Calculator

Intro!

Hi! I'm Vandi, the author of this project!

You can contact me in telegram or write an e-mail lev-person11@yandex.ru

Components

Calculator (Orchestrator)

This is the main service.

• Manges the external http requests
• Manages tasks with grpc requests in the internal network
• Works with the database for saving state.

Agent

The agent starts some workers that work independently from each other.

• Gets tasks by grpc stream
• Calculates tasks
• Sends back results and error

Mongo

The database for saving state. I'v chosen mongo because because of its simple and easy to use interface (sql is boring)

• Stores data in 3 collections
  1. Users: User data
  2. Expressions: Expression data, status etc.
  3. Nodes: Expression nodes.

Please don't rate my project lower because of MongoDB. It works and saves the state, so nothing is needed more.

How to launch the project

Clone the project

git clone https://github.com/vandi37/Calculator.git
cd Calculator # optional opening directory
code . # optional opening in vscode

• The project is working in docker-compose

Prepare

You can install docker here

For being able to run tests install go 1.24.2+ here

Configuration

All configurations are stored in env

You can edit some settings if needed, however I recommend you to use the default settings.

Launch

docker-compose up

It will start building and running the project.

It can take some time so be patient.

How to use the project

• The project is working on http. If you haven't changed any settings on http://localhost:8080

• I will show you example requests and results.

Creating an account

Request

curl --location 'http://localhost:8080/api/v1/register' --header 'Content-Type: application/json' --data '{
  "username": "your-username",
  "password": "your-password"
}'

Response 201 + {"id": "your-id"}

Errors

• Invalid body 400
• Username taken 409
• Invalid password 401
• Internal error 500+

Login

Request

curl --location 'http://localhost:8080/api/v1/login' --header 'Content-Type: application/json' --data '{
  "username": "your-username",
  "password": "your-password"
}'

Response 200 + {"token": "your-token"}

Errors

• Invalid body 400
• Username not found 404
• Wrong password 401
• Internal error 500+

Calculate

Request

curl --location 'http://localhost:8080/api/v1/calculate' --header 'Authorization: your-token' --header 'Content-Type: application/json' --data '{
   "expression": "your-expression"
}'

Response 200 + {"id": "your-id"}

Errors

• Invalid body 400
• Unauthorized 401
• Some parsing error 422

Get expression

Request

curl --location 'http://localhost:8080/api/v1/expressions/your-id' --header 'Authorization: your-token'

Response

200 + {"id": "your-id", "origin": "your-expression", "status":"0", "result":"your-result", "created_at":"your-date"} - Finished or {"id": "your-id", "origin": "your-expression", "status":"1", "error": "your-error", "created_at":"your-date"} - Erroror{"id": "your-id", "origin": "your-expression", "status":"2", "created_at":"your-date"}` - Pending

Errors

• Unauthorized 401
• Not found 404
• Internal error 500+

Get expressions

Request

curl --location 'http://localhost:8080/api/v1/expressions' --header 'Authorization: your-token'

Response 200 + [...expressions like in get one]

Errors

• Unauthorized 401
• Internal error 500+

Change username

Request

curl --location --request PATCH 'http://localhost:8080/api/v1/username' --header 'Authorization: your-token' --header 'Content-Type: application/json' --data '{
  "username": "your-new-username"
}'

Response 204 (No content)

Errors

• Invalid body 400
• Unauthorized 401
• Username taken 409
• Internal error 500+

Change password

Request

curl --location --request PATCH 'http://localhost:8080/api/v1/password' --header 'Authorization: your-token' --header 'Content-Type: application/json' --data '{
  "password": "your-new-password"
}'

Response 204 (No content)

Errors

• Invalid body 400
• Unauthorized 401
• Invalid password 401
• Internal error 500+

Delete account

Request

curl --location --request DELETE 'http://localhost:8080/api/v1/delete' --header 'Authorization: your-token'

Response 204 (No content)

Errors

• Unauthorized 401
• Internal error 500+

Running tests

Agent

cd agent
go test ./... -cover
cd ..

Orchestrator

cd calculator
go test ./... -cover
cd ..

The repository tests creates their own docker container with database and deletes them after finishing.

Integrated

1. Run the app in docker compose
2. Run the tests

cd calculator/integration
go test -cover --tags=integration
cd ../..

FAQ

• Where is the unary minus? Does it work?

  Yes it works. It is represented as '0 - expression''

• Is something like 5, -10 and so on an expression

  Yes! It is because My as tree node can be a binary expression or a number, so 5 it is just a tree with one node.