Script to add a command to the Windows right-click context menu for text files

m2p.go

// Copyright Jason Travis
package main

import (
	"encoding/csv"
	"errors"
	"fmt"
	"io"
	"log"
	"os"
	"path/filepath"
	"strconv"
	"strings"
	"unicode"
)

const (
	header = "ITEM ID,Item Description,Item Class,Inactive,Subject to Commission," +
		"Description for  Sales,Description for Purchases,Sales Price 1,Sales Price 1 Calculation," +
		"Sales Price 1 Rounding,Sales Price 1 Rounding #,Sales Price 2,Sales Price 2 Calculation," +
		"Sales Price 2 Rounding,Sales Price 2 Rounding #,Sales Price 3,Sales Price 3 Calculation," +
		"Sales Price 3 Rounding,Sales Price 3 Rounding #,Sales Price 4,Sales Price 4 Calculation," +
		"Sales Price 4 Rounding,Sales Price 4 Rounding #,Sales Price 5,Sales Price 5 Calculation," +
		"Sales Price 5 Rounding,Sales Price 5 Rounding #,Sales Price 6,Sales Price 6 Calculation," +
		"Sales Price 6 Rounding,Sales Price 6 Rounding #,Sales Price 7,Sales Price 7 Calculation," +
		"Sales Price 7 Rounding,Sales Price 7 Rounding #,Sales  Price 8,Sales Price 8 Calculation," +
		"Sales Price 8 Rounding,Sales Price 8 Rounding #,Sales Price 9,Sales Price 9 Calculation," +
		"Sales Price 9 Rounding,Sales Price 9 Rounding #,Sales Price 10,Sales Price 10 Calculation," +
		"Sales Price 10 Rounding,Sales Price 10 Rounding #,Quanity Disc.,Item Tax Type,Last Unit Cost," +
		"Costing Method,G/L Sales Account,G/L Inventory Account,G/L COGS/Salary Acct,UPC / SKU," +
		"Item Type,Location,Stocking U/M,Use Multi-Packs,Purchasing U/M,Purchasing U/M Description," +
		"Purch U/M No. of Stocking Units,Purchasing Weight,Purchasing UPC / SCC,Use Purchasing U/M as Default," +
		"Sales U/M,Sales U/M Description,Sales U/M No. of Stocking Units,Sales Weight,Sales UPC / SCC," +
		"Use Sales U/M as Default,Weight,Minimum Stock,Reorder Quantity,Vender ID,Buyer ID,Alternate Vendor," +
		"Substitution,Special Note,Special Order,Master Stock Item ID,Primary Attrib. ID 1," +
		"Primary Attrib. Desc. 1,Primary Attrib. ID 2,Primary Attrib. Desc. 2,Primary Attrib. ID 3," +
		"Primary Attrib. Desc. 3,Primary Attrib. ID 4,Primary Attrib. Desc. 4,Primary Attrib. ID 5," +
		"Primary Attrib. Desc. 5,Primary Attrib. ID 6,Primary Attrib. Desc. 6,Primary Attrib. ID 7," +
		"Primary Attrib. Desc. 7,Primary Attrib. ID 8,Primary Attrib. Desc. 8,Primary Attrib. ID 9," +
		"Primary Attrib. Desc. 9,Primary Attrib. ID 10,Primary Attrib. Desc. 10,Primary Attrib. ID 11," +
		"Primary Attrib. Desc. 11,Primary Attrib. ID 12,Primary Attrib. Desc. 12,Primary Attrib. ID 13," +
		"Primary Attrib. Desc. 13,Primary Attrib. ID 14,Primary Attrib. Desc. 14,Primary Attrib. ID 15," +
		"Primary Attrib. Desc. 15,Primary Attrib. ID 16,Primary Attrib. Desc. 16,Primary Attrib. ID 17," +
		"Primary Attrib. Desc. 17,Primary Attrib. ID 18,Primary Attrib. Desc. 18,Primary Attrib. ID 19," +
		"Primary Attrib. Desc. 19,Primary Attrib. ID 20,Primary Attrib. Desc. 20,Secondary Attrib. ID 1," +
		"Secondary Attrib. Desc. 1,Secondary Attrib. ID 2,Secondary Attrib. Desc. 2,Secondary Attrib. ID 3," +
		"Secondary Attrib. Desc. 3,Secondary Attrib. ID 4,Secondary Attrib. Desc. 4,Secondary Attrib. ID 5," +
		"Secondary Attrib. Desc. 5,Secondary Attrib. ID 6,Secondary Attrib. Desc. 6,Secondary Attrib. ID 7," +
		"Secondary Attrib. Desc. 7,Secondary Attrib. ID 8,Secondary Attrib. Desc. 8,Secondary Attrib. ID 9," +
		"Secondary Attrib. Desc. 9,Secondary Attrib. ID 10,Secondary Attrib. Desc. 10,Secondary Attrib. ID 11," +
		"Secondary Attrib. Desc. 11,Secondary Attrib. ID 12,Secondary Attrib. Desc. 12,Secondary Attrib. ID 13," +
		"Secondary Attrib. Desc. 13,Secondary Attrib. ID 14,Secondary Attrib. Desc. 14,Secondary Attrib. ID 15," +
		"Secondary Attrib. Desc. 15,Secondary Attrib. ID 16,Secondary Attrib. Desc. 16,Secondary Attrib. ID 17," +
		"Secondary Attrib. Desc. 17,Secondary Attrib. ID 18,Secondary Attrib. Desc. 18,Secondary Attrib. ID 19," +
		"Secondary Attrib. Desc. 19,Secondary Attrib. ID 20,Secondary Attrib. Desc. 20,Item Note,Print Components," +
		"Number of Components,Primary Attrib. Name,Substock Primary Attrib. ID,Substock Primary Attrib. Desc.," +
		"Secondary Attrib. Name,Substock Second Attrib. ID,Substock Second Attrib. Desc.,Warranty Period," +
		"Revision Number,Effective Date,Component Number,Component ID,Quantity Needed,Part Number"
	headerLength = 177
)

var pwd = os.Getenv("USERPROFILE")
var vendorFilename = filepath.FromSlash(pwd + "/m2p/vendor-list.csv")
var logFilename = filepath.FromSlash(pwd + "/m2p/m2p.log")

func main() {
	var inFile, outFile, vendorFile, logFile *os.File
	var err error

	if len(os.Args) < 2 {
		log.Fatal("Usage: m2p AutoPartPrices.txt")
	}

	log.Println("Opening " + logFilename)
	logFile, err = os.OpenFile(logFilename, os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0644)
	if err != nil {
		log.Fatal(err)
	}
	defer logFile.Close()

	log.SetOutput(logFile)
	log.SetFlags(log.Ldate | log.Lshortfile)
	//log.SetPrefix(os.Args[1] + " ")
	log.Println("Initializing")
	log.Printf("Command line arguments: %v", os.Args)

	log.Println("Loading " + os.Args[1])
	inFile, err = os.Open(os.Args[1])
	if err != nil {
		log.Fatal(err)
	}
	defer inFile.Close()
	inventory := NewInventory(inFile)

	log.Println("Loading " + vendorFilename)
	vendorFile, err = os.Open(vendorFilename)
	if err != nil {
		log.Fatal(err)
	}
	defer vendorFile.Close()
	vendor, err := NewVendor(vendorFile)
	if err != nil {
		log.Fatal(err)
	}

	// Filter similar entries
	if err := inventory.filter(vendor); err != nil {
		log.Fatal(err)
	}

	// Convert to a format Peachtree can import
	if err := inventory.format(); err != nil {
		log.Fatal(err)
	}

	// Replace the inFile extension with .csv to get the outFileName
	outFilename := inFile.Name()[0:len(inFile.Name())-len(filepath.Ext(inFile.Name()))] + ".csv"

	log.Println("Saving " + outFilename)
	outFile, err = os.Create(outFilename)
	if err != nil {
		log.Fatal(err)
		return
	}
	defer outFile.Close()
	inventory.save(outFile)
	log.Println("Done")
}

// Inventory TODO
type Inventory [][]string

// NewInventory TODO
func NewInventory(r io.Reader) Inventory {
	// Read inventory file
	inventory, err := parseCSV(r)
	if err != nil {
		log.Fatal(err)
	}
	return Inventory(inventory)
}

func (inventory *Inventory) filter(vendor Vendor) error {
	var n = len(*inventory)
	if n < 2 {
		return nil
	}
	var filtered = make(Inventory, 0, n)

	// Potential unit tests
	// empty inventory
	// odd inventory
	// 1 duplicate
	// 2 duplicates
	// duplicates in series
	// duplicate-unique-duplicate

	log.Printf("Total pre-filter: %d\n", len(*inventory))

	var duplicates = 0

	var ptr = 0
	for i := 1; i < n; i++ {
		if (*inventory)[i][1] == (*inventory)[ptr][1] {
			var p, c int
			var ok bool
			var err error
			duplicates++
			log.Println("duplicate item: " + (*inventory)[i][1] + " vendor " + (*inventory)[i][16] + " and " + (*inventory)[ptr][16])
			if p, ok = vendor[(*inventory)[ptr][16]]; !ok {
				log.Println("APPEND vendor " + (*inventory)[ptr][16] + " to " + vendorFilename)
				p = len(vendor) - 1
				err = vendor.append((*inventory)[ptr][16])
				if err != nil {
					return err
				}
			}
			if c, ok = vendor[(*inventory)[i][16]]; !ok {
				log.Println("APPEND vendor " + (*inventory)[i][16] + " to " + vendorFilename)
				c = len(vendor) - 1
				err = vendor.append((*inventory)[i][16])
				if err != nil {
					return err
				}
			}

			if p > c {
				log.Printf("Skipping %s %s vendor priority %d\n", (*inventory)[ptr][1], (*inventory)[ptr][16], p)
				ptr = i
			} else {
				log.Printf("Skipping %s %s vendor priority %d\n", (*inventory)[ptr][1], (*inventory)[ptr][16], p)
			}
		} else {
			filtered = append(filtered, (*inventory)[ptr])
			ptr = i
		}
	}
	filtered = append(filtered, (*inventory)[ptr])

	log.Printf("Duplicates: %d\n", duplicates)
	log.Printf("Expected total: %d\n", len(*inventory)-duplicates)
	log.Printf("Total post-filter: %d\n", len(filtered))

	*inventory = filtered
	return nil
}

// Vendor TODO
type Vendor map[string]int

// NewVendor TODO
func NewVendor(r io.Reader) (Vendor, error) {
	vendors, err := parseCSV(r)
	if err != nil {
		return nil, err
	}

	if len(vendors) < 1 || len(vendors[0]) < 1 {
		return nil, errors.New(vendorFilename + " is empty")
	}

	dict := make(Vendor, len(vendors[0]))

	for i, v := range vendors[0] {
		dict[v] = i
	}

	return dict, nil
}

func (v *Vendor) append(vendor string) error {
	vendorFile, err := os.OpenFile(vendorFilename, os.O_RDWR, 0644)
	if err != nil {
		return err
	}
	defer vendorFile.Close()

	vendors, err := parseCSV(vendorFile)
	if err != nil {
		return err
	}

	vendors[0] = append(vendors[0], vendor)

	// Rewind to the beginning of the file
	vendorFile.Seek(0, os.SEEK_SET)

	writer := csv.NewWriter(vendorFile)
	if err := writer.WriteAll(vendors); err != nil {
		return err
	}

	(*v)[vendor] = len(*v) - 1

	return nil
}

func parseCSV(r io.Reader) ([][]string, error) {
	reader := csv.NewReader(r)
	reader.LazyQuotes = true
	//reader.FieldsPerRecord = 20
	//reader.TrimLeadingSpace = true

	records, err := reader.ReadAll()

	// Trim whitespace and quotes from all fields
	for i := range records {
		for j := range records[i] {
			records[i][j] = strings.TrimFunc(records[i][j], func(r rune) bool {
				return unicode.IsSpace(r) || r == '"'
			})

		}
	}

	return records, err
}

func (inventory *Inventory) format() error {
	if len(*inventory) < 1 {
		return errors.New("format error: empty input")
	}

	if len((*inventory)[0]) != 20 {
		return fmt.Errorf("format error: expected input with 20 columns, found %d\n", len((*inventory)[0]))
	}

	// TODO validate input
	var output = make(Inventory, len(*inventory))

	for i := range *inventory {
		output[i] = make([]string, headerLength)

		// Fill in output columns with values from the input file.

		// input[0] UNUSED. input[8] contains the complete Item Type
		// input[4 and 5] Discount and Special Market UNUSED.
		// input[7,9,12-15] UNKNOWN.
		// input[17] DUPLICATE of input[1], but without the quotes

		// In descending order, right-to-left, reduce Sales Price by 3%
		salesPrice9 := 39
		salesPrice1 := 6
		stepSize := 4
		jobber, err := strconv.ParseFloat((*inventory)[i][3], 64)
		if err != nil {
			return err
		}
		for salesPriceN := salesPrice9; salesPriceN > salesPrice1; salesPriceN -= stepSize {
			// Convert jobber to a string with no exponent, infinite precision, assume the original was a float64
			output[i][salesPriceN] = strconv.FormatFloat(jobber, 'f', -1, 64)
			jobber *= .97 // .97 = 97% = reduce by 3%
		}
		output[i][0] = (*inventory)[i][1]                                // Item ID. (*inventory)[i]Tokens[1 or 17]
		output[i][43] = (*inventory)[i][2]                               // List
		output[i][49] = (*inventory)[i][6]                               // Last Unit Cost
		output[i][55] = strings.Replace((*inventory)[i][8], "-", "", -1) // Item Type
		output[i][56] = (*inventory)[i][10]                              // Location
		output[i][1] = (*inventory)[i][11]                               // Description
		output[i][5] = (*inventory)[i][11]                               // Description
		output[i][6] = (*inventory)[i][11]                               // Description
		output[i][74] = (*inventory)[i][16]                              // Vender ID

		// Fill in output columns with default values not provided by the (*inventory) file.
		// The typos are deliberate to reflect the Header element values.
		output[i][2] = "1"     // Item Class
		output[i][3] = "FALSE" // Inactive
		output[i][4] = "TRUE"  // Subject to Commission
		//output[i][47] = "FALSE" // Quantity Disc.
		output[i][48] = "2"     // Item Tax Type
		output[i][50] = "1"     // Costing Method
		output[i][51] = "4000"  // G/L Sales Account
		output[i][52] = "1200"  // G/L Inventory Account
		output[i][53] = "4500"  // G/L COGS/Salary Acct
		output[i][58] = "FALSE" // Use Multi-Packs
		output[i][61] = "0"     // Purch U/M No. of Stocking Units
		output[i][62] = "0"     // Purchasing Weight
		output[i][64] = "FALSE" // Use Purchasing U/M as Default
		output[i][67] = "0"     // Sales U/M No. of Stocking Units
		output[i][68] = "0"     // Sales Weight
		output[i][69] = "0"     // Sales UPC / SCC
		output[i][70] = "FALSE" // Use Sales U/M as Default
		output[i][71] = "0"     // Weight
		output[i][72] = "0"     // Minimum Stock
		output[i][73] = "0"     // Reorder Quantity
		output[i][75] = "1"     // Buyer ID
		// The remaining output columns are unused.
	}
	*inventory = output
	return nil
}

func (inventory *Inventory) save(w io.Writer) error {
	// Write header
	if _, err := w.Write([]byte(header + "\n")); err != nil {
		return err
	}

	// Write formatted inventory
	writer := csv.NewWriter(w)
	if err := writer.WriteAll([][]string(*inventory)); err != nil {
		return err
	}

	return nil
}

shellExt.bat

@echo "The root directory:"
@echo %USERPROFILE%
@echo "Check 1/2: Does the txtfile key exist?"
@REG QUERY HKEY_CLASSES_ROOT\txtfile
PAUSE
@echo "Check 2/2: Does the txtfile\shell key exist?"
@REG QUERY HKEY_CLASSES_ROOT\txtfile\shell
PAUSE
@ECHO "The next instructions will add a m2p command key"
PAUSE
@REG ADD HKEY_CLASSES_ROOT\txtfile\shell\m2p
@REG ADD HKEY_CLASSES_ROOT\txtfile\shell\m2p\command /ve /t REG_EXPAND_SZ /d "%USERPROFILE%\m2p\m2p.exe \"%1\""