require "pretty_print"
require "colorize"

class OpenAIChatBuilder
  alias OpenAIMessage = NamedTuple(role: String, content: String)
  alias OpenAIChat = Array(OpenAIMessage)

  getter verbose : Bool
  def initialize(@verbose)

  end

  # skip prelude_zone
  # skip future_zone
  def build(prompt : Prompt) : OpenAIChat
    chat = [] of OpenAIMessage

    token_limit = 2_900
    mandatory_token_count = (
      prompt.system_zone.token_count + 
      prompt.present_zone.token_count
    )

    ## Build mandatory system messages
    prompt.system_zone.each do |content|
      chat << { role: "system", content: content }
    end

    ## Build mandatory system messages
    tmp_chat = [] of OpenAIMessage
    tmp_token_count = 0
    prompt.past_zone.reverse_each do |content|
      estimated_token_count = (content.size/4) + tmp_token_count + mandatory_token_count
      pp tmp_chat.reverse if @verbose
      puts "ESTIMATE: #{estimated_token_count} (limit=#{token_limit})".colorize(:yellow).to_s if @verbose

      break if estimated_token_count >= token_limit

      tmp_chat << { role: "user", content: content }
      tmp_token_count += (content.size / 4)
    end
    chat.concat(tmp_chat.reverse)

    prompt.present_zone.each do |content|
      chat << { role: "user", content: content }
    end

    # pp chat
    chat
  end
end