// 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

import { Button, Palette, ScrollView, VerticalBox, GroupBox, LineEdit } from "std-widgets.slint";

export struct ComponentItem {
    name: string,
    defined_at: string,
    is_user_defined: bool,
    is_currently_shown: bool,
}

export struct ComponentListItem {
    category: string,
    components: [ComponentItem]
}

export component ComponentList {
    in property <[ComponentListItem]> known-components;

    in property <length> preview-area-position-x;
    in property <length> preview-area-position-y;
    in property <length> preview-area-width;
    in property <length> preview-area-height;

    private property <length> list-spacing: 6px;

    out property <bool> over-target;

    pure callback can-drop(string/* component_type */, length/* x */, length/* y */, bool/* on-drop-area */) -> bool;
    callback drop(string/* component_type */, length/* x */, length/* y */);
    callback add_new_component();
    callback rename_component(string/* old_name */, string/* defined_at */, string/* new_name */);
    callback show_preview_for(string/* name */, string/*url*/);

    private property <bool> preview-visible: preview-area-width > 0px && preview-area-height > 0px;
    private property <int> editing-in-category: -1;

    function start-edit-in-category(category-index: int) {
        self.editing-in-category = category-index;
    }

    VerticalBox {
        Text {
            text: @tr("Library");
            horizontal-alignment: center;
            font-size: 1.4rem;
            font-weight: 800;
        }

        ScrollView {
            VerticalLayout {
                spacing: root.list-spacing;
                for cli[index] in root.known-components: category := VerticalLayout {
                    private property <int> my-category-index: index;
                    private property <int> editing-component-index: -1;

                    function edit-component(component-index: int) {
                        root.start-edit-in-category(self.my-category-index);
                        self.editing-component-index = component-index;
                    }
                    
                    Rectangle {
                        height: title.preferred-height + 10px;
                        background: Palette.alternate-background;
                        title := Text {
                            font-size: 1.2rem;
                            font-weight: 800;
                            text: cli.category;
                        }
                    }

                    for ci[index] in cli.components: component := TouchArea {
                        private property <length> drop-x: self.absolute-position.x + self.mouse-x - root.preview-area-position-x;
                        private property <length> drop-y: self.absolute-position.y + self.mouse-y - root.preview-area-position-y;
                        private property <bool> on-drop-area:
                            drop-x >= 0 && drop-x <= root.preview-area-width && drop-y >= 0 && drop-y <= root.preview-area-height;
                        private property <bool> can-drop-here: !self.data.is-currently-shown && root.can-drop(self.data.name, drop-x, drop-y, on-drop-area);
                        private property <ComponentItem> data: ci;
                        private property <int> my-index: index; 

                        enabled: root.preview-visible;
                        width: 100%;

                        private property <bool> edit-me: self.data.is-user-defined && root.editing-in-category == category.my-category-index && category.editing-component-index == self.my-index;

                        VerticalLayout {
                            if component.edit-me: LineEdit {
                                horizontal-alignment: center;
                                text: component.data.name;
                                width: 100%;

                                accepted(name) => {
                                    category.edit-component(-1);
                                    root.rename_component(component.data.name, component.data.defined_at, name);
                                }
                            }
                            if !component.edit-me: Rectangle {
                                t := Text {
                                    text: component.data.name;
                                }

                                height: t.preferred-height + 2 * root.list-spacing;
                                width: 100%;
                            }
                        }

                        if ci.is_user_defined && !ci.is-currently-shown: preview-button := Button {
                            x: parent.x + parent.width - self.width - 4px;
                            text: "P";
                            width: self.min-width;
                            height: self.min-height;

                            clicked() => {
                                root.show_preview_for(component.data.name, component.data.defined_at)
                            }
                        }

                        pointer-event(event) => {
                            if (self.can-drop-here && event.kind == PointerEventKind.up && event.button == PointerEventButton.left) {
                                root.drop(self.data.name, drop-x, drop-y);
                            }
                        }
                        clicked => {
                            category.edit-component(self.my-index);
                        }
                        states [
                            dragging-no-drop when self.pressed && !self.can-drop-here: {
                                mouse-cursor: MouseCursor.no-drop;
                            }
                            dragging-can-drop when self.pressed && self.can-drop-here: {
                                mouse-cursor: MouseCursor.copy;
                            }
                            normal when !self.pressed: {
                                mouse-cursor: MouseCursor.default;
                            }
                        ]
                    }

                    if cli.category == "User Defined": Button {
                        height: self.min-height;
                        text: "Add Component";
                        clicked => {
                            root.add_new_component();
                        }
                    }
                }
            }
        }
    }
}