glocktobazel.go

// glocktobazel generates Bazel external repositories from a GLOCKFILE
package main

import (
	"bufio"
	"os"
	"strings"
	"fmt"
)

func main() {
	glockfile, err := os.Open("GLOCKFILE")
	defer glockfile.Close()
	if err != nil {
		panic(err)
	}
	var cmds []string
	packages := map[string]string{}
	scanner := bufio.NewScanner(glockfile)
	for scanner.Scan() {
		fields := strings.Fields(scanner.Text())
		if fields[0] == "cmd" {
			cmds = append(cmds, fields[1])
		} else {
			packages[fields[0]] = fields[1]
		}
	}

	fmt.Print(`
def go_repositories():
    loaded = native.existing_rules()`)

	for remote, commit := range packages {
		pkgName := remoteToPackageName(remote)
		fmt.Printf(`
    if "%s" not in loaded:
        native.new_git_repository(
            name = "%s",
            remote = "https://%s",
            commit = "%s",
            build_file = "BUILD",
        )
`, pkgName, pkgName, remote, commit)
	}

}

func remoteToPackageName(remote string) string {
	parts := strings.Split(remote, "/")
	domainParts := reverse(strings.Split(parts[0], "."))
	pathParts := safePaths(parts[1:])
	return strings.Join(append(domainParts, pathParts...), "_")
}

func reverse(arr []string) []string {
	for i, j := 0, len(arr)-1; i<j; i, j = i+1, j-1 {
		arr[i], arr[j] = arr[j], arr[i]
	}
	return arr
}

func safePaths(arr []string) []string {
	var ret []string
	for _, el := range arr {
		ret = append(ret, safePath(el)...)
	}
	return ret
}

func safePath(part string) []string {
	part = strings.Replace(part, "-", "_", -1)
	part = strings.Replace(part, ".", "_", -1)
	return strings.Split(part, "_")
}