pragma Singleton

import QtQuick
import Quickshell
import Quickshell.Io

// The liturgical day, from the `typikon` command.
//
// Computed locally, so this needs no network and cannot go stale. It only has
// to be re-read when the date changes, which a clock at minute precision
// notices without polling a subprocess every few seconds.
Singleton {
    id: root

    // Set this to a jurisdiction key — "rocor", "antiochian", "oca" — or leave
    // it empty to use whatever `typikon --set-default` wrote.
    property string jurisdiction: ""
    // Today plus the next six, so the week ahead is visible at a glance.
    property int days: 7
    // Empty means today. Set it to an ISO date to look at a different one --
    // useful for seeing what Great Week will ask of you before it arrives.
    property string forDate: ""

    property bool available: false
    property string error: ""

    property var week: []
    property var today: ({})

    readonly property string date:        today.date        ?? ""
    readonly property string weekday:     today.weekday     ?? ""
    readonly property string churchDate:  today.churchDate  ?? ""
    readonly property string season:      today.season      ?? ""
    readonly property string cycle:       today.cycle       ?? ""
    readonly property string feast:       today.feast       ?? ""
    readonly property string title:       today.title       ?? ""
    readonly property string rank:        today.rank        ?? ""
    readonly property string fast:        today.fast        ?? "none"
    readonly property string fastLabel:   today.fastLabel   ?? ""
    readonly property string emoji:       today.emoji       ?? ""
    readonly property string reason:      today.reason      ?? ""
    readonly property string obligation:  today.obligation  ?? ""
    readonly property string pascha:      today.pascha      ?? ""
    readonly property int    daysToPascha: today.daysToPascha ?? 0
    readonly property var    commemorations: today.commemorations ?? []

    readonly property bool obligatory: obligation === "obligatory"

    // A request made while a run is in flight is queued, not dropped. Dropping
    // it meant a jurisdiction or date set a moment after startup never took
    // effect at all -- the answer stayed yesterday's until midnight.
    property bool _queued: false

    function refresh() {
        if (proc.running) { root._queued = true; return; }
        proc.running = true;
    }

    SystemClock { id: clock; precision: SystemClock.Minutes }

    // Re-read when the day rolls over, not on a timer. The answer changes at
    // midnight and at no other moment.
    readonly property string _day: Qt.formatDateTime(clock.date, "yyyy-MM-dd")
    on_DayChanged: root.refresh()
    onJurisdictionChanged: root.refresh()
    onForDateChanged: root.refresh()
    Component.onCompleted: root.refresh()

    Process {
        id: proc
        onExited: if (root._queued) { root._queued = false; root.refresh(); }
        command: {
            const c = ["typikon", "--json", "--days", String(root.days)];
            if (root.jurisdiction !== "")
                c.push("--jurisdiction", root.jurisdiction);
            if (root.forDate !== "")
                c.push("--date", root.forDate);
            return c;
        }
        stdout: StdioCollector {
            onStreamFinished: {
                try {
                    const parsed = JSON.parse(this.text);
                    root.week = parsed.days ?? [parsed];
                    root.today = root.week.length ? root.week[0] : {};
                    root.available = true;
                    root.error = "";
                } catch (e) {
                    root.available = false;
                    root.error = "could not read typikon";
                }
            }
        }
        stderr: StdioCollector {
            onStreamFinished: {
                if (this.text.trim() !== "") {
                    root.available = false;
                    root.error = this.text.trim();
                }
            }
        }
    }
}