// The ordered LLM-ability registry: contract + golden-prompt tests (v0.40.0, #67).
//
// These tests pin the refactor's two load-bearing guarantees:
//
//   1. GOLDEN PROMPTS — the system prompt (both tool variants) and the user
//      prompt the refactored engine builds are BYTE-IDENTICAL to the committed
//      golden fixtures in ./goldens/ (captured in P1 from the pre-refactor
//      engine). Any transcription drift in an ability's schemaLine /
//      constraint / payload is caught here.
//
//   2. REGISTRY CONTRACT — the ABILITIES registry is the canonical ordered
//      list of the 8 abilities; each ability's default() equals the canonical
//      TurnResult default for its field, is a FRESH value (never a shared
//      reference), its default is not "meaningful" while a populated value is,
//      and the registry composes (a hypothetical extra ability can be appended
//      and every uniform loop still runs).
//
// Regenerate the goldens after an INTENTIONAL prompt change with:
//   REGEN_GOLDENS=1 npx vitest run server/abilities/registry.test.ts
// (the goldens are then rewritten from the current engine output; review the
// diff and commit). In a normal run (no env) the tests assert byte-equality.

import { readFileSync, writeFileSync, mkdirSync } from 'node:fs';
import path from 'node:path';
import { fileURLToPath } from 'node:url';
import { describe, expect, it } from 'vitest';
import {
  activeWarPairs,
  applyIndustryEffects,
  atWar,
  buildSystemPrompt,
  buildUserPrompt,
  freshNationId,
  freshWarId,
  HYBRID_STAT_EFFECT,
  isHybridOpType,
  isIndustryType,
  NEW_NATION_STATS,
  resolveNationRef,
  resolveRegionKey,
  shiftRelationTowardHostile,
  syncWarRelations,
  validateEconomyOps,
  validateHybridOps,
  validateIdeologyOps,
  validateIndustryOps,
  validateLeaderOps,
  validateNuclearOps,
  validateTakeovers,
  validateWarOps,
} from '../engine';
import { createPresetStore } from '../presets';
import { ABILITIES } from './index';
import type { Ability, AbilityField } from './types';
import type {
  Embargo,
  GameState,
  IndustryProject,
  Nation,
  NationStats,
  RegionResources,
  RelationStatus,
  RoundItem,
  TradeAgreement,
} from '../../shared/types';
import type { MarkerInfo, TurnResult, WarInfo } from '../../shared/protocol';

const here = path.dirname(fileURLToPath(import.meta.url));
const goldensDir = path.join(here, 'goldens');
const REGEN = process.env.REGEN_GOLDENS === '1';

// --- The preset the system-prompt goldens were captured with. ---
const root = path.resolve(here, '..', '..');
const store = createPresetStore(path.join(root, 'presets'));
const preset = store.get('wwii-1939');
if (!preset) throw new Error('wwii-1939 preset not found');

// --- The small, fully-controlled deterministic state that exercises EVERY
// --- optional branch of buildUserPrompt (re-embedded from the P1
// --- golden-capture so the committed goldens can be regenerated). ---
function nation(
  id: string,
  name: string,
  stats: NationStats,
  territory: string[],
  extra: Partial<Nation> = {},
): Nation {
  return { id, name, type: 'major', stats, territory, relations: {}, ...extra };
}

const s = (m: number, e: number, st: number, p: number): NationStats => ({
  military: m,
  economy: e,
  stability: st,
  population: p,
});

const a1 = nation('a1', 'Alpha', s(60, 55, 70, 80), ['a-r1', 'a-r2'], {
  nuclear: true,
  leader: { name: 'Alpha Leader' },
  ideology: 'democracy',
  relations: { b2: 'ally', c3: 'rival' },
});
const b2 = nation('b2', 'Bravo', s(75, 40, 20, 30), ['b-r1', 'b-r2'], {
  ideology: 'fascism',
  relations: { a1: 'ally' },
});
const c3 = nation('c3', 'Charlie', s(30, 35, 80, 20), ['c-r1'], {
  relations: { a1: 'rival' },
});

const state: GameState = {
  id: 'golden-0000-0000-0000-0000-000000000000',
  presetId: 'wwii-1939',
  presetTitle: preset.title,
  playerNationId: 'a1',
  turn: 4,
  date: '1940-02-14',
  nations: { a1, b2, c3 },
  events: [],
  pending: [],
  version: 9,
  unowned: ['x-unowned'],
  pendingNationOps: [],
  markers: [],
  regionStats: {
    'a-r1': s(60, 55, 70, 80),
    'a-r2': s(58, 53, 72, 78),
    'b-r1': s(75, 40, 20, 30),
    'b-r2': s(70, 42, 22, 28),
    'c-r1': s(30, 35, 80, 20),
  },
  wars: [],
  trades: [],
  embargoes: [],
  industry: [],
};

// --- buildUserPrompt arguments: every optional branch exercised. ---
const items: RoundItem[] = [
  { kind: 'action', text: 'Rearm the northern border' },
  { kind: 'diplomacy', to: 'b2', text: 'We can still talk terms, no?' },
];
const regionReference: Record<string, string> = {
  'a-r1': 'Alpha North (US)',
  'a-r2': 'Alpha South (US)',
  'b-r1': 'Bravo Plain (RU)',
  'b-r2': 'Bravo Coast (RU)',
  'c-r1': 'Charlie Isle (FR)',
  'x-unowned': 'X Released (UN)',
};
const frontier: string[] = ['b-r1']; // owned by b2 (a non-player) → frontierMilitary
const noMansLand: string[] = ['x-unowned'];
const markers: MarkerInfo[] = [
  { id: 'mk0001', type: 'gathering', name: 'Bravo Rally', regionKey: 'b-r1', owner: 'b2' },
  { id: 'mk0002', type: 'rocket', name: 'Charlie Silo', regionKey: 'c-r1', owner: 'c3' },
  { id: 'mk0003', type: 'capital', name: 'Alpha Cap', regionKey: 'a-r1', owner: 'a1' },
];
const wars: WarInfo[] = [
  { id: 'w1', sides: ['a1', 'b2'], aims: ['control the border'] },
  { id: 'w2', sides: ['b2', 'c3'] },
];
const relations: Record<string, RelationStatus> = { b2: 'ally', c3: 'rival' };
const trades: TradeAgreement[] = [{ a: 'a1', b: 'c3' }];
const embargoes: Embargo[] = [{ from: 'a1', target: 'b2' }];
const nationResources: Record<string, RegionResources> = {
  a1: { oil: 0.5, iron: 0.2, food: 0.3, industry: 0.8 },
  b2: { oil: 0.1, iron: 0.9, food: 0.1, industry: 0.2 },
  c3: { oil: 0.2, iron: 0.3, food: 0.7, industry: 0.4 },
};
const industryProjects: IndustryProject[] = [{ regionKey: 'a-r1', type: 'industry' }];
const nuclear: Record<string, boolean> = { a1: true, b2: false, c3: false };

/**
 * Assert the current prompt output is byte-identical to the committed golden —
 * or, under REGEN_GOLDENS=1, rewrite the golden from the current output (a
 * manual regeneration step; the test then passes without asserting).
 */
function checkGolden(name: string, current: string): void {
  const file = path.join(goldensDir, name);
  if (REGEN) {
    mkdirSync(goldensDir, { recursive: true });
    writeFileSync(file, current, 'utf8');
    return;
  }
  const expected = readFileSync(file, 'utf8');
  expect(current, `golden ${name} mismatch`).toBe(expected);
}

/** The canonical (default / no-op) value of EVERY TurnResult field. */
function fullDefaultTurn(): TurnResult {
  return {
    date: '1939-09-01',
    events: [],
    stateChanges: [],
    regionChanges: [],
    relations: [],
    territoryChanges: [],
    unowned: [],
    nationOps: [],
    takeovers: [],
    wars: { declare: [], end: [] },
    hybrid: { ops: [] },
    economy: { trade: [], embargo: [] },
    industry: { projects: [] },
    nuclear: { arm: [], strikes: [] },
    leaders: { changes: [] },
    ideology: { changes: [] },
    markers: { add: [], remove: [] },
  };
}

/** A "meaningful" (non-default) value for each ability field. */
function meaningfulFor(field: AbilityField): TurnResult[AbilityField] {
  switch (field) {
    case 'takeovers':
      return [{ nationRef: 'a1', newRegimeName: 'Alpha Regime' }];
    case 'wars':
      return { declare: [{ sides: ['a1', 'b2'] }], end: [] };
    case 'hybrid':
      return { ops: [{ type: 'spy', from: 'a1', target: 'b2' }] };
    case 'economy':
      return { trade: [{ a: 'a1', b: 'c3' }], embargo: [] };
    case 'industry':
      return { projects: [{ regionKey: 'a-r1', type: 'oil' }] };
    case 'nuclear':
      return { arm: ['a1'], strikes: [] };
    case 'leaders':
      return { changes: [{ target: 'a1', name: 'New Alpha Leader', cause: 'appointed' }] };
    case 'ideology':
      return { changes: [{ target: 'a1', to: 'democracy' }] };
  }
}

describe('ABILITIES registry (v0.40.0, #67)', () => {
  it('is the canonical 8-ability order (takeovers → ideology)', () => {
    expect(ABILITIES.map((a) => a.field)).toEqual([
      'takeovers',
      'wars',
      'hybrid',
      'economy',
      'industry',
      'nuclear',
      'leaders',
      'ideology',
    ]);
  });

  it('lists 8 distinct fields, each a key of TurnResult', () => {
    const fields = ABILITIES.map((a) => a.field);
    expect(fields).toHaveLength(8);
    expect(new Set(fields).size).toBe(8);
    const all = fullDefaultTurn();
    for (const f of fields) expect(f in all).toBe(true);
  });

  it('system prompt (no tool) is byte-identical to the committed golden', () => {
    checkGolden('system-no-tool.txt', buildSystemPrompt(preset, false));
  });

  it('system prompt (tool) is byte-identical to the committed golden', () => {
    checkGolden('system-tool.txt', buildSystemPrompt(preset, true));
  });

  it('user prompt is byte-identical to the committed golden', () => {
    checkGolden(
      'user.txt',
      buildUserPrompt(
        state,
        items,
        regionReference,
        frontier,
        noMansLand,
        markers,
        wars,
        relations,
        trades,
        embargoes,
        nationResources,
        industryProjects,
        nuclear,
      ),
    );
  });

  it("each ability's default() equals the canonical TurnResult default for its field", () => {
    const all = fullDefaultTurn();
    for (const a of ABILITIES) {
      expect(a.default(), `default() for ${a.field}`).toEqual(all[a.field]);
    }
  });

  it('default() is a FRESH value on every call (never a shared reference)', () => {
    for (const a of ABILITIES) {
      expect(a.default(), `${a.field} default should be a fresh object`).not.toBe(a.default());
    }
  });

  it('default() is never meaningful; a populated value always is', () => {
    for (const a of ABILITIES) {
      expect(a.isMeaningful(a.default()), `${a.field} default should not be meaningful`).toBe(false);
      expect(a.isMeaningful(meaningfulFor(a.field)), `${a.field} populated should be meaningful`).toBe(
        true,
      );
    }
  });

  it('declares exactly the durable GameState fields the db migration must default', () => {
    const owned: string[] = [];
    for (const a of ABILITIES) if (a.stateFields) owned.push(...a.stateFields);
    expect([...owned].sort()).toEqual(['embargoes', 'industry', 'trades', 'wars']);
  });

  it('composes: a hypothetical extra ability can be appended and every uniform loop still runs', () => {
    // The registry is a plain ordered array the engine iterates uniformly. A
    // structural (field-name-agnostic) loop over the abilities — schema line,
    // constraint bullet — must keep working when a 9th ability is appended.
    // This documents the extension point without widening the closed
    // AbilityField union.
    interface Loopable {
      field: string;
      schemaLine(): string;
      constraint(): string;
    }
    const dummy: Loopable = {
      field: 'custom',
      schemaLine: () => '  "custom": [],',
      constraint: () => '- A custom ability.',
    };
    const extended: readonly (Ability<AbilityField> | Loopable)[] = [...ABILITIES, dummy];
    expect(extended.map((a) => a.field)).toEqual([
      ...ABILITIES.map((a) => a.field),
      'custom',
    ]);
    // every uniform loop runs over all N abilities, the appended one included:
    expect(extended.map((a) => a.schemaLine())).toHaveLength(9);
    expect(extended.map((a) => a.constraint())).toHaveLength(9);
    expect(extended[8].schemaLine()).toBe('  "custom": [],');
  });

  it('the engine still re-exports every name its callers import from it', () => {
    // Backward compatibility: server/index.ts and engine.test.ts import these
    // from the engine; the re-export block must keep them all exported (a
    // missing re-export would also fail typecheck — this pins it at runtime).
    const reexported: Record<string, unknown> = {
      // shared primitives (./abilities/shared)
      freshNationId,
      freshWarId,
      NEW_NATION_STATS,
      resolveNationRef,
      resolveRegionKey,
      // ability modules (./abilities)
      isHybridOpType,
      isIndustryType,
      activeWarPairs,
      atWar,
      syncWarRelations,
      HYBRID_STAT_EFFECT,
      shiftRelationTowardHostile,
      validateEconomyOps,
      validateHybridOps,
      validateIdeologyOps,
      validateIndustryOps,
      validateLeaderOps,
      validateNuclearOps,
      validateTakeovers,
      validateWarOps,
      applyIndustryEffects,
    };
    for (const [name, value] of Object.entries(reexported)) {
      expect(value, `engine should re-export ${name}`).toBeDefined();
    }
  });
});