btrc-hub/backend/app/controllers/wiki_pages_controller.rb

class WikiPagesController < ApplicationController
  def show
    wiki_page = WikiPage.find(params[:id])
    return head :not_found unless wiki_page

    render json: wiki_page.as_json.merge(body: wiki_page.body)
  end

  def show_by_title
    wiki_page = WikiPage.find_by(title: params[:title])
    return head :not_found unless wiki_page

    render json: wiki_page.as_json.merge(body: wiki_page.body)
  end

  def create
    return head :unauthorized unless current_user
    return head :forbidden unless ['admin', 'member'].include?(current_user.role)

    wiki_page = WikiPage.new(title: params[:title], created_user: current_user, updated_user: current_user)
    if wiki_page.save
      wiki_page.set_body params[:body], user: current_user
      render json: wiki_page, status: :created
    else
      render json: { errors: wiki_page.errors.full_messages }, status: :unprocessable_entity
    end
  end

  def update
    return head :unauthorized unless current_user
    return head :forbidden unless ['admin', 'member'].include?(current_user.role)

    wiki_page = WikiPage.find(params[:id])
    return head :not_found unless wiki_page

    wiki_page.updated_user = current_user
    wiki_page.set_body params[:body], user: current_user
    wiki_page.save!
    head :ok
  end

  def search
    q = WikiPage.all

    if params[:title].present?
      title = params[:title].to_s.strip
      q = q.where('title LIKE ?', "%#{ WikiPage.sanitize_sql_like(title) }%")
    end

    render json: q.limit(20)
  end

  def changes
    id = params[:id]
    log = id.present? ? wiki.page("#{ id }.md")&.versions : wiki.repo.log('main', nil, max_count: 50)
    return render json: [] unless log

    render json: log.map { |commit|
        wiki_page = WikiPage.find(commit.message.split(' ')[1].to_i)
        user = User.find(commit.author.name.to_i)
        { sha:          commit.id,
          wiki_page:    wiki_page && { id: wiki_page.id, title: wiki_page.title },
          user:         user && { id: user.id, name: user.name },
          change_type:  commit.message.split(' ')[0].downcase[0...(-1)],
          timestamp:    commit.authored_date } }
  end

  private

  WIKI_PATH = Rails.root.join('wiki').to_s

  def wiki
    @wiki ||= Gollum::Wiki.new(WIKI_PATH)
  end
end