）：
//!   cargo run --release -p viewer-core --example rel_mouse_proof -- --host 127.0.0.1 --port 47800 --code t
//!
//! 安全：运行前记录光标原位，结束时还原（不污染用户桌面状态）。

use std::time::Duration;
use viewer_core::{ConnectConfig, Session};

fn arg(name: &str) -> Option<String> {
    let a: Vec<String> = std::env::args().collect();
    a.iter()
        .position(|x| x == name)
        .and_then(|i| a.get(i + 1))
        .cloned()
}

/// 读当前光标（物理像素）。用 windows crate 而不是 shell，避免进程 DPI 差异。
fn cursor() -> (i32, i32) {
    use windows::Win32::Foundation::POINT;
    use windows::Win32::UI::WindowsAndMessaging::GetCursorPos;
    let mut p = POINT::default();
    unsafe {
        let _ = GetCursorPos(&mut p);
    }
    (p.x, p.y)
}

fn set_cursor(x: i32, y: i32) {
    use windows::Win32::UI::WindowsAndMessaging::SetCursorPos;
    unsafe {
        let _ = SetCursorPos(x, y);
    }
}

fn screen_size() -> (i32, i32) {
    use windows::Win32::UI::WindowsAndMessaging::{GetSystemMetrics, SM_CXSCREEN, SM_CYSCREEN};
    unsafe { (GetSystemMetrics(SM_CXSCREEN), GetSystemMetrics(SM_CYSCREEN)) }
}

fn enable_dpi_awareness() {
    use windows::Win32::UI::HiDpi::{
        SetProcessDpiAwarenessContext, DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2,
    };
    unsafe {
        let _ = SetProcessDpiAwarenessContext(DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2);
    }
}

/// 发一串相对增量，每次之间留出注入完成的时间，然后读回光标。
fn apply_rel(session: &Session, steps: &[(i16, i16)], settle_ms: u64) {
    for &(dx, dy) in steps {
        session.send_mouse_rel(dx, dy);
        // 让 QUIC 上行 + agent 注入 + 光标更新都完成；太小会读到中间态
        std::thread::sleep(Duration::from_millis(settle_ms));
    }
}

#[tokio::main]
async fn main() -> anyhow::Result<()> {
    enable_dpi_awareness();
    let port: u16 = arg("--port").map(|s| s.parse()).transpose()?.unwrap_or(47800);
    let code = arg("--code").unwrap_or_else(|| "t".into());
    let host = arg("--host").unwrap_or_else(|| "127.0.0.1".into());

    let (sw, sh) = screen_size();
    println!("[proof] screen {sw}x{sh} (physical, DPI-aware)");

    let session = Session::connect(ConnectConfig::direct(&host, port, code)).await?;
    let (dw, dh) = session.desktop_size();
    println!("[proof] agent desktop {dw}x{dh}");

    // 记录原位，结束时还原（不污染桌面状态）
    let (ox, oy) = cursor();
    println!("[proof] cursor origin ({ox},{oy})");

    let mut failures = 0usize;

    // ---- V-B1a 方向与量值 ----
    println!("\n=== V-B1a direction & magnitude ===");
    for &delta in &[50i16, -50i16, 120i16, -120i16] {
        // 每次都从屏幕中心出发，避免被边界 clamp 干扰量值判定
        set_cursor(sw / 2, sh / 2);
        std::thread::sleep(Duration::from_millis(60));
        let (bx, _) = cursor();
        apply_rel(&session, &[(delta, 0)], 80);
        let (ax, _) = cursor();
        let applied = ax - bx;
        let ok = (applied - delta as i32).abs() <= 1;
        println!(
            "  dx={delta:+5}  from x={bx:4} to x={ax:4}  applied={applied:+5}  {}",
            if ok { "PASS" } else { "FAIL" }
        );
        if !ok {
            failures += 1;
        }
    }

    // 纵向同理（同一套代码路径，但轴不同，clamp 上界不同）
    for &delta in &[40i16, -40i16] {
        set_cursor(sw / 2, sh / 2);
        std::thread::sleep(Duration::from_millis(60));
        let (_, by) = cursor();
        apply_rel(&session, &[(0, delta)], 80);
        let (_, ay) = cursor();
        let applied = ay - by;
        let ok = (applied - delta as i32).abs() <= 1;
        println!(
            "  dy={delta:+5}  from y={by:4} to y={ay:4}  applied={applied:+5}  {}",
            if ok { "PASS" } else { "FAIL" }
        );
        if !ok {
            failures += 1;
        }
    }

    // ---- V-B1b 慢速小幅不丢位移 ----
    println!("\n=== V-B1b slow small steps must not be lost ===");
    {
        set_cursor(sw / 2, sh / 2);
        std::thread::sleep(Duration::from_millis(60));
        let (bx, _) = cursor();
        // 20 次 dx=+1：若注入层按 mickey 透传，dx=1 会被加速吞成 0 像素（实测如此）
        let steps: Vec<(i16, i16)> = (0..20).map(|_| (1i16, 0i16)).collect();
        apply_rel(&session, &steps, 45);
        std::thread::sleep(Duration::from_millis(120));
        let (ax, _) = cursor();
        let applied = ax - bx;
        let ok = (applied - 20).abs() <= 2;
        println!("  20 x dx=+1  from x={bx} to x={ax}  applied={applied:+}  (expect +20)  {}",
            if ok { "PASS" } else { "FAIL" });
        if !ok {
            failures += 1;
        }
    }

    // ---- V-B1c 撞边不积债 ----
    println!("\n=== V-B1c edge clamp leaves no step debt ===");
    {
        set_cursor(sw - 1, sh / 2);
        std::thread::sleep(Duration::from_millis(60));
        let (bx, _) = cursor();
        apply_rel(&session, &[(200, 0)], 80);
        let (mx, _) = cursor();
        let clamped = mx - bx;
        // 回滑必须立即生效（若累积器"记住"了被 clamp 丢掉的 200px，这里会先空转）
        apply_rel(&session, &[(-50, 0)], 80);
        let (ax, _) = cursor();
        let back = ax - mx;
        let ok = clamped == 0 && (back + 50).abs() <= 1;
        println!(
            "  at right edge x={bx}: +200 -> applied {clamped:+} (clamped); -50 -> applied {back:+}  {}",
            if ok { "PASS" } else { "FAIL" }
        );
        if !ok {
            failures += 1;
        }
    }

    // 还原光标
    set_cursor(ox, oy);

    println!("\n========== RESULT ==========");
    if failures == 0 {
        println!("REL MOUSE PROOF PASS (all V-B1a/b/c checks)");
    } else {
        println!("REL MOUSE PROOF FAIL ({failures} checks failed)");
    }
    session.close().await;
    if failures > 0 {
        std::process::exit(1);
    }
    Ok(())
}