Add report filtering capabilities

app/controllers/moderation/reports_controller.rb

@@ -4,10 +4,10 @@ class Moderation::ReportsController < ApplicationController
   before_action :authenticate_user!
 
   def index
-    @type = params[:type]
+    filter = ReportFilter.new(filter_params)
-    @reports = list_reports(type: @type, last_id: params[:last_id])
+    @reports = filter.cursored_results(last_id: params[:last_id])
     @reports_last_id = @reports.map(&:id).min
-    @more_data_available = !list_reports(type: @type, last_id: @reports_last_id, size: 1).count.zero?
+    @more_data_available = filter.cursored_results(last_id: @reports_last_id, size: 1).count.positive?
 
     respond_to do |format|
       format.html
@@ -17,6 +17,10 @@ class Moderation::ReportsController < ApplicationController
 
   private
 
+  def filter_params
+    params.slice(*ReportFilter::KEYS).permit(*ReportFilter::KEYS)
+  end
+
   def list_reports(type:, last_id:, size: nil)
     cursor_params = { last_id:, size: }.compact
 

app/models/report_filter.rb

@@ -0,0 +1,46 @@
+# frozen_string_literal: true
+
+class ReportFilter
+  include CursorPaginatable
+
+  define_cursor_paginator :cursored_results, :results
+
+  KEYS = %i[
+    user
+    target_user
+    type
+  ].freeze
+
+  attr_reader :params
+
+  def initialize(params)
+    @params = params
+  end
+
+  def results
+    scope = Report.where(deleted: false)
+                  .order(:created_at)
+                  .reverse_order
+
+    params.each do |key, value|
+      scope.merge!(scope_for(key, value)) if value.present?
+    end
+
+    scope
+  end
+
+  private
+
+  def scope_for(key, value)
+    case key.to_s
+    when "user"
+      Report.joins(:user)
+            .where(users: { screen_name: value })
+    when "target_user"
+      Report.joins(:target_user)
+            .where(users: { screen_name: value })
+    when "type"
+      Report.where('LOWER(type) = ?', "reports::#{value}")
+    end
+  end
+end