// Copyright (C) 2026 Danilo M. <danix@danix.xyz>
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License version 2 as
// published by the Free Software Foundation.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.

import Quickshell
import QtQuick

// The settings window: a normal toplevel, not a layer surface, so Hyprland
// tiles or floats it like any app. The drawer is the quick area; things set
// once and left alone live here. It hosts the pages of the modules that
// declare `settings: true`, from the same module list as the drawer, with a
// searchable list of them down the left and an About page as the landing.
Scope {
    id: root

    property list<QtObject> modules
    property bool open: false
    property string page: ""

    readonly property var pages: {
        const out = [];
        for (let i = 0; i < root.modules.length; i++)
            if (root.modules[i].settings) out.push(root.modules[i]);
        return out;
    }
    property string query: ""

    // The sidebar's width: the saved one, or the live one while its edge is
    // dragged (-1 when not), saved once on release.
    property real dragWidth: -1
    readonly property real sideWidth: root.dragWidth >= 0 ? root.dragWidth : Prefs.settingsSidebar

    // What the search keeps, as {mod, hit, key}. A page matched by its label
    // or a keyword has key "" and opens at the top; hit is the keyword when
    // the label did not match. Then each row inside a page that matches, from
    // the module's searchItems, with key naming that row.
    readonly property int perPage: 8
    readonly property var found: {
        const q = root.query.trim().toLowerCase();
        const out = [];
        for (const m of root.pages) {
            if (q === "" || m.label.toLowerCase().includes(q) || m.name.includes(q))
                out.push({ mod: m, hit: "", key: "" });
            else {
                const k = Array.from(m.keywords).find(w => w.toLowerCase().includes(q));
                if (k !== undefined) out.push({ mod: m, hit: k, key: "" });
            }
            if (q === "") continue;
            // ponytail: the first perPage rows per page; a narrower query finds the rest.
            for (const it of m.searchItems.filter(it => it.text.toLowerCase().includes(q)).slice(0, root.perPage))
                out.push({ mod: m, hit: it.text, key: it.key });
        }
        return out;
    }

    // The page is shown first so the Loader holds it, then asked to reveal.
    signal reveal(string key)
    function go(entry) {
        root.page = entry.mod.name;
        if (entry.key) root.reveal(entry.key);
    }

    // The search index is the modules' own copy of their rows, reread on
    // every open so it matches what the pages will show.
    onOpenChanged: if (root.open) for (const m of root.pages) m.refresh()

    // Null is the landing page.
    readonly property QtObject current: root.pages.find(m => m.name === root.page) ?? null

    // An unknown or empty name opens the landing page.
    function show(name) { root.page = name; root.open = true; }
    // One step out: a page to the landing page, the landing page closes.
    function back() {
        if (root.current) root.page = "";
        else root.close();
    }
    function close() { root.open = false; root.page = ""; root.query = ""; }

    LazyLoader {
        active: root.open

        FloatingWindow {
            title: "Settings"
            implicitWidth: 900
            implicitHeight: 640
            color: Theme.base
            onClosed: root.close()

            Item {
                anchors.fill: parent
                focus: true
                Keys.onEscapePressed: root.back()

                // Search: filters the list below by label and by each
                // module's keywords, the settings buried in its page. Enter
                // opens the first match; Escape clears, then steps out.
                Rectangle {
                    id: search
                    anchors { top: parent.top; left: parent.left; margins: 12 }
                    width: root.sideWidth
                    height: 34
                    radius: 8
                    color: Theme.surface

                    TextInput {
                        id: searchIn
                        anchors { fill: parent; leftMargin: 10; rightMargin: 30 }
                        verticalAlignment: TextInput.AlignVCenter
                        clip: true
                        selectByMouse: true
                        color: Theme.text
                        font { family: Theme.fontFamily; pixelSize: Theme.fontSize - 2 }
                        text: root.query
                        onTextEdited: root.query = text
                        onAccepted: if (root.found.length) root.go(root.found[0])
                        Keys.onEscapePressed: event => {
                            if (root.query !== "") root.query = "";
                            else event.accepted = false;
                        }
                        Text {
                            anchors.verticalCenter: parent.verticalCenter
                            visible: parent.text === ""
                            text: "Search settings"
                            color: Theme.subtext
                            font: parent.font
                        }
                    }

                    // Clear, there only while something is typed.
                    Text {
                        anchors { right: parent.right; rightMargin: 10; verticalCenter: parent.verticalCenter }
                        visible: root.query !== ""
                        // nf-fa-xmark, present in Inconsolata Nerd Font.
                        text: ""
                        font { family: Theme.iconFamily; pixelSize: Theme.fontSize - 2 }
                        color: clearArea.containsMouse ? Theme.text : Theme.subtext

                        MouseArea {
                            id: clearArea
                            anchors { fill: parent; margins: -6 }
                            hoverEnabled: true
                            cursorShape: Qt.PointingHandCursor
                            onClicked: { root.query = ""; searchIn.forceActiveFocus(); }
                        }
                    }
                }

                ListView {
                    id: side
                    anchors { top: search.bottom; left: parent.left; bottom: parent.bottom; margins: 12 }
                    width: root.sideWidth
                    spacing: 4
                    model: root.found

                    delegate: Rectangle {
                        id: entry
                        required property var modelData
                        readonly property bool selected: root.current === modelData.mod && modelData.key === ""
                        width: side.width
                        height: modelData.hit ? 46 : 36
                        radius: 8
                        color: selected ? Qt.alpha(Theme.accent, 0.22)
                             : area.containsMouse ? Qt.alpha(Theme.text, 0.06) : "transparent"

                        Text {
                            id: entryIcon
                            anchors { left: parent.left; leftMargin: 10; verticalCenter: parent.verticalCenter }
                            text: entry.modelData.mod.icon
                            font { family: Theme.iconFamily; pixelSize: Theme.fontSize }
                            color: Theme.text
                        }
                        Column {
                            anchors { left: entryIcon.right; leftMargin: 10; right: parent.right; rightMargin: 8
                                      verticalCenter: parent.verticalCenter }
                            Text {
                                text: entry.modelData.mod.label
                                font { family: Theme.fontFamily; pixelSize: Theme.fontSize - 2 }
                                color: Theme.text
                            }
                            // Which buried setting matched, when the label did not.
                            Text {
                                visible: entry.modelData.hit !== ""
                                width: parent.width
                                elide: Text.ElideRight
                                text: entry.modelData.hit
                                font { family: Theme.fontFamily; pixelSize: Theme.fontSize - 5 }
                                color: Theme.subtext
                            }
                        }

                        MouseArea {
                            id: area
                            anchors.fill: parent
                            hoverEnabled: true
                            cursorShape: Qt.PointingHandCursor
                            onClicked: root.go(entry.modelData)
                        }
                    }
                }

                Text {
                    anchors { top: search.bottom; left: parent.left; margins: 12; leftMargin: 22 }
                    visible: root.found.length === 0
                    text: "Nothing matches"
                    font { family: Theme.fontFamily; pixelSize: Theme.fontSize - 3 }
                    color: Theme.subtext
                }

                Rectangle {
                    id: rule
                    anchors { top: parent.top; bottom: parent.bottom; left: side.right; leftMargin: 12 }
                    width: 1
                    color: grip.containsMouse || grip.pressed ? Qt.alpha(Theme.accent, 0.6) : Qt.alpha(Theme.text, 0.12)
                }

                // The rule is the sidebar's edge: drag it to resize.
                MouseArea {
                    id: grip
                    anchors { top: parent.top; bottom: parent.bottom; horizontalCenter: rule.horizontalCenter }
                    width: 10
                    hoverEnabled: true
                    cursorShape: Qt.SplitHCursor
                    onPositionChanged: mouse => {
                        if (!pressed) return;
                        // The rule sits 12px right of the sidebar, which starts 12px in.
                        const x = mapToItem(parent, mouse.x, 0).x - 24;
                        root.dragWidth = Math.max(Prefs.sidebarMin, Math.min(Prefs.sidebarMax, x));
                    }
                    onReleased: {
                        if (root.dragWidth >= 0) Prefs.setSettingsSidebar(root.dragWidth);
                        root.dragWidth = -1;
                    }
                }

                // The landing page, where back returns to: what this shell is,
                // centred in the space beside the sidebar.
                Item {
                    anchors { top: parent.top; right: parent.right; bottom: parent.bottom; left: rule.right; margins: 16 }
                    visible: root.current === null

                    Column {
                        anchors.centerIn: parent
                        width: Math.min(parent.width, 560)
                        spacing: 12

                        Text {
                            width: parent.width
                            horizontalAlignment: Text.AlignHCenter
                            text: "About"
                            font { family: Theme.fontFamily; pixelSize: Theme.fontSize + 2; bold: true }
                            color: Theme.text
                        }

                        Text {
                            width: parent.width
                            horizontalAlignment: Text.AlignHCenter
                            wrapMode: Text.Wrap
                            textFormat: Text.PlainText
                            lineHeight: 1.25
                            font { family: Theme.fontFamily; pixelSize: Theme.fontSize - 2 }
                            color: Theme.text
                            text: "A desktop shell for Hyprland, built on Quickshell.\n\n"
                                + "SUPER alone opens the drawer, the quick area: notifications, sound, "
                                + "network, bluetooth, mail, VMs, performance, the clipboard and the "
                                + "rest of what changes during the day. The island at the top of the "
                                + "main screen carries the clock, volume, tray, keyboard layout and "
                                + "calendar, and SUPER+Home opens the assistant.\n\n"
                                + "This window holds what is set once and left alone. Pick a page on "
                                + "the left, or search for a setting by name."
                        }

                        Text {
                            width: parent.width
                            horizontalAlignment: Text.AlignHCenter
                            wrapMode: Text.Wrap
                            text: "GPLv2. Colours follow the wallpaper through unified-desktop-theme."
                            font { family: Theme.fontFamily; pixelSize: Theme.fontSize - 4 }
                            color: Theme.subtext
                        }
                    }
                }

                Loader {
                    id: pageLoader
                    anchors { top: parent.top; right: parent.right; bottom: parent.bottom; left: rule.right; margins: 16 }
                    sourceComponent: root.current?.page ?? null

                    // The Page's back arrow steps out to the landing page,
                    // dismiss closes the window, and go() moves to another
                    // settings page by name.
                    Connections {
                        target: root
                        function onReveal(key) { if (pageLoader.item?.reveal) pageLoader.item.reveal(key); }
                    }

                    onLoaded: {
                        if (item && item.back) item.back.connect(root.back);
                        if (item && item.dismiss) item.dismiss.connect(root.close);
                        if (item && item.go) item.go.connect(name => root.page = name);
                    }

                    Binding {
                        target: pageLoader.item
                        property: "icon"
                        value: root.current ? root.current.icon : ""
                        when: pageLoader.item !== null
                    }
                }
            }
        }
    }
}