class TracesController < ApplicationController
  layout "site", :except => :georss

  before_action :authorize_web
  before_action :set_locale
  before_action :check_database_readable

  authorize_resource

  before_action :check_database_writable, :only => [:new, :create, :edit, :delete]
  before_action :offline_warning, :only => [:mine, :show]
  before_action :offline_redirect, :only => [:new, :create, :edit, :delete, :data]

  # Counts and selects pages of GPX traces for various criteria (by user, tags, public etc.).
  #  target_user - if set, specifies the user to fetch traces for.  if not set will fetch all traces
  def index
    # from display name, pick up user id if one user's traces only
    display_name = params[:display_name]
    if display_name.present?
      target_user = User.active.where(:display_name => display_name).first
      if target_user.nil?
        render_unknown_user display_name
        return
      end
    end

    # set title
    @title = if target_user.nil?
               t ".public_traces"
             elsif current_user && current_user == target_user
               t ".my_traces"
             else
               t ".public_traces_from", :user => target_user.display_name
             end

    @title += t ".tagged_with", :tags => params[:tag] if params[:tag]

    # four main cases:
    # 1 - all traces, logged in = all public traces + all user's (i.e + all mine)
    # 2 - all traces, not logged in = all public traces
    # 3 - user's traces, logged in as same user = all user's traces
    # 4 - user's traces, not logged in as that user = all user's public traces
    @traces = if target_user.nil? # all traces
                if current_user
                  Trace.visible_to(current_user) # 1
                else
                  Trace.visible_to_all # 2
                end
              elsif current_user && current_user == target_user
                current_user.traces # 3 (check vs user id, so no join + can't pick up non-public traces by changing name)
              else
                target_user.traces.visible_to_all # 4
              end

    @traces = @traces.tagged(params[:tag]) if params[:tag]

    @params = params.permit(:display_name, :tag)

    @page = (params[:page] || 1).to_i
    @page_size = 20

    @traces = @traces.visible
    @traces = @traces.order(:id => :desc)
    @traces = @traces.offset((@page - 1) * @page_size)
    @traces = @traces.limit(@page_size)
    @traces = @traces.includes(:user, :tags)

    # put together SET of tags across traces, for related links
    tagset = {}
    @traces.each do |trace|
      trace.tags.reload if params[:tag] # if searched by tag, ActiveRecord won't bring back other tags, so do explicitly here
      trace.tags.each do |tag|
        tagset[tag.tag] = tag.tag
      end
    end

    # final helper vars for view
    @target_user = target_user
    @display_name = target_user.display_name if target_user
    @all_tags = tagset.values
  end

  def mine
    redirect_to :action => :index, :display_name => current_user.display_name
  end

  def show
    @trace = Trace.find(params[:id])

    if @trace&.visible? &&
       (@trace&.public? || @trace&.user == current_user)
      @title = t ".title", :name => @trace.name
    else
      flash[:error] = t ".trace_not_found"
      redirect_to :action => "index"
    end
  rescue ActiveRecord::RecordNotFound
    flash[:error] = t ".trace_not_found"
    redirect_to :action => "index"
  end

  def new
    @title = t ".upload_trace"
    @trace = Trace.new(:visibility => default_visibility)
  end

  def create
    @title = t ".upload_trace"

    logger.info(params[:trace][:gpx_file].class.name)

    if params[:trace][:gpx_file].respond_to?(:read)
      begin
        @trace = do_create(params[:trace][:gpx_file], params[:trace][:tagstring],
                           params[:trace][:description], params[:trace][:visibility])
      rescue StandardError => ex
        logger.debug ex
      end

      if @trace.id
        flash[:notice] = t ".trace_uploaded"
        flash[:warning] = t ".traces_waiting", :count => current_user.traces.where(:inserted => false).count if current_user.traces.where(:inserted => false).count > 4

        TraceImporterJob.perform_later(@trace) if Settings.trace_use_job_queue
        redirect_to :action => :index, :display_name => current_user.display_name
      else
        flash[:error] = t("traces.create.upload_failed") if @trace.valid?

        render :action => "new"
      end
    else
      @trace = Trace.new(:name => "Dummy",
                         :tagstring => params[:trace][:tagstring],
                         :description => params[:trace][:description],
                         :visibility => params[:trace][:visibility],
                         :inserted => false, :user => current_user,
                         :timestamp => Time.now.getutc)
      @trace.valid?
      @trace.errors.add(:gpx_file, "can't be blank")

      render :action => "new"
    end
  end

  def data
    trace = Trace.find(params[:id])

    if trace.visible? && (trace.public? || (current_user && current_user == trace.user))
      if Acl.no_trace_download(request.remote_ip)
        head :forbidden
      elsif request.format == Mime[:xml]
        send_data(trace.xml_file.read, :filename => "#{trace.id}.xml", :type => request.format.to_s, :disposition => "attachment")
      elsif request.format == Mime[:gpx]
        send_data(trace.xml_file.read, :filename => "#{trace.id}.gpx", :type => request.format.to_s, :disposition => "attachment")
      else
        send_file(trace.trace_name, :filename => "#{trace.id}#{trace.extension_name}", :type => trace.mime_type, :disposition => "attachment")
      end
    else
      head :not_found
    end
  rescue ActiveRecord::RecordNotFound
    head :not_found
  end

  def edit
    @trace = Trace.find(params[:id])

    if !@trace.visible?
      head :not_found
    elsif current_user.nil? || @trace.user != current_user
      head :forbidden
    else
      @title = t ".title", :name => @trace.name
    end
  rescue ActiveRecord::RecordNotFound
    head :not_found
  end

  def update
    @trace = Trace.find(params[:id])

    if !@trace.visible?
      head :not_found
    elsif current_user.nil? || @trace.user != current_user
      head :forbidden
    elsif @trace.update(trace_params)
      flash[:notice] = t ".updated"
      redirect_to :action => "show", :display_name => current_user.display_name
    else
      @title = t ".title", :name => @trace.name
      render :action => "edit"
    end
  rescue ActiveRecord::RecordNotFound
    head :not_found
  end

  def delete
    trace = Trace.find(params[:id])

    if !trace.visible?
      head :not_found
    elsif current_user.nil? || (trace.user != current_user && !current_user.administrator? && !current_user.moderator?)
      head :forbidden
    else
      trace.visible = false
      trace.save
      flash[:notice] = t ".scheduled_for_deletion"
      TraceDestroyerJob.perform_later(trace) if Settings.trace_use_job_queue
      redirect_to :action => :index, :display_name => trace.user.display_name
    end
  rescue ActiveRecord::RecordNotFound
    head :not_found
  end

  def georss
    @traces = Trace.visible_to_all.visible

    @traces = @traces.joins(:user).where(:users => { :display_name => params[:display_name] }) if params[:display_name]

    @traces = @traces.tagged(params[:tag]) if params[:tag]
    @traces = @traces.order("timestamp DESC")
    @traces = @traces.limit(20)
    @traces = @traces.includes(:user)
  end

  def picture
    trace = Trace.find(params[:id])

    if trace.visible? && trace.inserted?
      if trace.public? || (current_user && current_user == trace.user)
        expires_in 7.days, :private => !trace.public?, :public => trace.public?
        send_file(trace.large_picture_name, :filename => "#{trace.id}.gif", :type => "image/gif", :disposition => "inline")
      else
        head :forbidden
      end
    else
      head :not_found
    end
  rescue ActiveRecord::RecordNotFound
    head :not_found
  end

  def icon
    trace = Trace.find(params[:id])

    if trace.visible? && trace.inserted?
      if trace.public? || (current_user && current_user == trace.user)
        expires_in 7.days, :private => !trace.public?, :public => trace.public?
        send_file(trace.icon_picture_name, :filename => "#{trace.id}_icon.gif", :type => "image/gif", :disposition => "inline")
      else
        head :forbidden
      end
    else
      head :not_found
    end
  rescue ActiveRecord::RecordNotFound
    head :not_found
  end

  private

  def do_create(file, tags, description, visibility)
    # Sanitise the user's filename
    name = file.original_filename.gsub(/[^a-zA-Z0-9.]/, "_")

    # Get a temporary filename...
    filename = "/tmp/#{rand}"

    # ...and save the uploaded file to that location
    File.open(filename, "wb") { |f| f.write(file.read) }

    # Create the trace object, falsely marked as already
    # inserted to stop the import daemon trying to load it
    trace = Trace.new(
      :name => name,
      :tagstring => tags,
      :description => description,
      :visibility => visibility,
      :inserted => true,
      :user => current_user,
      :timestamp => Time.now.getutc
    )

    if trace.valid?
      Trace.transaction do
        begin
          # Save the trace object
          trace.save!

          # Rename the temporary file to the final name
          FileUtils.mv(filename, trace.trace_name)
        rescue StandardError
          # Remove the file as we have failed to update the database
          FileUtils.rm_f(filename)

          # Pass the exception on
          raise
        end

        begin
          # Clear the inserted flag to make the import daemon load the trace
          trace.inserted = false
          trace.save!
        rescue StandardError
          # Remove the file as we have failed to update the database
          FileUtils.rm_f(trace.trace_name)

          # Pass the exception on
          raise
        end
      end
    end

    # Finally save the user's preferred privacy level
    if pref = current_user.preferences.where(:k => "gps.trace.visibility").first
      pref.v = visibility
      pref.save
    else
      current_user.preferences.create(:k => "gps.trace.visibility", :v => visibility)
    end

    trace
  end

  def offline_warning
    flash.now[:warning] = t "traces.offline_warning.message" if Settings.status == "gpx_offline"
  end

  def offline_redirect
    redirect_to :action => :offline if Settings.status == "gpx_offline"
  end

  def default_visibility
    visibility = current_user.preferences.where(:k => "gps.trace.visibility").first

    if visibility
      visibility.v
    elsif current_user.preferences.where(:k => "gps.trace.public", :v => "default").first.nil?
      "private"
    else
      "public"
    end
  end

  def trace_params
    params.require(:trace).permit(:description, :tagstring, :visibility)
  end
end