import test from 'node:test';
import assert from 'node:assert/strict';

import {
  applyMcpCompaction,
  buildCompactSummary,
  compact,
  createMemoryCompactStore,
  fetchCompactPayload,
  resetMcpCompactStoresForTests,
  resolveMcpCompactMode,
  setDefaultMcpCompactStore,
} from './mcp-result-compactor.mjs';

test('resolveMcpCompactMode defaults to off', () => {
  assert.equal(resolveMcpCompactMode({}), 'off');
  assert.equal(resolveMcpCompactMode({ MEMIND_MCP_COMPACT_MODE: 'shadow' }), 'shadow');
  assert.equal(resolveMcpCompactMode({ MEMIND_MCP_COMPACT_MODE: 'bogus' }), 'off');
});

test('compact is no-op in off mode', async () => {
  const payload = 'x'.repeat(8000);
  const result = await compact(payload, {
    kind: 'tkmind_read',
    mode: 'off',
    budget: 1000,
  });
  assert.equal(result.text, payload);
  assert.equal(result.compacted, false);
});

test('compact keeps original payload in shadow mode', async () => {
  const payload = 'alpha '.repeat(800);
  const result = await compact(payload, {
    kind: 'tkmind_read',
    mode: 'shadow',
    budget: 400,
  });
  assert.equal(result.text, payload);
  assert.equal(result.compacted, false);
  assert.equal(result.mode, 'shadow');
  assert.ok(result.stats.savedRatio > 0);
  assert.ok(String(result.shadowSummary ?? '').length < payload.length);
});

test('compact stores handle and returns envelope in active mode', async () => {
  resetMcpCompactStoresForTests();
  const store = createMemoryCompactStore({ now: () => Date.now() });
  setDefaultMcpCompactStore(store);
  const payload = 'line\n'.repeat(900);
  const result = await compact(payload, {
    kind: 'excel_report',
    mode: 'active',
    budget: 500,
    store,
  });
  assert.equal(result.compacted, true);
  assert.ok(result.handle?.startsWith('mcpctx_'));
  assert.match(result.text, /use ctx_fetch to retrieve full payload/);

  const fetched = await fetchCompactPayload(result.handle, { store });
  assert.equal(fetched.ok, true);
  assert.equal(fetched.text, payload);
});

test('applyMcpCompaction fail-opens when store unavailable', async () => {
  const payload = 'payload '.repeat(500);
  const result = await applyMcpCompaction(payload, {
    kind: 'tkmind_research_status',
    env: { MEMIND_MCP_COMPACT_MODE: 'active', MEMIND_MCP_COMPACT_BUDGET_CHARS: '200' },
    store: {
      async put() {
        throw new Error('store down');
      },
      async get() {
        return null;
      },
    },
  });
  assert.equal(result.text, payload);
  assert.equal(result.compacted, false);
  assert.equal(result.fallback, 'store_unavailable');
});

test('buildCompactSummary preserves head and tail', () => {
  const summary = buildCompactSummary('0123456789abcdef'.repeat(20), 120);
  assert.match(summary, /^012/);
  assert.match(summary, /cdef$/);
  assert.match(summary, /omitted/);
});