// 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 Quickshell.Io
import QtQuick
import QtQuick.Controls

// 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: ""

    // Grouped: a group's pages together, groups in the order their first
    // page is declared, pages in declaration order within a group.
    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]);
        const order = [];
        for (const m of out) if (!order.includes(m.group)) order.push(m.group);
        return out.map((m, i) => ({ m, i }))
            .sort((a, b) => order.indexOf(a.m.group) - order.indexOf(b.m.group) || a.i - b.i)
            .map(x => x.m);
    }
    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 {
            id: win
            title: "Settings"
            implicitWidth: 900
            implicitHeight: 640
            color: Theme.base
            onClosed: root.close()

            // Window-wide, so it works with the focus in any field, unlike
            // Escape, which a field may take first.
            Shortcut {
                sequence: "Ctrl+Q"
                onActivated: root.close()
            }

            // A titlebar of its own, since Hyprland draws none: maximize, to
            // fill the monitor and back, and close.
            Row {
                id: titlebar
                anchors { top: parent.top; right: parent.right; topMargin: 8; rightMargin: 12 }
                height: 28
                spacing: 6

                Repeater {
                    // nf-fa-compress / nf-fa-expand and nf-fa-xmark, present
                    // in Inconsolata Nerd Font.
                    model: [
                        { icon: win.maximized ? "\uf066" : "\uf065", act: () => win.maximized = !win.maximized, danger: false },
                        { icon: "\uf00d", act: () => root.close(), danger: true },
                    ]
                    Rectangle {
                        required property var modelData
                        width: 28
                        height: 28
                        radius: 14
                        color: btnArea.containsMouse ? Qt.alpha(modelData.danger ? Theme.red : Theme.accent, 0.25) : "transparent"

                        Text {
                            anchors.centerIn: parent
                            text: parent.modelData.icon
                            font { family: Theme.iconFamily; pixelSize: Theme.fontSize - 2 }
                            color: Theme.text
                        }

                        MouseArea {
                            id: btnArea
                            anchors.fill: parent
                            hoverEnabled: true
                            cursorShape: Qt.PointingHandCursor
                            onClicked: parent.modelData.act()
                        }
                    }
                }
            }

            Text {
                anchors { horizontalCenter: parent.horizontalCenter; verticalCenter: titlebar.verticalCenter }
                text: "Keystone Settings"
                font { family: Theme.fontFamily; pixelSize: Theme.fontSize - 2; bold: true }
                color: Theme.subtext
            }

            Item {
                anchors { top: titlebar.bottom; left: parent.left; right: parent.right; bottom: parent.bottom }
                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
                    // Without it a scrolled list draws over the search box.
                    clip: true
                    model: root.found

                    // A group's heading above its first entry, then the entry.
                    delegate: Column {
                        id: slot
                        required property var modelData
                        required property int index
                        width: side.width

                        Text {
                            visible: slot.modelData.mod.group !== ""
                                     && (slot.index === 0 || root.found[slot.index - 1].mod.group !== slot.modelData.mod.group)
                            leftPadding: 10
                            topPadding: slot.index === 0 ? 4 : 14
                            bottomPadding: 4
                            text: slot.modelData.mod.group.toUpperCase()
                            font { family: Theme.fontFamily; pixelSize: Theme.fontSize - 5; bold: true; letterSpacing: 1 }
                            color: Theme.overlay
                        }

                        Rectangle {
                            id: entry
                            readonly property var modelData: slot.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
                                    // Unsaved changes in that page's draft.
                                    Rectangle {
                                        visible: entry.modelData.mod.dirty
                                        anchors { left: parent.right; leftMargin: 6; verticalCenter: parent.verticalCenter }
                                        width: 6; height: 6; radius: 3
                                        color: Theme.yellow
                                    }
                                }
                                // 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 {
                    id: landing
                    anchors { top: parent.top; right: parent.right; bottom: parent.bottom; left: rule.right; margins: 16 }
                    visible: root.current === null

                    // Versions read from the installed package names, as
                    // [label, package]. A package not installed shows a dash.
                    readonly property var base: [
                        ["glibc", "glibc"], ["Qt", "qt6"], ["Mesa", "mesa"], ["Wayland", "wayland"],
                        ["PipeWire", "pipewire"], ["D-Bus", "dbus"], ["elogind", "elogind"],
                        ["OpenSSL", "openssl"], ["FFmpeg", "ffmpeg"],
                    ]
                    readonly property var dev: [
                        ["GCC", "gcc"], ["LLVM", "llvm"], ["binutils", "binutils"], ["CMake", "cmake"],
                        ["Meson", "meson"], ["Git", "git"], ["Python", "python3"], ["Perl", "perl"],
                        ["Rust", "rust"], ["Node.js", "nodejs"],
                    ]

                    // System facts, sampled once per open of the window: the
                    // Slackware card from conky-theme-udt plus the machine.
                    // Ages are epochs, turned into text here.
                    property var sys: ({})
                    Process {
                        running: true
                        command: ["sh", "-c",
                            "printf 'version\\t%s\\n' \"$(cat /etc/slackware-version)\"\n"
                            // The trailing slash: /var/log/packages is a symlink.
                            + "printf 'packages\\t%s\\n' \"$(ls -1 /var/log/packages/ | wc -l)\"\n"
                            + "printf 'changelog\\t%s\\n' \"$(stat -c %Y /var/lib/slackpkg/ChangeLog.txt)\"\n"
                            // Filesystem birth time, 0 where the filesystem keeps none.
                            + "printf 'birth\\t%s\\n' \"$(stat -c %W /)\"\n"
                            + "printf 'kernel\\t%s\\n' \"$(uname -r)\"\n"
                            + "printf 'host\\t%s\\n' \"$(uname -n)\"\n"
                            + "printf 'uptime\\t%s\\n' \"$(cut -d' ' -f1 /proc/uptime)\"\n"
                            + "printf 'cpu\\t%s\\n' \"$(sed -n 's/^model name[^:]*: //p;T;q' /proc/cpuinfo)\"\n"
                            + "printf 'gpu\\t%s\\n' \"$(lspci | sed -n 's/.*\\(VGA\\|3D\\)[^:]*: //p' | head -1)\"\n"
                            + "printf 'memory\\t%s\\n' \"$(sed -n 's/^MemTotal: *\\([0-9]*\\).*/\\1/p' /proc/meminfo)\"\n"
                            + "printf 'hyprland\\t%s\\n' \"$(hyprctl version -j | jq -r .version)\"\n"
                            + "printf 'quickshell\\t%s\\n' \"$(qs --version | cut -d' ' -f2)\"\n"
                            // name-version-arch-build. The version must start
                            // with a digit, so gcc does not also match gcc-g++,
                            // and stops at an underscore, so qt6's snapshot
                            // suffix is dropped.
                            + "ls -1 /var/log/packages/ | sed -n 's/^\\("
                            + landing.base.concat(landing.dev).map(p => p[1]).join("\\|")
                            + "\\)-\\([0-9][^-_]*\\)[^-]*-[^-]*-[^-]*$/pkg:\\1\\t\\2/p'\n"]
                        stdout: StdioCollector {
                            onStreamFinished: {
                                const out = {};
                                for (const line of text.split("\n")) {
                                    const tab = line.indexOf("\t");
                                    if (tab > 0 && line.slice(tab + 1) !== "") out[line.slice(0, tab)] = line.slice(tab + 1);
                                }
                                landing.sys = out;
                            }
                        }
                    }

                    // Seconds as hours below two days, then days, as the conky card.
                    function age(s) {
                        if (!(s >= 0)) return "-";
                        return s < 172800 ? Math.floor(s / 3600) + "h" : Math.floor(s / 86400) + "d";
                    }
                    function pkgs(list) { return list.map(p => [p[0], sys["pkg:" + p[1]] ?? "-"]); }
                    readonly property real now: Date.now() / 1000
                    readonly property real changelogAge: sys.changelog > 0 ? now - sys.changelog : -1
                    readonly property var sections: [
                        { title: "System", rows: [
                            ["Version", (sys.version ?? "-").replace(/^Slackware\s+/, "")],
                            ["Packages", sys.packages ?? "-"],
                            ["Kernel", sys.kernel ?? "-"],
                            ["Installed", sys.birth > 0 ? age(now - sys.birth) + " ago" : "-"],
                            ["Host", sys.host ?? "-"],
                            ["Uptime", sys.uptime ? age(+sys.uptime) : "-"],
                            ["CPU", sys.cpu ?? "-"],
                            ["GPU", (sys.gpu ?? "-").replace(" Corporation", "")],
                            ["Memory", sys.memory ? (sys.memory / 1048576).toFixed(1) + " GiB" : "-"],
                            ["Hyprland", sys.hyprland ?? "-"],
                            ["Quickshell", sys.quickshell ?? "-"],
                        ] },
                        { title: "Base libraries", rows: pkgs(base) },
                        { title: "Development", rows: pkgs(dev) },
                    ]

                    Flickable {
                        id: landingFlick
                        anchors.fill: parent
                        contentHeight: about.height
                        clip: true
                        boundsBehavior: Flickable.StopAtBounds
                        ScrollBar.vertical: ScrollBar {}

                        Column {
                            id: about
                            // Centred while it fits, top-aligned once it scrolls.
                            x: (landingFlick.width - width) / 2
                            y: Math.max(0, (landingFlick.height - height) / 2)
                            width: Math.min(landingFlick.width - 16, 640)
                            spacing: 12

                            Text {
                                width: parent.width
                                horizontalAlignment: Text.AlignHCenter
                                text: "Keystone"
                                font { family: Theme.fontFamily; pixelSize: Theme.fontSize + 10; bold: true; letterSpacing: 2 }
                                color: Theme.accent
                            }

                            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"
                                    + "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
                            }

                            Rectangle {
                                width: parent.width
                                height: facts.implicitHeight + 28
                                radius: 10
                                color: Theme.surface

                                Column {
                                    id: facts
                                    anchors { fill: parent; margins: 14 }
                                    spacing: 4

                                    // The headline, as on the conky card: how long
                                    // since slackpkg's ChangeLog changed, green under
                                    // a day, yellow under a week, red past it.
                                    Item {
                                        width: parent.width
                                        height: 36
                                        Text {
                                            id: slackIcon
                                            anchors.verticalCenter: parent.verticalCenter
                                            // nf-linux-slackware, present in Inconsolata Nerd Font.
                                            text: ""
                                            font { family: Theme.iconFamily; pixelSize: Theme.fontSize + 8 }
                                            color: Theme.accent
                                        }
                                        Column {
                                            anchors { left: slackIcon.right; leftMargin: 10; verticalCenter: parent.verticalCenter }
                                            Text {
                                                text: "SLACKWARE"
                                                font { family: Theme.fontFamily; pixelSize: Theme.fontSize - 3; bold: true; letterSpacing: 1 }
                                                color: Theme.text
                                            }
                                            Text {
                                                text: "last slackpkg update"
                                                font { family: Theme.fontFamily; pixelSize: Theme.fontSize - 5 }
                                                color: Theme.subtext
                                            }
                                        }
                                        Text {
                                            anchors { right: parent.right; verticalCenter: parent.verticalCenter }
                                            text: landing.age(landing.changelogAge)
                                            font { family: Theme.fontFamily; pixelSize: Theme.fontSize + 8; bold: true }
                                            color: landing.changelogAge < 0 ? Theme.subtext
                                                 : landing.changelogAge < 86400 ? Theme.green
                                                 : landing.changelogAge < 604800 ? Theme.yellow : Theme.red
                                        }
                                    }

                                    Repeater {
                                        model: landing.sections
                                        Column {
                                            id: section
                                            required property var modelData
                                            width: facts.width
                                            spacing: 4

                                            Text {
                                                topPadding: 10
                                                bottomPadding: 2
                                                text: section.modelData.title.toUpperCase()
                                                font { family: Theme.fontFamily; pixelSize: Theme.fontSize - 5; bold: true; letterSpacing: 1 }
                                                color: Theme.overlay
                                            }

                                            // Two columns, filled row by row.
                                            Grid {
                                                id: cells
                                                columns: 2
                                                columnSpacing: 24
                                                rowSpacing: 4
                                                readonly property real cell: (facts.width - columnSpacing) / 2

                                                Repeater {
                                                    model: section.modelData.rows
                                                    Item {
                                                        required property var modelData
                                                        width: cells.cell
                                                        height: 20
                                                        Text {
                                                            id: key
                                                            text: parent.modelData[0]
                                                            font { family: Theme.fontFamily; pixelSize: Theme.fontSize - 4 }
                                                            color: Theme.subtext
                                                        }
                                                        Text {
                                                            anchors { right: parent.right; left: key.right; leftMargin: 12 }
                                                            horizontalAlignment: Text.AlignRight
                                                            elide: Text.ElideLeft
                                                            text: parent.modelData[1]
                                                            font { family: Theme.fontFamily; pixelSize: Theme.fontSize - 4 }
                                                            color: Theme.text
                                                        }
                                                    }
                                                }
                                            }
                                        }
                                    }
                                }
                            }
                        }
                    }
                }

                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
                    }
                }
            }
        }
    }
}