From a3830ff1d516062be993cd17b1a672a7173d684c Mon Sep 17 00:00:00 2001
From: velvettear <daniel.sommer@velvettear.de>
Date: Wed, 29 Nov 2023 16:43:30 +0100
Subject: [PATCH] removed environment variables for the amount of colors and
 the algorithm for the generation of the color palette in favor of query
 parameters

---
 README.md                 |  4 +---
 internal/api/server.go    |  6 +++++-
 internal/api/stream.go    | 12 ++++++++----
 internal/config/config.go | 19 -------------------
 slideshow-api.service     |  3 ---
 5 files changed, 14 insertions(+), 30 deletions(-)

diff --git a/README.md b/README.md
index a42d9fd..ba223d0 100644
--- a/README.md
+++ b/README.md
@@ -10,7 +10,7 @@ a simple web server serving (scaled) images and color palettes for [slideshow](h
 
 - `/`: request the name of a random image
 - `/image/<name-of-an-image.jpeg>[?resolution=1920x1080]`: request the named image (in the specified resolution)
-- `/palette/<name-of-an-image.jpeg>`: request the color palette of the named image
+- `/palette/<name-of-an-image.jpeg>[?colors=16&algorithm=wsm]`: request the color palette of the named image (with the specified amount of colors and algorithm)
 
 ## configuration
 
@@ -22,8 +22,6 @@ configuration is entirely done via environment variables.
 | SLIDESHOW_PORT              | 3000              | the port of the web server                                 |
 | SLIDESHOW_DIRECTORY         | "$HOME"           | path to a directory containing images                      |
 | SLIDESHOW_SCANINTERVAL      | 60                | the interval for directory scans in seconds                |
-| SLIDESHOW_PALETTE_ALGORITHM | "wsm"             | the algorithm used to generate the color palette           |
-| SLIDESHOW_PALETTE_COLORS    | 16                | the amount of colors generated                             |
 | SLIDESHOW_LOGLEVEL          | "info"            | the log level                                              |
 
 **note:**  
diff --git a/internal/api/server.go b/internal/api/server.go
index ac7f87f..404c5a1 100644
--- a/internal/api/server.go
+++ b/internal/api/server.go
@@ -66,5 +66,9 @@ func servePalette(writer http.ResponseWriter, request *http.Request) {
 		response.send(writer)
 		return
 	}
-	streamColorPalette(writer, image)
+	amount, _ := strconv.Atoi(request.URL.Query().Get("colors"))
+	if amount <= 0 {
+		amount = 16
+	}
+	streamColorPalette(writer, image, amount, request.URL.Query().Get("algorithm"))
 }
diff --git a/internal/api/stream.go b/internal/api/stream.go
index a2ab49e..e112fd4 100644
--- a/internal/api/stream.go
+++ b/internal/api/stream.go
@@ -26,11 +26,15 @@ func streamImage(writer http.ResponseWriter, image string, resolution string) {
 }
 
 // stream a color palette
-func streamColorPalette(writer http.ResponseWriter, image string) {
+func streamColorPalette(writer http.ResponseWriter, image string, amount int, algorithm string) {
 	timestamp := time.Now().UnixMilli()
 	var response response
-	amount := config.PaletteColors
-	colors, error := color_thief.GetPaletteFromFile(image, amount, config.PaletteAlgorithm)
+	algo := 1
+	algorithm = strings.ToLower(algorithm)
+	if algorithm == "wu" {
+		algo = 0
+	}
+	colors, error := color_thief.GetPaletteFromFile(image, amount, algo)
 	if error != nil {
 		loggo.Error("encountered an error getting the color palette from image '"+image+"'", error.Error())
 		response.error = error
@@ -51,7 +55,7 @@ func streamColorPalette(writer http.ResponseWriter, image string) {
 	}
 	data := []byte(palette)
 	writer.Write(data)
-	loggo.InfoTimed("successfully streamed color palette for image '"+image+"'", timestamp, "size: "+internal.FormatBytes(int64(len(data))))
+	loggo.InfoTimed("successfully streamed color palette for image '"+image+"'", timestamp, "size: "+internal.FormatBytes(int64(len(data))), "colors: "+strconv.Itoa(amount), "algorithm: "+algorithm)
 }
 
 // stream an unscaled image
diff --git a/internal/config/config.go b/internal/config/config.go
index a115041..8fc1e9c 100644
--- a/internal/config/config.go
+++ b/internal/config/config.go
@@ -14,9 +14,6 @@ var ServerAddress string
 var ServerPort int
 var Directory string
 var ScanInterval time.Duration
-var PaletteAlgorithm int
-var PaletteColors int
-var BufferSize int
 var ConvertAvailable bool
 
 // initialize the config
@@ -48,22 +45,6 @@ func Initialize() {
 		tmpInt = 60
 	}
 	ScanInterval = time.Duration(tmpInt) * time.Second
-	tmpString := os.Getenv("SLIDESHOW_PALETTE_ALGORITHM")
-	if strings.ToLower(tmpString) == "wu" {
-		PaletteAlgorithm = 0
-	} else {
-		PaletteAlgorithm = 1
-	}
-	tmpInt, _ = strconv.Atoi(os.Getenv("SLIDESHOW_PALETTE_COLORS"))
-	if tmpInt <= 0 {
-		tmpInt = 16
-	}
-	PaletteColors = tmpInt
-	tmpInt, _ = strconv.Atoi(os.Getenv("SLIDESHOW_BUFFERSIZE"))
-	if tmpInt <= 0 {
-		tmpInt = 4096
-	}
-	BufferSize = tmpInt
 	checkConvertCommand()
 }
 
diff --git a/slideshow-api.service b/slideshow-api.service
index e553eb9..07d9e06 100644
--- a/slideshow-api.service
+++ b/slideshow-api.service
@@ -9,9 +9,6 @@ Environment="SLIDESHOW_ADDRESS=0.0.0.0"
 Environment="SLIDESHOW_PORT=3000"
 Environment="SLIDESHOW_DIRECTORY=$HOME"
 Environment="SLIDESHOW_SCANINTERVAL=60"
-Environment="SLIDESHOW_RESOLUTION="
-Environment="SLIDESHOW_PALETTE_ALGORITHM=wsm"
-Environment="SLIDESHOW_PALETTE_COLORS=16"
 Environment="SLIDESHOW_LOGLEVEL=info"
 ExecStart=/opt/slideshow-api/slideshow-api