@Krunal2017 | Challenge2016 Solution

README.md

@@ -38,4 +38,73 @@ To submit a solution, fork this repo and send a Pull Request on Github.
 
 For any questions or clarifications, raise an issue on this repo and we'll answer your questions as fast as we can.
 
+## Solution Description
+The service starts an HTTP server to listen to incoming requests for creating distributors. It expects to receive the distributor data from POST request in the JSON format as given below:
+```
+{
+  "name": "DISTRIBUTOR2",
+        "inherits": "DISTRIBUTOR1",
+        "include": ["IN"],
+        "exclude": ["JK:IN"]
+}
+```
+The location codes follow the format `<city>:<province>:<country>`. To include the entire province or country, codes such as `<province>:<country>` or `<country>` could be used.
+
+The service can handle GET and POST requests currently, to perform the following operations:
+1. GET requests: Can be used to query whether a distributor has access to a certain location code.
+2. POST requests: Can be used to create new distributors. It returns a JSON response containing the data it has stored. It weeds out any locations the distributor cannot have access to.
+
+In future following requests could also be implemented:
+1. PATCH request: Can be used to update the include or exclude lists of a distributor
+2. PUT request: Can be used to replace the existing distributor
+
+
+### Running the service locally
+To run the service locally, use the command:
+```
+go run all
+```
+
+The following message will be visible on the terminal if the server starts successfully:
+```
+challenge2016>go run all
+Starting server on :8080...
+```
+
+### Limitations:
+Currently, a distributor cannot be updated once it is created via POST request. 
+
+### GET request example
+```
+curl "http://localhost:8080/distributor?distributor=DISTRIBUTOR1&location=UDHAP:JK:IN"
+```
+
+### POST request example
+```
+curl -X POST http://localhost:8080/distributor -H "Content-Type: application/json" -d '{
+  "name": "DISTRIBUTOR1",
+    "include": ["IN", "WS"],
+    "exclude": ["UP:IN", "YAVTM:MH:IN"]
+}'
+```
+
+### Expected responses
+StatusOK - 200 : Distributor can access the given location
+StatusCreated - 201 : Successfully created Distributor
+StatusNotFound - 404 : Distributor not found
+StatusForbidden - 403 :  Distributor cannot access the given location
+StatusBadRequest - 400 : Received invalid JSON input
+StatusConflict - 409 : Distributor already exists
+StatusInternalServerError - 500 : Error occurred while returning response
+
+## Run Unit tests
+
+Unit tests can be run using the command:
+go test
+
+## Bulk/Stress test:
+
+The script test.py can be used as follows:
+python3 test.py
 
+This script can be used to generate a chain of 50 distributors by default. Script can be modified to test more number of distributors or increasing the number of cities being included by the distributors.

constants.go

@@ -0,0 +1,13 @@
+package main
+
+const (
+	ErrDistributorNotExist   = "Error: distributor does not exist"
+	ErrDistributorExists     = "Error: distributor already exists"
+	ErrInvalidJSONPayload    = "Invalid JSON payload"
+	ErrInvalidJSONResponse    = "Invalid JSON response"
+	ErrMissingParams         = "Missing 'distributor' or 'location' parameter"
+	ErrMethodNotAllowed      = "Only GET & POST methods are allowed"
+	MsgDistributorCreated    = "Distributor created successfully"
+	MsgAccessGranted         = "YES"
+	MsgAccessDenied          = "NO"
+)

distributor.go

@@ -0,0 +1,52 @@
+package main
+
+// Request holds the input data
+type Request struct {
+	Name    string   `json:"name,require"`
+	Include []string `json:"include"`
+	Exclude []string `json:"exclude"`
+	Inherits string `json:"inherits,omitempty"`
+}
+
+// Distributor holds the permissions for each distributor
+type Distributor struct {
+	Name    string
+	Include []string
+	Exclude []string
+	Inherits string
+}
+
+var distributorDB = make(map[string]*Distributor)
+
+// createDistributor creates a new distributor or clones from a parent distributor if inheritance is defined.
+func (d *Request) createDistributor() *Distributor {
+	if d.Inherits != "" {
+		// If Inherits is set, we clone from the parent distributor
+		parent := distributorDB[d.Inherits]
+		return parent.clone(d)
+	}
+	// If no inheritance, create a new distributor
+	return &Distributor{
+		Name:    d.Name,
+		Include: d.Include,
+		Exclude: d.Exclude,
+		Inherits: d.Inherits, // Inheritance remains unchanged
+	}
+}
+
+// clone creates a new distributor based on the parent's permissions and merges the include/exclude lists
+func (d *Distributor) clone(inData *Request) *Distributor {
+	var includeList []string
+	for _, code := range inData.Include {
+		res,_ := checkDistributor(d.Name, code)
+		if res == MsgAccessGranted {
+			includeList = append(includeList, code)
+		}
+	}
+	return &Distributor{
+		Name:    inData.Name,
+		Include: includeList,
+		Exclude: append(d.Exclude, inData.Exclude...),
+		Inherits: inData.Inherits, // Inheritance remains unchanged
+	}
+}

distributor_test.go

@@ -0,0 +1,75 @@
+package main
+
+import (
+	"testing"
+)
+
+func TestCreateDistributor(t *testing.T) {
+	// Sample distributor data
+	request := &Request{
+		Name:    "test-distributor",
+		Include: []string{"city:province:country"},
+		Exclude: []string{"city:province:anotherCountry"},
+		Inherits: "",
+	}
+
+	// Create distributor from request
+	distributor := request.createDistributor()
+
+	// Check that distributor is not nil
+	if distributor == nil {
+		t.Fatalf("Expected distributor to be created, but got nil")
+	}
+
+	// Check if the distributor has the correct name
+	if distributor.Name != request.Name {
+		t.Errorf("Expected distributor name to be '%s', but got '%s'", request.Name, distributor.Name)
+	}
+
+	// Check the Include and Exclude lists
+	if len(distributor.Include) != 1 || distributor.Include[0] != "city:province:country" {
+		t.Errorf("Expected include list to have 1 item: 'city:province:country', but got %v", distributor.Include)
+	}
+
+	if len(distributor.Exclude) != 1 || distributor.Exclude[0] != "city:province:anotherCountry" {
+		t.Errorf("Expected exclude list to have 1 item: 'city:province:anotherCountry', but got %v", distributor.Exclude)
+	}
+}
+
+func TestCloneDistributor(t *testing.T) {
+	// Sample parent distributor
+	parent := &Distributor{
+		Name:    "parent-distributor",
+		Include: []string{"parentCountry"},
+		Exclude: []string{"excludeCountry"},
+		Inherits: "",
+	}
+
+	// Sample request to clone
+	request := &Request{
+		Name:    "child-distributor",
+		Include: []string{"city:province:parentCountry"},
+		Exclude: []string{"city:province:excludeCountry"},
+		Inherits: "parent-distributor",
+	}
+
+	// Add parent to the global distributorDB
+	distributorDB["parent-distributor"] = parent
+
+	// Create distributor from request (it should clone from parent)
+	distributor := request.createDistributor()
+
+	// Check that the distributor has inherited the parent's data
+	if len(distributor.Include) != 1 || distributor.Include[0] != "city:province:parentCountry" {
+		t.Errorf("Expected include list to have 'city:province:parentCountry', but got %v", distributor.Include)
+	}
+
+	if len(distributor.Exclude) != 2 || distributor.Exclude[0] != "excludeCountry" || distributor.Exclude[1] != "city:province:excludeCountry" {
+		t.Errorf("Expected exclude list to have both 'city:province:excludeCountry', but got %v", distributor.Exclude)
+	}
+
+	// Check inheritance
+	if distributor.Inherits != "parent-distributor" {
+		t.Errorf("Expected distributor to inherit from 'parent-distributor', but got '%s'", distributor.Inherits)
+	}
+}

go.mod

@@ -0,0 +1,3 @@
+module challenge2016
+
+go 1.21.1

main.go

@@ -0,0 +1,24 @@
+package main
+
+import (
+	"fmt"
+	"log"
+	"net/http"
+)
+
+func startServer(){
+	http.HandleFunc("/distributor", requestHandler)
+
+	fmt.Println("Starting server on :8080...")
+	err := http.ListenAndServe(":8080", nil)
+	if err != nil {
+		log.Fatalf("Server failed to start: %v", err)
+	}
+}
+
+// Main driver logic
+func main() {
+
+	startServer()
+
+}