// Slide 21: Short-term memory -- thread_id + checkpointer
// Code slide: persistent conversation per thread.

const ds = require('./design-system');

function createSlide(pres, theme) {
  const slide = pres.addSlide();
  ds.helpers.slideBase(slide, pres, theme);

  ds.helpers.addHeader(slide, pres, theme, {
    eyebrow: 'STAGE 1: CHAINS',
    section: 'Memory',
    title: 'Краткосрочная память: thread + checkpointer',
    sectionNumber: 1,
  });

  ds.helpers.addCodeBlock(slide, pres, theme, {
    x: 0.5, y: 1.5, w: 9.0, h: 3.25,
    language: 'python',
    filePath: 'examples/memory_short.py',
    code: [
      'from langchain.agents import create_agent',
      'from langgraph.checkpoint.memory import InMemorySaver',
      '',
      'checkpointer = InMemorySaver()',
      '',
      'agent = create_agent(',
      '    model="openai:gpt-4.1-mini",',
      '    tools=[...],',
      '    checkpointer=checkpointer,  # <-- persistent state',
      ')',
      '',
      'config = {"configurable": {"thread_id": "user-42"}}',
      '',
      '# Первый turn',
      'agent.invoke({"messages": [{"role": "user",',
      '    "content": "My name is Alice."}]}, config=config)',
      '',
      '# Второй turn -- модель помнит имя',
      'result = agent.invoke({"messages": [{"role": "user",',
      '    "content": "What is my name?"}]}, config=config)',
      'print(result["messages"][-1].content)  # "Alice"',
    ].join('\n'),
  });

  ds.helpers.addCallout(slide, pres, theme, {
    x: 0.5, y: 4.85, w: 9.0, h: 0.3,
    kind: 'success',
    text: 'InMemorySaver для dev. Для прода -- PostgresSaver / RedisSaver (те же LangGraph checkpointer-ы).',
  });

  ds.helpers.addSourceLine(slide, pres, theme, {
    source: 'docs.langchain.com/oss/python/langgraph/persistence',
  });
  ds.helpers.addPageNumber(slide, pres, theme, 21);
}

module.exports = { createSlide };