1 files changed, 80 insertions, 0 deletions
diff --git a/ast.go b/ast.go
new file mode 100644
index 0000000..beb6a1a
--- /dev/null
+++ b/ast.go
@@ -0,0 +1,80 @@
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"go/parser"
+	"go/printer"
+	"go/token"
+	"io/ioutil"
+	"os"
+	"path"
+	"strings"
+
+	"github.com/mgutz/ansi"
+	"golang.org/x/tools/go/ast/astutil"
+)
+
+func ProcessFileAST(filePath string, from string, to string) {
+
+	//Colors to be used on the console
+	red := ansi.ColorCode("red+bh")
+	white := ansi.ColorCode("white+bh")
+	greenUnderline := ansi.ColorCode("green+buh")
+	blackOnWhite := ansi.ColorCode("black+b:white+h")
+	//Reset the color
+	reset := ansi.ColorCode("reset")
+
+	// If the file is a go file scan it
+	if path.Ext(filePath) == ".go" {
+		// New FileSet to parse the go file to
+		fSet := token.NewFileSet()
+
+		// Parse the file
+		file, err := parser.ParseFile(fSet, filePath, nil, 0)
+		if err != nil {
+			fmt.Println(err)
+		}
+
+		// Get the list of imports from the ast
+		imports := astutil.Imports(fSet, file)
+
+		// Keep track of number of changes
+		numChanges := 0
+
+		// Iterate through the imports array
+		for _, mPackage := range imports {
+			for _, mImport := range mPackage {
+				// Since astutil returns the path string with quotes, remove those
+				importString := mImport.Path.Value
+
+				// If the path matches the oldpath, replace it with the new one
+				if strings.Contains(importString, from) {
+					//If it needs to be replaced, increase numChanges so we can write the file later
+					numChanges++
+
+					// Join the path of the import package with the remainder from the old one after removing the old import package
+					replacePackage := strings.Replace(importString, from, to, -1)
+
+					fmt.Println(red + "Updating import " + importString + " from file " + reset + white + filePath + reset + red + " to " + reset + white + replacePackage + reset)
+
+					// Remove the old import and replace it with the replacement
+					astutil.DeleteImport(fSet, file, importString)
+					astutil.AddImport(fSet, file, replacePackage)
+				}
+			}
+		}
+
+		// If the number of changes are more than 0, write file
+		if numChanges > 0 {
+			// Print the new AST tree to a new output buffer
+			var outputBuffer bytes.Buffer
+			printer.Fprint(&outputBuffer, fSet, file)
+
+			ioutil.WriteFile(filePath, outputBuffer.Bytes(), os.ModePerm)
+			fmt.Printf(blackOnWhite+"File "+filePath+" saved after %d changes."+reset+"\n", numChanges)
+		} else {
+			fmt.Println(greenUnderline + "No changes needed on file " + filePath + reset)
+		}
+	}
+}