class Api::V1::PartiesController < Api::V1::ApiController
  before_action :set_from_slug,
                except: %w[create destroy update index favorites]
  before_action :set, only: %w[update destroy]

  def create
    @party = Party.new(shortcode: random_string)
    @party.extra = party_params["extra"]

    @party.user = current_user if current_user

    render :show, status: :created if @party.save!
  end

  def show
    render_not_found_response if @party.nil?
  end

  def update
    if @party.user != current_user
      render_unauthorized_response
    else
      @party.attributes = party_params.except(:skill1_id, :skill2_id, :skill3_id)
      ap party_params
      # Determine which incoming keys contain new skills
      skill_keys = %w[skill1_id skill2_id skill3_id]
      if (party_params.keys & skill_keys).any?
        new_skill_keys = party_params.keys - skill_keys

        # If there are new skills, merge them with the existing skills
        unless new_skill_keys.empty?
          existing_skills = [@party.skill1, @party.skill2, @party.skill3]
          new_skill_ids = new_skill_keys.map { |key| party_params[key] }
          positions = extract_positions_from_keys(new_skill_keys)

          new_skills = merge_skills_with_existing_skills(existing_skills, new_skill_ids, positions)

          new_skill_ids = {}
          new_skills.each_with_index do |skill, index|
            new_skill_ids["skill#{index + 1}_id"] = skill.id
          end

          @party.attributes = new_skill_ids
        end
      end
    end

    render :update, status: :ok if @party.save!
  end

  def index
    @per_page = 15

    now = DateTime.current
    start_time =
      (
        now - request.params["recency"].to_i.seconds
      ).to_datetime.beginning_of_day unless request.params["recency"].blank?

    conditions = {}
    conditions[:element] = request.params["element"] unless request.params[
      "element"
    ].blank?
    conditions[:raid] = request.params["raid"] unless request.params[
      "raid"
    ].blank?
    conditions[:created_at] = start_time..now unless request.params[
      "recency"
    ].blank?
    conditions[:weapons_count] = 5..13

    @parties =
      Party
        .where(conditions)
        .order(created_at: :desc)
        .paginate(page: request.params[:page], per_page: @per_page)
        .each do |party|
        party.favorited =
          current_user ? party.is_favorited(current_user) : false
      end
    @count = Party.where(conditions).count

    render :all, status: :ok
  end

  def favorites
    raise Api::V1::UnauthorizedError unless current_user

    @per_page = 15

    now = DateTime.current
    start_time =
      (
        now - params["recency"].to_i.seconds
      ).to_datetime.beginning_of_day unless request.params["recency"].blank?

    conditions = {}
    conditions[:element] = request.params["element"] unless request.params[
      "element"
    ].blank?
    conditions[:raid] = request.params["raid"] unless request.params[
      "raid"
    ].blank?
    conditions[:created_at] = start_time..now unless request.params[
      "recency"
    ].blank?
    conditions[:favorites] = { user_id: current_user.id }

    @parties =
      Party
        .joins(:favorites)
        .where(conditions)
        .order("favorites.created_at DESC")
        .paginate(page: request.params[:page], per_page: @per_page)
        .each { |party| party.favorited = party.is_favorited(current_user) }
    @count = Party.joins(:favorites).where(conditions).count

    render :all, status: :ok
  end

  def destroy
    if @party.user != current_user
      render_unauthorized_response
    else
      render :destroyed, status: :ok if @party.destroy
    end
  end

  def weapons
    render_not_found_response if @party.nil?
    render :weapons, status: :ok
  end

  def summons
    render_not_found_response if @party.nil?
    render :summons, status: :ok
  end

  def characters
    render_not_found_response if @party.nil?
    render :characters, status: :ok
  end

  private

  def merge_skills_with_existing_skills(
    existing_skills,
    new_skill_ids,
    positions
  )
    new_skills = []
    new_skill_ids.each { |id| new_skills << JobSkill.find(id) }

    progress = existing_skills
    new_skills.each do |skill, index|
      progress = place_skill_in_existing_skills(progress, skill, positions[0])
    end

    progress
  end

  def place_skill_in_existing_skills(existing_skills, skill, position)
    old_position = existing_skills.index { |x| x.id == skill.id }

    if old_position
      existing_skills = swap_skills_at_position(existing_skills, skill, position, old_position)
    else
      # Test if skill will exceed allowances of skill types
      skill_type = skill.sub ? 'sub' : 'emp'
      unless can_add_skill_of_type(existing_skills, position, skill_type)
        raise Api::V1::TooManySkillsOfTypeError.new(skill_type: skill_type)
      end

      existing_skills[position] = skill
    end

    existing_skills
  end

  def swap_skills_at_position(skills, new_skill, position1, position2)
    # Check desired position for a skill
    displaced_skill = skills[position1] if skills[position1].present?

    # Put skill in new position
    skills[position1] = new_skill
    skills[position2] = displaced_skill

    skills
  end

  def can_add_skill_of_type(skills, position, type)
    max_skill_of_type = 2

    count = skills.reject
                  .with_index { |_el, index| index == position }
                  .reduce(0) do |sum, skill|
      sum + 1 if type == 'emp' && skill.emp
      sum + 1 if type == 'sub' && skill.sub
    end

    count + 1 <= max_skill_of_type
  end

  def extract_positions_from_keys(keys)
    # Subtract by 1 because we won't operate on the 0th skill, so we don't pass it
    keys.map { |key| key["skill".length].to_i - 1 }
  end

  def random_string
    numChars = 6
    o = [("a".."z"), ("A".."Z"), (0..9)].map(&:to_a).flatten
    return (0...numChars).map { o[rand(o.length)] }.join
  end

  def set_from_slug
    @party = Party.where("shortcode = ?", params[:id]).first
    @party.favorited =
      current_user && @party ? @party.is_favorited(current_user) : false
  end

  def set
    @party = Party.where("id = ?", params[:id]).first
  end

  def party_params
    params.require(:party).permit(
      :user_id,
      :extra,
      :name,
      :description,
      :raid_id,
      :job_id,
      :skill0_id,
      :skill1_id,
      :skill2_id,
      :skill3_id
    )
  end
end