Refactored - split functionalities into structs and interfaces

img.go

@@ -12,9 +12,16 @@ import (
 
 var pageMargin [4]float64
 var pageSize creator.PageSize
-var sizeHasSet, merginHasSet = false, false
+var sizeHasSet, marginHasSet = false, false
+
+type ImgSource struct {
+	source
+}
+
+func (s ImgSource) MergeTo(c *creator.Creator) error {
+	return addImage(s.path, c, s.mime)
+}
 
-// func addImageToPdf(inputPath string, outputPath string, imagePath string, pageNum int, xPos float64, yPos float64, iwidth float64) error {
 func addImage(filePath string, c *creator.Creator, fileType string) error {
 	debugInfo(fmt.Sprintf("Adding image: %s", filePath))
 
@@ -39,7 +46,7 @@ func addImage(filePath string, c *creator.Creator, fileType string) error {
 
 func setMargin(img *creator.Image, c *creator.Creator) {
 
-	if !merginHasSet {
+	if !marginHasSet {
 		for i, m := range strings.Split(margin, ",") {
 			floatVal, err := strconv.ParseFloat(m, 64)
 			if err != nil {
@@ -48,6 +55,7 @@ func setMargin(img *creator.Image, c *creator.Creator) {
 
 			pageMargin[i] = floatVal * creator.PPI
 		}
+		marginHasSet = true
 	}
 
 	c.SetPageMargins(pageMargin[0], pageMargin[1], pageMargin[2], pageMargin[3])

main.go

@@ -1,11 +1,8 @@
 package main
 
 import (
-	"errors"
 	"fmt"
 	"os"
-	"strconv"
-	"strings"
 
 	flag "github.com/ogier/pflag"
 	unicommon "github.com/unidoc/unidoc/common"
@@ -18,8 +15,8 @@ var JPEGQuality int
 
 const (
 	DefaultSize   = "IMG-SIZE"
-	DefaultMargin = "1,1,1,1"
-	VERSION       = "1.0.1"
+	DefaultMargin = "0,0,0,0"
+	VERSION       = "1.0.2"
 )
 
 func init() {
@@ -29,8 +26,8 @@ func init() {
 	flag.BoolVar(&scaleW, "scale-width", false, "Scale Image to page width. Only if --size specified.")
 	flag.BoolVar(&scaleH, "scale-height", false, "Scale Image to page height. Only if --size specified.")
 	flag.IntVar(&JPEGQuality, "jpeg-quality", 100, "Optimize JPEG Quality.")
-	flag.BoolVarP(&verbose, "verbose", "v", false, "Display debug info.")
-	flag.BoolVarP(&version, "version", "V", false, "Display debug info.")
+	flag.BoolVarP(&verbose, "verbose", "v", false, "Display debug information.")
+	flag.BoolVarP(&version, "version", "V", false, "Display Version information.")
 
 	flag.Usage = func() {
 		fmt.Println("merge2pdf [options...] <output_file> <input_file> [<input_file>...]")
@@ -58,79 +55,23 @@ func main() {
 	}
 
 	outputPath := args[0]
-	inputPaths := []string{}
-	inputPages := [][]int{}
+	inputPaths := args[1:]
 
-	for _, arg := range flag.Args()[1:] {
-		//inputPaths = append(inputPaths, arg)
-
-		fileInputParts := strings.Split(arg, "~")
-		inputPaths = append(inputPaths, fileInputParts[0])
-		pages := []int{}
-
-		if len(fileInputParts) > 1 {
-			for _, e := range strings.Split(fileInputParts[1], ",") {
-				pageNo, err := strconv.Atoi(strings.Trim(e, " \n"))
-				if err != nil {
-					fmt.Errorf("Invalid format! Example of a file input with page numbers: path/to/abc.pdf~1,2,3,5,6")
-					os.Exit(1)
-				}
-				pages = append(pages, pageNo)
-			}
-		}
-
-		inputPages = append(inputPages, pages)
-	}
-
-	// fmt.Println(inputPaths)
-	// fmt.Println(inputPages)
-	// os.Exit(1)
-
-	err := mergePdf(inputPaths, inputPages, outputPath)
-	if err != nil {
-		fmt.Printf("Error: %v\n", err)
-		os.Exit(1)
-	}
-
-	debugInfo(fmt.Sprintf("Complete, see output file: %s", outputPath))
-}
-
-func mergePdf(inputPaths []string, inputPages [][]int, outputPath string) error {
 	c := creator.New()
 
-	for i, inputPath := range inputPaths {
-
-		f, err := os.Open(inputPath)
+	for _, arg := range inputPaths {
+		err := NewSource(arg).MergeTo(c)
 		if err != nil {
-			return err
-		}
-		defer f.Close()
-
-		fileType, typeError := getFileType(f)
-		if typeError != nil {
-			return typeError
-		}
-
-		if fileType == "directory" {
-			// @TODO : Read all files in directory
-			return errors.New(inputPath + " is a drectory.")
-		} else if fileType == "application/pdf" {
-			err = addPdfPages(f, inputPages[i], c)
-		} else if fileType[:6] == "image/" {
-			err = addImage(inputPath, c, fileType)
-		} else {
-			err = errors.New("Unsupported type:" + inputPath)
-		}
-
-		if err != nil {
-			return err
+			fmt.Printf("Error: %s (%s) \n", err.Error(), arg)
+			os.Exit(1)
 		}
 	}
 
 	err := c.WriteToFile(outputPath)
 	if err != nil {
-		return err
+		fmt.Printf("Error: %s \n", err.Error())
 	}
 
-	return nil
+	debugInfo(fmt.Sprintf("Complete, see output file: %s", outputPath))
+	os.Exit(0)
 }

pdf.go

@@ -10,6 +10,15 @@ import (
 	pdf "github.com/unidoc/unidoc/pdf/model"
 )
 
+type PDFSource struct {
+	source
+}
+
+func (s PDFSource) MergeTo(c *creator.Creator) error {
+	f, _ := os.Open(s.path)
+	return addPdfPages(f, s.pages, c)
+}
+
 func getReader(rs io.ReadSeeker) (*pdf.PdfReader, error) {
 
 	pdfReader, err := pdf.NewPdfReader(rs)

source.go

@@ -0,0 +1,96 @@
+package main
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+
+	"github.com/labstack/gommon/log"
+	"github.com/unidoc/unidoc/pdf/creator"
+)
+
+type mergable interface {
+	MergeTo(c *creator.Creator) error
+}
+
+type source struct {
+	path, sourceType, mime, ext string
+	pages                       []int
+}
+
+// Initiate new source file from input argument
+func NewSource(input string) mergable {
+	fileInputParts := strings.Split(input, "~")
+
+	path := fileInputParts[0]
+	f, err := os.Open(fileInputParts[0])
+	if err != nil {
+		log.Fatal("Cannot read source file:", fileInputParts[0])
+	}
+
+	defer f.Close()
+
+	ext := filepath.Ext(f.Name())
+	mime, err := getMimeType(f)
+	if err != nil {
+		log.Fatal("Error in getting mime type of file:", fileInputParts[0])
+	}
+
+	sourceType, err := getFileType(mime, ext)
+	if err != nil {
+		log.Fatal("Error : %s (%s)", err.Error(), path)
+	}
+
+	pages := []int{}
+	if len(fileInputParts) > 1 {
+		pages = parsePageNums(fileInputParts[1])
+	}
+
+	source := source{path, sourceType, mime, ext, pages}
+
+	var m mergable
+	switch sourceType {
+	case "image":
+		m = ImgSource{source}
+	case "pdf":
+		m = PDFSource{source}
+	}
+
+	return m
+}
+
+func getFileType(mime, ext string) (string, error) {
+	pdfExts := []string{".pdf", ".PDF"}
+	imgExts := []string{".jpg", ".jpeg", ".gif", ".png", ".tiff", ".tif", ".JPG", ".JPEG", ".GIF", ".PNG", ".TIFF", ".TIF"}
+
+	switch {
+	case mime == "application/pdf":
+		return "pdf", nil
+	case mime[:6] == "image/":
+		return "image", nil
+	case mime == "application/octet-stream" && in_array(ext, pdfExts):
+		return "pdf", nil
+	case mime == "application/octet-stream" && in_array(ext, imgExts):
+		return "image", nil
+	}
+
+	return "error", errors.New("Could not detect file type.")
+}
+
+func parsePageNums(pagesInput string) []int {
+	pages := []int{}
+
+	for _, e := range strings.Split(pagesInput, ",") {
+		pageNo, err := strconv.Atoi(strings.Trim(e, " \n"))
+		if err != nil {
+			fmt.Errorf("Invalid format! Example of a file input with page numbers: path/to/abc.pdf~1,2,3,5,6")
+			os.Exit(1)
+		}
+		pages = append(pages, pageNo)
+	}
+
+	return pages
+}

util.go

@@ -7,8 +7,11 @@ import (
 	"reflect"
 )
 
-func in_array(val interface{}, array interface{}) (exists bool, index int) {
-	exists = false
+func in_array(val interface{}, array interface{}) bool {
+	return at_array(val, array) != -1
+}
+
+func at_array(val interface{}, array interface{}) (index int) {
 	index = -1
 
 	switch reflect.TypeOf(array).Kind() {
@@ -18,7 +21,6 @@ func in_array(val interface{}, array interface{}) (exists bool, index int) {
 		for i := 0; i < s.Len(); i++ {
 			if reflect.DeepEqual(val, s.Index(i).Interface()) == true {
 				index = i
-				exists = true
 				return
 			}
 		}
@@ -27,22 +29,17 @@ func in_array(val interface{}, array interface{}) (exists bool, index int) {
 	return
 }
 
-func getFileType(file *os.File) (string, error) {
+func getMimeType(file *os.File) (string, error) {
 	// Only the first 512 bytes are used to sniff the content type.
-	if info, stateErr := file.Stat(); stateErr != nil {
-		return "error", stateErr
-	} else if info.IsDir() {
-		return "directory", nil
-	} else {
-		buffer := make([]byte, 512)
-		_, readError := file.Read(buffer)
-		if readError != nil {
-			return "error", readError
-		}
-
-		// Always returns a valid content-type and "application/octet-stream" if no others seemed to match.
-		return http.DetectContentType(buffer), nil
+	buffer := make([]byte, 512)
+	_, readError := file.Read(buffer)
+	if readError != nil {
+		debugInfo("Read error for file: " + file.Name())
+		return "error", readError
 	}
+
+	// Always returns a valid content-type and "application/octet-stream" if no others seemed to match.
+	return http.DetectContentType(buffer), nil
 }
 
 func debugInfo(message string) {