module AiChatHistory

# File lib/ai/chat_history.rb, line 44
def exchange_relevance_score(entry, tokens)
  combined = "#{entry[:question]} #{entry[:answer]}"
  AiContext.relevance_score(combined, tokens)
end

# File lib/ai/chat_history.rb, line 40
def follow_up_question?(question)
  AiContext.follow_up_question?(question)
end

# File lib/ai/chat_history.rb, line 57
def format_exchange(entry, max_chars: MAX_LINE_CHARS)
  asker = (entry[:asker] || entry["asker"]).to_s
  question = truncate(entry[:question] || entry["question"], max_chars)
  answer = truncate(entry[:answer] || entry["answer"], max_chars)
  [
    "#{asker} asked: #{question}",
    "Rabbot answered: #{answer}"
  ]
end

# File lib/ai/chat_history.rb, line 36
def merge_entries(*groups)
  groups.flatten.uniq { |entry| [entry[:asker], entry[:question], entry[:answer]] }
end

# File lib/ai/chat_history.rb, line 49
def normalize_entry(entry)
  {
    asker: (entry[:asker] || entry["asker"]).to_s,
    question: (entry[:question] || entry["question"]).to_s,
    answer: (entry[:answer] || entry["answer"]).to_s
  }
end

# File lib/ai/chat_history.rb, line 16
def select_entries(entries, question, stop_words: [], max_context: MAX_CONTEXT)
  list = Array(entries).map { |entry| normalize_entry(entry) }
  return [] if list.empty?

  tokens = AiContext.query_tokens(question, stop_words: stop_words)
  selected = []

  if tokens.any?
    relevant = list.select { |entry| exchange_relevance_score(entry, tokens).positive? }
    selected = relevant.last(max_context) if relevant.any?
  end

  last = list.last
  if follow_up_question?(question) || selected.empty?
    selected = merge_entries(selected, [last])
  end

  selected.last(max_context)
end

# File lib/ai/chat_history.rb, line 67
def truncate(text, max_chars)
  line = text.to_s.strip
  return line if line.length <= max_chars

  "#{line[0, max_chars - 3]}..."
end