// Slide 06: Messages -- HumanMessage, AIMessage, SystemMessage, ToolMessage
// Code slide: the message contract, how to build multi-turn prompts.

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: 'Messages',
    title: 'Стандартизированные сообщения',
    sectionNumber: 1,
  });

  ds.helpers.addCodeBlock(slide, pres, theme, {
    x: 0.5, y: 1.5, w: 9.0, h: 3.25,
    language: 'python',
    filePath: 'examples/messages.py',
    code: [
      'from langchain.messages import (',
      '    HumanMessage, AIMessage, SystemMessage, ToolMessage,',
      ')',
      'from langchain.chat_models import init_chat_model',
      '',
      'model = init_chat_model("openai:gpt-4.1-mini")',
      '',
      'messages = [',
      '    SystemMessage(content="You are a concise assistant."),',
      '    HumanMessage(content="What is LCEL?"),',
      '    AIMessage(content="LCEL = pipe-based composition in LangChain."),',
      '    HumanMessage(content="Show a one-line example."),',
      ']',
      '',
      'response = model.invoke(messages)',
      'print(response.content)',
    ].join('\n'),
  });

  ds.helpers.addCallout(slide, pres, theme, {
    x: 0.5, y: 4.85, w: 9.0, h: 0.3,
    kind: 'info',
    text: 'С v1.0 контент -- стандартизированные content blocks: reasoning traces, citations, tool_call блоки.',
  });

  ds.helpers.addSourceLine(slide, pres, theme, {
    source: 'python.langchain.com/docs/concepts/messages/',
  });
  ds.helpers.addPageNumber(slide, pres, theme, 6);
}

module.exports = { createSlide };