import { describe, it, expect } from 'vitest';
import { ok, err } from '@shared/kernel/fp';
import { given } from '@shared/testing/machine';
import { expectTag } from '@shared/testing/expect-tag';
import {
  RegistratieState,
  STEPS,
  initial,
  currentStep,
  next,
  back,
  gaNaarStap,
  kiesDiploma,
  kiesHandmatig,
  declareerBeroep,
  setAntwoord,
  setField,
  prefillAdres,
  submit,
  primary,
  resolve,
  reduce,
} from './registratie-wizard.machine';
import { givenRegistratieWizard } from './registratie-wizard.testing';

/**
 * Every fixture below is built by replaying real `RegistratieMsg`s through the
 * real `reduce` (ADR-0006 §2) — never a hand-assembled `RegistratieState`
 * literal. Each helper reaches a named point in the wizard one transition at a
 * time, so a spec can only assert on a state the reducer can actually produce.
 */
const toAdresValid = (): RegistratieState =>
  givenRegistratieWizard(
    {
      tag: 'PrefillAdres',
      straat: 'Lange Voorhout 9',
      postcode: '2514 EA',
      woonplaats: 'Den Haag',
    },
    { tag: 'SetCorrespondentie', value: 'post' },
  );

const toBeroepStep = (): RegistratieState => reduce(toAdresValid(), { tag: 'Next' }); // cursor 0 -> 1, no diploma yet

const toBeroepStepWithDiploma = (): RegistratieState =>
  reduce(toBeroepStep(), { tag: 'KiesDiploma', diplomaId: 'd1', beroep: 'Arts', vraagIds: [] });

const toControleStep = (): RegistratieState => reduce(toBeroepStepWithDiploma(), { tag: 'Next' }); // cursor 1 -> 2

const toIndienen = (): RegistratieState => reduce(toControleStep(), { tag: 'Submit' });

// A complete, valid draft assembled WITHOUT ever advancing the cursor. Setting a
// field or choosing a diploma is never gated by cursor position, so this is a
// real, reachable 'Invullen' state at cursor 0 — matching what `submit()`
// (which validates the whole draft regardless of cursor) is exercised against
// in the tests below.
const toFullDraftAtCursor0 = (): RegistratieState =>
  givenRegistratieWizard(
    {
      tag: 'PrefillAdres',
      straat: 'Lange Voorhout 9',
      postcode: '2514 EA',
      woonplaats: 'Den Haag',
    },
    { tag: 'SetCorrespondentie', value: 'post' },
    { tag: 'KiesDiploma', diplomaId: 'd1', beroep: 'Arts', vraagIds: [] },
  );

describe('STEPS (fixed)', () => {
  it('always has the same three steps', () => {
    expect(STEPS).toEqual(['adres', 'beroep', 'controle']);
  });
});

describe('navigation', () => {
  it('Next is a no-op (sets errors) when the adres step is invalid', () => {
    const s = expectTag(next(initial), 'Invullen');
    expect(s.tag).toBe('Invullen');
    expect(s.cursor).toBe(0);
    expect(s.errors.straat).toBeTruthy();
    expect(s.errors.correspondentie).toBeTruthy();
  });

  it('Next advances once the adres step is valid', () => {
    const s = expectTag(next(toAdresValid()), 'Invullen');
    expect(s.cursor).toBe(1);
    expect(currentStep(s)).toBe('beroep');
  });

  it('requires a valid e-mail only when the channel is email', () => {
    const withEmailChannel = givenRegistratieWizard(
      {
        tag: 'PrefillAdres',
        straat: 'Lange Voorhout 9',
        postcode: '2514 EA',
        woonplaats: 'Den Haag',
      },
      { tag: 'SetCorrespondentie', value: 'email' },
    );
    const bad = expectTag(next(withEmailChannel), 'Invullen');
    expect(bad.errors.email).toBeTruthy();
    const good = expectTag(
      next(given(reduce, withEmailChannel)({ tag: 'SetField', key: 'email', value: 'a@b.nl' })),
      'Invullen',
    );
    expect(good.cursor).toBe(1);
  });

  it('beroep step requires a chosen diploma', () => {
    const noDiploma = expectTag(next(toBeroepStep()), 'Invullen');
    expect(noDiploma.cursor).toBe(1);
    expect(noDiploma.errors.diploma).toBeTruthy();
    const withDiploma = expectTag(next(toBeroepStepWithDiploma()), 'Invullen');
    expect(withDiploma.cursor).toBe(2);
  });

  it('Back never goes below the first step and preserves the draft', () => {
    expect(back(initial)).toBe(initial);
    const s = expectTag(back(toControleStep()), 'Invullen');
    expect(s.cursor).toBe(1);
    expect(s.draft.beroep).toBe('Arts');
  });

  it('GaNaarStap only jumps backwards', () => {
    expect(expectTag(gaNaarStap(toControleStep(), 0), 'Invullen').cursor).toBe(0);
    expect(expectTag(gaNaarStap(toBeroepStepWithDiploma(), 2), 'Invullen').cursor).toBe(1); // forward jump rejected
  });
});

describe('adres origin (BRP vs handmatig)', () => {
  it('prefillAdres flags origin brp', () => {
    const s = expectTag(
      prefillAdres(initial, 'Lange Voorhout 9', '2514 EA', 'Den Haag'),
      'Invullen',
    );
    expect(s.draft.adresHerkomst).toBe('brp');
    expect(s.draft.straat).toBe('Lange Voorhout 9');
  });

  it('editing a prefilled address field flips origin to handmatig', () => {
    const prefilled = prefillAdres(initial, 'Lange Voorhout 9', '2514 EA', 'Den Haag');
    const edited = expectTag(setField(prefilled, 'woonplaats', 'Rotterdam'), 'Invullen');
    expect(edited.draft.adresHerkomst).toBe('handmatig');
  });

  it('typing an address with no BRP prefill yields handmatig', () => {
    const s = expectTag(setField(initial, 'straat', 'Kerkstraat 1'), 'Invullen');
    expect(s.draft.adresHerkomst).toBe('handmatig');
  });

  it('editing the e-mail field does not change the address origin', () => {
    const prefilled = prefillAdres(initial, 'Lange Voorhout 9', '2514 EA', 'Den Haag');
    const edited = expectTag(setField(prefilled, 'email', 'a@b.nl'), 'Invullen');
    expect(edited.draft.adresHerkomst).toBe('brp');
  });

  it('a manually entered address still submits (only manual diploma is gated)', () => {
    const manualAdres = givenRegistratieWizard(
      { tag: 'SetField', key: 'straat', value: 'Kerkstraat 1' },
      { tag: 'SetField', key: 'postcode', value: '1234 AB' },
      { tag: 'SetField', key: 'woonplaats', value: 'Utrecht' },
      { tag: 'SetCorrespondentie', value: 'post' },
      { tag: 'KiesDiploma', diplomaId: 'd1', beroep: 'Arts', vraagIds: [] },
    );
    const indienen = expectTag(submit(manualAdres), 'Indienen');
    expect(indienen.data.adresHerkomst).toBe('handmatig');
  });
});

describe('kiesDiploma', () => {
  it('derives the beroep from the chosen diploma and flags origin duo', () => {
    const s = expectTag(kiesDiploma(initial, 'd9', 'Verpleegkundige', []), 'Invullen');
    expect(s.draft.diplomaId).toBe('d9');
    expect(s.draft.beroep).toBe('Verpleegkundige');
    expect(s.draft.diplomaHerkomst).toBe('duo');
  });
});

describe('policy questions (geldigheidsvragen)', () => {
  it('a diploma with questions blocks Next until they are answered', () => {
    let s = kiesDiploma(toBeroepStep(), 'd2', 'Arts', ['nl-taalvaardigheid']);
    const blocked = expectTag(next(s), 'Invullen');
    expect(blocked.cursor).toBe(1);
    expect(blocked.errors.antwoorden?.['nl-taalvaardigheid']).toBeTruthy();
    s = setAntwoord(s, 'nl-taalvaardigheid', 'ja');
    expect(expectTag(next(s), 'Invullen').cursor).toBe(2);
  });

  it('validateAll keeps only the answers to the questions that applied', () => {
    // DRIFT (see rb-31.md): the old literal put the wizard at cursor 2 before any
    // diploma was chosen. That combination cannot occur in the real reducer —
    // advancing past 'beroep' (cursor 1 -> 2) requires a diploma to already be
    // set. Replayed here at cursor 1 instead; submit() validates the whole draft
    // regardless of cursor, so the assertion below is unaffected.
    let s = kiesDiploma(toBeroepStep(), 'd2', 'Arts', ['nl-taalvaardigheid']);
    s = setAntwoord(s, 'nl-taalvaardigheid', 'ja');
    s = setAntwoord(s, 'stale', 'x'); // not in vraagIds
    const done = expectTag(submit(s), 'Indienen');
    expect(done.data.antwoorden).toEqual({ 'nl-taalvaardigheid': 'ja' });
  });
});

describe('manual diploma fallback', () => {
  const maxIds = ['nl-taalvaardigheid', 'diploma-erkend', 'toelichting'];

  it('KiesHandmatig flags handmatig with the maximal question set and no beroep yet', () => {
    const s = expectTag(kiesHandmatig(toBeroepStep(), maxIds), 'Invullen');
    expect(s.draft.diplomaHerkomst).toBe('handmatig');
    expect(s.draft.beroep).toBeUndefined();
    expect(s.draft.vraagIds).toEqual(maxIds);
  });

  it('requires a declared beroep + all maximal questions before submit', () => {
    // DRIFT (see rb-31.md): same unreachable cursor-2-before-diploma combination
    // as above. Replayed at cursor 1; submit() is cursor-agnostic.
    let s = kiesHandmatig(toBeroepStep(), maxIds);
    expect(submit(s).tag).toBe('Invullen'); // no beroep declared
    s = declareerBeroep(s, 'Fysiotherapeut');
    expect(submit(s).tag).toBe('Invullen'); // questions unanswered
    for (const id of maxIds) s = setAntwoord(s, id, 'ja');
    const done = expectTag(submit(s), 'Indienen');
    expect(done.data.diplomaHerkomst).toBe('handmatig');
    expect(done.data.beroep).toBe('Fysiotherapeut');
  });
});

describe('submit', () => {
  it('stays in Invullen when the draft is incomplete (no diploma)', () => {
    expect(submit(toAdresValid()).tag).toBe('Invullen');
  });

  it('reaches Indienen with a complete, valid draft, carrying its data', () => {
    const good = expectTag(submit(toFullDraftAtCursor0()), 'Indienen');
    expect(good.data.beroep).toBe('Arts');
    expect(good.data.adres.postcode).toBe('2514 EA');
    expect(good.data.adresHerkomst).toBe('brp');
  });

  it('resolve maps Indienen to Ingediend with the referentie', () => {
    const ingediend = expectTag(
      resolve(submit(toFullDraftAtCursor0()), ok('BIG-2026-001')),
      'Ingediend',
    );
    expect(ingediend.referentie).toBe('BIG-2026-001');
  });

  it('resolve maps Indienen to Mislukt on a failed submit', () => {
    expect(resolve(submit(toFullDraftAtCursor0()), err('boom')).tag).toBe('Mislukt');
  });
});

describe('primary', () => {
  it('Primary advances to the next step from a non-final step', () => {
    const s = toBeroepStepWithDiploma(); // Invullen, beroep step — not the final step
    expect(currentStep(expectTag(s, 'Invullen'))).toBe('beroep');
    expect(reduce(s, { tag: 'Primary' })).toEqual(reduce(s, { tag: 'Next' }));
    expect(currentStep(expectTag(primary(s), 'Invullen'))).toBe('controle');
  });

  it('Primary submits from the final step', () => {
    const s = toControleStep(); // Invullen, controle step — the final step
    expect(reduce(s, { tag: 'Primary' })).toEqual(reduce(s, { tag: 'Submit' }));
    expect(primary(s).tag).toBe('Indienen');
  });

  it('Primary is a no-op from a non-editing state', () => {
    const indienen = toIndienen();
    expect(primary(indienen)).toBe(indienen);
  });
});

describe('reduce (message-driven happy path)', () => {
  it('adres and correspondentie set, Next advances from adres to beroep', () => {
    // Given the initial wizard.
    // When the adres is prefilled, correspondentie chosen, and Next dispatched...
    const s = toBeroepStep();

    // Then the wizard advances to the beroep step.
    expect(currentStep(expectTag(s, 'Invullen'))).toBe('beroep');
  });

  it('diploma chosen, Next advances from beroep to controle', () => {
    // Given a wizard on the beroep step.
    // When a diploma is chosen and Next dispatched...
    const s = toControleStep();

    // Then the wizard advances to the controle step.
    expect(currentStep(expectTag(s, 'Invullen'))).toBe('controle');
  });

  it('Submit moves a complete Invullen draft to Indienen', () => {
    // Given a wizard on the controle step with a complete, valid draft.
    // When Submit is dispatched...
    const s = toIndienen();

    // Then the wizard moves to Indienen.
    expect(s.tag).toBe('Indienen');
  });

  it('SubmitConfirmed moves Indienen to Ingediend', () => {
    // Given a wizard mid-submit (Indienen).
    // When SubmitConfirmed arrives with a referentie...
    const s = reduce(toIndienen(), { tag: 'SubmitConfirmed', referentie: 'BIG-2026-001' });

    // Then the wizard reaches Ingediend.
    expect(s.tag).toBe('Ingediend');
  });

  it('SubmitFailed moves Indienen to Mislukt', () => {
    const s = reduce(reduce(toFullDraftAtCursor0(), { tag: 'Submit' }), {
      tag: 'SubmitFailed',
      error: 'boom',
    });
    expect(s.tag).toBe('Mislukt');
  });

  it('Retry returns Mislukt to Indienen with the same data', () => {
    const mislukt = reduce(reduce(toFullDraftAtCursor0(), { tag: 'Submit' }), {
      tag: 'SubmitFailed',
      error: 'boom',
    });
    const s = expectTag(reduce(mislukt, { tag: 'Retry' }), 'Indienen');
    expect(s.data.beroep).toBe('Arts');
  });
});

describe('inline document upload (beroep step)', () => {
  const cat = {
    categoryId: 'diploma',
    label: 'Diploma',
    description: '',
    required: true,
    acceptedTypes: [],
    maxSizeMb: 10,
    multiple: false,
    allowPostDelivery: true,
  };

  it('routes Upload messages through the upload reducer', () => {
    const s = expectTag(
      reduce(toFullDraftAtCursor0(), {
        tag: 'Upload',
        msg: { type: 'CategoriesLoaded', categories: [cat] },
      }),
      'Invullen',
    );
    expect(s.upload.categories).toHaveLength(1);
  });

  it('blocks the beroep step until a required category is satisfied', () => {
    let s = reduce(toBeroepStepWithDiploma(), {
      tag: 'Upload',
      msg: { type: 'CategoriesLoaded', categories: [cat] },
    });
    s = reduce(s, { tag: 'Next' }); // beroep → controle blocked
    let invullenState = expectTag(s, 'Invullen');
    expect(currentStep(invullenState)).toBe('beroep');
    expect(invullenState.errors.documenten).toBeTruthy();
    // choosing post delivery satisfies the requirement
    s = reduce(s, {
      tag: 'Upload',
      msg: { type: 'DeliveryChannelChanged', categoryId: 'diploma', channel: 'post' },
    });
    s = reduce(s, { tag: 'Next' });
    invullenState = expectTag(s, 'Invullen');
    expect(currentStep(invullenState)).toBe('controle');
  });

  it('includes delivery refs in the submitted data', () => {
    let s = reduce(toFullDraftAtCursor0(), {
      tag: 'Upload',
      msg: { type: 'CategoriesLoaded', categories: [cat] },
    });
    s = reduce(s, {
      tag: 'Upload',
      msg: { type: 'DeliveryChannelChanged', categoryId: 'diploma', channel: 'post' },
    });
    const done = expectTag(submit(s), 'Indienen');
    expect(done.data.documents).toEqual([{ categoryId: 'diploma', channel: 'post' }]);
  });
});