package test

import (
	"RenewCMS/api/pkg/apperr"
	"net/http"
	"strconv"
	"sync"
	"testing"
)

const concurrentSaveRounds = 20

func TestArticleConcurrentSavesHTTP(t *testing.T) {
	t.Run("Two saves of the same article with the same if_revision: one wins, the other conflicts", func(t *testing.T) {
		for round := 0; round < concurrentSaveRounds; round++ {
			w := newStoryWorld(t)
			revision, _ := revisionsOf(w, 10)
			bodies := []string{"<p>Mine</p>", "<p>Theirs</p>"}
			responses := make([]storyResponse, len(bodies))
			start := make(chan struct{})
			var saves sync.WaitGroup
			for i, body := range bodies {
				saves.Add(1)
				go func() {
					defer saves.Done()
					<-start
					responses[i] = w.send(storyUpdater, http.MethodPatch, "/v1/article/10", `{"body":"`+body+`","if_revision":`+strconv.FormatUint(uint64(revision), 10)+`}`)
				}()
			}
			close(start)
			saves.Wait()

			winners, losers := 0, 0
			var winningBody string
			for i, response := range responses {
				switch response.Code {
				case http.StatusOK:
					winners++
					winningBody = bodies[i]
				case http.StatusConflict:
					losers++
					if response.text() != apperr.RevisionConflictErrorMessage+"\n" {
						t.Fatalf("conflict body %q", response.text())
					}
					if response.header(apperr.CurrentRevisionHeader) != strconv.FormatUint(uint64(revision+1), 10) {
						t.Fatalf("current revision header %q", response.header(apperr.CurrentRevisionHeader))
					}
				default:
					t.Fatalf("unexpected %d %q", response.Code, response.text())
				}
			}
			if winners != 1 || losers != 1 {
				t.Fatalf("round %d: %d saved, %d conflicted", round, winners, losers)
			}
			if stored, _ := revisionsOf(w, 10); stored != revision+1 || w.stored(10).Body != winningBody {
				t.Fatalf("round %d: stored revision %d body %q, the winner sent %q", round, stored, w.stored(10).Body, winningBody)
			}
		}
	})
}