handler.go

package main

import (
	"encoding/json"
	"net/http"
)

type EventHandler struct {
	channel chan<- PullRequestEvent
}

func (e EventHandler) Handle() http.Handler {
	return http.HandlerFunc(func(writer http.ResponseWriter, request *http.Request) {
		var event PullRequestEvent

		err := json.NewDecoder(request.Body).Decode(&event)

		if err != nil || event.PullRequest == nil {
			writer.WriteHeader(http.StatusBadRequest)
			return
		}

		// take only merged state
		if event.PullRequest.State != Merged {
			writer.WriteHeader(http.StatusUnprocessableEntity)
			return
		}

		// notify the channel
		select {
		case e.channel <- event:
			writer.WriteHeader(http.StatusCreated)
		default:
			writer.WriteHeader(http.StatusTooManyRequests)
		}
	})
}

func (e EventHandler) CheckToken(token string, next http.Handler) http.Handler {
	return http.HandlerFunc(func(writer http.ResponseWriter, request *http.Request) {
		if token != request.URL.Query().Get("token") {
			writer.WriteHeader(http.StatusForbidden)
			return
		}
		next.ServeHTTP(writer, request)
	})
}

func NewEventHandler(c chan PullRequestEvent) *EventHandler {
	return &EventHandler{channel: c}
}