Add http server

cmd/convert.go

@@ -5,27 +5,19 @@ Copyright © 2022 NAME HERE <EMAIL ADDRESS>
 package cmd
 
 import (
-	"image"
-	"image/color"
-	_ "image/gif"
-	_ "image/jpeg"
-	_ "image/png"
 	"io"
 	"log"
 	"os"
 
+	"github.com/saunaclub/inkpot-cli/epd"
 	"github.com/spf13/cobra"
-	"golang.org/x/image/draw"
 )
 
 var width int
 var height int
+var infile string
 var outfile string
 
-func Foobar () (io.Writer, error) {
-	return os.Stdout, nil
-}
-
 // convertCmd represents the convert command
 var convertCmd = &cobra.Command{
 	Use:   "convert <file|->",
@@ -50,9 +42,9 @@ Pass "-" as the filename to read from stdin.`,
 			defer input.Close()
 		}
 
-	    // write to given outfile, default to stdout
-	    var output io.Writer
-		if outfile == "" {
+		// write to given outfile, default to stdout
+		var output io.Writer
+		if outfile == "" || outfile == "-" {
 			output = os.Stdout
 		} else {
 			file, err := os.OpenFile(outfile, os.O_RDWR|os.O_CREATE, 0644)
@@ -63,7 +55,7 @@ Pass "-" as the filename to read from stdin.`,
 			output = file
 		}
 
-		result, err := convertImage(input, width, height)
+		result, err := epd.ConvertImage(input, width, height)
 		if err != nil {
 			log.Fatalf("Could not convert image: %v", err)
 		}
@@ -78,58 +70,3 @@ func init() {
 	convertCmd.Flags().IntVarP(&height, "height", "y", 960, "target height")
 	convertCmd.Flags().StringVarP(&outfile, "output", "o", "", "file to write the result to (default stdout)")
 }
-
-// Returns a new Rectangle that is resized and centered in `dst`
-func fitRectInto(src *image.Rectangle, dst *image.Rectangle) image.Rectangle {
-	var targetWidth int
-	var targetHeight int
-	var scale float64
-
-	srcRatio := float64(src.Max.X) / float64(src.Max.Y)
-	dstRatio := float64(dst.Max.X) / float64(dst.Max.Y)
-
-	if srcRatio < dstRatio {
-		// center horizontally, scale vertically
-		scale = float64(dst.Max.Y) / float64(src.Max.Y)
-	} else {
-		// center vertically, scale horizontally
-		scale = float64(dst.Max.X) / float64(src.Max.X)
-	}
-
-	targetWidth = int(float64(src.Max.X) * scale)
-	targetHeight = int(float64(src.Max.Y) * scale)
-
-	targetX := (dst.Max.X - targetWidth) / 2
-	targetY := (dst.Max.Y - targetHeight) / 2
-
-	return image.Rect(targetX, targetY, targetWidth+targetX, targetHeight+targetY)
-}
-
-func convertImage(input io.Reader, width int, height int) ([]byte, error) {
-	src, _, err := image.Decode(input)
-	if err != nil {
-		return nil, err
-	}
-	dst := image.NewGray(image.Rect(0, 0, width, height))
-
-	srcBounds := src.Bounds()
-	targetRect := fitRectInto(&srcBounds, &dst.Rect)
-
-	draw.Draw(dst, dst.Bounds(), &image.Uniform{color.White}, image.ZP, draw.Src)
-	draw.CatmullRom.Scale(dst, targetRect, src, src.Bounds(), draw.Over, nil)
-
-	// the actual conversion works by packing two nibbles together in a byte
-	var result = make([]byte, (width*height+1)/2)
-	for i, p := range dst.Pix {
-		res := uint8((uint16(p) + 8) / 16)
-		if i%2 == 0 {
-			result[i/2] = (res << 4)
-		} else {
-			// note that integer division makes sure we're writing at the same
-			// index for odd and even indices
-			result[i/2] = result[i/2] | res
-		}
-	}
-
-	return result, nil
-}

cmd/root.go

@@ -22,8 +22,6 @@ import (
 	"github.com/spf13/cobra"
 )
 
-
-
 // rootCmd represents the base command when called without any subcommands
 var rootCmd = &cobra.Command{
 	Use:   "inkpot-cli",
@@ -32,9 +30,6 @@ var rootCmd = &cobra.Command{
 resizing them, rotating them and converting them to 16-color
 grayscale so they can be comfortably displayed on e-ink
 displays powered by the epdiy driver.`,
-	// Uncomment the following line if your bare application
-	// has an action associated with it:
-	// Run: func(cmd *cobra.Command, args []string) { },
 }
 
 // Execute adds all child commands to the root command and sets flags appropriately.
@@ -47,15 +42,4 @@ func Execute() {
 }
 
 func init() {
-	// Here you will define your flags and configuration settings.
-	// Cobra supports persistent flags, which, if defined here,
-	// will be global for your application.
-
-	// rootCmd.PersistentFlags().StringVar(&cfgFile, "config", "", "config file (default is $HOME/.inkpot-cli.yaml)")
-
-	// Cobra also supports local flags, which will only run
-	// when this action is called directly.
-	// rootCmd.Flags().BoolP("toggle", "t", false, "Help message for toggle")
 }
-
-

cmd/serve.go

@@ -0,0 +1,165 @@
+/*
+Copyright © 2022 NAME HERE <EMAIL ADDRESS>
+
+*/
+package cmd
+
+import (
+	"bytes"
+	"fmt"
+	"net/http"
+
+	"github.com/gin-gonic/gin"
+	"github.com/saunaclub/inkpot-cli/epd"
+	"github.com/spf13/cobra"
+)
+
+var defaultWidth int = 540
+var defaultHeight int = 960
+var port int
+
+type Params struct {
+	Width  int    `form:"height"`
+	Height int    `form:"width"`
+	Url    string `form:"url"`
+}
+
+// serveCmd represents the serve command
+var serveCmd = &cobra.Command{
+	Use:   "serve",
+	Short: "Run a webserver to convert images via HTTP",
+	Run: func(cmd *cobra.Command, args []string) {
+		router := gin.Default()
+		// Set a lower memory limit for multipart forms (default is 32 MiB)
+		router.MaxMultipartMemory = 8 << 20 // 8 MiB
+		router.GET("/", getIndex)
+		router.GET("/convert", getConvert)
+		router.PUT("/convert", putConvert)
+		router.Run(fmt.Sprintf(":%d", port))
+	},
+}
+
+func getIndex(c *gin.Context) {
+	usage := `# inkpot-convert
+
+A webserver to convert GIFs, PNGs and JPEGs to 4-bit grayscale images.
+
+## Routes
+
+- PUT /convert can be used to convert a file on your filesystem
+- GET /convert/[url] can be used to convert a file publically accessible via URL
+
+Both routes accept a "width" and a "height" parameter to configure the output size.
+
+## Examples
+
+Via curl:
+
+curl -X PUT http://localhost:8080/convert \
+  -F "file=@my_cat.jpeg" \
+  -H "Content-Type: multipart/form-data"
+
+Via httpie:
+
+http --form PUT :8080/convert file@my_cat.jpg
+`
+
+	c.String(http.StatusOK, usage)
+}
+
+func min(a, b int) int {
+	if a < b {
+		return a
+	}
+	return b
+}
+
+func getConvert(c *gin.Context) {
+	var params Params
+	err := c.ShouldBindQuery(&params)
+	if err != nil {
+		c.Error(err)
+	}
+
+	if params.Url == "" {
+		c.String(http.StatusBadRequest, "Please supply an image URL.")
+		return
+	}
+
+	width := min(params.Width, 2000)
+	height := min(params.Height, 2000)
+	if width <= 0 {
+		width = defaultWidth
+	}
+	if height <= 0 {
+		height = defaultHeight
+	}
+
+	response, err := http.Get(params.Url)
+	if err != nil || response.StatusCode != http.StatusOK {
+		c.Status(http.StatusServiceUnavailable)
+		return
+	}
+
+	reader := response.Body
+	defer reader.Close()
+
+	converted, err := epd.ConvertImage(reader, width, height)
+	if err != nil {
+		c.Error(err)
+	}
+
+	extraHeaders := map[string]string{
+		"X-Image-Width":  fmt.Sprintf("%d", width),
+		"X-Image-height": fmt.Sprintf("%d", height),
+	}
+
+	c.DataFromReader(http.StatusOK, int64(len(converted)), "x-image/inkpot-epd", bytes.NewReader(converted), extraHeaders)
+}
+
+func putConvert(c *gin.Context) {
+	var params Params
+	err := c.ShouldBindQuery(&params)
+	if err != nil {
+		c.Error(err)
+	}
+
+	width := min(params.Width, 2000)
+	height := min(params.Height, 2000)
+	if width <= 0 {
+		width = defaultWidth
+	}
+	if height <= 0 {
+		height = defaultHeight
+	}
+
+	// Single file
+	file, err := c.FormFile("file")
+	if err != nil {
+		c.Error(err)
+	}
+
+	reader, err := file.Open()
+	if err != nil {
+		c.Error(err)
+	}
+	defer reader.Close()
+
+	converted, err := epd.ConvertImage(reader, width, height)
+	if err != nil {
+		c.Error(err)
+	}
+
+	extraHeaders := map[string]string{
+		"X-Image-Width":  fmt.Sprintf("%d", width),
+		"X-Image-height": fmt.Sprintf("%d", height),
+	}
+
+	c.DataFromReader(http.StatusOK, int64(len(converted)), "x-image/inkpot-epd", bytes.NewReader(converted), extraHeaders)
+}
+
+func init() {
+	rootCmd.AddCommand(serveCmd)
+	serveCmd.Flags().IntVarP(&port, "port", "p", 8080, "port to bind to")
+	// gin.SetMode(gin.ReleaseMode)
+}