import { test, describe } from "node:test";
import assert from "node:assert/strict";
import { layoutDaySegments, computeEventOverlapLayout } from "../../src/lib/weekly/event-layout.ts";
import type { CalendarEventSegment } from "../../src/lib/weekly/types.ts";

/**
 * Charakterisierungstests der Spaltenaufteilung im Tagesraster.
 *
 * Beobachtbares Verhalten: Termine, die sich zeitlich überschneiden, stehen
 * nebeneinander statt übereinander; Termine, die sich nicht berühren, bekommen
 * die volle Breite.
 */

const at = (h: number, min = 0) => new Date(2026, 8, 10, h, min, 0, 0).toISOString();

const segment = (key: string, startHour: number, endHour: number): CalendarEventSegment => ({
    id: key,
    title: key,
    startTime: at(startHour),
    endTime: at(endHour),
    source: "google",
    segmentKey: key,
    segmentIndex: 0,
    segmentCount: 1,
    continuesFromPreviousDay: false,
    continuesOnNextDay: false,
    sourceEvent: { id: key, title: key, startTime: at(startHour), endTime: at(endHour), source: "google" },
});

describe("layoutDaySegments", () => {
    test("ein einzelner Termin nimmt die volle Breite ein", () => {
        const layout = layoutDaySegments([segment("a", 9, 10)]);
        assert.deepEqual(layout.a, { column: 0, totalColumns: 1 });
    });

    test("zwei überschneidende Termine teilen sich zwei Spalten", () => {
        const layout = layoutDaySegments([segment("a", 9, 11), segment("b", 10, 12)]);
        assert.equal(layout.a.totalColumns, 2);
        assert.equal(layout.b.totalColumns, 2);
        assert.notEqual(layout.a.column, layout.b.column);
    });

    test("aufeinanderfolgende Termine bekommen dieselbe Spalte und volle Breite", () => {
        const layout = layoutDaySegments([segment("a", 9, 10), segment("b", 10, 11)]);
        assert.deepEqual(layout.a, { column: 0, totalColumns: 1 });
        assert.deepEqual(layout.b, { column: 0, totalColumns: 1 });
    });

    test("drei gleichzeitige Termine ergeben drei Spalten", () => {
        const layout = layoutDaySegments([segment("a", 9, 12), segment("b", 9, 12), segment("c", 9, 12)]);
        const columns = ["a", "b", "c"].map((k) => layout[k].column).sort();
        assert.deepEqual(columns, [0, 1, 2]);
        assert.equal(layout.a.totalColumns, 3);
    });

    test("die Reihenfolge der Eingabe ändert das Ergebnis nicht", () => {
        const forward = layoutDaySegments([segment("a", 9, 11), segment("b", 10, 12)]);
        const backward = layoutDaySegments([segment("b", 10, 12), segment("a", 9, 11)]);
        assert.deepEqual(forward, backward);
    });
});

describe("computeEventOverlapLayout", () => {
    test("fasst mehrere Tage in einer Zuordnung zusammen", () => {
        const layout = computeEventOverlapLayout(
            new Map([
                ["2026-09-10", [segment("a", 9, 11), segment("b", 10, 12)]],
                ["2026-09-11", [segment("c", 9, 10)]],
            ]),
        );
        assert.equal(layout.a.totalColumns, 2);
        assert.equal(layout.c.totalColumns, 1);
    });
});