Implement creating new games

pkg/gameCreator/gameCreator.go

@@ -0,0 +1,120 @@
+package gameCreator
+
+import (
+	"encoding/csv"
+	"errors"
+	"io"
+	"strconv"
+	"time"
+)
+
+func CreateTemplate(w io.Writer, questions uint64, choicesPerQuestion uint64) (retE error) {
+	csvW := csv.NewWriter(w)
+	defer func() {
+		csvW.Flush()
+		if err := csvW.Error(); err != nil && retE != nil {
+			retE = err
+		}
+	}()
+
+	for i := uint64(0); i < questions; i++ {
+		var length string
+		if i == 0 {
+			length = "10000"
+		}
+		if err := csvW.Write([]string{"Nadpis otázky", length, ""}); err != nil {
+			return err
+		}
+		for j := uint64(0); j < choicesPerQuestion; j++ {
+			var correct string
+			if j == 0 {
+				correct = "1"
+			}
+			if err := csvW.Write([]string{"", "Nadpis možnosti", correct}); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+type Game struct {
+	Questions []Question
+}
+
+type Question struct {
+	Title   string
+	Choices []Choice
+	Length  uint64
+}
+
+type Choice struct {
+	Title   string
+	Correct bool
+}
+
+var ErrTooManyQuestions = errors.New("there were questions above the limit")
+var ErrTooManyChoices = errors.New("there were choices above the limit")
+var ErrInvalidSyntax = errors.New("")
+
+func Parse(r io.Reader, maxQuestions uint64, maxChoicesPerQuestion uint64) (Game, error) {
+	var g Game
+	var csvR = csv.NewReader(r)
+	csvR.FieldsPerRecord = 3
+	csvR.TrimLeadingSpace = true
+	var questions, choices uint64
+	for {
+		if row, err := csvR.Read(); err == nil {
+			if row[0] == "" && row[1] == "" && row[2] == "" {
+				continue
+			} else if row[0] == "" {
+				choices++
+				if questions == 0 {
+					return g, ErrInvalidSyntax
+				}
+				if choices > maxChoicesPerQuestion {
+					return g, ErrTooManyChoices
+				}
+				var correct bool
+				if row[2] == "1" {
+					correct = true
+				}
+				g.Questions[len(g.Questions)-1].Choices = append(g.Questions[len(g.Questions)-1].Choices, Choice{
+					Title:   row[1],
+					Correct: correct,
+				})
+			} else {
+				questions++
+				choices = 0
+				if questions > maxQuestions {
+					return g, ErrTooManyQuestions
+				}
+				var length uint64
+				if row[1] != "" {
+					if l, err := strconv.ParseUint(row[1], 10, 64); err == nil {
+						length = l
+					} else {
+						return g, ErrInvalidSyntax
+					}
+				} else {
+					if questions > 1 {
+						length = g.Questions[len(g.Questions)-1].Length
+					} else {
+						length = uint64((10 * time.Second).Milliseconds())
+					}
+				}
+				g.Questions = append(g.Questions, Question{
+					Title:  row[0],
+					Length: length,
+				})
+			}
+		} else if err == io.EOF {
+			break
+		} else if err == csv.ErrFieldCount {
+			return g, ErrInvalidSyntax
+		} else {
+			return g, err
+		}
+	}
+	return g, nil
+}

pkg/gameCreator/gameCreator_test.go

@@ -0,0 +1,66 @@
+package gameCreator
+
+import (
+	"bytes"
+	"reflect"
+	"strings"
+	"testing"
+)
+
+func TestCreateTemplate(t *testing.T) {
+	const expected = "Nadpis otázky,10000,\n,Nadpis možnosti,1\n,Nadpis možnosti,\n,Nadpis možnosti,\n,Nadpis možnosti,\n" +
+		"Nadpis otázky,,\n,Nadpis možnosti,1\n,Nadpis možnosti,\n,Nadpis možnosti,\n,Nadpis možnosti,\n" +
+		"Nadpis otázky,,\n,Nadpis možnosti,1\n,Nadpis možnosti,\n,Nadpis možnosti,\n,Nadpis možnosti,\n" +
+		"Nadpis otázky,,\n,Nadpis možnosti,1\n,Nadpis možnosti,\n,Nadpis možnosti,\n,Nadpis možnosti,\n" +
+		"Nadpis otázky,,\n,Nadpis možnosti,1\n,Nadpis možnosti,\n,Nadpis možnosti,\n,Nadpis možnosti,\n"
+	var actual bytes.Buffer
+	actual.Grow(len(expected))
+	if err := CreateTemplate(&actual, 5, 4); err != nil {
+		t.Fatalf("Unexpected error returned from CreateTemplate: %v", err)
+	}
+	if act := actual.String(); act != expected {
+		t.Fatalf("Wrong template generated. Expected:\n%s\n\nGot:\n%s\n", expected, act)
+	}
+}
+func TestParse(t *testing.T) {
+	const input = "H2O is,3000,\n,Gasoline,\n,Salt,\n,Water,1\n" +
+		"π is rational,,\n,Yes,\n,No,1\n" +
+		"IPv4 address length is,5000,\n,8b,\n,16b,\n,32b,1\n,64b,\n,128b,\n"
+	var expected = Game{
+		Questions: []Question{
+			{
+				Title:  "H2O is",
+				Length: 3000,
+				Choices: []Choice{
+					{Title: "Gasoline"},
+					{Title: "Salt"},
+					{Title: "Water", Correct: true},
+				},
+			},
+			{
+				Title:  "π is rational",
+				Length: 3000,
+				Choices: []Choice{
+					{Title: "Yes"},
+					{Title: "No", Correct: true},
+				},
+			},
+			{
+				Title:  "IPv4 address length is",
+				Length: 5000,
+				Choices: []Choice{
+					{Title: "8b"},
+					{Title: "16b"},
+					{Title: "32b", Correct: true},
+					{Title: "64b"},
+					{Title: "128b"},
+				},
+			},
+		},
+	}
+	if g, err := Parse(strings.NewReader(input), 10, 10); err == nil && !reflect.DeepEqual(g, expected) {
+		t.Fatalf("Parse:\n\tActual: %#v\n\tExpected: %#v", g, expected)
+	} else if err != nil {
+		t.Fatalf("Unexpected error from Parse: %v", err)
+	}
+}