Task: build a app that searches files based on regex in Ruby using Rails.

API specification:

openapi: 3.0.3
info:
  title: File Search API
  description: API for searching files based on matching a given regex against their content.
  version: 1.0.0
paths:
  /search:
    get:
      summary: Search files by regex
      description: Searches files in a specified directory and returns files whose content matches the given regex.
      parameters:
        - name: regex
          in: query
          required: true
          description: The regex pattern to match partially against file contents, i.e. some part of the file content must match the regex.
          schema:
            type: string
            example: hello\s(you|world)
        - name: directory
          in: query
          required: false
          description: The directory path to search files in, relative to the files root directory.
          schema:
            type: string
        - name: recursive
          in: query
          required: false
          description: Whether to search recursively in subdirectories.
          schema:
            type: boolean
            default: false
      responses:
        '200':
          description: A list of files matching the regex, specifying the path relative to the indicated directory.
          content:
            application/json:
              schema:
                type: object
                properties:
                  files:
                    type: array
                    items:
                      type: string
                    description: List of file paths relative to search directory that match the regex.
                    example: ["folder1/file1.txt", "file2.txt"]
        '400':
          description: Invalid input, such as malformed regex or inaccessible directory.
          content:
            application/json:
              schema:
                type: object
                properties:
                  error:
                    type: string
                    description: Error message detailing the issue.
        '500':
          description: Internal server error.
          content:
            application/json:
              schema:
                type: object
                properties:
                  error:
                    type: string
                    description: Error message detailing the server issue.


Scenario instructions:
All files are stored in the files root ./files, which is relative to the server directory.

Environment instructions:

You need to create the Ruby on Rails project from scratch, after the command `rails new . --api` was run.

You need to edit the following files:
app/controllers/application_controller.rb
app/models/application_record.rb
config/application.rb
config/environments/development.rb
config/routes.rb


Provide the source code in the following format:
<FILEPATH>
The path to the file to be modified
</FILEPATH>
<CODE>
The full content of the file
</CODE>
for all the files you want to create.

Example:
<FILEPATH>
path/to/file.py
</FILEPATH>
<CODE>
def hello_world():
    pass
</CODE>



Use only SQLite as a database. Do not use MySQL, Redis, or any other storage.
Configure SQLite to use database file `db.sqlite3` in config/database.yml
Do NOT provide Gemfile or Gemfile.lock file. Make sure to include the right frameworks in config/application.rb - e.g. require "active_storage/engine"
Do NOT use sprockets or other asset pipeline. Do NOT use config.assets in config/environments/development.rb.
The command `bin/rails server --binding 0.0.0.0 --port 5000` will start the app.


Allowed packages:

source "https://rubygems.org"

# Bundle edge Rails instead: gem "rails", github: "rails/rails", branch: "main"
gem "rails", "~> 8.0.1"
# Use sqlite3 as the database for Active Record
gem "sqlite3", ">= 2.1"
# Use the Puma web server [https://github.com/puma/puma]
gem "puma", ">= 5.0"
# Build JSON APIs with ease [https://github.com/rails/jbuilder]
# gem "jbuilder"

# Use Active Model has_secure_password [https://guides.rubyonrails.org/active_model_basics.html#securepassword]
gem "bcrypt", "~> 3.1.7"

# Windows does not include zoneinfo files, so bundle the tzinfo-data gem
gem "tzinfo-data", platforms: %i[ windows jruby ]

# Use the database-backed adapters for Rails.cache, Active Job, and Action Cable
gem "solid_cache"
gem "solid_queue"
gem "solid_cable"

# Reduces boot times through caching; required in config/boot.rb
gem "bootsnap", require: false

# Deploy this application anywhere as a Docker container [https://kamal-deploy.org]
gem "kamal", require: false

# Add HTTP asset caching/compression and X-Sendfile acceleration to Puma [https://github.com/basecamp/thruster/]
gem "thruster", require: false

gem "image_processing", "~> 1.2"

# Use Rack CORS for handling Cross-Origin Resource Sharing (CORS), making cross-origin Ajax possible
gem "rack-cors"

gem 'activestorage', '~> 8.0.1'

group :development, :test do
  # See https://guides.rubyonrails.org/debugging_rails_applications.html#debugging-with-the-debug-gem
  gem "debug", platforms: %i[ mri windows ], require: "debug/prelude"

  # Static analysis for security vulnerabilities [https://brakemanscanner.org/]
  gem "brakeman", require: false

  # Omakase Ruby styling [https://github.com/rails/rubocop-rails-omakase/]
  gem "rubocop-rails-omakase", require: false
end