use {
    crate::{enums::ReedlineEvent, EditCommand},
    crossterm::event::{KeyCode, KeyModifiers},
    serde::{Deserialize, Serialize},
    std::collections::HashMap,
};

#[derive(Serialize, Deserialize, Clone, PartialEq, Eq, Hash, Debug)]
pub struct KeyCombination {
    pub modifier: KeyModifiers,
    pub key_code: KeyCode,
}

/// Main definition of editor keybindings
#[derive(Serialize, Deserialize, Clone, Debug)]
pub struct Keybindings {
    /// Defines a keybinding for a reedline event
    pub bindings: HashMap<KeyCombination, ReedlineEvent>,
}

impl Default for Keybindings {
    fn default() -> Self {
        Self::new()
    }
}

impl Keybindings {
    /// New keybining
    pub fn new() -> Self {
        Self {
            bindings: HashMap::new(),
        }
    }

    /// Defines an empty keybinding object
    pub fn empty() -> Self {
        Self::new()
    }

    /// Adds a keybinding
    ///
    /// # Panics
    ///
    /// If `command` is an empty [`ReedlineEvent::UntilFound`]
    pub fn add_binding(
        &mut self,
        modifier: KeyModifiers,
        key_code: KeyCode,
        command: ReedlineEvent,
    ) {
        if let ReedlineEvent::UntilFound(subcommands) = &command {
            assert!(
                !subcommands.is_empty(),
                "UntilFound should contain a series of potential events to handle"
            );
        }

        let key_combo = KeyCombination { modifier, key_code };
        self.bindings.insert(key_combo, command);
    }

    /// Find a keybinding based on the modifier and keycode
    pub fn find_binding(&self, modifier: KeyModifiers, key_code: KeyCode) -> Option<ReedlineEvent> {
        let key_combo = KeyCombination { modifier, key_code };
        self.bindings.get(&key_combo).cloned()
    }

    /// Remove a keybinding
    ///
    /// Returns `Some(ReedlineEvent)` if the key combination was previously bound to a particular [`ReedlineEvent`]
    pub fn remove_binding(
        &mut self,
        modifier: KeyModifiers,
        key_code: KeyCode,
    ) -> Option<ReedlineEvent> {
        let key_combo = KeyCombination { modifier, key_code };
        self.bindings.remove(&key_combo)
    }

    /// Get assigned keybindings
    pub fn get_keybindings(&self) -> &HashMap<KeyCombination, ReedlineEvent> {
        &self.bindings
    }
}

pub fn edit_bind(command: EditCommand) -> ReedlineEvent {
    ReedlineEvent::Edit(vec![command])
}

/// Add the basic special keybindings
///
/// `Ctrl-C`, `Ctrl-D`, `Ctrl-O`, `Ctrl-R`
/// + `Esc`
/// + `Ctrl-O` to open the external editor
pub fn add_common_control_bindings(kb: &mut Keybindings) {
    use KeyCode as KC;
    use KeyModifiers as KM;

    kb.add_binding(KM::NONE, KC::Esc, ReedlineEvent::Esc);
    kb.add_binding(KM::CONTROL, KC::Char('c'), ReedlineEvent::CtrlC);
    kb.add_binding(KM::CONTROL, KC::Char('d'), ReedlineEvent::CtrlD);
    kb.add_binding(KM::CONTROL, KC::Char('l'), ReedlineEvent::ClearScreen);
    kb.add_binding(KM::CONTROL, KC::Char('r'), ReedlineEvent::SearchHistory);
    kb.add_binding(KM::CONTROL, KC::Char('o'), ReedlineEvent::OpenEditor);
}
/// Add the arrow navigation and its `Ctrl` variants
pub fn add_common_navigation_bindings(kb: &mut Keybindings) {
    use EditCommand as EC;
    use KeyCode as KC;
    use KeyModifiers as KM;

    // Arrow keys without modifier
    kb.add_binding(
        KM::NONE,
        KC::Up,
        ReedlineEvent::UntilFound(vec![ReedlineEvent::MenuUp, ReedlineEvent::Up]),
    );
    kb.add_binding(
        KM::NONE,
        KC::Down,
        ReedlineEvent::UntilFound(vec![ReedlineEvent::MenuDown, ReedlineEvent::Down]),
    );
    kb.add_binding(
        KM::NONE,
        KC::Left,
        ReedlineEvent::UntilFound(vec![ReedlineEvent::MenuLeft, ReedlineEvent::Left]),
    );
    kb.add_binding(
        KM::NONE,
        KC::Right,
        ReedlineEvent::UntilFound(vec![
            ReedlineEvent::HistoryHintComplete,
            ReedlineEvent::MenuRight,
            ReedlineEvent::Right,
        ]),
    );

    // Ctrl Left and Right
    kb.add_binding(
        KM::CONTROL,
        KC::Left,
        edit_bind(EC::MoveWordLeft { select: false }),
    );
    kb.add_binding(
        KM::CONTROL,
        KC::Right,
        ReedlineEvent::UntilFound(vec![
            ReedlineEvent::HistoryHintWordComplete,
            edit_bind(EC::MoveWordRight { select: false }),
        ]),
    );
    // Home/End & ctrl+a/ctrl+e
    kb.add_binding(
        KM::NONE,
        KC::Home,
        edit_bind(EC::MoveToLineStart { select: false }),
    );
    kb.add_binding(
        KM::CONTROL,
        KC::Char('a'),
        edit_bind(EC::MoveToLineStart { select: false }),
    );
    kb.add_binding(
        KM::NONE,
        KC::End,
        ReedlineEvent::UntilFound(vec![
            ReedlineEvent::HistoryHintComplete,
            edit_bind(EC::MoveToLineEnd { select: false }),
        ]),
    );
    kb.add_binding(
        KM::CONTROL,
        KC::Char('e'),
        ReedlineEvent::UntilFound(vec![
            ReedlineEvent::HistoryHintComplete,
            edit_bind(EC::MoveToLineEnd { select: false }),
        ]),
    );
    // Ctrl Home/End
    kb.add_binding(
        KM::CONTROL,
        KC::Home,
        edit_bind(EC::MoveToStart { select: false }),
    );
    kb.add_binding(
        KM::CONTROL,
        KC::End,
        edit_bind(EC::MoveToEnd { select: false }),
    );
    // EMACS arrows
    kb.add_binding(
        KM::CONTROL,
        KC::Char('p'),
        ReedlineEvent::UntilFound(vec![ReedlineEvent::MenuUp, ReedlineEvent::Up]),
    );
    kb.add_binding(
        KM::CONTROL,
        KC::Char('n'),
        ReedlineEvent::UntilFound(vec![ReedlineEvent::MenuDown, ReedlineEvent::Down]),
    );
}

/// Add basic functionality to edit
///
/// `Delete`, `Backspace` and the basic variants do delete words
pub fn add_common_edit_bindings(kb: &mut Keybindings) {
    use EditCommand as EC;
    use KeyCode as KC;
    use KeyModifiers as KM;
    kb.add_binding(KM::NONE, KC::Backspace, edit_bind(EC::Backspace));
    kb.add_binding(KM::NONE, KC::Delete, edit_bind(EC::Delete));
    kb.add_binding(KM::CONTROL, KC::Backspace, edit_bind(EC::BackspaceWord));
    kb.add_binding(KM::CONTROL, KC::Delete, edit_bind(EC::DeleteWord));
    // Base commands should not affect cut buffer
    kb.add_binding(KM::CONTROL, KC::Char('h'), edit_bind(EC::Backspace));
    kb.add_binding(KM::CONTROL, KC::Char('w'), edit_bind(EC::BackspaceWord));
    #[cfg(feature = "system_clipboard")]
    kb.add_binding(
        KM::CONTROL | KM::SHIFT,
        KC::Char('x'),
        edit_bind(EC::CutSelectionSystem),
    );
    #[cfg(feature = "system_clipboard")]
    kb.add_binding(
        KM::CONTROL | KM::SHIFT,
        KC::Char('c'),
        edit_bind(EC::CopySelectionSystem),
    );
    #[cfg(feature = "system_clipboard")]
    kb.add_binding(
        KM::CONTROL | KM::SHIFT,
        KC::Char('v'),
        edit_bind(EC::PasteSystem),
    );
}

pub fn add_common_selection_bindings(kb: &mut Keybindings) {
    use EditCommand as EC;
    use KeyCode as KC;
    use KeyModifiers as KM;

    kb.add_binding(
        KM::SHIFT,
        KC::Left,
        edit_bind(EC::MoveLeft { select: true }),
    );
    kb.add_binding(
        KM::SHIFT,
        KC::Right,
        edit_bind(EC::MoveRight { select: true }),
    );
    kb.add_binding(
        KM::SHIFT | KM::CONTROL,
        KC::Left,
        edit_bind(EC::MoveWordLeft { select: true }),
    );
    kb.add_binding(
        KM::SHIFT | KM::CONTROL,
        KC::Right,
        edit_bind(EC::MoveWordRight { select: true }),
    );
    kb.add_binding(
        KM::SHIFT,
        KC::End,
        edit_bind(EC::MoveToLineEnd { select: true }),
    );
    kb.add_binding(
        KM::SHIFT | KM::CONTROL,
        KC::End,
        edit_bind(EC::MoveToEnd { select: true }),
    );
    kb.add_binding(
        KM::SHIFT,
        KC::Home,
        edit_bind(EC::MoveToLineStart { select: true }),
    );
    kb.add_binding(
        KM::SHIFT | KM::CONTROL,
        KC::Home,
        edit_bind(EC::MoveToStart { select: true }),
    );
    kb.add_binding(
        KM::CONTROL | KM::SHIFT,
        KC::Char('a'),
        edit_bind(EC::SelectAll),
    );
}