From 91a94f001e9b0ee6acb3bedea0d2ba0265679365 Mon Sep 17 00:00:00 2001
From: Tobias Lindberg <tobias.ehlert@gmail.com>
Date: Tue, 9 Feb 2021 09:44:14 +0100
Subject: [PATCH] adding endpoint /cars/<CarID>/updates

---
 src/TeslaMateAPICarsUpdates.go | 116 +++++++++++++++++++++++++++++++++
 src/webserver.go               |  18 +++++
 2 files changed, 134 insertions(+)
 create mode 100644 src/TeslaMateAPICarsUpdates.go

diff --git a/src/TeslaMateAPICarsUpdates.go b/src/TeslaMateAPICarsUpdates.go
new file mode 100644
index 0000000..4ddb1e6
--- /dev/null
+++ b/src/TeslaMateAPICarsUpdates.go
@@ -0,0 +1,116 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"log"
+
+	_ "github.com/lib/pq"
+)
+
+// TeslaMateAPICarsUpdates func
+func TeslaMateAPICarsUpdates(CarID int, ResultPage int, ResultShow int) (string, bool) {
+
+	// creating structs for /cars/<CarID>/updates
+	// Car struct - child of Data
+	type Car struct {
+		CarID int `json:"id"` // smallint
+	}
+	// Updates struct - child of Data
+	type Updates struct {
+		ID        int    `json:"updates_id"` // smallint
+		StartDate string `json:"start_date"` // string
+		EndDate   string `json:"end_date"`   // string
+		Version   string `json:"version"`    // string
+	}
+	// Data struct - child of JSONData
+	type Data struct {
+		Car     Car       `json:"car"`
+		Updates []Updates `json:"updates"`
+	}
+	// JSONData struct - main
+	type JSONData struct {
+		Data Data `json:"data"`
+	}
+
+	// creating required vars
+	var UpdatesData []Updates
+	var ValidResponse bool // default is false
+
+	// calculate offset based on page (page 0 is not possible, since first page is minimum 1)
+	if ResultPage > 0 {
+		ResultPage--
+	} else {
+		ResultPage = 0
+	}
+	ResultPage = (ResultPage * ResultShow)
+
+	// getting data from database
+	query := `
+		SELECT
+			id,
+			start_date,
+			end_date,
+			version
+		FROM updates
+		WHERE car_id = $1
+		ORDER BY start_date DESC
+		LIMIT $2 OFFSET $3;`
+	rows, err := db.Query(query, CarID, ResultShow, ResultPage)
+
+	// checking for errors in query
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	// defer closing rows
+	defer rows.Close()
+
+	// looping through all results
+	for rows.Next() {
+
+		// creating update object based on struct
+		update := Updates{}
+
+		// scanning row and putting values into the update
+		err = rows.Scan(
+			&update.ID,
+			&update.StartDate,
+			&update.EndDate,
+			&update.Version,
+		)
+
+		// checking for errors after scanning
+		if err != nil {
+			log.Fatal(err)
+		}
+
+		// appending update to UpdatesData
+		UpdatesData = append(UpdatesData, update)
+		ValidResponse = true
+	}
+
+	// checking for errors in the rows result
+	err = rows.Err()
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	//
+	// build the data-blob
+	jsonData := JSONData{
+		Data{
+			Car: Car{
+				CarID: CarID,
+			},
+			Updates: UpdatesData,
+		},
+	}
+
+	// print readable output to log
+	log.Printf("data for /cars/%d/updates created:", CarID)
+
+	js, _ := json.Marshal(jsonData)
+	fmt.Printf("%s\n", js)
+	return string(js), ValidResponse
+}
diff --git a/src/webserver.go b/src/webserver.go
index 122bf8e..caee3ae 100644
--- a/src/webserver.go
+++ b/src/webserver.go
@@ -38,6 +38,24 @@ func main() {
 		}
 	})
 
+	// /cars/<CarID>/updates endpoint
+	r.GET("/cars/:CarID/updates", func(c *gin.Context) {
+		// getting CarID param from URL
+		CarID := convertStringToInteger(c.Param("CarID"))
+		// query options to modify query when collecting data
+		ResultPage := convertStringToInteger(c.DefaultQuery("page", "1"))
+		ResultShow := convertStringToInteger(c.DefaultQuery("show", "100"))
+		// TeslaMateAPICarsUpdates to get data
+		result, ValidResponse := TeslaMateAPICarsUpdates(CarID, ResultPage, ResultShow)
+
+		c.Header("Content-Type", "application/json")
+		if ValidResponse {
+			c.String(http.StatusOK, result)
+		} else {
+			c.String(http.StatusNotFound, result)
+		}
+	})
+
 	// /ping endpoint
 	r.GET("/ping", func(c *gin.Context) {
 		c.JSON(http.StatusOK, gin.H{