const { mockClient } = require('aws-sdk-client-mock');
const { BedrockRuntimeClient, ConverseStreamCommand } = require('@aws-sdk/client-bedrock-runtime');
const { runFullContext } = require('../src/strategies/fullContext');
const { parseCitations } = require('../src/citations');
const { chatConfig, sampleBook, textStream, usage } = require('./fixture');

const bedrock = mockClient(BedrockRuntimeClient);

async function collect(iterable) {
  const events = [];
  for await (const event of iterable) events.push(event);
  return events;
}

describe('full context', () => {
  let client;

  beforeEach(() => {
    bedrock.reset();
    client = new BedrockRuntimeClient({ region: 'ap-south-1' });
  });

  it('reports cache reads on the second turn', async () => {
    let call = 0;
    bedrock.on(ConverseStreamCommand).callsFake(async () => {
      call += 1;
      return {
        stream: textStream('In chapter 1 (p. 2).', usage({
          cacheReadInputTokens: call === 1 ? 0 : 8000,
          cacheWriteInputTokens: call === 1 ? 8000 : 0,
        })),
      };
    });
    const session = { channel: 'chat', history: [], rollingSummary: '', lastCacheTouchAt: null, keepaliveCount: 0, sessionId: 's' };
    const ctx = {
      config: chatConfig(),
      logger: { info() {}, warn() {} },
      bedrock: client,
      book: sampleBook(),
      session,
      userText: 'Where is that?',
    };
    const first = await collect(runFullContext(ctx));
    session.history = [{ role: 'user', text: 'Hi' }, { role: 'assistant', text: 'Hello' }];
    session.lastCacheTouchAt = new Date().toISOString();
    const second = await collect(runFullContext({ ...ctx, userText: 'And then?' }));
    const finalEvent = second.find((event) => event.type === 'final');
    expect(finalEvent.usage.cacheReadTokens).toBe(8000);
    expect(first.find((event) => event.type === 'final').usage.cacheWriteTokens).toBe(8000);
    expect(finalEvent.usage.estimatedCostUsd).toBeGreaterThan(0);
  });

  it('drops citations for pages that are not in the book', () => {
    const items = parseCitations('See (p. 2) and (p. 99).', sampleBook());
    expect(items.map((item) => item.page)).toEqual([2]);
  });

  it('strips markers before text deltas and emits a citation chip', async () => {
    bedrock.on(ConverseStreamCommand).resolves({
      stream: (async function* () {
        yield { contentBlockDelta: { contentBlockIndex: 0, delta: { text: 'The dose is 50 mg ' } } };
        yield { contentBlockDelta: { contentBlockIndex: 0, delta: { text: '[[p:2-4]]' } } };
        yield { contentBlockDelta: { contentBlockIndex: 0, delta: { text: '.' } } };
        yield { messageStop: { stopReason: 'end_turn' } };
        yield { metadata: { usage: usage({ outputTokens: 12 }) } };
      })(),
    });
    const events = await collect(runFullContext({
      config: chatConfig(),
      logger: { info() {}, warn() {} },
      bedrock: client,
      book: sampleBook(),
      session: { channel: 'chat', history: [], rollingSummary: '', lastCacheTouchAt: null, keepaliveCount: 0, sessionId: 's' },
      userText: 'What was the dose?',
    }));
    const spoken = events.filter((event) => event.type === 'text_delta').map((event) => event.text).join('');
    expect(spoken).toBe('The dose is 50 mg.');
    expect(spoken).not.toContain('[[');
    const citations = events.find((event) => event.type === 'citations');
    expect(citations.items[0]).toMatchObject({ page: 2, pageEnd: 4, chapterNo: 1 });
    expect(citations.items[0].verified).toBeUndefined();
    const finalEvent = events.find((event) => event.type === 'final');
    expect(finalEvent.text).toBe('The dose is 50 mg.');
    expect(finalEvent.rawText).toContain('[[p:2-4]]');
  });
});