3 files changed, 111 insertions(+), 24 deletions(-)

M go.mod
M go.sum
M main.go

@@ 2,4 2,7 @@ module git.sr.ht/~mendelmaleh/csvgen
 
 go 1.18
 
-require github.com/dave/jennifer v1.5.0 // indirect
+require (
+	github.com/dave/jennifer v1.5.0
+	github.com/mitchellh/hashstructure v1.1.0
+)

@@ 7,6 7,8 @@ github.com/dave/jennifer v1.5.0/go.mod h1:4MnyiFIlZS3l5tSDn8VnzE6ffAhYBMB2SZntBs
 github.com/dave/kerr v0.0.0-20170318121727-bc25dd6abe8e/go.mod h1:qZqlPyPvfsDJt+3wHJ1EvSXDuVjFTK0j2p/ca+gtsb8=
 github.com/dave/patsy v0.0.0-20210517141501-957256f50cba/go.mod h1:qfR88CgEGLoiqDaE+xxDCi5QA5v4vUoW0UCX2Nd5Tlc=
 github.com/dave/rebecca v0.9.1/go.mod h1:N6XYdMD/OKw3lkF3ywh8Z6wPGuwNFDNtWYEMFWEmXBA=
+github.com/mitchellh/hashstructure v1.1.0 h1:P6P1hdjqAAknpY/M1CGipelZgp+4y9ja9kmUZPXP+H0=
+github.com/mitchellh/hashstructure v1.1.0/go.mod h1:xUDAozZz0Wmdiufv0uyhnHkUTN6/6d8ulp4AwfLKrmA=
 github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/yuin/goldmark v1.4.1/go.mod h1:mwnBkeHKe2W/ZEtQ+71ViKU8L12m81fl3OWwC1Zlc8k=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=

@@ 2,14 2,15 @@ package main
 
 import (
 	"bufio"
-	"fmt"
 	"go/token"
 	"log"
 	"os"
+	"sort"
 	"strings"
 	"unicode"
 
 	"github.com/dave/jennifer/jen"
+	"github.com/mitchellh/hashstructure"
 )
 
 func identifier(id string) string {


@@ 24,43 25,124 @@ func identifier(id string) string {
 	return strings.Join(words, "")
 }
 
-func main() {
-	// TODO: help flag
+func groupname(x []int) string {
+	r := make([]rune, len(x))
+	for i, v := range x {
+		r[i] = 'A' + rune(v)
+	}
 
+	return string(r)
+}
+
+func main() {
+	// headers
 	scanner := bufio.NewScanner(os.Stdin)
 
-	var header string
-	if scanner.Scan() {
-		header = scanner.Text()
+	var headers [][]string
+	for scanner.Scan() {
+		headers = append(headers, strings.Split(scanner.Text(), ","))
 	}
 
 	if err := scanner.Err(); err != nil {
 		log.Fatalf("error reading header from stdin: %s")
 	}
 
-	// TODO: sep flag, unquote fields
-	fields := strings.Split(header, ",")
+	// fields to header indexes
+	fields := make(map[string][]int)
 
-	/*
-		fmt.Println(strings.Join(fields, "\n"))
-		os.Exit(0)
-	*/
+	for i, header := range headers {
+		for _, field := range header {
+			fields[field] = append(fields[field], i)
+		}
+	}
 
-	// TODO: struct name flag
-	t := jen.Type().Id("Raw").StructFunc(func(g *jen.Group) {
-		for _, v := range fields {
-			id := identifier(v)
-			if !token.IsIdentifier(id) {
-				log.Fatalf("invalid identifier: %q", id)
-			}
+	// header index group
+	var groups [][]int
 
-			g.Id(id).String().Tag(map[string]string{"csv": v})
+	// header index group hash to fields
+	parts := make(map[uint64][]string)
+
+	for k, v := range fields {
+		hash, err := hashstructure.Hash(v, nil)
+		if err != nil {
+			log.Fatal(err)
 		}
+
+		if _, ok := parts[hash]; !ok {
+			groups = append(groups, v)
+		}
+
+		parts[hash] = append(parts[hash], k)
+	}
+
+	// sort groups
+	sort.Slice(groups, func(i, j int) bool {
+		li := len(groups[i])
+		lj := len(groups[j])
+
+		if li == lj {
+			for x := 0; x < li; x++ {
+				xi := groups[i][x]
+				xj := groups[j][x]
+
+				if xi != xj {
+					return xi < xj
+				}
+			}
+		}
+
+		// descending, biggest group (most common part) to least
+		return li > lj
 	})
 
-	if err := t.Render(os.Stdout); err != nil {
-		log.Fatal(err)
+	// header index to header groups
+	backrefs := make([][]int, len(headers))
+
+	for i, group := range groups {
+		if len(group) == 1 {
+			break
+		}
+
+		for _, v := range group {
+			backrefs[v] = append(backrefs[v], i)
+		}
+	}
+
+	// output
+	f := jen.NewFile("main")
+
+	for _, v := range groups {
+		hash, err := hashstructure.Hash(v, nil)
+		if err != nil {
+			log.Fatal(err)
+		}
+
+		sort.Strings(parts[hash])
+		// spew.Dump(parts[hash])
+
+		f.Type().Id(groupname(v)).StructFunc(func(g *jen.Group) {
+			// common parts
+			if len(v) == 1 {
+				for _, v := range backrefs[v[0]] {
+					g.Id(groupname(groups[v]))
+				}
+				g.Line()
+			}
+
+			// fields
+			for _, v := range parts[hash] {
+				id := identifier(v)
+				if !token.IsIdentifier(id) {
+					log.Fatalf("invalid identifier: %q", id)
+				}
+
+				g.Id(id).String().Tag(map[string]string{"csv": v})
+			}
+		}).Line()
+
 	}
 
-	fmt.Println()
+	if err := f.Render(os.Stdout); err != nil {
+		log.Fatal(err)
+	}
 }