Initial documentation update with some refactor

README.md

@@ -13,6 +13,187 @@ The requirement of this application is to bring up a go based REST API which wil
 ## The Pricing formula
 > Total Rental Cost = BaseFare based on the Duration * Factor based on Age * Factor based on the Insurance Group * Factor based on Licence Validity
 
+
+## Understanding the existing setup
+The current application is built on top on an existing code as per the [Requirements](./REQUIREMENTS.md). The setup typically had a layered data flow among the components as follows:
+- The main.go file which typically invoked the service.
+- The service that serves various REST end point for the application and passing on the data to RPC layer.
+- The RPC which typically takes care of doing the conversion from HTTP middleware understandable data to the Application understandable data.
+- Then the RPC passes the application understandable data to the *App* component which has all the business logics of computing the pricing and serving the required data.
+
+
+## The Approach in solving the problem
+
+
+## The Flow
+
+
+## The Endpoints
+### Generate Pricing for a customer
+#### Add a new transaction
+##### Request
+```http
+POST /generate_pricing HTTP/1.1
+Host: localhost:3000
+Content-Type: application/json
+
+{
+ "date_of_birth": "1970-12-04",
+ "insurance_group": 12,
+ "license_held_since": "1988-08-01"
+}
+```
+### Request format:
+*date_of_birth* – Date of Birth of the customer who is trying to rent the vehicle
+*insurance_group* – the insurance group to which the customer belongs to
+*license_held_since* – The date of acquiring of the Driver's licence by the existing customer
+
+##### Response
+Returns: Empty body with one of the following:
+
+200 – in case of success
+
+
+```http
+HTTP/1.1 200 OK
+Content-Type: application/json
+{
+ "input": {
+ "date_of_birth": "1970-12-04",
+ "insurance_group": 12,
+ "license_held_since": "1988-08-01"
+ },
+ "is-eligible": true,
+ "message": "Success",
+ "pricing": [
+ {
+ "premium": 278.28254999999996,
+ "currency": "£",
+ "fare_group": "0.5 hours, Driver Age >26, Insurance Group:9-16, Licence Validity:6"
+ },
+ {....},
+ {....},
+ .....
+ ]
+}
+
+```
+
+#### Get current pricing configuration ranges
+##### Request
+```http
+GET /statistics HTTP/1.1
+Host: localhost:3000
+
+
+```
+
+##### Response
+Returns: The computed statistics for all the posted transaction or empty if there are no transactions present.
+
+```http
+HTTP/1.1 200
+Content-Type: application/json;charset=UTF-8
+{
+ "base-rate": [
+ {
+ "Start": 0,
+ "End": 1800,
+ "IsEligible": true,
+ "Value": 273,
+ "Label": "0.5 hours"
+ },
+ {....}
+ ....
+ ],
+ "driver-age-factor": [
+ {
+ "Start": 0,
+ "End": 16,
+ "IsEligible": false,
+ "Value": 0,
+ "Label": "Driver Age:0-16"
+ },
+ {...}
+ ....
+ ],
+ "insurance-group-factor": [
+ {
+ "Start": 1,
+ "End": 8,
+ "IsEligible": true,
+ "Value": 1,
+ "Label": "Insurance Group:1-8"
+ },
+ {...},
+ ....
+ ],
+ "licence-validity-factor": [
+ {
+ "Start": 0,
+ "End": 1,
+ "IsEligible": true,
+ "Value": 1.1,
+ "Label": "Licence Validity:0-1"
+ },
+ {...}
+ .....
+ ]
+ }
+```
+
+
+
+## Setting up the environment
+This application is purely build on goLang. To run this application in your local you need to follow the below steps
+
+#### Build:
+```
+go build ./cmd/.
+```
+
+#### Run
+```
+go run ./cmd/.
+```
+
+
+#### Test
+```
+go test ./test/.
+```
+
 ## References:
 - setting up go environment : https://pkg.go.dev/cmd/go
 - go packages : https://medium.com/rungo/everything-you-need-to-know-about-packages-in-go-b8bac62b74cc
+- maps and struts : https://tour.golang.org/moretypes/19
+- getting query params : https://golangbyexample.com/net-http-package-get-query-params-golang/
+- current working directory: https://stackoverflow.com/a/31464648
+- parsing json: https://www.sohamkamani.com/golang/parsing-json/
+- reading json file : https://tutorialedge.net/golang/parsing-json-with-golang/
+- generic struct type parsing unmarshall : https://stackoverflow.com/a/49002939
+- fix for `implicit assignment of unexported field` issue: https://stackoverflow.com/a/48130761
+- logging in go: https://www.loggly.com/use-cases/logging-in-golang-how-to-start/
+- logging in detail: https://www.honeybadger.io/blog/golang-logging/
+- passing functions as parameters: https://stackoverflow.com/a/12655719
+- fixing cast exception from `interface{}` to other `structs array` : https://stackoverflow.com/a/42740448
+- unbounded list creation, updation : https://stackoverflow.com/a/3387362
+- sorting struct list : https://yourbasic.org/golang/how-to-sort-in-go/
+- https://stackoverflow.com/a/42382736
+- https://stackoverflow.com/a/29000001
+- time/date formatting : https://stackoverflow.com/a/54314594
+- days between dates: https://yourbasic.org/golang/days-between-dates/
+- https://stackoverflow.com/a/46298277
+- collections-functions : https://gobyexample.com/collection-functions
+- String to int: https://stackoverflow.com/a/4279644
+- int to String : https://stackoverflow.com/a/10105983
+- max integer value : https://stackoverflow.com/a/6878625
+- check empty string : https://stackoverflow.com/a/18594463
+- splitting string: https://stackoverflow.com/a/16551613
+- https://www.educative.io/edpresso/how-to-split-a-string-in-golang
+- pointers and references: https://medium.com/wesionary-team/pointers-and-passby-value-reference-in-golang-a00c8c59b7f1
+- string formatting : https://gobyexample.com/string-formatting
+- https://pkg.go.dev/fmt
+- handling error messages: https://stackoverflow.com/a/22171548
+- no nil check for struct variables: https://stackoverflow.com/a/25350005
+- https://stackoverflow.com/a/28447372

service/app/generate_pricing.go

@@ -80,7 +80,7 @@ func (a *App) GeneratePricing(ctx context.Context, request *pricingengine.Genera
 }
 
 // GeneratePricingConfig fetch and cache the configs related to pricing computations
-//
+// Just forms a map[]{} based on the config in the cache
 func (a *App) GeneratePricingConfig(ctx context.Context) (interface{}, error) {
  log.Println("Entering GeneratePricingConfig")
  a.Cache.Fetcher = config.ConfigFetcher{Path: "/config/"} // Initialise with actual path