From c72a94952971a5bb977542e60295b75f4624f7a7 Mon Sep 17 00:00:00 2001
From: Fred Boniface <fred@fjla.uk>
Date: Sat, 12 Aug 2023 08:20:28 +0100
Subject: [PATCH] Server now responds with image in PNG format

---
 imaging/circles.go  | 19 ++++---------------
 imaging/generate.go |  4 ++--
 run/cli.go          |  2 +-
 run/server.go       | 32 +++++++++++++++-----------------
 4 files changed, 22 insertions(+), 35 deletions(-)

diff --git a/imaging/circles.go b/imaging/circles.go
index 4f5edff..cf6ea4f 100644
--- a/imaging/circles.go
+++ b/imaging/circles.go
@@ -1,17 +1,15 @@
 package imaging
 
 import (
-	"fmt"
 	"image"
 	"math"
 
 	"git.fjla.uk/fred.boniface/map-dots/data"
 	"git.fjla.uk/fred.boniface/map-dots/log"
 	"github.com/fogleman/gg"
-	"go.uber.org/zap"
 )
 
-func mapCirclesToCanvas(img *image.RGBA, locations []data.LocationData) {
+func mapCirclesToCanvas(img *image.RGBA, locations []data.LocationData) image.Image {
 	log.Msg.Debug("Mapping locations to canvas")
 	dc := gg.NewContextForRGBA(img)
 	dc.SetRGB(1, 1, 1) // Set canvas background color (white in this case)
@@ -62,18 +60,10 @@ func mapCirclesToCanvas(img *image.RGBA, locations []data.LocationData) {
 		dc.Fill()
 	}
 
-	// Optional: Save the canvas as an image file
-	err := dc.SavePNG("output.png")
-	if err != nil {
-		log.Msg.Error("Error saving file")
-	} else {
-		fmt.Println("Canvas saves to file")
-	}
-
-	fmt.Println(minLat)
-	fmt.Println(minLon)
+	return img
 }
 
+/*
 func convertCoordinatesToPixels(latitude, longitude float64, centerLat, centerLon, latRange, lonRange float64, canvasWidth, canvasHeight int) (int, int) {
 	// Calculate normalized latitude and longitude distances from the center
 	latDist := (latitude - centerLat) / (latRange * 0.5)
@@ -91,9 +81,8 @@ func convertCoordinatesToPixels(latitude, longitude float64, centerLat, centerLo
 	pixelY := int((0.5 - adjustedLatDist) * float64(canvasHeight))
 
 	return pixelX, pixelY
-}
+}*/
 
 func equirectangularProjection(lat float64) float64 {
-	log.Msg.Debug("Running equirectangular calculation", zap.Float64("lat", lat))
 	return lat * (math.Pi / 180) // Convert degrees to radians
 }
diff --git a/imaging/generate.go b/imaging/generate.go
index a99303b..05ff536 100644
--- a/imaging/generate.go
+++ b/imaging/generate.go
@@ -8,8 +8,8 @@ import (
 	"git.fjla.uk/fred.boniface/map-dots/log"
 )
 
-func Generate(height, width int, style, format string, data []data.LocationData) image.Image {
-	log.Msg.Debug("Image generation request: " + fmt.Sprint(width) + "x" + fmt.Sprint(height) + " " + format + " " + style)
+func Generate(height, width int, style string, data []data.LocationData) image.Image {
+	log.Msg.Debug("Image generation request: " + fmt.Sprint(width) + "x" + fmt.Sprint(height) + " " + style)
 	img := createCanvas(width, height)
 
 	switch style {
diff --git a/run/cli.go b/run/cli.go
index a6638ff..39adc35 100644
--- a/run/cli.go
+++ b/run/cli.go
@@ -25,7 +25,7 @@ func CLI(height, width uint64, style, format, input string) {
 	// Use relevent package to parse file
 	// Pass parsed data to imaging package
 	var testing []data.LocationData
-	var _ image.Image = imaging.Generate(1, 1, "circle", "png", testing)
+	var _ image.Image = imaging.Generate(1, 1, "circle", testing)
 	fmt.Println("End of implementation")
 }
 
diff --git a/run/server.go b/run/server.go
index 9b8f895..ce7e517 100644
--- a/run/server.go
+++ b/run/server.go
@@ -1,9 +1,9 @@
 package run
 
 import (
-	"encoding/json"
 	"errors"
 	"fmt"
+	"image/png"
 	"net/http"
 	"net/url"
 	"strconv"
@@ -33,8 +33,6 @@ func Server() {
 }
 
 func handleTraccarRequest(w http.ResponseWriter, r *http.Request) {
-	w.Header().Set("Content-Type", "application/json")
-
 	queryValues := r.URL.Query()
 
 	id, from, to, height, width, style, format, err := validateAndProcessParams(queryValues)
@@ -66,22 +64,22 @@ func handleTraccarRequest(w http.ResponseWriter, r *http.Request) {
 		}
 	}
 
-	var _ = imaging.Generate(height, width, style, format, locations)
+	img := imaging.Generate(height, width, style, locations)
 
-	message := map[string]string{
-		"status":  "success",
-		"message": "Hello from map-dots",
+	fmt.Printf("Requested format, %s, returning PNG as only supported format", format)
+
+	switch format {
+	case "png":
+		w.Header().Set("Content-Type", "image/png")
+		err = png.Encode(w, img)
+		if err != nil {
+			http.Error(w, "Error encoding image", http.StatusInternalServerError)
+			return
+		}
+	default:
+		w.Header().Set("Content-Type", "text/plain")
+		w.Write([]byte("Unsupported format, only 'PNG' is supported at present"))
 	}
-
-	// Marshal the JSON data
-	jsonData, err := json.Marshal(message)
-	if err != nil {
-		http.Error(w, "JSON encoding error", http.StatusInternalServerError)
-		return
-	}
-
-	// Write the JSON response
-	w.Write(jsonData)
 }
 
 func validateAndProcessParams(queryValues url.Values) (string, time.Time, time.Time, int, int, string, string, error) {