// Copyright © SixtyFPS GmbH <info@slint.dev>
// SPDX-License-Identifier: GPL-3.0-only OR LicenseRef-Slint-Royalty-free-2.0 OR LicenseRef-Slint-Software-3.0

//! This file contains a generic implementation of the MenuBar and ContextMenu

import { Palette } from "std-widgets-impl.slint";

component MenuItemImpl {
    in property <bool> is-current;
    in property <MenuEntry> entry;

    callback set-current();
    callback clear-current();
    callback activate(entry : MenuEntry, y: length);

    background-layer := Rectangle {
        background: Palette.background;
        border-radius: 3px;
        border-width: 1px;

        HorizontalLayout {
            spacing: 7px;
            padding-left: 11px;
            padding-top: 4px;
            padding-bottom: 6px;

            menu-text := Text {
                text: entry.title;
                horizontal-stretch: 1;
                color: Palette.foreground;
            }

            if entry.has-sub-menu : Image {
                source: @image-url("../fluent/_arrow_forward.svg");
                colorize: menu-text.color;
                accessible-role: none;
            }
        }

        TouchArea {
            pointer-event(event) => {
                if event.kind == PointerEventKind.move && !root.is-current {
                    root.set-current()
                } else if event.kind == PointerEventKind.down && entry.has-sub-menu {
                    activate(entry, self.absolute-position.y);
                } else if event.kind == PointerEventKind.up
                        && self.mouse-y > 0 && self.mouse-y < self.height
                        && self.mouse-x > 0 && self.mouse-x < self.width {
                    // can't put this in `clicked` because then the menu would close causing a panic in the pointer-event
                    activate(entry, self.absolute-position.y);
                }
            }

            changed has-hover => {
                if !self.has-hover && root.is-current {
                    root.clear-current();
                }
            }
        }
    }

    states [
        is-current when root.is-current: {
            // FIXME: note that the fluent style uses the secondary color for highlighted item
            background-layer.background: Palette.accent-background;
            menu-text.color: Palette.accent-foreground;
        }
    ]
}

export component PopupMenuImpl inherits Window {
    in property <[MenuEntry]> entries: [];

    property <int> current: -1;
    property <length> px: 1rem / 14;

    callback sub-menu(menu-entry: MenuEntry) -> [MenuEntry];
    callback activated(menu-entry: MenuEntry);
    callback close();

    forward-focus: focus-scope;

    Rectangle {
        border-radius: 7px;
        border-color: Palette.border;
        border-width: 1px;
        background: Palette.background;
        drop-shadow-blur: 2px;
        drop-shadow-color: Palette.foreground.transparentize(0.5);
        min-width: 10rem;
    }

    focus-scope := FocusScope {
        layout := VerticalLayout {
            padding: 5px;

            for entry[index] in entries: MenuItemImpl {
                entry: entry;
                is-current: current == index;

                set-current => {
                    focus-scope.focus();
                    root.current = index;
                    open-sub-menu-after-timeout.running = true;
                }

                clear-current => {
                    root.current = -1;
                }

                activate(entry, y) => {
                    root.activate(entry, y);
                }
            }
        }

        open-sub-menu-after-timeout := Timer {
            interval: 500ms;
            running: false;

            triggered => {
                self.running = false;

                if current >= 0 {
                    if entries[current].has-sub-menu {
                        activate(entries[current], y-pos(current));
                    } else {
                        sub-menu.close();
                    }
                }
            }
        }

        function y-pos(idx: int) -> length {
            layout.padding + idx * (layout.height - 2 * layout.padding) / entries.length
        }

        key-pressed(event) => {
            open-sub-menu-after-timeout.running = false;

            if event.text == Key.UpArrow {
                if current >= 1 {
                    current -= 1;
                } else {
                    current = entries.length - 1;
                }
                return accept;
            } else if event.text == Key.DownArrow {
                if current < entries.length - 1 {
                    current += 1;
                } else {
                    current = 0;
                }
                return accept;
            } else if event.text == Key.Return {
                if current >= 0 && current < entries.length {
                    activate(entries[current], y-pos(current));
                }
                return accept;
            } else if event.text == Key.RightArrow {
                if current >= 0 && current < entries.length && entries[current].has-sub-menu {
                    activate(entries[current], y-pos(current));
                }
                return accept;
            } else if event.text == Key.LeftArrow {
                // TODO: should close only if this menu is a sub menu
                root.close();
            }

            reject
        }
    }

    sub-menu := ContextMenuInternal {
        x: 0; y: 0; width: 0; height: 0;

        sub-menu(entry) => { root.sub-menu(entry); }

        activated(entry) => {
            root.activated(entry);
            root.close();
        }
    }

    function activate(entry : MenuEntry, y: length) {
        open-sub-menu-after-timeout.running = false;
        if entry.has-sub-menu {
            sub-menu.entries = root.sub-menu(entry);
            sub-menu.show({
                x: root.width,
                y: y - sub-menu.absolute-position.y,
            });
        } else {
            activated(entry);
            close();
        }
    }
}

export component MenuBarImpl {
    callback activated(MenuEntry);
    callback sub-menu(MenuEntry) -> [MenuEntry];

    property <[MenuEntry]> entries;
    property <length> px: 1rem / 14;

    preferred-width: 100%;
    height: layout.preferred-height;

    layout := HorizontalLayout {
        padding: 5px;
        alignment: start;
        spacing: 1px;

        for entry in entries: e := Rectangle {
            // FIXME: note that the fluent style uses the secondary color for highlighted item
            background: touch-area.has-hover || touch-area.pressed ? Palette.accent-background : transparent;
            border-radius: 3px;

            HorizontalLayout {
                padding: 11px;
                padding-top: 4px;
                padding-bottom: 6px;

                Text {
                    text: entry.title;
                    color: touch-area.has-hover || touch-area.pressed ? Palette.accent-foreground : Palette.foreground;
                }
            }

            touch-area := TouchArea {
                clicked => {
                    context-menu.entries = root.sub-menu(entry);
                    context-menu.show({ x: e.x, y: root.height });
                }
            }
        }

        // For the default size when there is no entries
        Rectangle {
            HorizontalLayout {
                padding-top: 0.4rem;
                padding-bottom: 0.6rem;

                Text {
                    text: "";
                }
            }
        }
    }


    context-menu := ContextMenuInternal {
        activated(entry) => { root.activated(entry); self.close(); }
        sub-menu(entry) => { root.sub-menu(entry); }
    }
}