1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105

use crate::{
    client::ClientHandle,
    editor::{Editor, EditorContext, EditorFlow, KeysIterator},
    plugin::PluginHandle,
};

mod command;
mod insert;
mod normal;
pub(crate) mod picker;
pub(crate) mod readline;

pub(crate) trait ModeState {
    fn on_enter(editor: &mut Editor);
    fn on_exit(editor: &mut Editor);
    fn on_keys(
        ctx: &mut EditorContext,
        client_handle: ClientHandle,
        keys: &mut KeysIterator,
    ) -> Option<EditorFlow>;
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub enum ModeKind {
    Normal,
    Insert,
    Command,
    ReadLine,
    Picker,
    Plugin,
}

impl Default for ModeKind {
    fn default() -> Self {
        Self::Normal
    }
}

#[derive(Default)]
pub struct Mode {
    kind: ModeKind,

    pub normal_state: normal::State,
    pub insert_state: insert::State,
    pub command_state: command::State,
    pub readline_state: readline::State,
    pub picker_state: picker::State,
    pub plugin_handle: Option<PluginHandle>,
}

impl Mode {
    pub fn kind(&self) -> ModeKind {
        self.kind
    }

    pub(crate) fn change_to(editor: &mut Editor, next: ModeKind) {
        if editor.mode.kind == next {
            return;
        }

        match editor.mode.kind {
            ModeKind::Normal => normal::State::on_exit(editor),
            ModeKind::Insert => insert::State::on_exit(editor),
            ModeKind::Command => command::State::on_exit(editor),
            ModeKind::ReadLine => readline::State::on_exit(editor),
            ModeKind::Picker => picker::State::on_exit(editor),
            ModeKind::Plugin => editor.mode.plugin_handle = None,
        }

        editor.mode.kind = next;

        match editor.mode.kind {
            ModeKind::Normal => normal::State::on_enter(editor),
            ModeKind::Insert => insert::State::on_enter(editor),
            ModeKind::Command => command::State::on_enter(editor),
            ModeKind::ReadLine => readline::State::on_enter(editor),
            ModeKind::Picker => picker::State::on_enter(editor),
            ModeKind::Plugin => (),
        }
    }

    pub(crate) fn on_keys(
        ctx: &mut EditorContext,
        client_handle: ClientHandle,
        keys: &mut KeysIterator,
    ) -> Option<EditorFlow> {
        match ctx.editor.mode.kind {
            ModeKind::Normal => normal::State::on_keys(ctx, client_handle, keys),
            ModeKind::Insert => insert::State::on_keys(ctx, client_handle, keys),
            ModeKind::Command => command::State::on_keys(ctx, client_handle, keys),
            ModeKind::ReadLine => readline::State::on_keys(ctx, client_handle, keys),
            ModeKind::Picker => picker::State::on_keys(ctx, client_handle, keys),
            ModeKind::Plugin => match ctx.editor.mode.plugin_handle {
                Some(plugin_handle) => {
                    let on_keys = ctx.plugins.get(plugin_handle).on_keys;
                    on_keys(plugin_handle, ctx, client_handle, keys)
                }
                None => {
                    Mode::change_to(&mut ctx.editor, ModeKind::default());
                    None
                }
            },
        }
    }
}