goimport for protobuf

1 files changed, 161 insertions, 0 deletions

diff --git a/protoReformat.go b/protoReformat.go
new file mode 100644
index 0000000..26fae1f
--- /dev/null
+++ b/protoReformat.go
@@ -0,0 +1,161 @@
+package main
+
+import (
+	"fmt"
+	"os"
+	"strings"
+
+	"go.wit.com/log"
+)
+
+// like 'goimport' but for .proto files
+
+var maxVarname int
+var maxVartype int
+
+func protoReformat(filename string) error {
+	// read in the .proto file
+	data, err := os.ReadFile(filename)
+	if err != nil {
+		log.Info("file read failed", filename, err)
+		return err
+	}
+
+	pf, err := os.OpenFile(filename+".new", os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0644)
+	if err != nil {
+		log.Info("file open error. permissions?", filename, err)
+		return err
+	}
+	defer pf.Close()
+
+	var inMessage bool
+	var curmsg []string
+
+	// gets the max vartype and varname
+	for _, line := range strings.Split(string(data), "\n") {
+		if strings.HasPrefix(line, "message ") {
+			inMessage = true
+			continue
+		}
+
+		// find the end of the message
+		if strings.HasPrefix(line, "}") {
+			inMessage = false
+			formatMessage(curmsg)
+			curmsg = nil
+			continue
+		}
+
+		// don't format or change anything when not in a "message {" section
+		if !inMessage {
+			continue
+		}
+		curmsg = append(curmsg, line)
+	}
+
+	// parse the proto file for message struct names
+	for _, line := range strings.Split(string(data), "\n") {
+		if strings.HasPrefix(line, "message ") {
+			inMessage = true
+			parts := strings.Fields(line)
+			if len(parts) > 3 {
+				start := parts[0] + " " + parts[1] + " " + parts[2]
+				end := strings.Join(parts[3:], " ")
+				offset := maxVarname + maxVartype + 16 - len(start)
+				pad := fmt.Sprintf("%d", offset)
+				hmm := "%s     %" + pad + "s %s"
+				line = fmt.Sprintf(hmm, start, " ", end)
+			}
+			fmt.Fprintln(pf, line)
+			continue
+		}
+
+		// find the end of the message
+		if strings.HasPrefix(line, "}") {
+			inMessage = false
+			for _, newline := range formatMessage(curmsg) {
+				fmt.Fprintln(pf, newline)
+			}
+			fmt.Fprintln(pf, line)
+			curmsg = nil
+			continue
+		}
+
+		// don't format or change anything when not in a "message {" section
+		if !inMessage {
+			fmt.Fprintln(pf, line)
+			continue
+		}
+		curmsg = append(curmsg, line)
+	}
+
+	// for i, s := range slices.Backward(pf.ToSort) {
+	return nil
+}
+
+func formatMessage(curmsg []string) []string {
+	var newmsg []string
+
+	// find the max length of varname and vartype
+	for _, line := range curmsg {
+		parts := strings.Split(line, ";")
+		if len(parts) < 2 {
+			log.Info("parse error", line)
+			return curmsg
+		}
+
+		vartype, varname, _, _ := tokenMsgVar(line)
+		if len(vartype) > maxVartype {
+			maxVartype = len(vartype)
+		}
+		if len(varname) > maxVarname {
+			maxVarname = len(varname)
+		}
+	}
+
+	for _, line := range curmsg {
+		mt := fmt.Sprintf("%d", maxVartype)
+		mv := fmt.Sprintf("%d", maxVarname)
+
+		hmm := "        %-" + mt + "s   %-" + mv + "s     = %-3s %s"
+
+		vartype, varname, id, end := tokenMsgVar(line)
+		end = strings.TrimSpace(end)
+		id = id + ";"
+
+		newline := fmt.Sprintf(hmm, vartype, varname, id, end)
+		newmsg = append(newmsg, newline)
+	}
+	return newmsg
+}
+
+// returns vartype, varname, id, end
+func tokenMsgVar(line string) (string, string, string, string) {
+	parts := strings.Split(line, ";")
+	front := parts[0]
+	end := strings.Join(parts[1:], ";")
+
+	var id string
+	var varname string
+	var vartype string
+
+	parts = strings.Fields(front)
+	parts, id = slicesPop(parts)
+	parts, _ = slicesPop(parts) // this is the "=" sign
+	parts, varname = slicesPop(parts)
+	vartype = strings.Join(parts, " ")
+
+	return vartype, varname, id, end
+}
+
+func slicesPop(parts []string) ([]string, string) {
+	if len(parts) == 0 {
+		return nil, ""
+	}
+	if len(parts) == 1 {
+		return nil, parts[0]
+	}
+	x := len(parts)
+	end := parts[x-1]
+	return parts[0 : x-1], end
+}