use egui::{os::OperatingSystem, Key, KeyboardShortcut, Modifiers};
use smallvec::{smallvec, SmallVec};

/// Interface for sending [`UICommand`] messages.
pub trait UICommandSender {
    fn send_ui(&self, command: UICommand);
}

/// All the commands we support.
///
/// Most are available in the GUI,
/// some have keyboard shortcuts,
/// and all are visible in the [`crate::CommandPalette`].
#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash, strum_macros::EnumIter)]
pub enum UICommand {
    // Listed in the order they show up in the command palette by default!
    Open,
    Import,
    SaveRecording,
    SaveRecordingSelection,
    SaveBlueprint,
    CloseCurrentRecording,
    CloseAllRecordings,

    Undo,
    Redo,

    #[cfg(not(target_arch = "wasm32"))]
    Quit,

    OpenWebHelp,
    OpenRerunDiscord,

    ResetViewer,
    ClearAndGenerateBlueprint,

    #[cfg(not(target_arch = "wasm32"))]
    OpenProfiler,

    TogglePanelStateOverrides,
    ToggleMemoryPanel,
    ToggleTopPanel,
    ToggleBlueprintPanel,
    ToggleSelectionPanel,
    ToggleTimePanel,
    ToggleChunkStoreBrowser,
    Settings,

    #[cfg(debug_assertions)]
    ToggleBlueprintInspectionPanel,

    #[cfg(debug_assertions)]
    ToggleEguiDebugPanel,

    ToggleFullscreen,
    #[cfg(not(target_arch = "wasm32"))]
    ZoomIn,
    #[cfg(not(target_arch = "wasm32"))]
    ZoomOut,
    #[cfg(not(target_arch = "wasm32"))]
    ZoomReset,

    ToggleCommandPalette,

    // Playback:
    PlaybackTogglePlayPause,
    PlaybackFollow,
    PlaybackStepBack,
    PlaybackStepForward,
    PlaybackRestart,

    // Dev-tools:
    #[cfg(not(target_arch = "wasm32"))]
    ScreenshotWholeApp,
    #[cfg(not(target_arch = "wasm32"))]
    PrintChunkStore,
    #[cfg(not(target_arch = "wasm32"))]
    PrintBlueprintStore,
    #[cfg(not(target_arch = "wasm32"))]
    PrintPrimaryCache,

    #[cfg(debug_assertions)]
    ResetEguiMemory,

    #[cfg(target_arch = "wasm32")]
    CopyDirectLink,

    // Graphics options:
    #[cfg(target_arch = "wasm32")]
    RestartWithWebGl,
    #[cfg(target_arch = "wasm32")]
    RestartWithWebGpu,
}

impl UICommand {
    pub fn text(self) -> &'static str {
        self.text_and_tooltip().0
    }

    pub fn tooltip(self) -> &'static str {
        self.text_and_tooltip().1
    }

    pub fn text_and_tooltip(self) -> (&'static str, &'static str) {
        match self {
            Self::SaveRecording => ("Save recording…", "Save all data to a Rerun data file (.rrd)"),

            Self::SaveRecordingSelection => (
                "Save current time selection…",
                "Save data for the current loop selection to a Rerun data file (.rrd)",
            ),

            Self::SaveBlueprint => ("Save blueprint…", "Save the current viewer setup as a Rerun blueprint file (.rbl)"),

            Self::Open => ("Open…", "Open any supported files (.rrd, images, meshes, …) in a new recording"),
            Self::Import => ("Import…", "Import any supported files (.rrd, images, meshes, …) in the current recording"),

            Self::CloseCurrentRecording => (
                "Close current recording",
                "Close the current recording (unsaved data will be lost)",
            ),

            Self::CloseAllRecordings => ("Close all recordings",
                "Close all open current recording (unsaved data will be lost)"),

            Self::Undo => ("Undo", "Undo the last blueprint edit for the open recording"),
            Self::Redo => ("Redo", "Redo the last undone thing"),

            #[cfg(not(target_arch = "wasm32"))]
            Self::Quit => ("Quit", "Close the Rerun Viewer"),

            Self::OpenWebHelp => ("Help", "Visit the help page on our website, with troubleshooting tips and more"),
            Self::OpenRerunDiscord => ("Rerun Discord", "Visit the Rerun Discord server, where you can ask questions and get help"),

            Self::ResetViewer => (
                "Reset Viewer",
                "Reset the Viewer to how it looked the first time you ran it, forgetting all stored blueprints and UI state",
            ),

            Self::ClearAndGenerateBlueprint => (
                "Clear and generate new blueprint",
                "Clear the current blueprint and generate a new one based on heuristics."
            ),


            #[cfg(not(target_arch = "wasm32"))]
            Self::OpenProfiler => (
                "Open profiler",
                "Starts a profiler, showing what makes the viewer run slow",
            ),

            Self::ToggleMemoryPanel => (
                "Toggle memory panel",
                "View and track current RAM usage inside Rerun Viewer",
            ),

            Self::TogglePanelStateOverrides => ("Toggle panel state overrides", "Toggle panel state between app blueprint and overrides"),
            Self::ToggleTopPanel => ("Toggle top panel", "Toggle the top panel"),
            Self::ToggleBlueprintPanel => ("Toggle blueprint panel", "Toggle the left panel"),
            Self::ToggleSelectionPanel => ("Toggle selection panel", "Toggle the right panel"),
            Self::ToggleTimePanel => ("Toggle time panel", "Toggle the bottom panel"),
            Self::ToggleChunkStoreBrowser => ("Toggle chunk store browser", "Toggle the chunk store browser"),
            Self::Settings => ("Settings…", "Show the settings screen"),

            #[cfg(debug_assertions)]
            Self::ToggleBlueprintInspectionPanel => (
                "Toggle blueprint inspection panel",
                "Inspect the timeline of the internal blueprint data.",
            ),

            #[cfg(debug_assertions)]
            Self::ToggleEguiDebugPanel => (
                "Toggle egui debug panel",
                "View and change global egui style settings",
            ),


            #[cfg(not(target_arch = "wasm32"))]
            Self::ToggleFullscreen => (
                "Toggle fullscreen",
                "Toggle between windowed and fullscreen viewer",
            ),

            #[cfg(target_arch = "wasm32")]
            Self::ToggleFullscreen => (
                "Toggle fullscreen",
                "Toggle between full viewport dimensions and initial dimensions"
            ),

            #[cfg(not(target_arch = "wasm32"))]
            Self::ZoomIn => ("Zoom in", "Increases the UI zoom level"),
            #[cfg(not(target_arch = "wasm32"))]
            Self::ZoomOut => ("Zoom out", "Decreases the UI zoom level"),
            #[cfg(not(target_arch = "wasm32"))]
            Self::ZoomReset => (
                "Reset zoom",
                "Resets the UI zoom level to the operating system's default value",
            ),

            Self::ToggleCommandPalette => ("Command palette…", "Toggle the Command Palette"),

            Self::PlaybackTogglePlayPause => {
                ("Toggle play/pause", "Either play or pause the time")
            }
            Self::PlaybackFollow => ("Follow", "Follow on from end of timeline"),
            Self::PlaybackStepBack => (
                "Step time back",
                "Move the time marker back to the previous point in time with any data",
            ),
            Self::PlaybackStepForward => (
                "Step time forward",
                "Move the time marker to the next point in time with any data",
            ),
            Self::PlaybackRestart => ("Restart", "Restart from beginning of timeline"),

            #[cfg(not(target_arch = "wasm32"))]
            Self::ScreenshotWholeApp => (
                "Screenshot",
                "Copy screenshot of the whole app to clipboard",
            ),
            #[cfg(not(target_arch = "wasm32"))]
            Self::PrintChunkStore => (
                "Print datastore",
                "Prints the entire chunk store to the console and clipboard. WARNING: this may be A LOT of text.",
            ),
            #[cfg(not(target_arch = "wasm32"))]
            Self::PrintBlueprintStore => (
                "Print blueprint store",
                "Prints the entire blueprint store to the console and clipboard. WARNING: this may be A LOT of text.",
            ),
            #[cfg(not(target_arch = "wasm32"))]
            Self::PrintPrimaryCache => (
                "Print primary cache",
                "Prints the state of the entire primary cache to the console and clipboard. WARNING: this may be A LOT of text.",
            ),

            #[cfg(debug_assertions)]
            Self::ResetEguiMemory => (
                "Reset egui memory",
                "Reset egui memory, useful for debugging UI code.",
            ),

            #[cfg(target_arch = "wasm32")]
            Self::CopyDirectLink => (
                "Copy direct link",
                "Copy a link to the viewer with the URL parameter set to the current .rrd data source."
            ),

            #[cfg(target_arch = "wasm32")]
            Self::RestartWithWebGl => (
                "Restart with WebGL",
                "Reloads the webpage and force WebGL for rendering. All data will be lost."
            ),
            #[cfg(target_arch = "wasm32")]
            Self::RestartWithWebGpu => (
                "Restart with WebGPU",
                "Reloads the webpage and force WebGPU for rendering. All data will be lost."
            ),

        }
    }

    /// All keyboard shortcuts, with the primary first.
    pub fn kb_shortcuts(self, os: OperatingSystem) -> SmallVec<[KeyboardShortcut; 2]> {
        fn key(key: Key) -> KeyboardShortcut {
            KeyboardShortcut::new(Modifiers::NONE, key)
        }

        fn ctrl(key: Key) -> KeyboardShortcut {
            KeyboardShortcut::new(Modifiers::CTRL, key)
        }

        fn cmd(key: Key) -> KeyboardShortcut {
            KeyboardShortcut::new(Modifiers::COMMAND, key)
        }

        fn cmd_shift(key: Key) -> KeyboardShortcut {
            KeyboardShortcut::new(Modifiers::COMMAND | Modifiers::SHIFT, key)
        }

        fn cmd_alt(key: Key) -> KeyboardShortcut {
            KeyboardShortcut::new(Modifiers::COMMAND | Modifiers::ALT, key)
        }

        fn ctrl_shift(key: Key) -> KeyboardShortcut {
            KeyboardShortcut::new(Modifiers::CTRL | Modifiers::SHIFT, key)
        }

        match self {
            Self::SaveRecording => smallvec![cmd(Key::S)],
            Self::SaveRecordingSelection => smallvec![cmd_alt(Key::S)],
            Self::SaveBlueprint => smallvec![],
            Self::Open => smallvec![cmd(Key::O)],
            Self::Import => smallvec![cmd_shift(Key::O)],
            Self::CloseCurrentRecording => smallvec![],
            Self::CloseAllRecordings => smallvec![],

            Self::Undo => smallvec![cmd(Key::Z)],
            Self::Redo => {
                if os == OperatingSystem::Mac {
                    smallvec![cmd_shift(Key::Z), cmd(Key::Y)]
                } else {
                    smallvec![ctrl(Key::Y), ctrl_shift(Key::Z)]
                }
            }

            #[cfg(all(not(target_arch = "wasm32"), target_os = "windows"))]
            Self::Quit => smallvec![KeyboardShortcut::new(Modifiers::ALT, Key::F4)],

            Self::OpenWebHelp => smallvec![],
            Self::OpenRerunDiscord => smallvec![],

            #[cfg(all(not(target_arch = "wasm32"), not(target_os = "windows")))]
            Self::Quit => smallvec![cmd(Key::Q)],

            Self::ResetViewer => smallvec![ctrl_shift(Key::R)],
            Self::ClearAndGenerateBlueprint => smallvec![],

            #[cfg(not(target_arch = "wasm32"))]
            Self::OpenProfiler => smallvec![ctrl_shift(Key::P)],
            Self::ToggleMemoryPanel => smallvec![ctrl_shift(Key::M)],
            Self::TogglePanelStateOverrides => smallvec![],
            Self::ToggleTopPanel => smallvec![],
            Self::ToggleBlueprintPanel => smallvec![ctrl_shift(Key::B)],
            Self::ToggleSelectionPanel => smallvec![ctrl_shift(Key::S)],
            Self::ToggleTimePanel => smallvec![ctrl_shift(Key::T)],
            Self::ToggleChunkStoreBrowser => smallvec![ctrl_shift(Key::D)],
            Self::Settings => smallvec![cmd(Key::Comma)],

            #[cfg(debug_assertions)]
            Self::ToggleBlueprintInspectionPanel => smallvec![ctrl_shift(Key::I)],

            #[cfg(debug_assertions)]
            Self::ToggleEguiDebugPanel => smallvec![ctrl_shift(Key::U)],

            #[cfg(not(target_arch = "wasm32"))]
            Self::ToggleFullscreen => smallvec![key(Key::F11)],
            #[cfg(target_arch = "wasm32")]
            Self::ToggleFullscreen => smallvec![],

            #[cfg(not(target_arch = "wasm32"))]
            Self::ZoomIn => smallvec![egui::gui_zoom::kb_shortcuts::ZOOM_IN],
            #[cfg(not(target_arch = "wasm32"))]
            Self::ZoomOut => smallvec![egui::gui_zoom::kb_shortcuts::ZOOM_OUT],
            #[cfg(not(target_arch = "wasm32"))]
            Self::ZoomReset => smallvec![egui::gui_zoom::kb_shortcuts::ZOOM_RESET],

            Self::ToggleCommandPalette => smallvec![cmd(Key::P)],

            Self::PlaybackTogglePlayPause => smallvec![key(Key::Space)],
            Self::PlaybackFollow => smallvec![cmd(Key::ArrowRight)],
            Self::PlaybackStepBack => smallvec![key(Key::ArrowLeft)],
            Self::PlaybackStepForward => smallvec![key(Key::ArrowRight)],
            Self::PlaybackRestart => smallvec![cmd(Key::ArrowLeft)],

            #[cfg(not(target_arch = "wasm32"))]
            Self::ScreenshotWholeApp => smallvec![],
            #[cfg(not(target_arch = "wasm32"))]
            Self::PrintChunkStore => smallvec![],
            #[cfg(not(target_arch = "wasm32"))]
            Self::PrintBlueprintStore => smallvec![],
            #[cfg(not(target_arch = "wasm32"))]
            Self::PrintPrimaryCache => smallvec![],

            #[cfg(debug_assertions)]
            Self::ResetEguiMemory => smallvec![],

            #[cfg(target_arch = "wasm32")]
            Self::CopyDirectLink => smallvec![],

            #[cfg(target_arch = "wasm32")]
            Self::RestartWithWebGl => smallvec![],
            #[cfg(target_arch = "wasm32")]
            Self::RestartWithWebGpu => smallvec![],
        }
    }

    /// Primary keyboard shortcut
    fn primary_kb_shortcut(self, os: OperatingSystem) -> Option<KeyboardShortcut> {
        self.kb_shortcuts(os).first().copied()
    }

    /// Return the keyboard shortcut for this command, nicely formatted
    pub fn formatted_kb_shortcut(self, egui_ctx: &egui::Context) -> Option<String> {
        // Note: we only show the primary shortcut to the user.
        // The fallbacks are there for people who have muscle memory for the other shortcuts.
        self.primary_kb_shortcut(egui_ctx.os())
            .map(|shortcut| egui_ctx.format_shortcut(&shortcut))
    }

    /// Add e.g. " (Ctrl+F11)" as a suffix
    pub fn format_shortcut_tooltip_suffix(self, egui_ctx: &egui::Context) -> String {
        if let Some(shortcut_text) = self.formatted_kb_shortcut(egui_ctx) {
            format!(" ({shortcut_text})")
        } else {
            Default::default()
        }
    }

    pub fn icon(self) -> Option<&'static crate::Icon> {
        match self {
            Self::OpenWebHelp => Some(&crate::icons::EXTERNAL_LINK),
            Self::OpenRerunDiscord => Some(&crate::icons::DISCORD),
            _ => None,
        }
    }

    pub fn is_link(self) -> bool {
        matches!(self, Self::OpenWebHelp | Self::OpenRerunDiscord)
    }

    #[must_use = "Returns the Command that was triggered by some keyboard shortcut"]
    pub fn listen_for_kb_shortcut(egui_ctx: &egui::Context) -> Option<Self> {
        use strum::IntoEnumIterator as _;

        let anything_has_focus = egui_ctx.memory(|mem| mem.focused().is_some());
        if anything_has_focus {
            return None; // e.g. we're typing in a TextField
        }

        let mut commands: Vec<(KeyboardShortcut, Self)> = Self::iter()
            .flat_map(|cmd| {
                cmd.kb_shortcuts(egui_ctx.os())
                    .into_iter()
                    .map(move |kb_shortcut| (kb_shortcut, cmd))
            })
            .collect();

        // If the user pressed `Cmd-Shift-S` then egui will match that
        // with both `Cmd-Shift-S` and `Cmd-S`.
        // The reason is that `Shift` (and `Alt`) are sometimes required to produce certain keys,
        // such as `+` (`Shift =` on an american keyboard).
        // The result of this is that we must check for `Cmd-Shift-S` before `Cmd-S`, etc.
        // So we order the commands here so that the commands with `Shift` and `Alt` in them
        // are checked first.
        commands.sort_by_key(|(kb_shortcut, _cmd)| {
            let num_shift_alts =
                kb_shortcut.modifiers.shift as i32 + kb_shortcut.modifiers.alt as i32;
            -num_shift_alts // most first
        });

        egui_ctx.input_mut(|input| {
            for (kb_shortcut, command) in commands {
                if input.consume_shortcut(&kb_shortcut) {
                    return Some(command);
                }
            }
            None
        })
    }

    /// Show this command as a menu-button.
    ///
    /// If clicked, enqueue the command.
    pub fn menu_button_ui(
        self,
        ui: &mut egui::Ui,
        command_sender: &impl UICommandSender,
    ) -> egui::Response {
        let button = self.menu_button(ui.ctx());
        let mut response = ui.add(button).on_hover_text(self.tooltip());

        if self.is_link() {
            response = response.on_hover_cursor(egui::CursorIcon::PointingHand);
        }

        if response.clicked() {
            command_sender.send_ui(self);
            ui.close_menu();
        }

        response
    }

    pub fn menu_button(self, egui_ctx: &egui::Context) -> egui::Button<'static> {
        let mut button = if let Some(icon) = self.icon() {
            egui::Button::image_and_text(
                icon.as_image()
                    .fit_to_exact_size(crate::DesignTokens::small_icon_size()),
                self.text(),
            )
        } else {
            egui::Button::new(self.text())
        };

        if let Some(shortcut_text) = self.formatted_kb_shortcut(egui_ctx) {
            button = button.shortcut_text(shortcut_text);
        }

        button
    }

    pub fn tooltip_with_shortcut(self, egui_ctx: &egui::Context) -> String {
        format!(
            "{}{}",
            self.tooltip(),
            self.format_shortcut_tooltip_suffix(egui_ctx)
        )
    }
}

#[test]
fn check_for_clashing_command_shortcuts() {
    fn clashes(a: KeyboardShortcut, b: KeyboardShortcut) -> bool {
        if a.logical_key != b.logical_key {
            return false;
        }

        if a.modifiers.alt != b.modifiers.alt {
            return false;
        }

        if a.modifiers.shift != b.modifiers.shift {
            return false;
        }

        // On Non-Mac, command is interpreted as ctrl!
        (a.modifiers.command || a.modifiers.ctrl) == (b.modifiers.command || b.modifiers.ctrl)
    }

    use strum::IntoEnumIterator as _;

    for os in [
        OperatingSystem::Mac,
        OperatingSystem::Windows,
        OperatingSystem::Nix,
    ] {
        for a_cmd in UICommand::iter() {
            for a_shortcut in a_cmd.kb_shortcuts(os) {
                for b_cmd in UICommand::iter() {
                    if a_cmd == b_cmd {
                        continue;
                    }
                    for b_shortcut in b_cmd.kb_shortcuts(os) {
                        assert!(
                            !clashes(a_shortcut, b_shortcut),
                            "Command '{a_cmd:?}' and '{b_cmd:?}' have overlapping keyboard shortcuts: {:?} vs {:?}",
                            a_shortcut.format(&egui::ModifierNames::NAMES, true),
                            b_shortcut.format(&egui::ModifierNames::NAMES, true),
                        );
                    }
                }
            }
        }
    }
}