From 975955236fa700dda7823148c9aa80bd1b5d871c Mon Sep 17 00:00:00 2001
From: Leon Mika <lmika@lmika.org>
Date: Fri, 3 Jun 2022 10:29:06 +1000
Subject: [PATCH] Added support for TSV files

This uses a similar parser as CSV files, except configured for tabs.
Have also fixed the configured parser to ignore column counts.
---
 README.md      |  8 ++++++--
 main.go        | 22 ++++++++++++++++++++--
 modelsource.go | 38 ++++++++++++++++++++++++++------------
 3 files changed, 52 insertions(+), 16 deletions(-)

diff --git a/README.md b/README.md
index b527ab2..6c1151a 100644
--- a/README.md
+++ b/README.md
@@ -15,10 +15,14 @@ go get github.com/lmika/ted
 ## Usage
 
 ```
-ted <csvfile>
+ted [FLAGS] FILE
 ```
 
-Can either be a new CSV file, or an existing CSV file.
+Flags:
+
+- `-c <codec>` the format that the file is in.  Either `csv` or `tsv` files are supported.  Default is `csv`
+
+File can either be a new file, or an existing file.
 
 TED is similar to Vim in that it is modal.  After opening a file, the editor starts off in view mode, which permits navigating around.
 
diff --git a/main.go b/main.go
index 6aca219..5d7acf0 100644
--- a/main.go
+++ b/main.go
@@ -1,13 +1,14 @@
 package main
 
 import (
-	"github.com/lmika/ted/ui"
 	"flag"
 	"fmt"
+	"github.com/lmika/ted/ui"
 	"os"
 )
 
 func main() {
+	var flagCodec = flag.String("c", "csv", "file codec to use")
 	flag.Parse()
 	if flag.NArg() == 0 {
 		fmt.Fprintln(os.Stderr, "usage: ted FILENAME")
@@ -20,8 +21,14 @@ func main() {
 	}
 	defer uiManager.Close()
 
+	codecBuilder, hasCodec := codecModelSourceBuilders[*flagCodec]
+	if !hasCodec {
+		fmt.Fprintf(os.Stderr, "unrecognised codec: %v", *flagCodec)
+		os.Exit(1)
+	}
+
 	frame := NewFrame(uiManager)
-	session := NewSession(uiManager, frame, CsvFileModelSource{flag.Arg(0)})
+	session := NewSession(uiManager, frame, codecBuilder(flag.Arg(0)))
 	session.LoadFromSource()
 
 	uiManager.SetRootComponent(frame.RootComponent())
@@ -29,3 +36,14 @@ func main() {
 
 	uiManager.Loop()
 }
+
+type codecModelSourceBuilder func(filename string) ModelSource
+
+var codecModelSourceBuilders = map[string]codecModelSourceBuilder{
+	"csv": func(filename string) ModelSource {
+		return NewCsvFileModelSource(filename, CsvFileModelSourceOptions{Comma: ','})
+	},
+	"tsv": func(filename string) ModelSource {
+		return NewCsvFileModelSource(filename, CsvFileModelSourceOptions{Comma: '\t'})
+	},
+}
diff --git a/modelsource.go b/modelsource.go
index 9b5c4fe..cde8efa 100644
--- a/modelsource.go
+++ b/modelsource.go
@@ -1,10 +1,10 @@
 package main
 
 import (
-	"path/filepath"
-	"os"
 	"encoding/csv"
 	"io"
+	"os"
+	"path/filepath"
 )
 
 // ModelSource is a source of models.  At a minimum, it must be able to read models.
@@ -26,22 +26,34 @@ type WritableModelSource interface {
 
 // A model source backed by a CSV file
 type CsvFileModelSource struct {
-	Filename string
+	filename string
+	options  CsvFileModelSourceOptions
+}
+
+type CsvFileModelSourceOptions struct {
+	Comma rune
+}
+
+func NewCsvFileModelSource(filename string, options CsvFileModelSourceOptions) CsvFileModelSource {
+	return CsvFileModelSource{
+		filename: filename,
+		options:  options,
+	}
 }
 
 // Describes the source
 func (s CsvFileModelSource) String() string {
-	return filepath.Base(s.Filename)
+	return filepath.Base(s.filename)
 }
 
 // Read the model from the given source
 func (s CsvFileModelSource) Read() (Model, error) {
 	// Check if the file exists.  If not, return an empty model
-	if _, err := os.Stat(s.Filename); os.IsNotExist(err) {
+	if _, err := os.Stat(s.filename); os.IsNotExist(err) {
 		return NewSingleCellStdModel(), nil
 	}
 
-	f, err := os.Open(s.Filename)
+	f, err := os.Open(s.filename)
 	if err != nil {
 		return nil, err
 	}
@@ -49,12 +61,13 @@ func (s CsvFileModelSource) Read() (Model, error) {
 
 	model := new(StdModel)
 	r := csv.NewReader(f)
+	r.Comma = s.options.Comma
+	r.FieldsPerRecord = -1
 	for {
 		record, err := r.Read()
 		if err == io.EOF {
 			break
-		}
-		if err != nil {
+		} else if err != nil {
 			return nil, err
 		}
 
@@ -66,19 +79,20 @@ func (s CsvFileModelSource) Read() (Model, error) {
 }
 
 func (s CsvFileModelSource) Write(m Model) error {
-	f, err := os.Create(s.Filename)
+	f, err := os.Create(s.filename)
 	if err != nil {
 		return err
 	}
 
 	w := csv.NewWriter(f)
+	w.Comma = s.options.Comma
 
 	rows, cols := m.Dimensions()
 
 	for r := 0; r < rows; r++ {
-		record := make([]string, cols)		// Reuse the record slice
+		record := make([]string, cols) // Reuse the record slice
 		for c := 0; c < cols; c++ {
-			record[c] =  m.CellValue(r, c)
+			record[c] = m.CellValue(r, c)
 		}
 		if err := w.Write(record); err != nil {
 			f.Close()
@@ -93,4 +107,4 @@ func (s CsvFileModelSource) Write(m Model) error {
 	}
 
 	return f.Close()
-}
\ No newline at end of file
+}