ESCAPE BLOCK puzzle solver & REST API

Escape Block Puzzle | Breadth First Search Algorithm | Haskell | REST API based on Scotty and Aeson

Demo

• https://esc-block.herokuapp.com/

• curl -X POST -d "{\"board\":[{\"dir\":\"h\",\"len\":2,\"row\":1},{\"dir\":\"h\",\"len\":2,\"row\":2},{\"dir\":\"h\",\"len\":3,\"row\":3},{\"dir\":\"h\",\"len\":2,\"row\":5},{\"dir\":\"h\",\"len\":2,\"row\":5},{\"dir\":\"v\",\"len\":3,\"row\":0},{\"dir\":\"v\",\"len\":2,\"row\":2},{\"dir\":\"v\",\"len\":2,\"row\":3},{\"dir\":\"v\",\"len\":3,\"row\":4},{\"dir\":\"v\",\"len\":2,\"row\":5},{\"dir\":\"v\",\"len\":2,\"row\":5}],\"state\":[1,2,0,0,3,0,4,0,2,0,3],\"target\":{\"index\":1,\"position\":4}}" https://esc-block.herokuapp.com/backtrack

• curl -X POST -d "{\"board\":[{\"dir\":\"h\",\"len\":2,\"row\":1},{\"dir\":\"h\",\"len\":2,\"row\":2},{\"dir\":\"h\",\"len\":3,\"row\":3},{\"dir\":\"h\",\"len\":2,\"row\":5},{\"dir\":\"h\",\"len\":2,\"row\":5},{\"dir\":\"v\",\"len\":3,\"row\":0},{\"dir\":\"v\",\"len\":2,\"row\":2},{\"dir\":\"v\",\"len\":2,\"row\":3},{\"dir\":\"v\",\"len\":3,\"row\":4},{\"dir\":\"v\",\"len\":2,\"row\":5},{\"dir\":\"v\",\"len\":2,\"row\":5}],\"state\":[1,2,0,0,3,0,4,0,2,0,3],\"target\":{\"index\":1,\"position\":4}}" https://esc-block.herokuapp.com/backtrack-length

• curl -X POST -d "{\"board\":[{\"dir\":\"h\",\"len\":2,\"row\":1},{\"dir\":\"h\",\"len\":2,\"row\":2},{\"dir\":\"h\",\"len\":3,\"row\":3},{\"dir\":\"h\",\"len\":2,\"row\":5},{\"dir\":\"h\",\"len\":2,\"row\":5},{\"dir\":\"v\",\"len\":3,\"row\":0},{\"dir\":\"v\",\"len\":2,\"row\":2},{\"dir\":\"v\",\"len\":2,\"row\":3},{\"dir\":\"v\",\"len\":3,\"row\":4},{\"dir\":\"v\",\"len\":2,\"row\":5},{\"dir\":\"v\",\"len\":2,\"row\":5}],\"state\":[1,2,0,0,3,0,4,0,2,0,3],\"target\":{\"index\":1,\"position\":4}}" https://esc-block.herokuapp.com/length

Containerize haskell stack

Build docker image for haskell stack

docker build -t hstack .

Run container from the image:

cd <shared dir>

docker run --name hstack -v $(pwd):/mnt -p 5000:5000 -it hstack bash

Work inside container

Go to project directory

cd /mnt/<project dir>

Build project

stack build

Run server

stack exec escape-block-rest-exe

Run tests

stack test

Run REPL

stack ghci

Copy executable to prod

cp $(stack exec -- which escape-block-rest-exe) prod/

Deploy on Heroku

cd prod/

heroku container:login

heroku container:push web --app esc-block

heroku container:release web --app esc-block

Endpoints

Description	Path	Method	Req body	Example
Information	/	get	-	curl https://esc-block.herokuapp.com/
Solution	/backtrack	post	json	curl -X POST -d @test/01.json https://esc-block.herokuapp.com/backtrack
Number of steps	/backtrack-length	post	json	curl -X POST -d @test/01.json https://esc-block.herokuapp.com/backtrack-length
Number of states	/length	post	json	curl -X POST -d @test/01.json https://esc-block.herokuapp.com/length

Board examples

start: [1,2,0,0,3,0,4,0,2,0,3]
        0   1   2   3   4   5
      ┌───┬───┬───┬───┬───┬───┐
   0  │ 1 │   │   │ 3 │   │ 5 │
      ├───┼───┼───┼───┼───┼───┤
   1  │ 1 │ a │ a │ 3 │   │ 5 │
      ├───┼───┼───┼───┼───┼───┤
   2  │ 1 │   │ b │ b │ 4 │    => escape
      ├───┼───┼───┼───┼───┼───┤
   3  │ c │ c │ c │   │ 4 │ 6 │
      ├───┼───┼───┼───┼───┼───┤
   4  │   │   │ 2 │   │ 4 │ 6 │
      ├───┼───┼───┼───┼───┼───┤
   5  │ d │ d │ 2 │ e │ e │   │
      └───┴───┴───┴───┴───┴───┘

 finish: [0,4,1,0,2,2,0,0,3,0,4]
        0   1   2   3   4   5
      ┌───┬───┬───┬───┬───┬───┐
   0  │   │   │ 2 │ 3 │   │   │
      ├───┼───┼───┼───┼───┼───┤
   1  │ a │ a │ 2 │ 3 │   │   │
      ├───┼───┼───┼───┼───┼───┤
   2  │ 1 │   │   │   │ b │ b  => escape
      ├───┼───┼───┼───┼───┼───┤
   3  │ 1 │ c │ c │ c │ 4 │   │
      ├───┼───┼───┼───┼───┼───┤
   4  │ 1 │   │   │   │ 4 │ 6 │
      ├───┼───┼───┼───┼───┼───┤
   5  │ d │ d │ e │ e │ 4 │ 6 │
      └───┴───┴───┴───┴───┴───┘

Request body (file test/01.json)

{
  "board": [
    { "dir": "h", "len": 2, "row": 1 },
    { "dir": "h", "len": 2, "row": 2 },
    { "dir": "h", "len": 3, "row": 3 },
    { "dir": "h", "len": 2, "row": 5 },
    { "dir": "h", "len": 2, "row": 5 },
    { "dir": "v", "len": 3, "row": 0 },
    { "dir": "v", "len": 2, "row": 2 },
    { "dir": "v", "len": 2, "row": 3 },
    { "dir": "v", "len": 3, "row": 4 },
    { "dir": "v", "len": 2, "row": 5 },
    { "dir": "v", "len": 2, "row": 5 }
  ],
  "state": [1, 2, 0, 0, 3, 0, 4, 0 ,2, 0, 3],
  "target": { "index": 1, "position": 4 }
}

Request

curl -X POST -d @test/01.json http://localhost:5000/backtrack

Response

[
  [1,2,0,0,3,0,4,0,2,0,3], // start state
  [1,2,0,0,3,0,4,0,0,0,3],
  [1,2,0,0,3,0,4,0,0,0,4],
  [1,2,3,0,3,0,4,0,0,0,4],
  [1,2,3,0,3,0,3,0,0,0,4],
  [1,2,3,1,3,0,3,0,0,0,4],
  [1,2,3,1,3,3,3,0,0,0,4],
  [0,2,3,1,3,3,3,0,0,0,4],
  [0,0,3,1,3,3,3,0,0,0,4],
  [0,0,3,1,3,3,0,0,0,0,4],
  [0,0,1,1,3,3,0,0,0,0,4],
  [0,1,1,1,3,3,0,0,0,0,4],
  [0,1,1,1,3,2,0,0,0,0,4],
  [0,1,1,0,3,2,0,0,0,0,4],
  [0,1,1,0,2,2,0,0,0,0,4],
  [0,1,1,0,2,2,0,0,3,0,4],
  [0,4,1,0,2,2,0,0,3,0,4]  // finish state
]