import { describe, expect, it } from 'vitest';
import * as Y from 'yjs';
import { Binding, initialUpdate, readDocument, REMOTE } from '../ydoc';
import type { DocumentState, TableObject } from '../../store/types';
import { createSeedDocument } from '../../data/seed';

function docWithTable(cells: Record<string, string>, rows = 5, cols = 3): DocumentState {
  const t: TableObject = {
    kind: 'table',
    id: 't1',
    name: 'Tabelle 1',
    x: 0,
    y: 0,
    rows,
    cols,
    colWidths: { 1: 120 },
    rowHeights: { 2: 40 },
    cells,
    formats: { '0,0': { bold: true } },
    view: { mode: 'auto', width: 640, height: 320, frozenRows: 0, frozenCols: 0 },
  };
  return {
    version: 2,
    sheets: [{ id: 's1', name: 'Blatt 1', objects: [t] }],
    activeSheetId: 's1',
    activeObjectId: null,
    selection: null,
    locale: 'de-DE',
    csvDelimiter: ',',
    customFunctions: [],
    namedRanges: [],
    macros: [],
  };
}

const table = (d: DocumentState) => d.sheets[0].objects[0] as TableObject;
const clone = <T>(x: T): T => JSON.parse(JSON.stringify(x));

/** two people on the same document, updates exchanged explicitly */
function pair(start: DocumentState) {
  const a = new Y.Doc();
  const b = new Y.Doc();
  Y.applyUpdate(a, initialUpdate(start), REMOTE);
  Y.applyUpdate(b, initialUpdate(start), REMOTE);
  const exchange = () => {
    Y.applyUpdate(b, Y.encodeStateAsUpdate(a, Y.encodeStateVector(b)), REMOTE);
    Y.applyUpdate(a, Y.encodeStateAsUpdate(b, Y.encodeStateVector(a)), REMOTE);
  };
  return { a, b, ba: new Binding(a), bb: new Binding(b), exchange };
}

describe('Yjs document form', () => {
  it('round-trips the whole document (seed)', () => {
    const seed = createSeedDocument();
    const y = new Y.Doc();
    Y.applyUpdate(y, initialUpdate(seed));
    const back = readDocument(y);
    const strip = (d: DocumentState) => ({
      ...d,
      activeSheetId: '',
      activeObjectId: null,
      selection: null,
      sheets: d.sheets.map((s) => ({ ...s, zoom: undefined })),
    });
    expect(JSON.parse(JSON.stringify(strip(back)))).toEqual(JSON.parse(JSON.stringify(strip(seed))));
  });

  it('initial update is deterministic, so two conversions merge into one', () => {
    const d = docWithTable({ '0,0': 'x' });
    expect(initialUpdate(d)).toEqual(initialUpdate(d));
    const y = new Y.Doc();
    Y.applyUpdate(y, initialUpdate(d));
    Y.applyUpdate(y, initialUpdate(d));
    expect(table(readDocument(y)).cells).toEqual({ '0,0': 'x' });
  });

  it('edits to different cells by two people merge', () => {
    const { a, b, ba, bb, exchange } = pair(docWithTable({}));
    const da = readDocument(a);
    table(da).cells['0,0'] = 'Anna';
    ba.sync(da);
    const db = readDocument(b);
    table(db).cells['2,4'] = 'Bob';
    bb.sync(db);
    exchange();
    expect(table(readDocument(a)).cells).toEqual({ '0,0': 'Anna', '2,4': 'Bob' });
    expect(readDocument(b)).toEqual(readDocument(a));
  });

  it('a row inserted by one person does not misplace what the other types', () => {
    const start = docWithTable({ '0,3': 'row 4 before' });
    const { a, b, ba, bb, exchange } = pair(start);

    // Anna inserts a row at index 1 (the store shifts cells, and reports it)
    const da = readDocument(a);
    const ta = table(da);
    ta.cells = { '0,4': 'row 4 before' };
    ta.rowHeights = { 3: 40 };
    ta.rows += 1;
    ba.structure('t1', 'row', 1, 1);
    ba.sync(da);

    // meanwhile Bob, not having seen that, types next to "row 4 before"
    const db = readDocument(b);
    table(db).cells['1,3'] = 'Bob';
    bb.sync(db);

    exchange();
    const cells = table(readDocument(a)).cells;
    expect(cells).toEqual({ '0,4': 'row 4 before', '1,4': 'Bob' });
    expect(table(readDocument(a)).rows).toBe(6);
    expect(table(readDocument(a)).rowHeights).toEqual({ 3: 40 });
    expect(readDocument(b)).toEqual(readDocument(a));
  });

  it('deleting a column removes its cells and widths', () => {
    const { a, ba } = pair(docWithTable({ '0,0': 'a', '1,0': 'b', '2,0': 'c' }));
    const d = readDocument(a);
    const t = table(d);
    t.cells = { '0,0': 'a', '1,0': 'c' };
    t.colWidths = {};
    t.cols = 2;
    ba.structure('t1', 'col', 1, -1);
    ba.sync(d);
    const back = table(readDocument(a));
    expect(back.cells).toEqual({ '0,0': 'a', '1,0': 'c' });
    expect(back.colWidths).toEqual({});
    expect(back.cols).toBe(2);
  });

  it('growing and shrinking at the edge needs no structure event', () => {
    const { a, ba } = pair(docWithTable({ '0,4': 'last' }));
    const d = readDocument(a);
    table(d).rows = 8;
    table(d).cells['0,7'] = 'new last';
    ba.sync(d);
    expect(table(readDocument(a)).rows).toBe(8);
    const d2 = readDocument(a);
    table(d2).rows = 5;
    delete table(d2).cells['0,7'];
    ba.sync(d2);
    expect(table(readDocument(a)).rows).toBe(5);
    expect(table(readDocument(a)).cells).toEqual({ '0,4': 'last' });
  });

  it('sheets, objects and lists: add, change, reorder, remove', () => {
    const { a, b, ba, exchange } = pair(docWithTable({}));
    const d = clone(readDocument(a));
    d.sheets.push({ id: 's2', name: 'Zwei', objects: [] });
    d.sheets[0].objects.push({ kind: 'text', id: 'x1', name: 'Text', x: 1, y: 2, width: 10, height: 10, text: 'Hi', fontSize: 14, align: 'left' });
    d.customFunctions.push({ id: 'f1', name: 'DOPPELT', params: ['x'], body: 'x*2', kind: 'expression' });
    ba.sync(d);
    exchange();
    const got = readDocument(b);
    expect(got.sheets.map((s) => s.id)).toEqual(['s1', 's2']);
    expect(got.sheets[0].objects.map((o) => o.id)).toEqual(['t1', 'x1']);
    expect(got.customFunctions[0].name).toBe('DOPPELT');

    const d2 = clone(readDocument(a));
    d2.sheets.reverse();
    d2.sheets[1].objects.reverse(); // z-order
    d2.customFunctions = [];
    ba.sync(d2);
    exchange();
    const got2 = readDocument(b);
    expect(got2.sheets.map((s) => s.id)).toEqual(['s2', 's1']);
    expect(got2.sheets[1].objects.map((o) => o.id)).toEqual(['x1', 't1']);
    expect(got2.customFunctions).toEqual([]);
  });

  it('a sync without changes produces no update', () => {
    const { a, ba } = pair(docWithTable({ '0,0': 'x' }));
    let updates = 0;
    a.on('update', () => updates++);
    ba.sync(readDocument(a));
    expect(updates).toBe(0);
  });
});