Add support for both static template vars and csv mapped vars

Author: Jeewes

README.md

@@ -20,8 +20,10 @@ input: test_data/products.csv
 templates: "test_data/templates/"
 output: output/
 variables:
+csvMapping:  # CSV to Template variable mapping
   ProductName: 6          # CSV column no for product name
   ProductPrice: 14        # CSV column no for product price
   ProductImage: 21        # CSV column no for product image
-  VideoFile: "video.avi"  # Hard coded string value
+staticVariables:  # Hard coded template variables
+  VideoFile: "video.avi"
 ```

nerc.go

@@ -13,7 +13,6 @@ import (
 	"os"
 	"path"
 	"path/filepath"
-	"reflect"
 	"strconv"
 	"text/template"
 )
@@ -29,10 +28,11 @@ type TemplateVariable struct {
 }
 
 type NercConf struct {
-	Input     string                 `yaml:"input"`
-	Templates string                 `yaml:"templates"`
-	Output    string                 `yaml:"output"`
-	Variables map[string]interface{} `yaml:"variables"`
+	Input           string                 `yaml:"input"`
+	Templates       string                 `yaml:"templates"`
+	Output          string                 `yaml:"output"`
+	StaticVariables map[string]interface{} `yaml:"staticVariables"`
+	CSVMapping      map[string]int         `yaml:"csvMapping"`
 }
 
 func main() {
@@ -144,12 +144,11 @@ func csvToConfigs(r *csv.Reader, nercConf NercConf) {
 
 func writeConf(row []string, template string, i int, nercConf NercConf) {
 	templateVars := make(map[string]interface{})
-	for k, v := range nercConf.Variables {
-		if reflect.TypeOf(v).Kind() == reflect.Int {
-			templateVars[k] = row[v.(int)]
-		} else {
-			templateVars[k] = v
-		}
+	for k, v := range nercConf.StaticVariables {
+		templateVars[k] = v
+	}
+	for k, v := range nercConf.CSVMapping {
+		templateVars[k] = row[v]
 	}
 	conf := ProcessFile(template, templateVars)
 	outputFile := "sku_" + row[0] + "_version_" + strconv.Itoa(i) + ".json"