Refactor createVotes in two different functions (only for the part that was nested in ifs)

cmd/web/handlers.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	api "code.dlmw.ch/dlmw/qv/internal"
+	"code.dlmw.ch/dlmw/qv/internal/models"
 	"code.dlmw.ch/dlmw/qv/internal/validator"
 	"database/sql"
 	"encoding/json"
@@ -165,71 +166,17 @@ func (app *application) createVotes(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	// this snippet of code also inserts in the `voters` table
-	voterIdentity := func() string {
-		var voterIdentity string
-		if election.AreVotersKnown {
-			if request.VoterIdentity == nil || validator.Blank(*request.VoterIdentity) {
-				app.unprocessableEntityErrorSingle(w, fmt.Errorf("election has known voters; you must provide an identity provided by the organizer"))
-				return ""
-			}
-
-			voterIdentity = *request.VoterIdentity
-			hasCastVotes, err := app.votes.Exists(voterIdentity, election.ID)
-			if err != nil {
-				app.serverError(w, r, err)
-				return ""
-			}
-			if hasCastVotes {
-				app.unprocessableEntityErrorSingle(w, fmt.Errorf("you already voted"))
-				return ""
-			}
-
-			voterExists, err := app.voters.Exists(voterIdentity, election.ID)
-			if err != nil {
-				app.serverError(w, r, err)
-				return ""
-			}
-			if !voterExists {
-				app.unprocessableEntityErrorSingle(w, fmt.Errorf("invalid voter identity"))
-				return ""
-			}
-		} else {
-			voterIdentity = r.RemoteAddr
-
-			// if voters are known, voter will always exist
-			voterExists, err := app.voters.Exists(voterIdentity, election.ID)
-			if err != nil {
-				app.serverError(w, r, err)
-				return ""
-			}
-			if voterExists {
-				app.unprocessableEntityErrorSingle(w, fmt.Errorf("you already voted"))
-				return ""
-			}
-
-			_, err = app.voters.Insert(voterIdentity, election.ID)
-			if err != nil {
-				app.serverError(w, r, err)
-				return ""
-			}
-		}
-		return voterIdentity
-	}()
-
-	if voterIdentity == "" {
-		return
-	}
-
-	if !election.AreVotersKnown {
-		voterCount, err := app.voters.CountByElection(election.ID)
-		if err != nil && !errors.Is(sql.ErrNoRows, err) {
-			app.serverError(w, r, err)
+	var voterIdentity string
+	if election.AreVotersKnown {
+		voterIdentity, err = app.createVotesHandleKnownVotersElection(w, r, request, election)
+		if err != nil {
+			// everything will have been logged already
 			return
 		}
-		// if voters are known, voterCount == election.MaxVoters in all cases
-		if voterCount == election.MaxVoters {
-			app.unprocessableEntityErrorSingle(w, fmt.Errorf("maximum voters reached"))
+	} else {
+		voterIdentity, err = app.createVotesHandleUnknownVotersElection(w, r, election)
+		if err != nil {
+			// everything will have been logged already
 			return
 		}
 	}
@@ -243,3 +190,70 @@ func (app *application) createVotes(w http.ResponseWriter, r *http.Request) {
 
 	w.WriteHeader(http.StatusCreated)
 }
+
+func (app *application) createVotesHandleKnownVotersElection(w http.ResponseWriter, r *http.Request, request createVotesRequestWithValidator, election *models.Election) (string, error) {
+	if request.VoterIdentity == nil || validator.Blank(*request.VoterIdentity) {
+		err := fmt.Errorf("election has known voters; you must provide an identity provided by the organizer")
+		app.unprocessableEntityErrorSingle(w, err)
+		return "", err
+	}
+
+	voterIdentity := *request.VoterIdentity
+	hasCastVotes, err := app.votes.Exists(voterIdentity, election.ID)
+	if err != nil {
+		app.serverError(w, r, err)
+		return "", err
+	}
+	if hasCastVotes {
+		err := fmt.Errorf("you already voted")
+		app.unprocessableEntityErrorSingle(w, err)
+		return "", err
+	}
+
+	voterExists, err := app.voters.Exists(voterIdentity, election.ID)
+	if err != nil {
+		app.serverError(w, r, err)
+		return "", err
+	}
+	if !voterExists {
+		err := fmt.Errorf("invalid voter identity")
+		app.unprocessableEntityErrorSingle(w, err)
+		return "", err
+	}
+
+	return voterIdentity, nil
+}
+
+func (app *application) createVotesHandleUnknownVotersElection(w http.ResponseWriter, r *http.Request, election *models.Election) (string, error) {
+	voterIdentity := r.RemoteAddr
+
+	voterExists, err := app.voters.Exists(voterIdentity, election.ID)
+	if err != nil {
+		app.serverError(w, r, err)
+		return "", err
+	}
+	if voterExists {
+		err := fmt.Errorf("you already voted")
+		app.unprocessableEntityErrorSingle(w, err)
+		return "", err
+	}
+
+	_, err = app.voters.Insert(voterIdentity, election.ID)
+	if err != nil {
+		app.serverError(w, r, err)
+		return "", err
+	}
+
+	voterCount, err := app.voters.CountByElection(election.ID)
+	if err != nil && !errors.Is(sql.ErrNoRows, err) {
+		app.serverError(w, r, err)
+		return "", err
+	}
+	if voterCount == election.MaxVoters {
+		err := fmt.Errorf("maximum voters reached")
+		app.unprocessableEntityErrorSingle(w, err)
+		return "", err
+	}
+
+	return voterIdentity, nil
+}