# frozen_string_literal: true

module DiscourseChatIntegration::Provider::SlackProvider
  class SlackMessage
    def initialize(raw_message, transcript)
      @raw = raw_message
      @transcript = transcript
    end

    def username
      if user
        user["_transcript_username"]
      elsif @raw.key?("username")
        # This is for bot messages
        @raw["username"].gsub(' ', '_')
      end
    end

    def avatar
      user["profile"]["image_24"] if user
    end

    def url
      channel_id = @transcript.channel_id
      ts = @raw['ts'].gsub('.', '')
      "https://slack.com/archives/#{channel_id}/p#{ts}"
    end

    def text
      text = @raw['text'].nil? ? "" : @raw['text']

      pre = {}

      # Extract code blocks and replace with placeholder
      text = text.gsub(/```(.*?)```/m) do |match|
        key = "pre:" + SecureRandom.alphanumeric(50)
        pre[key] = HTMLEntities.new.decode $1
        "\n```\n#{key}\n```\n"
      end

      # # Extract inline code and replace with placeholder
      text = text.gsub(/(?<!`)`([^`]+?)`(?!`)/) do |match|
        key = "pre:" + SecureRandom.alphanumeric(50)
        pre[key] = HTMLEntities.new.decode $1
        "`#{key}`"
      end

      # Format links (don't worry about special cases @ # !)
      text = text.gsub(/<(.*?)>/) do |match|
        group = $1
        parts = group.split('|')
        link = parts[0].start_with?('@', '#', '!') ? nil : parts[0]
        text = parts.length > 1 ? parts[1] : parts[0]

        if parts[0].start_with?('@')
          user_id = parts[0][1..-1]
          if user = @transcript.users[user_id]
            user_name = user['_transcript_username']
          else
            user_name = user_id
          end
          next "@#{user_name}"
        end

        if link.nil?
          text
        elsif link == text
          "<#{link}>"
        else
          "[#{text}](#{link})"
        end
      end

      # Add an extra * to each side for bold
      text = text.gsub(/\*.*?\*/) do |match|
        "*#{match}*"
      end

      # Add an extra ~ to each side for strikethrough
      text = text.gsub(/~.*?~/) do |match|
        "~#{match}~"
      end

      # Replace emoji - with _
      text = text.gsub(/:[a-z0-9_-]+:/) do |match|
        match.gsub("-") { "_" }
      end

      # Restore pre-formatted code block content
      pre.each do |key, value|
        text = text.gsub(key) { value }
      end

      text
    end

    def attachments_string
      string = ""
      string += "\n" if !attachments.empty?
      attachments.each do |attachment|
        string += " - #{attachment}\n"
      end
      string
    end

    def processed_text_with_attachments
      self.text + attachments_string
    end

    def raw_text
      raw_text = @raw['text'].nil? ? "" : @raw['text']
      raw_text += attachments_string
      raw_text
    end

    def attachments
      attachments = []

      return attachments unless @raw.key?('attachments')

      @raw["attachments"].each do |attachment|
        next unless attachment.key?("fallback")
        attachments << attachment["fallback"]
      end

      attachments
    end

    def ts
      @raw["ts"]
    end

    private

    def user
      return nil unless user_id = @raw["user"]
      @transcript.users[user_id]
    end
  end
end