From 5f6ac135e9be2cace69912767d8b6a1514cfe094 Mon Sep 17 00:00:00 2001
From: Rauno <rots@NeleSalestesMBP.local>
Date: Tue, 16 Oct 2018 20:41:32 +0200
Subject: [PATCH] Add smart statement export

---
 api.go         | 32 ++++++++++++++++++++++++++++++--
 cmd/n26/n26.go | 30 ++++++++++++++++++++++--------
 2 files changed, 52 insertions(+), 10 deletions(-)

diff --git a/api.go b/api.go
index 5df98e1..ffaafca 100644
--- a/api.go
+++ b/api.go
@@ -3,10 +3,13 @@ package n26
 import (
 	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
+	"io"
 	"io/ioutil"
 	"net/http"
 	"net/url"
+	"os"
 
 	"golang.org/x/oauth2"
 )
@@ -224,7 +227,7 @@ func NewClient(a Auth) (*Client, error) {
 	return (*Client)(c.Client(ctx, tok)), nil
 }
 
-func (c *Client) n26Request(requestMethod, endpoint string, params map[string]string) []byte {
+func (c *Client) n26RawRequest(requestMethod, endpoint string, params map[string]string, callback func(io.Reader) error) error {
 	var req *http.Request
 	var err error
 
@@ -244,7 +247,15 @@ func (c *Client) n26Request(requestMethod, endpoint string, params map[string]st
 	res, err := (*http.Client)(c).Do(req)
 	check(err)
 	defer res.Body.Close()
-	body, err := ioutil.ReadAll(res.Body)
+	return callback(res.Body)
+}
+func (c *Client) n26Request(requestMethod, endpoint string, params map[string]string) []byte {
+	var body []byte
+	err := c.n26RawRequest(requestMethod, endpoint, params, func(r io.Reader) error {
+		var err error
+		body, err = ioutil.ReadAll(r)
+		return err
+	})
 	check(err)
 	return body
 }
@@ -358,6 +369,23 @@ func (auth *Client) GetTransactions(from, to TimeStamp, limit string) (*Transact
 	return transactions, nil
 }
 
+// Get transactions for the given time window as N26 CSV file. Stored as 'smrt_statement.csv'
+func (auth *Client) GetSmartStatementCsv(from, to TimeStamp) error {
+	//Filter is applied only if both values are set
+	if from.IsZero() || to.IsZero() {
+		return errors.New("Start and end time must be set")
+	}
+	return auth.n26RawRequest(http.MethodGet, fmt.Sprintf("/api/smrt/reports/%v/%v/statements", from.AsMillis(), to.AsMillis()), nil, func(r io.Reader) error {
+		file, err := os.Create("smrt_statement.csv")
+		if err != nil {
+			return err
+		}
+		defer file.Close()
+		_, err = io.Copy(file, r)
+		return err
+	})
+}
+
 func (auth *Client) GetStatements(retType string) (string, *Statements) {
 	body := auth.n26Request(http.MethodGet, "/api/statements", nil)
 	statements := &Statements{}
diff --git a/cmd/n26/n26.go b/cmd/n26/n26.go
index feb4e25..1ef0311 100644
--- a/cmd/n26/n26.go
+++ b/cmd/n26/n26.go
@@ -228,8 +228,8 @@ func main() {
 		},
 		{
 			Name:      "transactions",
-			Usage:     "list your past transactions. Supports CSV output",
-			ArgsUsage: "[csv|json|table]",
+			Usage:     "list your past transactions. Supports CSV output.",
+			ArgsUsage: "[csv|json|table|smartcsv]",
 			Flags: []cli.Flag{
 				cli.StringFlag{Name: "limit", Value: "10", Usage: "retrieve last N transactions. Default to 10."},
 				cli.StringFlag{Name: "from", Usage: "retrieve transactions from this date. " +
@@ -239,18 +239,32 @@ func main() {
 			},
 			Action: func(c *cli.Context) (err error) {
 				const dateFormat = "2006-01-02"
+				var from, to n26.TimeStamp
+				if c.IsSet("from") {
+					from.Time, err = time.Parse(dateFormat, c.String("from"))
+					check(err)
+				}
+				if c.IsSet("to") {
+					to.Time, err = time.Parse(dateFormat, c.String("to"))
+					check(err)
+				}
 				API, err := authentication()
 				check(err)
+
+				if c.Args().First() == "smartcsv" {
+					if from.IsZero() || to.IsZero() {
+						fmt.Println("Start and end time must be set for smart CSV!")
+						return nil
+					}
+					err = API.GetSmartStatementCsv(from, to)
+					fmt.Println("Report saved as smrt_statement.csv.")
+					return
+				}
 				writer, err := getTransactionWriter(c.Args().First())
 				check(err)
 				limit := c.String("limit")
 				var transactions *n26.Transactions
-				if c.IsSet("from") && c.IsSet("to") {
-					var from, to n26.TimeStamp
-					from.Time, err = time.Parse(dateFormat, c.String("from"))
-					check(err)
-					to.Time, err = time.Parse(dateFormat, c.String("to"))
-					check(err)
+				if !from.IsZero() && !to.IsZero() {
 					transactions, err = API.GetTransactions(from, to, limit)
 				} else {
 					transactions, err = API.GetLastTransactions(limit)