import { test } from 'node:test';
import assert from 'node:assert/strict';
import { saveSession, loadSession, clearSession } from '../src/storage.js';
import {
  createSession,
  commitAssignment,
  proposeAssignment,
  moveEntry,
  removeEntry,
} from '../src/session.js';
import { emptySpec } from '../src/spec.js';

function fakeStore() {
  const data = new Map();
  return {
    data,
    getItem: (key) => (data.has(key) ? data.get(key) : null),
    setItem: (key, value) => data.set(key, value),
    removeItem: (key) => data.delete(key),
  };
}

test('leerer Speicher liefert null', () => {
  assert.equal(loadSession(fakeStore()), null);
});

test('Sitzung ueberlebt Sichern und Laden', () => {
  const store = fakeStore();
  const session = createSession();
  commitAssignment(session, { ...emptySpec(), capacityGb: 64 }, 'barcode', 'A');
  saveSession(session, store);

  const reloaded = loadSession(store);
  assert.equal(reloaded.stacks.length, 1);
  assert.equal(reloaded.stacks[0].count, 1);
  assert.equal(reloaded.entries[0].spec.capacityGb, 64);
  assert.equal(reloaded.nextEntryId, 2);
});

test('clearSession raeumt auf', () => {
  const store = fakeStore();
  saveSession(createSession(), store);
  clearSession(store);
  assert.equal(loadSession(store), null);
});

test('kaputter Inhalt liefert null statt einer Ausnahme', () => {
  const store = fakeStore();
  store.setItem('ram-sortierhilfe:session', '{kein json');
  assert.equal(loadSession(store), null);
});

test('Sichern ohne funktionierenden Speicher wirft nicht', () => {
  const broken = {
    getItem: () => null,
    setItem: () => { throw new Error('quota exceeded'); },
    removeItem: () => {},
  };
  assert.doesNotThrow(() => saveSession(createSession(), broken));
});

test('stacks mit Nicht-Objekten liefert null', () => {
  const store = fakeStore();
  store.setItem('ram-sortierhilfe:session', JSON.stringify({
    stacks: ['x', 'y'],
    entries: [],
    nextEntryId: 1,
  }));
  assert.equal(loadSession(store), null);
});

test('fehlender nextEntryId liefert null', () => {
  const store = fakeStore();
  store.setItem('ram-sortierhilfe:session', JSON.stringify({
    stacks: [],
    entries: [],
  }));
  assert.equal(loadSession(store), null);
});

test('nextEntryId als Zeichenkette liefert null', () => {
  const store = fakeStore();
  store.setItem('ram-sortierhilfe:session', JSON.stringify({
    stacks: [],
    entries: [],
    nextEntryId: '2',
  }));
  assert.equal(loadSession(store), null);
});

test('Stapel mit Zaehler als Zeichenkette liefert null', () => {
  const store = fakeStore();
  store.setItem('ram-sortierhilfe:session', JSON.stringify({
    stacks: [{ id: 'A', count: '3', spec: emptySpec() }],
    entries: [],
    nextEntryId: 1,
  }));
  assert.equal(loadSession(store), null);
});

test('Eintrag ohne Spec liefert null', () => {
  const store = fakeStore();
  store.setItem('ram-sortierhilfe:session', JSON.stringify({
    stacks: [],
    entries: [{ entryId: 1, stackId: 'A' }],
    nextEntryId: 2,
  }));
  assert.equal(loadSession(store), null);
});

test('Stapelzaehler wird beim Laden aus den Eintraegen neu berechnet', () => {
  const store = fakeStore();
  store.setItem('ram-sortierhilfe:session', JSON.stringify({
    stacks: [{ id: 'A', count: 5, spec: emptySpec() }],
    entries: [{ entryId: 1, stackId: 'A', spec: emptySpec(), source: 'barcode' }],
    nextEntryId: 2,
  }));
  const reloaded = loadSession(store);
  assert.notEqual(reloaded, null);
  assert.equal(reloaded.stacks[0].count, 1);
});

test('Stapelzaehler werden beim Laden fuer mehrere Stapel unabhaengig neu berechnet, auch fuer einen ohne Eintraege', () => {
  const store = fakeStore();
  store.setItem('ram-sortierhilfe:session', JSON.stringify({
    stacks: [
      { id: 'A', count: 99, spec: emptySpec() },
      { id: 'B', count: 99, spec: emptySpec() },
      { id: 'C', count: 99, spec: emptySpec() },
    ],
    entries: [
      { entryId: 1, stackId: 'A', spec: emptySpec(), source: 'barcode' },
      { entryId: 2, stackId: 'A', spec: emptySpec(), source: 'barcode' },
      { entryId: 3, stackId: 'B', spec: emptySpec(), source: 'ocr' },
    ],
    nextEntryId: 4,
  }));
  const reloaded = loadSession(store);
  assert.notEqual(reloaded, null);
  assert.equal(reloaded.stacks.find((s) => s.id === 'A').count, 2, 'Stapel A hat zwei zugeordnete Eintraege');
  assert.equal(reloaded.stacks.find((s) => s.id === 'B').count, 1, 'Stapel B hat einen zugeordneten Eintrag');
  assert.equal(reloaded.stacks.find((s) => s.id === 'C').count, 0, 'Stapel C ohne jeden Eintrag wird auf 0 neu berechnet, nicht auf den gespeicherten Wert');
});

test('Eintrag mit unbekannter Stapelkennung liefert null', () => {
  const store = fakeStore();
  store.setItem('ram-sortierhilfe:session', JSON.stringify({
    stacks: [],
    entries: [{ entryId: 1, stackId: 'Z', spec: emptySpec(), source: 'barcode' }],
    nextEntryId: 2,
  }));
  assert.equal(loadSession(store), null);
});

test('doppelte Eintragsnummern liefert null', () => {
  const store = fakeStore();
  store.setItem('ram-sortierhilfe:session', JSON.stringify({
    stacks: [{ id: 'A', count: 2, spec: emptySpec() }],
    entries: [
      { entryId: 1, stackId: 'A', spec: emptySpec(), source: 'barcode' },
      { entryId: 1, stackId: 'A', spec: emptySpec(), source: 'barcode' },
    ],
    nextEntryId: 2,
  }));
  assert.equal(loadSession(store), null);
});

test('doppelte Stapelkennungen liefert null', () => {
  const store = fakeStore();
  store.setItem('ram-sortierhilfe:session', JSON.stringify({
    stacks: [
      { id: 'A', count: 0, spec: emptySpec() },
      { id: 'A', count: 0, spec: emptySpec() },
    ],
    entries: [],
    nextEntryId: 1,
  }));
  assert.equal(loadSession(store), null);
});

test('nextEntryId nicht groesser als vorhandene Eintragsnummer liefert null', () => {
  const store = fakeStore();
  store.setItem('ram-sortierhilfe:session', JSON.stringify({
    stacks: [{ id: 'A', count: 1, spec: emptySpec() }],
    entries: [{ entryId: 5, stackId: 'A', spec: emptySpec(), source: 'barcode' }],
    nextEntryId: 5,
  }));
  assert.equal(loadSession(store), null);
});

test('nach Sichern und Laden funktioniert Weiterarbeiten weiterhin', () => {
  const store = fakeStore();
  const session = createSession();
  const spec = { ...emptySpec(), capacityGb: 64 };
  commitAssignment(session, spec, 'barcode', 'A');
  const secondEntry = commitAssignment(session, spec, 'barcode', 'A');
  saveSession(session, store);

  const reloaded = loadSession(store);

  const proposal = proposeAssignment(reloaded, spec);
  assert.equal(proposal.kind, 'match');
  assert.equal(proposal.stackId, 'A');
  commitAssignment(reloaded, spec, 'barcode', proposal.stackId);
  assert.equal(reloaded.stacks[0].count, 3);
  assert.equal(reloaded.nextEntryId, 4);

  moveEntry(reloaded, secondEntry.entryId, 'B');
  assert.equal(reloaded.stacks.find((s) => s.id === 'A').count, 2);
  assert.equal(reloaded.stacks.find((s) => s.id === 'B').count, 1);

  removeEntry(reloaded, secondEntry.entryId);
  assert.equal(reloaded.entries.find((e) => e.entryId === secondEntry.entryId), undefined);
  assert.equal(reloaded.stacks.find((s) => s.id === 'B'), undefined);
});

test('nextEntryId als negative Zahl liefert null', () => {
  const store = fakeStore();
  store.setItem('ram-sortierhilfe:session', JSON.stringify({
    stacks: [],
    entries: [],
    nextEntryId: -5,
  }));
  assert.equal(loadSession(store), null);
});

test('nextEntryId als gebrochene Zahl liefert null', () => {
  const store = fakeStore();
  store.setItem('ram-sortierhilfe:session', JSON.stringify({
    stacks: [],
    entries: [],
    nextEntryId: 1.5,
  }));
  assert.equal(loadSession(store), null);
});

test('nextEntryId als Null liefert null', () => {
  const store = fakeStore();
  store.setItem('ram-sortierhilfe:session', JSON.stringify({
    stacks: [],
    entries: [],
    nextEntryId: 0,
  }));
  assert.equal(loadSession(store), null);
});

test('Eintrag mit gebrochener entryId liefert null', () => {
  const store = fakeStore();
  store.setItem('ram-sortierhilfe:session', JSON.stringify({
    stacks: [{ id: 'A', count: 1, spec: emptySpec() }],
    entries: [{ entryId: 1.5, stackId: 'A', spec: emptySpec(), source: 'barcode' }],
    nextEntryId: 2,
  }));
  assert.equal(loadSession(store), null);
});