In this milestone you are setting up basic endpoints of web service for a music service "Splatify". These endpoints will receive http POST requests to store data and http GET requests to read data (more info on request types). The data will be sent and received as JSON. JSON is a simple textual data format, that can store objects (e.g. dictionary or map), a list, or primitive values. Your web service will respond to http requests with a JSON response body and a numeric http response code that indicates a valid request (200), that something was created (201), an unknown error occurred (400), or that a lookup did not find the requested data (404). See the link for a detailed list of response codes. This project is a "REST"-like set up, where operations like create and read data get mapped to a URL. At its core, REST is a simple http APIs to create, read, update, and delete data using stateless web requests. If you are interested in learning more about REST see this link.

For this project, we have given you a few components to work with:

• server/app.py has the skeleton code for the web/http server. All requests made to the server get mapped to a function in this file (an endpoint). These functions get arguments (either from the URL or from data that was sent as the "body" of a post request). Most endpoints will in turn make a call to the underlying database.
• server/db.py is the data access layer. This class will hold the connection to the database (sqlite3) and provide functions that insert and read data. Almost all of your work will be in this file.
• client/client.py is the client/driver for testing your application. This program reads a workload file that specifies a list of files, that each give an endpoint, an expected http response code, an optional payload (data to send), and an option response body to verify against. You will not need to change this file at all, but it will be used heavily in testing and developing your code. You should not modify the client (or if you do, do NOT commit any changes).
• You are free to add additional Python classes/files to handle certain aspects of your application, such as a models for holding state based on the DB and/or data access objects that provide the functions to interact with the database. Most of your changes will be in the db.py file to start. Be sure to add/check-in any new files.

The code in app.py/db.py has instances of #TODO milestone splat that represent various pieces of functionality that you need to implement to complete the milestone. If the TODO is followed by a return or raise, you will need to replace the following line with the appropriate return value. These can be found in app.py (the main web/app service) and db.py (the data access object/layer that will interface with the DBMS). You can add new classes/files to help with abstracting functionality if you want. Remember to check these files in!

This assignment uses a few popular and lightweight technologies in addition to the aforementioned concepts (e.g. JSON, http).

• Python3. We will assume you are using python3 for this assignment. It is a very simple language. Here as a quick tutorial from someplace that I found on the web after a quick search and not much checking. Python3 is very easy to install and is readily available on most OSes. If you want to write a web service in another language, let us know at least 2 week before the deadline -- this will likely result in more work for you though.
• Flask is a lightweight and popular web framework written in Python. Depending on your OS you will need to figure out how to install flask. If you are on Ubuntu, the easiest way is sudo apt install python3-flask. Using PIP or easy_install is probably preferred. More detailed installation instructions here. Flask provides an easy way to map http requests to a function and return http/html/json responses.
• SQLite is an embedded relational database. It does not have the full set of features as something like PostgreSQL but is very easy to use and install. We will be using the sqlite3 database driver to connect and interact with the DBMS via Python. Note that sqlite will create a single file for the entire database on the first time you access/open it. Only one process can interact with the database at a time (single threaded). It would be unlikely that you would use sqlite for such a project, but given the ease of use of sqlite and the ubiquity of it, we choose to use it for this project.

For this project we will specify exactly what python packages/module you are allowed to use. Any additional package that is not specified or approved will result in a 50% point penalty the module is used on. Use your favorite installer (pip3) To start we will use:

• flask
• requests

We have provided a small reference solution for you to work from. Please see the SampleServer.md write up for details on how to walk through/test the sample server.

See the documentation on the endpoints at http://people.cs.uchicago.edu/~aelmore/class/db/splatify.html to see what functionality you will need to implement. The descriptions of the end points are basic, but contains enough information for you to complete the required functionality. This includes what the input and output should be. Note that this project has two "types" of requirements. "All" is for every student in the class (graduating and non-graduating students), and "NonGrad" is only for students that are not graduating this quarter.

We have provided you with a simple web (html) interface to the underlying JSON Rest endpoints. This is to allow you to test the end points in a browser, as opposed to sending JSON http requests via program like CURL or Python. After starting the server, visit http://localhost:5000/ and see the top menu links to the web wrappers. In app.py these are all prefixed with /web and as you can see in the code, most of these just take the input from the form and call the REST JSON endpoint and return the results. The exception to this is the query endpoint which will let you run an arbitrary SQL statement against the database. NEVER do run arbitrary SQL outside testing/class, it is a huge security risk.

We have provided a set of suggested steps to complete this project. Please see the SuggestedSteps.md write up for details on how to walk through/test the sample server.

Please add a write up splat.txt about what functionality is not complete. Please indicate how much time you spent on the project and if you got stuck on any particular part. With this your splatify should be good to go! Feel free to do additional testing.