// 示範教學: record the person doing a task on this Mac so a bot can learn the steps and do it
// again later. The original: 「錄下你執行任務的過程。{Bot} 會學習這些步驟，之後可以自行再次執行。」
// and 「{Bot} 正在觀看並學習」 (it records the screen with ffmpeg plus an input-event log; see
// local-exec-daemon saveRecordingDataPackage {inputEvents, displayWidth, apiWidth…}).
// Here a listen-only event tap collects clicks, keys and scrolls (nothing is blocked or changed),
// and they're written up as numbered steps with screenshot coordinates.

use serde::{Deserialize, Serialize};
use std::sync::Mutex;
use std::time::Instant;

/// Two clicks closer than this (and near each other) are a double click (estimated).
const DOUBLE_CLICK_MS: u128 = 400;
/// Scrolls closer than this are one step (estimated).
const SCROLL_MERGE_MS: u128 = 1500;

#[derive(Clone, Serialize, Deserialize, Debug, PartialEq)]
pub struct Demo {
    pub name: String,
    pub created: String,
    pub steps: Vec<String>,
    /// The screen recording (mp4), like the original's ffmpeg recording; empty when none.
    #[serde(default)]
    pub video: String,
    /// The screen at each step (a JPEG per step; empty when not captured).
    #[serde(default)]
    pub shots: Vec<String>,
}

#[derive(Clone, Debug)]
enum Raw {
    Click { x: f64, y: f64, right: bool, app: String, at: Instant },
    Key { text: String, code: i64, flags: u64, app: String },
    Scroll { dy: i64, app: String, at: Instant },
}

static EVENTS: Mutex<Vec<Raw>> = Mutex::new(Vec::new());
/// The frame number showing on screen when each event happened (same order as EVENTS).
static EVENT_FRAMES: Mutex<Vec<usize>> = Mutex::new(Vec::new());
static FRAMES: std::sync::atomic::AtomicUsize = std::sync::atomic::AtomicUsize::new(0);
static FRAME_STOP: std::sync::atomic::AtomicBool = std::sync::atomic::AtomicBool::new(false);
static FRAME_HANDLE: Mutex<Option<std::thread::JoinHandle<()>>> = Mutex::new(None);
static REC_DIR: Mutex<Option<std::path::PathBuf>> = Mutex::new(None);
/// Screen pictures per second while recording (estimated; the original records video).
pub const FRAMES_PER_SEC: u64 = 2;
/// Width of the recorded pictures (the original's render proxy is 1080p; smaller here).
pub const FRAME_WIDTH: u32 = 1280;
#[cfg_attr(not(target_os = "macos"), allow(dead_code))]
static RUNLOOP: Mutex<usize> = Mutex::new(0);
pub static RECORDING: Mutex<Option<(String, Instant)>> = Mutex::new(None);

pub fn recording() -> Option<(String, Instant)> {
    RECORDING.lock().unwrap().clone()
}

/// Start recording for a bot. Err when macOS hasn't allowed listening to input yet.
pub fn start(bot_name: &str) -> Result<(), String> {
    if RECORDING.lock().unwrap().is_some() {
        return Err("已經在錄了".into());
    }
    EVENTS.lock().unwrap().clear();
    EVENT_FRAMES.lock().unwrap().clear();
    // Zero the frame counter before the listener starts: events that arrive in the first
    // half second used to carry the *previous* recording's frame numbers (start_frames
    // cleared it only after mac::start), mapping steps to pictures from an old demo.
    FRAMES.store(0, std::sync::atomic::Ordering::SeqCst);
    mac::start()?;
    *RECORDING.lock().unwrap() = Some((bot_name.to_string(), Instant::now()));
    start_frames();
    Ok(())
}

fn demos_dir() -> std::path::PathBuf {
    crate::model::State::path().parent().map(|p| p.to_path_buf()).unwrap_or_else(std::env::temp_dir).join("demos")
}

/// Pictures of the screen while recording: frame_00000.jpg, frame_00001.jpg…
fn start_frames() {
    let dir = demos_dir().join(chrono::Local::now().format("%Y%m%d-%H%M%S").to_string());
    if std::fs::create_dir_all(&dir).is_err() {
        return;
    }
    *REC_DIR.lock().unwrap() = Some(dir.clone());
    FRAMES.store(0, std::sync::atomic::Ordering::SeqCst);
    FRAME_STOP.store(false, std::sync::atomic::Ordering::SeqCst);
    *FRAME_HANDLE.lock().unwrap() = Some(std::thread::spawn(move || {
        while !FRAME_STOP.load(std::sync::atomic::Ordering::SeqCst) {
            let t0 = Instant::now();
            if crate::computer::screen_supported() && crate::computer::screen_capture_ok() {
                if let Ok(img) = crate::computer::capture_screen() {
                    {
                        let (w, h) = img.dimensions();
                        let small = if w > FRAME_WIDTH { image::imageops::resize(&img, FRAME_WIDTH, (h as u64 * FRAME_WIDTH as u64 / w.max(1) as u64) as u32, image::imageops::FilterType::Triangle) } else { img };
                        let n = FRAMES.load(std::sync::atomic::Ordering::SeqCst);
                        if small.save(dir.join(format!("frame_{n:05}.jpg"))).is_ok() {
                            FRAMES.fetch_add(1, std::sync::atomic::Ordering::SeqCst);
                        }
                    }
                }
            }
            let wait = std::time::Duration::from_millis(1000 / FRAMES_PER_SEC);
            if let Some(rest) = wait.checked_sub(t0.elapsed()) {
                std::thread::sleep(rest);
            }
        }
    }));
}

/// Stop the pictures and turn them into a video when ffmpeg is there. Returns (dir, video).
fn stop_frames() -> Option<(std::path::PathBuf, String)> {
    FRAME_STOP.store(true, std::sync::atomic::Ordering::SeqCst);
    // Let the capturing thread finish its current picture and exit (it ends within a second).
    // The old fixed 700 ms sleep raced slow captures (dirty files after the video was made)
    // and froze the window for its whole duration.
    if let Some(h) = FRAME_HANDLE.lock().unwrap().take() {
        let _ = h.join();
    }
    let dir = REC_DIR.lock().unwrap().take()?;
    // Encoding runs off the window thread (ffmpeg on a long demo takes seconds; the window
    // used to freeze for all of it). The mp4 file appears when it is done.
    if dir.join("frame_00000.jpg").exists() {
        let d = dir.clone();
        std::thread::spawn(move || {
            if make_video(&d).is_some() {
                // The video holds the motion; drop the single pictures it consumed.
                if let Ok(rd) = std::fs::read_dir(&d) {
                    for e in rd.flatten() {
                        if e.file_name().to_string_lossy().starts_with("frame_") {
                            let _ = std::fs::remove_file(e.path());
                        }
                    }
                }
            }
        });
        return Some((dir.clone(), dir.join("recording.mp4").display().to_string()));
    }
    Some((dir, String::new()))
}

/// frame_*.jpg → recording.mp4 (H.264, like the original's render proxy).
pub fn make_video(dir: &std::path::Path) -> Option<String> {
    if !dir.join("frame_00000.jpg").exists() {
        return None;
    }
    let out = dir.join("recording.mp4");
    let ok = std::process::Command::new("ffmpeg")
        .env("PATH", crate::cloudbox::tool_path())
        .args(["-hide_banner", "-loglevel", "error", "-y", "-framerate", &FRAMES_PER_SEC.to_string(), "-i"])
        .arg(dir.join("frame_%05d.jpg"))
        .args(["-vf", "scale=trunc(iw/2)*2:trunc(ih/2)*2,format=yuv420p", "-c:v", "libx264", "-preset", "veryfast", "-movflags", "+faststart"])
        .arg(&out)
        .stdin(std::process::Stdio::null())
        .stdout(std::process::Stdio::null())
        .stderr(std::process::Stdio::null())
        .status()
        .map(|s| s.success())
        .unwrap_or(false);
    ok.then(|| out.display().to_string())
}

/// Stop and write up the steps.
pub fn finish(name: &str) -> Demo {
    mac::stop();
    // The listener stops asynchronously (the X11 one polls every 150 ms): give the last
    // events of the demo time to arrive — they used to be cut off the recording.
    std::thread::sleep(std::time::Duration::from_millis(300));
    *RECORDING.lock().unwrap() = None;
    let raw = std::mem::take(&mut *EVENTS.lock().unwrap());
    let frames_at = std::mem::take(&mut *EVENT_FRAMES.lock().unwrap());
    let compiled = compile(&raw, crate::computer::points_to_shot());
    let rec = stop_frames();
    let mut shots = vec![];
    let mut video = String::new();
    if let Some((dir, v)) = &rec {
        video = v.clone();
        for (i, (_, first)) in compiled.iter().enumerate() {
            // The picture just before the step happened (what the person was looking at).
            let f = frames_at.get(*first).copied().unwrap_or(0);
            let src = dir.join(format!("frame_{f:05}.jpg"));
            let dst = dir.join(format!("step_{:02}.jpg", i + 1));
            shots.push(if std::fs::copy(&src, &dst).is_ok() { dst.display().to_string() } else { String::new() });
        }
        // The frame pictures are removed by the encoder thread once the video is written.
    }
    Demo { name: name.trim().to_string(), created: chrono::Local::now().format("%Y-%m-%d %H:%M").to_string(), steps: compiled.into_iter().map(|c| c.0).collect(), video, shots }
}

pub fn cancel() {
    mac::stop();
    *RECORDING.lock().unwrap() = None;
    EVENTS.lock().unwrap().clear();
    EVENT_FRAMES.lock().unwrap().clear();
    if let Some((dir, _)) = stop_frames() {
        let _ = std::fs::remove_dir_all(dir);
    }
}

/// The view_demo_step tool: the screen at one step of a demonstration, for the bot to look at.
pub fn view_step_spec() -> serde_json::Value {
    serde_json::json!({"name": "view_demo_step", "description": "See what the person's screen looked like at one step of a demonstration they recorded for you (a picture), to find the right buttons when you repeat it.",
        "parameters": {"type": "object", "properties": {"demo": {"type": "string", "description": "The demonstration's name"}, "step": {"type": "integer", "description": "Step number, from 1"}}, "required": ["demo", "step"]}})
}

/// Returns (text, ok, picture as base64 JPEG).
pub fn view_step(demos: &[Demo], args: &str) -> (String, bool, Option<String>) {
    use base64::Engine;
    let v: serde_json::Value = serde_json::from_str(args).unwrap_or_default();
    let name = v["demo"].as_str().unwrap_or("").trim();
    let Some(d) = demos.iter().find(|d| d.name == name).or_else(|| demos.iter().find(|d| d.name.contains(name) && !name.is_empty())) else {
        return (format!("沒有叫「{name}」的示範。有：{}", demos.iter().map(|d| d.name.as_str()).collect::<Vec<_>>().join("、")), false, None);
    };
    let n = v["step"].as_u64().unwrap_or(0) as usize;
    if n == 0 || n > d.steps.len() {
        return (format!("「{}」有 {} 個步驟，請給 1 到 {}。", d.name, d.steps.len(), d.steps.len()), false, None);
    }
    let text = format!("「{}」第 {n} 步：{}", d.name, d.steps[n - 1]);
    let Some(path) = d.shots.get(n - 1).filter(|p| !p.is_empty()) else {
        return (format!("{text}\n（這一步沒有存到畫面）"), true, None);
    };
    match std::fs::read(path).ok().and_then(|b| image::load_from_memory(&b).ok()) {
        Some(img) => {
            let img = img.to_rgb8();
            let (w, h) = img.dimensions();
            let (fw, fh, resize) = crate::computer::fit(w, h);
            let img = if resize { image::imageops::resize(&img, fw, fh, image::imageops::FilterType::Triangle) } else { img };
            match crate::computer::encode_jpeg(&img) {
                Some(j) => (format!("{text}\n這是使用者做這一步之前的畫面（{fw}×{fh}，座標和步驟裡的一樣）。"), true, Some(base64::engine::general_purpose::STANDARD.encode(j))),
                None => (format!("{text}\n（畫面太大，沒辦法送出）"), true, None),
            }
        }
        None => (format!("{text}\n（畫面檔案不見了）"), true, None),
    }
}

fn key_name(code: i64) -> Option<&'static str> {
    Some(match code {
        36 => "return",
        48 => "tab",
        49 => "space",
        51 => "delete",
        53 => "escape",
        117 => "forwarddelete",
        123 => "left",
        124 => "right",
        125 => "down",
        126 => "up",
        115 => "home",
        119 => "end",
        116 => "pageup",
        121 => "pagedown",
        _ => return None,
    })
}

const CMD: u64 = 1 << 20;
const SHIFT: u64 = 1 << 17;
const CTRL: u64 = 1 << 18;
const OPT: u64 = 1 << 19;

/// Raw events → steps a bot can follow.
fn compile(raw: &[Raw], to_shot: f64) -> Vec<(String, usize)> {
    let mut steps: Vec<(String, usize)> = vec![];
    let mut typed_from = 0usize;
    let mut typed = String::new();
    let mut typed_app = String::new();
    let mut last_app = String::new();
    let flush = |steps: &mut Vec<(String, usize)>, typed: &mut String, app: &str, from: usize| {
        if !typed.is_empty() {
            steps.push((format!("在「{app}」輸入「{typed}」"), from));
            typed.clear();
        }
    };
    let mut i = 0;
    while i < raw.len() {
        match &raw[i] {
            Raw::Click { x, y, right, app, at } => {
                flush(&mut steps, &mut typed, &typed_app, typed_from);
                let start = i;
                let mut count = 1;
                while let Some(Raw::Click { x: x2, y: y2, right: r2, at: t2, .. }) = raw.get(i + 1) {
                    if r2 == right && (x2 - x).abs() < 6.0 && (y2 - y).abs() < 6.0 && t2.duration_since(*at).as_millis() < DOUBLE_CLICK_MS * count as u128 {
                        count += 1;
                        i += 1;
                    } else {
                        break;
                    }
                }
                let verb = match (right, count) {
                    (true, _) => "按右鍵".to_string(),
                    (false, 1) => "點".to_string(),
                    (false, n) => format!("連點 {n} 下"),
                };
                let switch = if *app != last_app && !app.is_empty() { format!("切到「{app}」，") } else { String::new() };
                steps.push((format!("{switch}在「{app}」{verb} ({:.0}, {:.0})", x * to_shot, y * to_shot), start));
                last_app = app.clone();
            }
            Raw::Key { text, code, flags, app } => {
                let mods: Vec<&str> = [(CMD, "cmd"), (CTRL, "control"), (OPT, "option")].iter().filter(|(f, _)| flags & f != 0).map(|(_, n)| *n).collect();
                if mods.is_empty() && *code == 51 && !typed.is_empty() {
                    typed.pop();
                } else if mods.is_empty() && key_name(*code).is_none() && !text.is_empty() && !text.chars().any(char::is_control) {
                    if typed.is_empty() {
                        typed_app = app.clone();
                        typed_from = i;
                    }
                    typed.push_str(text);
                } else {
                    flush(&mut steps, &mut typed, &typed_app, typed_from);
                    let key = key_name(*code).map(String::from).unwrap_or_else(|| text.to_lowercase());
                    if key.is_empty() {
                        i += 1;
                        continue;
                    }
                    let mut combo: Vec<String> = mods.iter().map(|m| m.to_string()).collect();
                    if flags & SHIFT != 0 && !mods.is_empty() {
                        combo.push("shift".into());
                    }
                    combo.push(key);
                    steps.push((format!("按 {}", combo.join("+")), i));
                }
                last_app = app.clone();
            }
            Raw::Scroll { dy, app, at } => {
                flush(&mut steps, &mut typed, &typed_app, typed_from);
                let start = i;
                let mut total = *dy;
                let mut last = *at;
                while let Some(Raw::Scroll { dy: d2, at: t2, .. }) = raw.get(i + 1) {
                    if t2.duration_since(last).as_millis() < SCROLL_MERGE_MS && d2.signum() == dy.signum() {
                        total += d2;
                        last = *t2;
                        i += 1;
                    } else {
                        break;
                    }
                }
                steps.push((format!("在「{app}」往{}捲動", if total < 0 { "下" } else { "上" }), start));
            }
        }
        i += 1;
    }
    flush(&mut steps, &mut typed, &typed_app, typed_from);
    steps
}

/// The steps as told to the bot.
pub fn prompt_section(demos: &[Demo]) -> String {
    if demos.is_empty() {
        return String::new();
    }
    let mut s = String::from("\n\n你學過的示範（使用者在他的 Mac 上做給你看的步驟）。使用者要你做同樣的事時，照著在「你的電腦」上做：開始先截圖一次，之後每一步做完都會附上新畫面，座標是錄製時截圖上的位置，畫面不同就找對應的按鈕；輸入的內容可以依新的需求調整。想看某一步當時的畫面，用 view_demo_step。");
    for d in demos {
        s.push_str(&format!("\n### {}（{}）\n", d.name, d.created));
        for (i, st) in d.steps.iter().enumerate() {
            s.push_str(&format!("{}. {st}\n", i + 1));
        }
    }
    s
}

fn push(e: Raw) {
    // AnyBot's own window (its Stop button, the bar) isn't part of the task.
    let own = match &e {
        Raw::Click { app, .. } | Raw::Key { app, .. } | Raw::Scroll { app, .. } => app.to_lowercase().contains("anybot"),
    };
    if !own {
        EVENTS.lock().unwrap().push(e);
        // The last picture taken before this moment.
        EVENT_FRAMES.lock().unwrap().push(FRAMES.load(std::sync::atomic::Ordering::SeqCst).saturating_sub(1));
    }
}

#[cfg(target_os = "macos")]
mod mac {
    use super::*;
    use std::ffi::c_void;

    #[repr(C)]
    #[derive(Clone, Copy)]
    struct CGPoint {
        x: f64,
        y: f64,
    }
    type Cb = extern "C" fn(*mut c_void, u32, *mut c_void, *mut c_void) -> *mut c_void;

    #[link(name = "CoreGraphics", kind = "framework")]
    extern "C" {
        fn CGEventTapCreate(tap: u32, place: u32, options: u32, mask: u64, cb: Cb, user: *mut c_void) -> *mut c_void;
        fn CGEventTapEnable(tap: *mut c_void, enable: bool);
        fn CGEventGetLocation(e: *mut c_void) -> CGPoint;
        fn CGEventGetFlags(e: *mut c_void) -> u64;
        fn CGEventGetIntegerValueField(e: *mut c_void, field: u32) -> i64;
        fn CGEventKeyboardGetUnicodeString(e: *mut c_void, max: usize, actual: *mut usize, buf: *mut u16);
    }
    #[link(name = "CoreFoundation", kind = "framework")]
    extern "C" {
        fn CFMachPortCreateRunLoopSource(alloc: *const c_void, port: *mut c_void, order: isize) -> *mut c_void;
        fn CFRunLoopGetCurrent() -> *mut c_void;
        fn CFRunLoopAddSource(rl: *mut c_void, src: *mut c_void, mode: *const c_void);
        fn CFRunLoopRun();
        fn CFRunLoopStop(rl: *mut c_void);
        static kCFRunLoopCommonModes: *const c_void;
    }

    static TAP: Mutex<usize> = Mutex::new(0);
    // The foreground app barely moves between keystrokes, and the window-list query is the
    // slowest call in the tap callback — slow callbacks make macOS disable the tap (events
    // lost until it is re-enabled). Answer keystrokes from a short cache.
    static FRONT_CACHE: Mutex<Option<(Instant, String)>> = Mutex::new(None);
    fn front_cached() -> String {
        let mut c = FRONT_CACHE.lock().unwrap_or_else(|e| e.into_inner());
        if let Some((t, n)) = c.as_ref() {
            if t.elapsed() < std::time::Duration::from_millis(400) {
                return n.clone();
            }
        }
        let n = crate::computer::frontmost_app().unwrap_or_default();
        *c = Some((Instant::now(), n.clone()));
        n
    }

    extern "C" fn callback(_proxy: *mut c_void, kind: u32, e: *mut c_void, _user: *mut c_void) -> *mut c_void {
        unsafe {
            match kind {
                1 | 3 => {
                    let p = CGEventGetLocation(e);
                    let app = crate::computer::app_at_point(p.x, p.y).unwrap_or_default();
                    push(Raw::Click { x: p.x, y: p.y, right: kind == 3, app, at: Instant::now() });
                }
                10 => {
                    let mut buf = [0u16; 8];
                    let mut n = 0usize;
                    CGEventKeyboardGetUnicodeString(e, buf.len(), &mut n, buf.as_mut_ptr());
                    let text = String::from_utf16_lossy(&buf[..n.min(buf.len())]);
                    let code = CGEventGetIntegerValueField(e, 9);
                    let app = front_cached();
                    push(Raw::Key { text, code, flags: CGEventGetFlags(e), app });
                }
                22 => {
                    let dy = CGEventGetIntegerValueField(e, 11);
                    if dy != 0 {
                        let p = CGEventGetLocation(e);
                        let app = crate::computer::app_at_point(p.x, p.y).unwrap_or_default();
                        push(Raw::Scroll { dy, app, at: Instant::now() });
                    }
                }
                // The system turned the tap off (slow callback): turn it back on.
                0xFFFF_FFFE | 0xFFFF_FFFF => {
                    let t = *TAP.lock().unwrap();
                    if t != 0 {
                        CGEventTapEnable(t as *mut c_void, true);
                    }
                }
                _ => {}
            }
        }
        e
    }

    pub fn start() -> Result<(), String> {
        let (tx, rx) = std::sync::mpsc::channel();
        std::thread::spawn(move || unsafe {
            let mask: u64 = (1 << 1) | (1 << 3) | (1 << 10) | (1 << 22);
            // kCGSessionEventTap, head insert, listen only.
            let tap = CGEventTapCreate(1, 0, 1, mask, callback, std::ptr::null_mut());
            if tap.is_null() {
                let _ = tx.send(false);
                return;
            }
            *TAP.lock().unwrap() = tap as usize;
            let src = CFMachPortCreateRunLoopSource(std::ptr::null(), tap, 0);
            let rl = CFRunLoopGetCurrent();
            CFRunLoopAddSource(rl, src, kCFRunLoopCommonModes);
            CGEventTapEnable(tap, true);
            *RUNLOOP.lock().unwrap() = rl as usize;
            let _ = tx.send(true);
            CFRunLoopRun();
            CGEventTapEnable(tap, false);
            *TAP.lock().unwrap() = 0;
        });
        match rx.recv_timeout(std::time::Duration::from_secs(3)) {
            Ok(true) => Ok(()),
            _ => {
                let _ = crate::computer::spawn_reaped(&mut std::process::Command::new("open").arg("x-apple.systempreferences:com.apple.preference.security?Privacy_ListenEvent"));
                Err("macOS 還沒讓 AnyBot 觀看你的操作。我已經打開「系統設定 → 隱私權與安全性 → 輸入監控」：把 AnyBot（或「終端機」）打開，再按一次「開始錄製」。".into())
            }
        }
    }

    pub fn stop() {
        let rl = std::mem::take(&mut *RUNLOOP.lock().unwrap());
        if rl != 0 {
            unsafe { CFRunLoopStop(rl as *mut c_void) };
        }
    }
}

/// Linux: the X RECORD extension shows every click and key (nothing is blocked or changed).
#[cfg(target_os = "linux")]
mod mac {
    use super::*;
    use std::sync::atomic::{AtomicBool, Ordering};

    static STOP: AtomicBool = AtomicBool::new(false);

    pub fn start() -> Result<(), String> {
        if crate::desk::kind() != crate::desk::Kind::X11 {
            return Err(if crate::desk::wayland() {
                "在 Wayland 上，系統不讓 App 看到你按了哪裡、打了什麼，所以沒辦法錄製示範（Bot 還是可以操作畫面）。要錄示範，請在登入畫面改選 Xorg 工作階段。"
            } else {
                "錄製示範需要桌面畫面（X11）。"
            }
            .into());
        }
        STOP.store(false, Ordering::SeqCst);
        let (tx, rx) = std::sync::mpsc::channel();
        std::thread::spawn(move || {
            let tx2 = tx.clone();
            let r = crate::x11::record(
                |input| push(to_raw(input)),
                move || {
                    let _ = tx2.send(Ok(()));
                    !STOP.load(Ordering::SeqCst)
                },
            );
            if let Err(e) = r {
                let _ = tx.send(Err(e));
            }
        });
        // On a timeout the record thread may still be spinning up: close the gate so its
        // keep_going() ends it — a thread left running meant a second RECORD context
        // (double events) on the next try, plus a leaked X connection.
        match rx.recv_timeout(std::time::Duration::from_secs(3)) {
            Ok(Ok(())) => Ok(()),
            Ok(Err(e)) => Err(e),
            Err(_) => {
                STOP.store(true, Ordering::SeqCst);
                Err("沒辦法開始錄製（X11 沒有回應）".into())
            }
        }
    }

    /// X input → the same events the macOS tap gives (key codes and flags in macOS terms, so
    /// the steps read the same; Linux's Ctrl shows as "control").
    pub fn to_raw(i: crate::x11::Input) -> Raw {
        let app = |x: f64, y: f64| crate::x11::window_at(x, y).map(|a| a.0).or_else(|| crate::x11::front_app().map(|a| a.0)).unwrap_or_default();
        match i {
            crate::x11::Input::Click { x, y, right } => Raw::Click { x, y, right, app: app(x, y), at: Instant::now() },
            crate::x11::Input::Scroll { dy } => Raw::Scroll { dy, app: crate::x11::front_app().map(|a| a.0).unwrap_or_default(), at: Instant::now() },
            crate::x11::Input::Key { text, keysym, mods } => {
                let code = crate::x11::keysym_name(keysym)
                    .and_then(crate::computer::key_code)
                    .or_else(|| crate::x11::char_of_keysym(keysym).and_then(|c| crate::computer::key_code(&c.to_lowercase().to_string())))
                    .map(|c| c as i64)
                    .unwrap_or(-1);
                let mut flags = 0;
                if mods & 1 != 0 {
                    flags |= SHIFT;
                }
                if mods & 4 != 0 {
                    flags |= CTRL;
                }
                if mods & 8 != 0 {
                    flags |= OPT;
                }
                if mods & 64 != 0 {
                    flags |= CMD;
                }
                let text = if keysym == 0xff0d { "\r".into() } else { text };
                Raw::Key { text, code, flags, app: crate::x11::front_app().map(|a| a.0).unwrap_or_default() }
            }
        }
    }

    pub fn stop() {
        STOP.store(true, Ordering::SeqCst);
    }
}

#[cfg(not(any(target_os = "macos", target_os = "linux")))]
mod mac {
    pub fn start() -> Result<(), String> {
        Err("這個系統還不能錄製示範".into())
    }
    pub fn stop() {}
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn frames_become_a_video() {
        let dir = std::env::temp_dir().join(format!("anybot-demo-test-{}", std::process::id()));
        std::fs::create_dir_all(&dir).unwrap();
        for i in 0..4u8 {
            image::RgbImage::from_pixel(64, 40, image::Rgb([i * 60, 100, 200])).save(dir.join(format!("frame_{i:05}.jpg"))).unwrap();
        }
        let v = make_video(&dir);
        if std::process::Command::new("ffmpeg").env("PATH", crate::cloudbox::tool_path()).arg("-version").output().is_ok() {
            let v = v.expect("video made");
            assert!(std::fs::metadata(&v).unwrap().len() > 0);
        }
        let demo = Demo { name: "報表".into(), created: String::new(), steps: vec!["點 (1, 2)".into()], video: String::new(), shots: vec![dir.join("frame_00002.jpg").display().to_string()] };
        let (t, ok, img) = view_step(&[demo.clone()], r#"{"demo":"報表","step":1}"#);
        assert!(ok && img.is_some() && t.contains("第 1 步"), "{t}");
        assert!(!view_step(&[demo], r#"{"demo":"報表","step":5}"#).1);
        let _ = std::fs::remove_dir_all(&dir);
    }

    #[test]
    fn steps_read_like_instructions() {
        let t0 = Instant::now();
        let ms = |n: u64| t0 + std::time::Duration::from_millis(n);
        let raw = vec![
            Raw::Click { x: 100.0, y: 50.0, right: false, app: "Safari".into(), at: ms(0) },
            Raw::Key { text: "h".into(), code: 4, flags: 0, app: "Safari".into() },
            Raw::Key { text: "i".into(), code: 34, flags: 0, app: "Safari".into() },
            Raw::Key { text: "x".into(), code: 7, flags: 0, app: "Safari".into() },
            Raw::Key { text: "".into(), code: 51, flags: 0, app: "Safari".into() },
            Raw::Key { text: "\r".into(), code: 36, flags: 0, app: "Safari".into() },
            Raw::Key { text: "c".into(), code: 8, flags: CMD, app: "Safari".into() },
            Raw::Click { x: 300.0, y: 200.0, right: false, app: "備忘錄".into(), at: ms(2000) },
            Raw::Click { x: 301.0, y: 201.0, right: false, app: "備忘錄".into(), at: ms(2200) },
            Raw::Scroll { dy: -3, app: "備忘錄".into(), at: ms(3000) },
            Raw::Scroll { dy: -2, app: "備忘錄".into(), at: ms(3300) },
        ];
        let s: Vec<String> = compile(&raw, 0.5).into_iter().map(|c| c.0).collect();
        assert_eq!(
            s,
            vec![
                "切到「Safari」，在「Safari」點 (50, 25)",
                "在「Safari」輸入「hi」",
                "按 return",
                "按 cmd+c",
                "切到「備忘錄」，在「備忘錄」連點 2 下 (150, 100)",
                "在「備忘錄」往下捲動",
            ]
        );
    }
}