require "discordcr"
require "json"
require "uuid"
require "./responses"
require "./reactions"

token = ENV["DISCORD_BOT_TOKEN"]? || raise "Missing DISCORD_BOT_TOKEN env variable"

puts("Bot #{token}")

client = Discord::Client.new(
  token: "Bot #{token}",
  client_id: 1475668463363293398_u64
)

DICT_FILE = "./dictionary.json"
USER_LIMIT = 100

def load_dict
  if File.exists?(DICT_FILE)
    JSON.parse(File.read(DICT_FILE)).as_h.transform_values do |defs|
      defs.as_a.map do |d|
        {
          "id" => d["id"].as_s,
          "definition" => d["definition"].as_s,
          "author" => d["author"].as_s,
          "upvotes" => d["upvotes"].as_i,
          "downvotes" => d["downvotes"].as_i
        }
      end
    end
  else
    {} of String => Array(Hash(String, String|Int32))
  end
end

def save_dict(dict)
  File.write(DICT_FILE, dict.to_json)
end

dictionary = load_dict

def user_def_count(dict, username)
  dict.values.flatten.count { |d| d["author"] == username }
end

client.on_message_create do |payload|
  content = payload.content
  args = content.split(" ", 3)
  command = args[0]?
  user = payload.author.username

  if payload.author.bot
    next
  end

  case command
  when "!add"
    word = args[1]?
    definition = args[2]?

    if word.nil? || definition.nil?
      client.create_message(payload.channel_id, "usage: !add <word> <definition>")
      next
    end

    if user_def_count(dictionary, user) >= USER_LIMIT
      client.create_message(payload.channel_id, "#{user}, you reached the limit of #{USER_LIMIT} definitions.")
      next
    end

    dictionary[word] ||= [] of Hash(String, String | Int32)
    dictionary[word] << {
      "id" => UUID.random.to_s,
      "definition" => definition,
      "author" => user,
      "upvotes" => 0,
      "downvotes" => 0
    }

    save_dict(dictionary)
    client.create_message(payload.channel_id, "added definition for **#{word}** by #{user}.")

  when "!define"
    word = args[1]?
    if word.nil?
      client.create_message(payload.channel_id, "usage: !define <word>")
      next
    end

    defs = dictionary[word]?
    if defs
      text = defs.map_with_index do |d, i|
        "#{i+1}. #{d["definition"]} (by #{d["author"]}) 👍#{d["upvotes"]} 👎#{d["downvotes"]}"
      end.join("\n")
      client.create_message(payload.channel_id, "**#{word}**:\n#{text}")
    else
      client.create_message(payload.channel_id, "no definition for **#{word}**.")
    end

  when "!list"
    word = args[1]?
    if word.nil?
      client.create_message(payload.channel_id, "usage: !list <word>")
      next
    end

    defs = dictionary[word]?
    if defs
      text = defs.map_with_index do |d, i|
        "#{i+1}. #{d["definition"]} (by #{d["author"]}) 👍#{d["upvotes"]} 👎#{d["downvotes"]}"
      end.join("\n")
      client.create_message(payload.channel_id, "**#{word}** definitions:\n#{text}")
    else
      client.create_message(payload.channel_id, "no definitions found.")
    end

  when "!upvote", "!downvote"
    word = args[1]?
    index = args[2]? ? args[2].to_i : nil

    if word.nil? || index.nil?
      client.create_message(payload.channel_id, "usage: #{command} <word> <definition_number>")
      next
    end

    defs = dictionary[word]?
    if defs && index > 0 && index <= defs.size
      target = defs[index - 1]
      if command == "!upvote"
        target["upvotes"] = target["upvotes"].to_i + 1
      else
        target["downvotes"] = target["downvotes"].to_i + 1
      end
      save_dict(dictionary)
      client.create_message(payload.channel_id, "updated votes for definition #{index} of **#{word}**.")
    else
      client.create_message(payload.channel_id, "invalid word or definition number.")
    end

  when "!random"
    if dictionary.empty?
      client.create_message(payload.channel_id, "nichectionary is empty.")
      next
    end

    word = dictionary.keys.sample
    defs = dictionary[word]
    def_choice = defs.sample
    client.create_message(payload.channel_id,
      "**#{word}**:\n#{def_choice["definition"]} (by #{def_choice["author"]}) 👍#{def_choice["upvotes"]} 👎#{def_choice["downvotes"]}"
    )

  when "!search"
    term = args[1]?
    if term.nil?
      client.create_message(payload.channel_id, "usage: !search <term>")
      next
    end

    matches = dictionary.select { |w, _| w.includes?(term) }
    if matches.empty?
      client.create_message(payload.channel_id, "no words matched `#{term}`.")
      next
    end

    text = matches.keys.join(", ")
    client.create_message(payload.channel_id, "words matching `#{term}`: #{text}")
  end

  Reactions.check_message(content).each do |emoji|
    client.create_reaction(payload.channel_id, payload.id, emoji)
  end

  preset_reply = Responses.check_message(content)
  if preset_reply
    client.trigger_typing_indicator(payload.channel_id)
    sleep 500.milliseconds
    client.create_message(payload.channel_id, preset_reply, message_reference: payload.message_reference())
    next
  end
end

client.run