class MergeRequestsController < ApplicationController
  before_filter :authenticate_user!
  before_filter :project
  before_filter :module_enabled
  before_filter :merge_request, :only => [:edit, :update, :destroy, :show, :commits, :diffs, :automerge]
  layout "project"

  # Authorize
  before_filter :add_project_abilities

  # Allow read any merge_request
  before_filter :authorize_read_merge_request!

  # Allow write(create) merge_request
  before_filter :authorize_write_merge_request!, :only => [:new, :create]

  # Allow modify merge_request
  before_filter :authorize_modify_merge_request!, :only => [:close, :edit, :update, :sort]

  # Allow destroy merge_request
  before_filter :authorize_admin_merge_request!, :only => [:destroy]

  def index
    @merge_requests = @project.merge_requests

    @merge_requests = case params[:f].to_i
                      when 1 then @merge_requests
                      when 2 then @merge_requests.closed
                      when 3 then @merge_requests.opened.assigned(current_user)
                      else @merge_requests.opened
                      end.page(params[:page]).per(20)

    @merge_requests = @merge_requests.includes(:author, :project).order("created_at desc")
  end

  def show
    unless @project.repo.heads.map(&:name).include?(@merge_request.target_branch) && 
      @project.repo.heads.map(&:name).include?(@merge_request.source_branch)
      git_not_found! and return 
    end

    @note = @project.notes.new(:noteable => @merge_request)

    # Get commits from repository 
    # or from cache if already merged
    @commits = @merge_request.commits

    if @merge_request.unchecked? 
      @merge_request.check_if_can_be_merged
    end

    respond_to do |format|
      format.html
      format.js
    end
  end

  def diffs
    @diffs = @merge_request.diffs
    @commit = @merge_request.last_commit

    @comments_allowed = true
    @line_notes = @merge_request.notes.where("line_code is not null")
  end

  def new
    @merge_request = @project.merge_requests.new
  end

  def edit
  end

  def create
    @merge_request = @project.merge_requests.new(params[:merge_request])
    @merge_request.author = current_user

    respond_to do |format|
      if @merge_request.save
        @merge_request.reload_code
        format.html { redirect_to [@project, @merge_request], notice: 'Merge request was successfully created.' }
        format.json { render json: @merge_request, status: :created, location: @merge_request }
      else
        format.html { render action: "new" }
        format.json { render json: @merge_request.errors, status: :unprocessable_entity }
      end
    end
  end

  def update
    respond_to do |format|
      if @merge_request.update_attributes(params[:merge_request].merge(:author_id_of_changes => current_user.id))
        @merge_request.reload_code
        format.html { redirect_to [@project, @merge_request], notice: 'Merge request was successfully updated.' }
        format.json { head :ok }
      else
        format.html { render action: "edit" }
        format.json { render json: @merge_request.errors, status: :unprocessable_entity }
      end
    end
  end

  def automerge
    render_404 unless @merge_request.open? && @merge_request.can_be_merged?
    message = @merge_request.automerge! ? "Successfully merged" : "Can not be merged"
    redirect_to [@merge_request.project, @merge_request], :alert => message
  end

  def destroy
    @merge_request.destroy

    respond_to do |format|
      format.html { redirect_to project_merge_requests_url(@project) }
      format.json { head :ok }
    end
  end

  def branch_from
    @commit = project.commit(params[:ref])
  end

  def branch_to
    @commit = project.commit(params[:ref])
  end

  protected

  def merge_request
    @merge_request ||= @project.merge_requests.find(params[:id])
  end

  def authorize_modify_merge_request!
    return render_404 unless can?(current_user, :modify_merge_request, @merge_request)
  end

  def authorize_admin_merge_request!
    return render_404 unless can?(current_user, :admin_merge_request, @merge_request)
  end

  def module_enabled
    return render_404 unless @project.merge_requests_enabled
  end
end