// What is on the disk, drawn as the disk.
//
// One bar whose segments add up to the whole filesystem, because the question
// people bring to this page is "what is taking my space" and the only answer
// that cannot mislead is one where the parts sum to the total. Four of the five
// segments are measured; the fifth is what is left over, and it is labelled as
// exactly that rather than being called "System" and quietly absorbing every
// measurement error in the other four.
//
// The legend carries the numbers. A bar this wide can hold a 2% segment but it
// cannot label one, and a segment nobody can name is decoration.

import QtQuick
import qs.config
import qs.services

Column {
    id: root

    readonly property var breakdown: Disks.breakdown ?? null

    readonly property var segments: {
        const source = root.breakdown?.segments ?? null;
        if (!source)
            return [];
        return [
            {
                key: "home",
                label: "Home",
                detail: "Your files, not counting caches",
                bytes: Number(source.home ?? 0),
                color: Theme.accent
            },
            {
                key: "applications",
                label: "Applications",
                detail: "Flatpak applications and the runtimes they share",
                bytes: Number(source.applications ?? 0),
                color: Theme.teal
            },
            {
                key: "caches",
                label: "Caches",
                detail: "~/.cache, rebuilt as applications run",
                bytes: Number(source.caches ?? 0),
                color: Theme.warn
            },
            {
                key: "system",
                label: "System & everything else",
                detail: "Whatever the measured segments do not account for",
                bytes: Number(source.system ?? 0),
                color: Theme.magenta
            },
            {
                key: "free",
                label: "Free",
                detail: "Reported by the filesystem",
                bytes: Number(source.free ?? 0),
                color: Theme.alpha(Theme.fg, 0.1)
            }
        ];
    }

    readonly property real total: root.segments.reduce(
        (sum, segment) => sum + Math.max(0, segment.bytes), 0)

    width: parent ? parent.width : 620
    spacing: 10

    Text {
        width: parent.width
        visible: root.total <= 0
        text: Disks.measuringBreakdown
            ? "Measuring what is on this disk…"
            : (Disks.lastError !== "" ? Disks.lastError : "Not measured yet.")
        color: Theme.fgDim
        font.family: Theme.fontFamily
        font.pixelSize: Theme.fontSize
        wrapMode: Text.WordWrap
    }

    Rectangle {
        width: parent.width
        visible: root.total > 0
        height: 26
        radius: 8
        clip: true
        color: Theme.alpha(Theme.fg, 0.06)
        border.width: 1
        border.color: Theme.alpha(Theme.fg, 0.1)

        Row {
            anchors.fill: parent
            anchors.margins: 1
            spacing: 0

            Repeater {
                model: root.segments

                delegate: Rectangle {
                    required property var modelData

                    // A measured segment always gets a sliver, so "1 GB of
                    // caches" is visible as a fact rather than rounded away.
                    width: root.total > 0 && modelData.bytes > 0
                        ? Math.max(parent.width * (modelData.bytes / root.total), 2)
                        : 0
                    height: parent.height
                    color: modelData.color
                    border.width: 0
                }
            }
        }
    }

    Flow {
        width: parent.width
        visible: root.total > 0
        spacing: 14

        Repeater {
            model: root.segments

            delegate: Row {
                required property var modelData

                spacing: 6

                Rectangle {
                    anchors.verticalCenter: parent.verticalCenter
                    width: 9
                    height: 9
                    radius: 3
                    color: modelData.key === "free"
                        ? Theme.alpha(Theme.fg, 0.25)
                        : modelData.color
                    border.width: 0
                }

                Text {
                    anchors.verticalCenter: parent.verticalCenter
                    text: modelData.label + " " + Disks.formatBytes(modelData.bytes)
                    color: Theme.fgDim
                    font.family: Theme.fontFamily
                    font.features: Theme.tabularFigures
                    font.pixelSize: Theme.fontSizeSmall
                }
            }
        }
    }

}