class Api::V1::PullRequestsController < Api::V1::BaseController
  respond_to :json

  before_filter :authenticate_user!
  skip_before_filter :authenticate_user!, only: [:show, :index, :group_index, :commits, :files] if APP_CONFIG['anonymous_access']

  load_resource :group, only: :group_index, find_by: :id, parent: false
  load_resource :project
  load_resource :issue, through: :project, find_by: :serial_id, parent: false, only: [:show, :index, :commits, :files, :merge, :update]
  load_and_authorize_resource instance_name: :pull, through: :issue, singleton: true, only: [:show, :index, :commits, :files, :merge, :update]

  def index
    @pulls = @project.pull_requests
    @pulls_url = api_v1_project_pull_requests_path(@project, format: :json)
    render_pulls_list
  end

  def all_index
    project_ids = get_all_project_ids Project.accessible_by(current_ability, :membered).pluck(:id)
    @pulls = PullRequest.where('pull_requests.to_project_id IN (?)', project_ids)
    @pulls_url = api_v1_pull_requests_path format: :json
    render_pulls_list
  end

  def user_index
    project_ids = get_all_project_ids current_user.projects.pluck(:id)
    @pulls = PullRequest.where('pull_requests.to_project_id IN (?)', project_ids)
    @pulls_url = pull_requests_api_v1_user_path format: :json
    render_pulls_list
  end

  def group_index
    project_ids = @group.projects.pluck(:id)
    project_ids = Project.accessible_by(current_ability, :membered).where(id: project_ids).pluck(:id)
    @pulls = PullRequest.where(to_project_id: project_ids)
    @pulls_url = pull_requests_api_v1_group_path
    render_pulls_list
  end

  def show
    redirect_to api_v1_project_issue_path(@project.id, @issue.serial_id) if @pull.nil?
    respond_to :json
  end

  def create
    from_project = Project.find(pull_params[:from_project_id]) if pull_params[:from_project_id].present?
    from_project ||= @project
    authorize! :read, from_project

    @pull = @project.pull_requests.new
    @pull.build_issue title: pull_params[:title], body: pull_params[:body]
    @pull.from_project            = @project
    @pull.to_ref, @pull.from_ref  = pull_params[:to_ref], pull_params[:from_ref]
    @pull.issue.assignee_id       = pull_params[:assignee_id] if can?(:write, @project)
    @pull.issue.user, @pull.issue.project = current_user, @project
    @pull.issue.new_pull_request  = true
    render_validation_error(@pull, "#{@pull.class.name} has not been created") && return unless @pull.valid?

    @pull.save # set pull id
    @pull.reload
    @pull.check(false) # don't make event transaction
    if @pull.already?
      @pull.destroy
      error_message = I18n.t('projects.pull_requests.up_to_date', to_ref: @pull.to_ref, from_ref: @pull.from_ref)
      render_json_response(@pull, error_message, 422)
    else
      @pull.send(@pull.status == 'blocked' ? 'block' : @pull.status)
      render_json_response @pull, "#{@pull.class.name} has been created successfully"
    end
  end

  def update
    @pull = @project.pull_requests.includes(:issue).where(issues: {serial_id: params[:id]}).first
    authorize! :update, @pull

    if pull_params.present?
      attrs = pull_params.slice(:title, :body)
      attrs.merge!(assignee_id: pull_params[:assignee_id]) if can?(:write, @project)

      if (action = pull_params[:status]) && %w(close reopen).include?(pull_params[:status])
        if @pull.send("can_#{action}?")
          @pull.set_user_and_time current_user
          need_check = true if action == 'reopen' && @pull.valid?
        end
      end
    end

    class_name = @pull.class.name
    if @pull.issue.update_attributes(attrs)
      @pull.send(action) if action.present?
      @pull.check if need_check
      render_json_response @pull, "#{class_name} has been updated successfully"
    else
      render_validation_error @pull, "#{class_name} has not been updated"
    end
  end

  def commits
    @commits = @pull.repo.commits_between(@pull.to_commit, @pull.from_commit).paginate(paginate_params)
    respond_to :json
  end

  def files
    @stats = @pull.diff_stats.zip(@pull.diff).paginate(paginate_params)
    respond_to :json
  end

  def merge
    class_name = @pull.class.name
    if @pull.merge!(current_user)
      render_json_response @pull, "#{class_name} has been merged successfully"
    else
      render_validation_error @pull, "#{class_name} has not been merged"
    end
  end

  private

  def render_pulls_list
    @pulls = @pulls.includes(issue: [:user, :assignee])
    if params[:status] == 'closed'
      @pulls = @pulls.closed_or_merged
    else
      @pulls = @pulls.not_closed_or_merged
    end

    if action_name == 'index' && params[:assignee].present?
      case params[:assignee]
      when 'none'
        @pulls = @pulls.where('issues.assigned_id IS NULL')
      when '*'
        @pulls = @pulls.where('issues.assigned_id IS NOT NULL')
      else
        @pulls = @pulls.where('assignees_issues.uname = ?', params[:assignee])
      end
    end

    if %w[all_index user_index group_index].include?(action_name)
      case params[:filter]
      when 'created'
        @pulls = @pulls.where('issues.user_id = ?', current_user.id)
      when 'all'
      else
        @pulls = @pulls.where('issues.assignee_id = ?', current_user.id)
      end
    else
      @pulls.where('users.uname = ?', params[:creator]) if params[:creator].present?
    end

    sort = params[:sort] == 'updated' ? 'issues.updated_at' : 'issues.created_at'
    direction = params[:direction] == 'asc' ? 'ASC' : 'DESC'
    @pulls = @pulls.order("#{sort} #{direction}")

    @pulls = @pulls.where('issues.created_at >= to_timestamp(?)', params[:since]) if params[:since] =~ /\A\d+\z/
    @pulls = @pulls.paginate(paginate_params)

    respond_to do |format|
      format.json { render :index }
    end
  end

  def get_all_project_ids default_project_ids
    project_ids = []
    if ['created', 'all'].include? params[:filter]
      # add own pulls
      project_ids = Project.accessible_by(current_ability, :show).joins(:issues).
                            where(issues: {user_id: current_user.id}).pluck('projects.id')
    end
    project_ids |= default_project_ids
  end


  def pull_params
    @pull_params ||= params[:pull_request] || {}
  end
end