Complete rewrite (#7)

- Adds an API client
- CSV formatting has its own package and tests
- Supports pagination

Closes #5

README.md

@@ -13,7 +13,7 @@ Little helper to get transactions from Viseca One and print them in CSV format.
 
 1.  ```
     source .env
-    go run viseca-exporter.go "$CARDID" "$COOKIE" > data/export.csv
+    go run main.go "$CARDID" "$COOKIE" > data/export.csv
     ```
 
 
@@ -22,9 +22,17 @@ Little helper to get transactions from Viseca One and print them in CSV format.
 ### Env file
 ```
 export CARDID=0000000AAAAA0000
-export COOKIE=AL_SESS-S=AAAAAAAAAA...
+export COOKIE=AAAAAAAAAA...
 ```
 
+## API
+
+### Known issues
+
+The API returns `500 Internal Server Error` without any additional information when a request doesn't meet the API requirements.
+
+Large page sizes (e.g. 1000) lead to an error.
+
 ### API Output
 
 ```json

csv/transactions.go

@@ -0,0 +1,46 @@
+package csv
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/anothertobi/viseca-exporter/viseca"
+)
+
+// TransactionsString() returns a CSV representation of the transactions.
+func TransactionsString(transactions viseca.Transactions) string {
+	var stringBuilder strings.Builder
+
+	stringBuilder.WriteString(`"TransactionID","Date","Merchant","Amount","PFMCategoryID","PFMCategoryName"`)
+	stringBuilder.WriteString("\n")
+
+	for _, transaction := range transactions.Transactions {
+		stringBuilder.WriteString(TransactionString(transaction))
+		stringBuilder.WriteString("\n")
+	}
+
+	return stringBuilder.String()
+}
+
+// TransactionString returns a CSV record.
+func TransactionString(transaction viseca.Transaction) string {
+	innerRecord := strings.Join([]string{
+		transaction.TransactionID,
+		transaction.Date,
+		prettiestMerchantName(transaction),
+		fmt.Sprintf("%.2f", transaction.Amount),
+		transaction.PFMCategory.ID,
+		transaction.PFMCategory.Name,
+	}, `","`)
+
+	return fmt.Sprintf(`"%s"`, innerRecord)
+}
+
+// prettiestMerchantName extracts the prettiest merchant name from a transaction.
+func prettiestMerchantName(transaction viseca.Transaction) string {
+	if transaction.PrettyName != "" {
+		return transaction.PrettyName
+	} else {
+		return transaction.MerchantName
+	}
+}

csv/transactions_test.go

@@ -0,0 +1,59 @@
+package csv_test
+
+import (
+	"testing"
+
+	"github.com/anothertobi/viseca-exporter/csv"
+	"github.com/anothertobi/viseca-exporter/viseca"
+	"github.com/stretchr/testify/assert"
+)
+
+var inputTransaction = viseca.Transaction{
+	TransactionID:    "AUTH8c919db2-1c23-43f1-8862-61c31336d9b6",
+	CardID:           "0000000AAAAA0000",
+	MaskedCardNumber: "XXXXXXXXXXXX0000",
+	CardName:         "Mastercard",
+	Date:             "2021-10-20T17:05:44",
+	ShowTimestamp:    true,
+	Amount:           50.55,
+	Currency:         "CHF",
+	OriginalAmount:   50.55,
+	OriginalCurrency: "CHF",
+	MerchantName:     "Aldi Suisse 00",
+	PrettyName:       "ALDI",
+	MerchantPlace:    "",
+	IsOnline:         false,
+	PFMCategory: viseca.PFMCategory{
+		ID:                  "cv_groceries",
+		Name:                "Lebensmittel",
+		LightColor:          "#E2FDD3",
+		MediumColor:         "#A5D58B",
+		Color:               "#51A127",
+		ImageURL:            "https://api.one.viseca.ch/v1/media/categories/icon_with_background/ic_cat_tile_groceries_v2.png",
+		TransparentImageURL: "https://api.one.viseca.ch/v1/media/categories/icon_without_background/ic_cat_tile_groceries_v2.png",
+	},
+	StateType: "authorized",
+	Details:   "Aldi Suisse 00",
+	Type:      "merchant",
+	IsBilled:  false,
+	Links: viseca.TransactionLinks{
+		Transactiondetails: "/v1/card/0000000AAAAA0000/transaction/AUTH8c919db2-1c23-43f1-8862-61c31336d9b6",
+	},
+}
+
+func TestTransactionString(t *testing.T) {
+	expected := `"AUTH8c919db2-1c23-43f1-8862-61c31336d9b6","2021-10-20T17:05:44","ALDI","50.55","cv_groceries","Lebensmittel"`
+
+	assert.Equal(t, expected, csv.TransactionString(inputTransaction))
+}
+
+func TestTransactionsString(t *testing.T) {
+	inputTransactions := viseca.Transactions{Transactions: []viseca.Transaction{inputTransaction}}
+	expected :=
+		`"TransactionID","Date","Merchant","Amount","PFMCategoryID","PFMCategoryName"` +
+			"\n" +
+			`"AUTH8c919db2-1c23-43f1-8862-61c31336d9b6","2021-10-20T17:05:44","ALDI","50.55","cv_groceries","Lebensmittel"` +
+			"\n"
+
+	assert.Equal(t, expected, csv.TransactionsString(inputTransactions))
+}

go.mod

@@ -1,3 +1,11 @@
 module github.com/anothertobi/viseca-exporter
 
 go 1.19
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/stretchr/objx v0.5.0 // indirect
+	github.com/stretchr/testify v1.8.3 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)

go.sum

@@ -0,0 +1,17 @@
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/objx v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSSt89Yw=
+github.com/stretchr/objx v0.5.0 h1:1zr/of2m5FGMsad5YfcqgdqdWrIhu+EBEJRhR1U7z/c=
+github.com/stretchr/objx v0.5.0/go.mod h1:Yh+to48EsGEfYuaHDzXPcE3xhTkx73EhmCGUpEOglKo=
+github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
+github.com/stretchr/testify v1.8.3 h1:RP3t2pwF7cMEbC1dqtB6poj3niw/9gnV4Cjg5oW5gtY=
+github.com/stretchr/testify v1.8.3/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

main.go

@@ -0,0 +1,75 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"net/http"
+	"net/http/cookiejar"
+	"os"
+	"strings"
+
+	"github.com/anothertobi/viseca-exporter/csv"
+	"github.com/anothertobi/viseca-exporter/viseca"
+)
+
+const sessionCookieName = "AL_SESS-S"
+
+// arg0: cardID
+// arg1: sessionCookie (e.g. `AL_SESS-S=...`)
+func main() {
+	if len(os.Args) < 3 {
+		log.Fatal("card ID and session cookie args required")
+	}
+	visecaClient, err := initClient(os.Args[2])
+	if err != nil {
+		log.Fatalf("error initializing Viseca API client: %v", err)
+	}
+
+	transactions, err := ListAllTransactions(visecaClient, os.Args[1])
+	if err != nil {
+		log.Fatal(err)
+	}
+	fmt.Println(csv.TransactionsString(*transactions))
+}
+
+func initClient(sessionCookie string) (*viseca.Client, error) {
+	cookieJar, err := cookiejar.New(nil)
+	if err != nil {
+		return nil, err
+	}
+	httpClient := http.Client{
+		Jar: cookieJar,
+	}
+	visecaClient := viseca.NewClient(&httpClient)
+	cookie := &http.Cookie{
+		Name:  sessionCookieName,
+		Value: extractSessionCookieValue(sessionCookie),
+	}
+	httpClient.Jar.SetCookies(visecaClient.BaseURL, []*http.Cookie{cookie})
+
+	return visecaClient, nil
+}
+
+func ListAllTransactions(visecaClient *viseca.Client, cardID string) (*viseca.Transactions, error) {
+	ctx := context.Background()
+	listOptions := viseca.NewDefaultListOptions()
+	transactions, err := visecaClient.ListTransactions(ctx, cardID, listOptions)
+	if err != nil {
+		return nil, err
+	}
+	for listOptions.Offset+listOptions.PageSize < transactions.TotalCount {
+		listOptions.Offset += listOptions.PageSize
+		transactionsPage, err := visecaClient.ListTransactions(ctx, cardID, listOptions)
+		if err != nil {
+			return nil, err
+		}
+		transactions.Transactions = append(transactions.Transactions, transactionsPage.Transactions...)
+	}
+
+	return transactions, nil
+}
+
+func extractSessionCookieValue(sessionCookie string) string {
+	return strings.TrimPrefix(sessionCookie, fmt.Sprintf("%s=", sessionCookieName))
+}

viseca/card.go

@@ -0,0 +1,25 @@
+package viseca
+
+import (
+	"context"
+	"fmt"
+)
+
+func (client *Client) ListTransactions(ctx context.Context, card string, listOptions ListOptions) (*Transactions, error) {
+	path := fmt.Sprintf("card/%s/transactions", card)
+
+	request, err := client.NewRequest(path, "GET", nil)
+	if err != nil {
+		return nil, err
+	}
+	addListOptions(request.URL, listOptions)
+
+	transactions := &Transactions{}
+
+	_, err = client.Do(ctx, request, transactions)
+	if err != nil {
+		return nil, err
+	}
+
+	return transactions, err
+}