/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at https://mozilla.org/MPL/2.0/. */

use std::fs::File;
use std::io::Write;
use std::rc::Rc;
use std::time::Duration;
use std::{env, thread};

use arboard::Clipboard;
use euclid::{Point2D, Vector2D};
use keyboard_types::{Key, KeyboardEvent, Modifiers, ShortcutMatcher};
use log::{debug, error, info, trace, warn};
use servo::compositing::windowing::{EmbedderEvent, WebRenderDebugOption};
use servo::embedder_traits::{
    CompositorEventVariant, ContextMenuResult, EmbedderMsg, FilterPattern, PermissionPrompt,
    PermissionRequest, PromptDefinition, PromptOrigin, PromptResult,
};
use servo::msg::constellation_msg::{TopLevelBrowsingContextId as BrowserId, TraversalDirection};
use servo::script_traits::TouchEventType;
use servo::servo_config::opts;
use servo::servo_url::ServoUrl;
use servo::webrender_api::ScrollLocation;
use tinyfiledialogs::{self, MessageBoxIcon, OkCancel, YesNo};

use crate::keyutils::{CMD_OR_ALT, CMD_OR_CONTROL};
use crate::parser::location_bar_input_to_url;
use crate::window_trait::{WindowPortsMethods, LINE_HEIGHT};

pub struct Browser<Window: WindowPortsMethods + ?Sized> {
    current_url: Option<ServoUrl>,
    current_url_string: Option<String>,

    /// id of the top level browsing context. It is unique as tabs
    /// are not supported yet. None until created.
    browser_id: Option<BrowserId>,

    // A rudimentary stack of "tabs".
    // EmbedderMsg::BrowserCreated will push onto it.
    // EmbedderMsg::CloseBrowser will pop from it,
    // and exit if it is empty afterwards.
    browsers: Vec<BrowserId>,

    title: Option<String>,

    window: Rc<Window>,
    event_queue: Vec<EmbedderEvent>,
    clipboard: Option<Clipboard>,
    shutdown_requested: bool,
}

pub struct ServoEventResponse {
    pub need_present: bool,
    pub history_changed: bool,
}

impl<Window> Browser<Window>
where
    Window: WindowPortsMethods + ?Sized,
{
    pub fn new(window: Rc<Window>) -> Browser<Window> {
        Browser {
            title: None,
            current_url: None,
            current_url_string: None,
            browser_id: None,
            browsers: Vec::new(),
            window,
            clipboard: match Clipboard::new() {
                Ok(c) => Some(c),
                Err(e) => {
                    warn!("Error creating clipboard context ({})", e);
                    None
                },
            },
            event_queue: Vec::new(),
            shutdown_requested: false,
        }
    }

    pub fn browser_id(&self) -> Option<BrowserId> {
        self.browser_id
    }

    pub fn current_url_string(&self) -> Option<&str> {
        self.current_url_string.as_deref()
    }

    pub fn get_events(&mut self) -> Vec<EmbedderEvent> {
        std::mem::take(&mut self.event_queue)
    }

    pub fn handle_window_events(&mut self, events: Vec<EmbedderEvent>) {
        for event in events {
            trace!("embedder <- window EmbedderEvent {:?}", event);
            match event {
                EmbedderEvent::Keyboard(key_event) => {
                    self.handle_key_from_window(key_event);
                },
                event => {
                    self.event_queue.push(event);
                },
            }
        }
    }

    pub fn shutdown_requested(&self) -> bool {
        self.shutdown_requested
    }

    /// Handle key events before sending them to Servo.
    fn handle_key_from_window(&mut self, key_event: KeyboardEvent) {
        ShortcutMatcher::from_event(key_event.clone())
            .shortcut(CMD_OR_CONTROL, 'R', || {
                if let Some(id) = self.browser_id {
                    self.event_queue.push(EmbedderEvent::Reload(id));
                }
            })
            .shortcut(CMD_OR_CONTROL, 'L', || {
                if !opts::get().minibrowser {
                    let url: String = if let Some(ref current_url) = self.current_url {
                        current_url.to_string()
                    } else {
                        String::from("")
                    };
                    let title = "URL or search query";
                    let input = tinyfiledialogs::input_box(title, title, &tiny_dialog_escape(&url));
                    if let Some(input) = input {
                        if let Some(url) = location_bar_input_to_url(&input) {
                            if let Some(id) = self.browser_id {
                                self.event_queue.push(EmbedderEvent::LoadUrl(id, url));
                            }
                        }
                    }
                }
            })
            .shortcut(CMD_OR_CONTROL, 'Q', || {
                self.event_queue.push(EmbedderEvent::Quit);
            })
            .shortcut(CMD_OR_CONTROL, 'P', || {
                let rate = env::var("SAMPLING_RATE")
                    .ok()
                    .and_then(|s| s.parse().ok())
                    .unwrap_or(10);
                let duration = env::var("SAMPLING_DURATION")
                    .ok()
                    .and_then(|s| s.parse().ok())
                    .unwrap_or(10);
                self.event_queue.push(EmbedderEvent::ToggleSamplingProfiler(
                    Duration::from_millis(rate),
                    Duration::from_secs(duration),
                ));
            })
            .shortcut(Modifiers::CONTROL, Key::F9, || {
                self.event_queue.push(EmbedderEvent::CaptureWebRender)
            })
            .shortcut(Modifiers::CONTROL, Key::F10, || {
                self.event_queue.push(EmbedderEvent::ToggleWebRenderDebug(
                    WebRenderDebugOption::RenderTargetDebug,
                ));
            })
            .shortcut(Modifiers::CONTROL, Key::F11, || {
                self.event_queue.push(EmbedderEvent::ToggleWebRenderDebug(
                    WebRenderDebugOption::TextureCacheDebug,
                ));
            })
            .shortcut(Modifiers::CONTROL, Key::F12, || {
                self.event_queue.push(EmbedderEvent::ToggleWebRenderDebug(
                    WebRenderDebugOption::Profiler,
                ));
            })
            .shortcut(CMD_OR_ALT, Key::ArrowRight, || {
                if let Some(id) = self.browser_id {
                    let event = EmbedderEvent::Navigation(id, TraversalDirection::Forward(1));
                    self.event_queue.push(event);
                }
            })
            .shortcut(CMD_OR_ALT, Key::ArrowLeft, || {
                if let Some(id) = self.browser_id {
                    let event = EmbedderEvent::Navigation(id, TraversalDirection::Back(1));
                    self.event_queue.push(event);
                }
            })
            .shortcut(Modifiers::empty(), Key::Escape, || {
                let state = self.window.get_fullscreen();
                if state {
                    if let Some(id) = self.browser_id {
                        let event = EmbedderEvent::ExitFullScreen(id);
                        self.event_queue.push(event);
                    }
                } else {
                    self.event_queue.push(EmbedderEvent::Quit);
                }
            })
            .otherwise(|| self.platform_handle_key(key_event));
    }

    #[cfg(not(target_os = "win"))]
    fn platform_handle_key(&mut self, key_event: KeyboardEvent) {
        if let Some(id) = self.browser_id {
            if let Some(event) = ShortcutMatcher::from_event(key_event.clone())
                .shortcut(CMD_OR_CONTROL, '[', || {
                    EmbedderEvent::Navigation(id, TraversalDirection::Back(1))
                })
                .shortcut(CMD_OR_CONTROL, ']', || {
                    EmbedderEvent::Navigation(id, TraversalDirection::Forward(1))
                })
                .otherwise(|| EmbedderEvent::Keyboard(key_event))
            {
                self.event_queue.push(event)
            }
        }
    }

    #[cfg(target_os = "win")]
    fn platform_handle_key(&mut self, _key_event: KeyboardEvent) {}

    /// Handle key events after they have been handled by Servo.
    fn handle_key_from_servo(&mut self, _: Option<BrowserId>, event: KeyboardEvent) {
        ShortcutMatcher::from_event(event)
            .shortcut(CMD_OR_CONTROL, '=', || {
                self.event_queue.push(EmbedderEvent::Zoom(1.1))
            })
            .shortcut(CMD_OR_CONTROL, '+', || {
                self.event_queue.push(EmbedderEvent::Zoom(1.1))
            })
            .shortcut(CMD_OR_CONTROL, '-', || {
                self.event_queue.push(EmbedderEvent::Zoom(1.0 / 1.1))
            })
            .shortcut(CMD_OR_CONTROL, '0', || {
                self.event_queue.push(EmbedderEvent::ResetZoom)
            })
            .shortcut(Modifiers::empty(), Key::PageDown, || {
                let scroll_location = ScrollLocation::Delta(Vector2D::new(
                    0.0,
                    -self.window.page_height() + 2.0 * LINE_HEIGHT,
                ));
                self.scroll_window_from_key(scroll_location, TouchEventType::Move);
            })
            .shortcut(Modifiers::empty(), Key::PageUp, || {
                let scroll_location = ScrollLocation::Delta(Vector2D::new(
                    0.0,
                    self.window.page_height() - 2.0 * LINE_HEIGHT,
                ));
                self.scroll_window_from_key(scroll_location, TouchEventType::Move);
            })
            .shortcut(Modifiers::empty(), Key::Home, || {
                self.scroll_window_from_key(ScrollLocation::Start, TouchEventType::Move);
            })
            .shortcut(Modifiers::empty(), Key::End, || {
                self.scroll_window_from_key(ScrollLocation::End, TouchEventType::Move);
            })
            .shortcut(Modifiers::empty(), Key::ArrowUp, || {
                self.scroll_window_from_key(
                    ScrollLocation::Delta(Vector2D::new(0.0, 3.0 * LINE_HEIGHT)),
                    TouchEventType::Move,
                );
            })
            .shortcut(Modifiers::empty(), Key::ArrowDown, || {
                self.scroll_window_from_key(
                    ScrollLocation::Delta(Vector2D::new(0.0, -3.0 * LINE_HEIGHT)),
                    TouchEventType::Move,
                );
            })
            .shortcut(Modifiers::empty(), Key::ArrowLeft, || {
                self.scroll_window_from_key(
                    ScrollLocation::Delta(Vector2D::new(LINE_HEIGHT, 0.0)),
                    TouchEventType::Move,
                );
            })
            .shortcut(Modifiers::empty(), Key::ArrowRight, || {
                self.scroll_window_from_key(
                    ScrollLocation::Delta(Vector2D::new(-LINE_HEIGHT, 0.0)),
                    TouchEventType::Move,
                );
            });
    }

    fn scroll_window_from_key(&mut self, scroll_location: ScrollLocation, phase: TouchEventType) {
        let event = EmbedderEvent::Scroll(scroll_location, Point2D::zero(), phase);
        self.event_queue.push(event);
    }

    /// Returns true if the caller needs to manually present a new frame.
    pub fn handle_servo_events(
        &mut self,
        events: Vec<(Option<BrowserId>, EmbedderMsg)>,
    ) -> ServoEventResponse {
        let mut need_present = false;
        let mut history_changed = false;
        for (browser_id, msg) in events {
            trace!(
                "embedder <- servo EmbedderMsg ({:?}, {:?})",
                browser_id.map(|x| format!("{}", x)),
                msg
            );
            match msg {
                EmbedderMsg::Status(_status) => {
                    // FIXME: surface this status string in the UI somehow
                },
                EmbedderMsg::ChangePageTitle(title) => {
                    self.title = title;

                    let fallback_title: String = if let Some(ref current_url) = self.current_url {
                        current_url.to_string()
                    } else {
                        String::from("Untitled")
                    };
                    let title = match self.title {
                        Some(ref title) if !title.is_empty() => &**title,
                        _ => &fallback_title,
                    };
                    let title = format!("{} - Servo", title);
                    self.window.set_title(&title);
                },
                EmbedderMsg::MoveTo(point) => {
                    self.window.set_position(point);
                },
                EmbedderMsg::ResizeTo(size) => {
                    self.window.set_inner_size(size);
                },
                EmbedderMsg::Prompt(definition, origin) => {
                    let res = if opts::get().headless {
                        match definition {
                            PromptDefinition::Alert(_message, sender) => sender.send(()),
                            PromptDefinition::YesNo(_message, sender) => {
                                sender.send(PromptResult::Primary)
                            },
                            PromptDefinition::OkCancel(_message, sender) => {
                                sender.send(PromptResult::Primary)
                            },
                            PromptDefinition::Input(_message, default, sender) => {
                                sender.send(Some(default.to_owned()))
                            },
                        }
                    } else {
                        thread::Builder::new()
                            .name("AlertDialog".to_owned())
                            .spawn(move || match definition {
                                PromptDefinition::Alert(mut message, sender) => {
                                    if origin == PromptOrigin::Untrusted {
                                        message = tiny_dialog_escape(&message);
                                    }
                                    tinyfiledialogs::message_box_ok(
                                        "Alert!",
                                        &message,
                                        MessageBoxIcon::Warning,
                                    );
                                    sender.send(())
                                },
                                PromptDefinition::YesNo(mut message, sender) => {
                                    if origin == PromptOrigin::Untrusted {
                                        message = tiny_dialog_escape(&message);
                                    }
                                    let result = tinyfiledialogs::message_box_yes_no(
                                        "",
                                        &message,
                                        MessageBoxIcon::Warning,
                                        YesNo::No,
                                    );
                                    sender.send(match result {
                                        YesNo::Yes => PromptResult::Primary,
                                        YesNo::No => PromptResult::Secondary,
                                    })
                                },
                                PromptDefinition::OkCancel(mut message, sender) => {
                                    if origin == PromptOrigin::Untrusted {
                                        message = tiny_dialog_escape(&message);
                                    }
                                    let result = tinyfiledialogs::message_box_ok_cancel(
                                        "",
                                        &message,
                                        MessageBoxIcon::Warning,
                                        OkCancel::Cancel,
                                    );
                                    sender.send(match result {
                                        OkCancel::Ok => PromptResult::Primary,
                                        OkCancel::Cancel => PromptResult::Secondary,
                                    })
                                },
                                PromptDefinition::Input(mut message, mut default, sender) => {
                                    if origin == PromptOrigin::Untrusted {
                                        message = tiny_dialog_escape(&message);
                                        default = tiny_dialog_escape(&default);
                                    }
                                    let result = tinyfiledialogs::input_box("", &message, &default);
                                    sender.send(result)
                                },
                            })
                            .unwrap()
                            .join()
                            .expect("Thread spawning failed")
                    };
                    if let Err(e) = res {
                        let reason = format!("Failed to send Prompt response: {}", e);
                        self.event_queue
                            .push(EmbedderEvent::SendError(browser_id, reason));
                    }
                },
                EmbedderMsg::AllowUnload(sender) => {
                    // Always allow unload for now.
                    if let Err(e) = sender.send(true) {
                        let reason = format!("Failed to send AllowUnload response: {}", e);
                        self.event_queue
                            .push(EmbedderEvent::SendError(browser_id, reason));
                    }
                },
                EmbedderMsg::AllowNavigationRequest(pipeline_id, _url) => {
                    if let Some(_browser_id) = browser_id {
                        self.event_queue
                            .push(EmbedderEvent::AllowNavigationResponse(pipeline_id, true));
                    }
                },
                EmbedderMsg::AllowOpeningBrowser(response_chan) => {
                    // Note: would be a place to handle pop-ups config.
                    // see Step 7 of #the-rules-for-choosing-a-browsing-context-given-a-browsing-context-name
                    if let Err(e) = response_chan.send(true) {
                        warn!("Failed to send AllowOpeningBrowser response: {}", e);
                    };
                },
                EmbedderMsg::BrowserCreated(new_browser_id) => {
                    // TODO: properly handle a new "tab"
                    self.browsers.push(new_browser_id);
                    if self.browser_id.is_none() {
                        self.browser_id = Some(new_browser_id);
                    } else {
                        error!("Multiple top level browsing contexts not supported yet.");
                    }
                    self.event_queue
                        .push(EmbedderEvent::SelectBrowser(new_browser_id));
                },
                EmbedderMsg::Keyboard(key_event) => {
                    self.handle_key_from_servo(browser_id, key_event);
                },
                EmbedderMsg::GetClipboardContents(sender) => {
                    let contents = self
                        .clipboard
                        .as_mut()
                        .and_then(|clipboard| clipboard.get_text().ok())
                        .unwrap_or_else(|| {
                            warn!("Error getting clipboard text. Returning empty string.");
                            String::new()
                        });
                    if let Err(e) = sender.send(contents) {
                        warn!("Failed to send clipboard ({})", e);
                    }
                },
                EmbedderMsg::SetClipboardContents(text) => {
                    if let Some(ref mut clipboard) = self.clipboard {
                        if let Err(e) = clipboard.set_text(text) {
                            warn!("Error setting clipboard contents ({})", e);
                        }
                    }
                },
                EmbedderMsg::SetCursor(cursor) => {
                    self.window.set_cursor(cursor);
                },
                EmbedderMsg::NewFavicon(_url) => {
                    // FIXME: show favicons in the UI somehow
                },
                EmbedderMsg::HeadParsed => {
                    // FIXME: surface the loading state in the UI somehow
                },
                EmbedderMsg::HistoryChanged(urls, current) => {
                    self.current_url = Some(urls[current].clone());
                    self.current_url_string = Some(urls[current].clone().into_string());
                    history_changed = true;
                },
                EmbedderMsg::SetFullscreenState(state) => {
                    self.window.set_fullscreen(state);
                },
                EmbedderMsg::LoadStart => {
                    // FIXME: surface the loading state in the UI somehow
                },
                EmbedderMsg::LoadComplete => {
                    // FIXME: surface the loading state in the UI somehow
                },
                EmbedderMsg::CloseBrowser => {
                    // TODO: close the appropriate "tab".
                    let _ = self.browsers.pop();
                    if let Some(prev_browser_id) = self.browsers.last() {
                        self.browser_id = Some(*prev_browser_id);
                        self.event_queue
                            .push(EmbedderEvent::SelectBrowser(*prev_browser_id));
                    } else {
                        self.event_queue.push(EmbedderEvent::Quit);
                    }
                },
                EmbedderMsg::Shutdown => {
                    self.shutdown_requested = true;
                },
                EmbedderMsg::Panic(_reason, _backtrace) => {},
                EmbedderMsg::GetSelectedBluetoothDevice(devices, sender) => {
                    let selected = platform_get_selected_devices(devices);
                    if let Err(e) = sender.send(selected) {
                        let reason =
                            format!("Failed to send GetSelectedBluetoothDevice response: {}", e);
                        self.event_queue
                            .push(EmbedderEvent::SendError(None, reason));
                    };
                },
                EmbedderMsg::SelectFiles(patterns, multiple_files, sender) => {
                    let res = match (
                        opts::get().headless,
                        get_selected_files(patterns, multiple_files),
                    ) {
                        (true, _) | (false, None) => sender.send(None),
                        (false, Some(files)) => sender.send(Some(files)),
                    };
                    if let Err(e) = res {
                        let reason = format!("Failed to send SelectFiles response: {}", e);
                        self.event_queue
                            .push(EmbedderEvent::SendError(None, reason));
                    };
                },
                EmbedderMsg::PromptPermission(prompt, sender) => {
                    let permission_state = prompt_user(prompt);
                    let _ = sender.send(permission_state);
                },
                EmbedderMsg::ShowIME(_kind, _text, _multiline, _rect) => {
                    debug!("ShowIME received");
                },
                EmbedderMsg::HideIME => {
                    debug!("HideIME received");
                },
                EmbedderMsg::ReportProfile(bytes) => {
                    let filename = env::var("PROFILE_OUTPUT").unwrap_or("samples.json".to_string());
                    let result = File::create(&filename).and_then(|mut f| f.write_all(&bytes));
                    if let Err(e) = result {
                        error!("Failed to store profile: {}", e);
                    }
                },
                EmbedderMsg::MediaSessionEvent(_) => {
                    debug!("MediaSessionEvent received");
                    // TODO(ferjm): MediaSession support for winit based browsers.
                },
                EmbedderMsg::OnDevtoolsStarted(port, _token) => match port {
                    Ok(p) => info!("Devtools Server running on port {}", p),
                    Err(()) => error!("Error running devtools server"),
                },
                EmbedderMsg::ShowContextMenu(sender, ..) => {
                    let _ = sender.send(ContextMenuResult::Ignored);
                },
                EmbedderMsg::ReadyToPresent => {
                    need_present = true;
                },
                EmbedderMsg::EventDelivered(event) => match (browser_id, event) {
                    (Some(browser_id), CompositorEventVariant::MouseButtonEvent) => {
                        // TODO Focus browser and/or raise to top if needed.
                        trace!("{}: Got a mouse button event", browser_id);
                    },
                    (_, _) => {},
                },
            }
        }

        ServoEventResponse {
            need_present,
            history_changed,
        }
    }
}

#[cfg(target_os = "linux")]
fn prompt_user(prompt: PermissionPrompt) -> PermissionRequest {
    if opts::get().headless {
        return PermissionRequest::Denied;
    }

    let message = match prompt {
        PermissionPrompt::Request(permission_name) => {
            format!("Do you want to grant permission for {:?}?", permission_name)
        },
        PermissionPrompt::Insecure(permission_name) => {
            format!(
                "The {:?} feature is only safe to use in secure context, but servo can't guarantee\n\
                that the current context is secure. Do you want to proceed and grant permission?",
                permission_name
            )
        },
    };

    match tinyfiledialogs::message_box_yes_no(
        "Permission request dialog",
        &message,
        MessageBoxIcon::Question,
        YesNo::No,
    ) {
        YesNo::Yes => PermissionRequest::Granted,
        YesNo::No => PermissionRequest::Denied,
    }
}

#[cfg(not(target_os = "linux"))]
fn prompt_user(_prompt: PermissionPrompt) -> PermissionRequest {
    // TODO popup only supported on linux
    PermissionRequest::Denied
}

#[cfg(target_os = "linux")]
fn platform_get_selected_devices(devices: Vec<String>) -> Option<String> {
    thread::Builder::new()
        .name("DevicePicker".to_owned())
        .spawn(move || {
            let dialog_rows: Vec<&str> = devices.iter().map(|s| s.as_ref()).collect();
            let dialog_rows: Option<&[&str]> = Some(dialog_rows.as_slice());

            match tinyfiledialogs::list_dialog("Choose a device", &["Id", "Name"], dialog_rows) {
                Some(device) => {
                    // The device string format will be "Address|Name". We need the first part of it.
                    device.split('|').next().map(|s| s.to_string())
                },
                None => None,
            }
        })
        .unwrap()
        .join()
        .expect("Thread spawning failed")
}

#[cfg(not(target_os = "linux"))]
fn platform_get_selected_devices(devices: Vec<String>) -> Option<String> {
    for device in devices {
        if let Some(address) = device.split("|").next().map(|s| s.to_string()) {
            return Some(address);
        }
    }
    None
}

fn get_selected_files(patterns: Vec<FilterPattern>, multiple_files: bool) -> Option<Vec<String>> {
    let picker_name = if multiple_files {
        "Pick files"
    } else {
        "Pick a file"
    };
    thread::Builder::new()
        .name("FilePicker".to_owned())
        .spawn(move || {
            let mut filters = vec![];
            for p in patterns {
                let s = "*.".to_string() + &p.0;
                filters.push(tiny_dialog_escape(&s))
            }
            let filter_ref = &(filters.iter().map(|s| s.as_str()).collect::<Vec<&str>>()[..]);
            let filter_opt = if !filters.is_empty() {
                Some((filter_ref, ""))
            } else {
                None
            };

            if multiple_files {
                tinyfiledialogs::open_file_dialog_multi(picker_name, "", filter_opt)
            } else {
                let file = tinyfiledialogs::open_file_dialog(picker_name, "", filter_opt);
                file.map(|x| vec![x])
            }
        })
        .unwrap()
        .join()
        .expect("Thread spawning failed")
}

// This is a mitigation for #25498, not a verified solution.
// There may be codepaths in tinyfiledialog.c that this is
// inadquate against, as it passes the string via shell to
// different programs depending on what the user has installed.
#[cfg(target_os = "linux")]
fn tiny_dialog_escape(raw: &str) -> String {
    let s: String = raw
        .chars()
        .filter_map(|c| match c {
            '\n' => Some('\n'),
            '\0'..='\x1f' => None,
            '<' => Some('\u{FF1C}'),
            '>' => Some('\u{FF1E}'),
            '&' => Some('\u{FF06}'),
            _ => Some(c),
        })
        .collect();
    shellwords::escape(&s)
}

#[cfg(not(target_os = "linux"))]
fn tiny_dialog_escape(raw: &str) -> String {
    raw.to_string()
}