// Slide 17: RunnableParallel + RunnableBranch -- fan-out / conditional routing
// Code slide: parallel execution and if/else logic in a chain.

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: 'Runnable helpers',
    title: 'Parallel + Branch -- fan-out и роутинг',
    sectionNumber: 1,
  });

  ds.helpers.addCodeBlock(slide, pres, theme, {
    x: 0.5, y: 1.5, w: 9.0, h: 3.25,
    language: 'python',
    filePath: 'examples/runnable_parallel.py',
    code: [
      'from langchain_core.runnables import RunnableParallel, RunnableBranch',
      '',
      '# Parallel -- один вход, несколько параллельных Runnable-ов, dict на выходе',
      'joke_chain = ChatPromptTemplate.from_template("Tell a joke about {topic}") | model',
      'poem_chain = ChatPromptTemplate.from_template("Write a poem about {topic}") | model',
      '',
      'parallel = RunnableParallel(joke=joke_chain, poem=poem_chain)',
      'result = parallel.invoke({"topic": "cats"})',
      'print(result.keys())  # dict_keys(["joke", "poem"])',
      '',
      '# Branch -- if/else роутинг по условию',
      'branch = RunnableBranch(',
      '    (lambda x: "code" in x["topic"].lower(), code_chain),',
      '    (lambda x: "math" in x["topic"].lower(), math_chain),',
      '    general_chain,  # default',
      ')',
      'print(branch.invoke({"topic": "code review"}))',
    ].join('\n'),
  });

  ds.helpers.addCallout(slide, pres, theme, {
    x: 0.5, y: 4.85, w: 9.0, h: 0.3,
    kind: 'success',
    text: 'RunnableParallel выполняется параллельно -- отлично для multi-aspect анализа (sentiment + summary + keywords).',
  });

  ds.helpers.addSourceLine(slide, pres, theme, {
    source: 'python.langchain.com/docs/how_to/branching/',
  });
  ds.helpers.addPageNumber(slide, pres, theme, 17);
}

module.exports = { createSlide };