lang: funcs: Autogenerated a lot of new functions

Signed-off-by: Julien Pivotto <roidelapluie@inuits.eu>

lang/funcs/funcgen/pkg.go

@@ -18,13 +18,39 @@
 package main
 
 import (
+	"bytes"
+	"errors"
+	"fmt"
 	"io/ioutil"
 	"log"
+	"os/exec"
 	"path/filepath"
+	"regexp"
+	"strings"
 
+	"github.com/iancoleman/strcase"
 	yaml "gopkg.in/yaml.v2"
 )
 
+var (
+	validSignature = regexp.MustCompile(`^func (?P<name>[A-Z][a-zA-Z0-9]+)\((?P<args>([a-zA-Z]+( (string|bool|float64|int64|int))?(, )?){0,})\) (?P<return>(string|float64|int64|bool|int)|\((string|float64|int64|bool|int), error\))$`)
+	errExcluded    = errors.New("function is excluded")
+)
+
+type golangPackages []*golangPackage
+
+type golangPackage struct {
+	// Name is the name of the go package.
+	Name string `yaml:"name"`
+	// Alias is the alias of the package when imported in golang.
+	// e.g. import rand "os.rand"
+	Alias string `yaml:"alias,omitempty"`
+	// MgmtAlias is the name of the package inside mcl.
+	MgmtAlias string `yaml:"mgmtAlias,omitempty"`
+	// Exclude is a list of golang function names that we do not want.
+	Exclude []string `yaml:"exclude,omitempty"`
+}
+
 func parsePkg(path, filename, templates string) error {
 	var c config
 	filePath := filepath.Join(path, filename)
@@ -37,9 +63,173 @@ func parsePkg(path, filename, templates string) error {
 	if err != nil {
 		return err
 	}
-	err = parseFuncs(c, path, templates)
+	functions, err := parsePackages(c)
+	if err != nil {
+		return err
+	}
+	err = parseFuncs(c, functions, path, templates)
 	if err != nil {
 		return err
 	}
 	return nil
 }
+
+func parsePackages(c config) (functions, error) {
+	var funcs []function
+	for _, golangPackage := range c.Packages {
+		fn, err := golangPackage.parsefuncs()
+		if err != nil {
+			return funcs, err
+		}
+		funcs = append(funcs, fn...)
+	}
+	return funcs, nil
+}
+
+func (obj *golangPackage) parsefuncs() (functions, error) {
+	var funcs []function
+	cmd := exec.Command("go", "doc", obj.Name)
+	var out bytes.Buffer
+	cmd.Stdout = &out
+	err := cmd.Run()
+	if err != nil {
+		return funcs, err
+	}
+	return obj.extractFuncs(out.String(), true)
+}
+
+func (obj *golangPackage) extractFuncs(doc string, getHelp bool) (functions, error) {
+	var funcs []function
+	for _, line := range strings.Split(doc, "\n") {
+		if validSignature.MatchString(line) {
+			f, err := obj.parseFunctionLine(line, getHelp)
+			if err != nil && err != errExcluded {
+				return funcs, err
+			}
+			if f != nil {
+				funcs = append(funcs, *f)
+			}
+		}
+	}
+
+	return funcs, nil
+}
+
+func (obj *golangPackage) parseFunctionLine(line string, getHelp bool) (*function, error) {
+	match := validSignature.FindStringSubmatch(line)
+	result := make(map[string]string)
+	for i, name := range validSignature.SubexpNames() {
+		if i != 0 && name != "" {
+			result[name] = match[i]
+		}
+	}
+
+	name := result["name"]
+
+	for _, e := range obj.Exclude {
+		if e == name {
+			return nil, errExcluded
+		}
+	}
+
+	errorFul, err := regexp.MatchString(`, error\)$`, result["return"])
+	if err != nil {
+		return nil, err
+	}
+
+	returns := parseReturn(result["return"])
+	if len(returns) == 0 {
+		return nil, errExcluded
+	}
+
+	mgmtpackage := obj.Name
+	if obj.MgmtAlias != "" {
+		mgmtpackage = obj.MgmtAlias
+	}
+	mgmtpackage = fmt.Sprintf("golang/%s", mgmtpackage)
+
+	internalName := fmt.Sprintf("%s%s", strcase.ToCamel(strings.Replace(obj.Name, "/", "", -1)), name)
+	internalName = strings.Replace(internalName, "Html", "HTML", -1)
+	var help string
+	if getHelp {
+		help, err = obj.getHelp(name, internalName)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return &function{
+		MgmtPackage:   mgmtpackage,
+		MclName:       strcase.ToSnake(name),
+		InternalName:  internalName,
+		Help:          help,
+		GolangPackage: obj,
+		GolangFunc:    name,
+		Errorful:      errorFul,
+		Args:          parseArgs(result["args"]),
+		Return:        returns,
+	}, nil
+}
+
+func reverseArgs(s []arg) {
+	last := len(s) - 1
+	for i := 0; i < len(s)/2; i++ {
+		s[i], s[last-i] = s[last-i], s[i]
+	}
+}
+func reverse(s []string) {
+	last := len(s) - 1
+	for i := 0; i < len(s)/2; i++ {
+		s[i], s[last-i] = s[last-i], s[i]
+	}
+}
+
+func parseArgs(str string) []arg {
+	var args []arg
+	s := strings.Split(str, ",")
+	reverse(s)
+	var currentType string
+	for _, currentArg := range s {
+		if currentArg == "" {
+			continue
+		}
+		v := strings.Split(strings.TrimSpace(currentArg), " ")
+		if len(v) == 2 {
+			currentType = v[1]
+		}
+		args = append(args, arg{Name: v[0], Type: currentType})
+	}
+	reverseArgs(args)
+	return args
+}
+
+func parseReturn(str string) []arg {
+	var returns []arg
+	re := regexp.MustCompile(`(int64|float64|string|bool|int)`)
+	t := string(re.Find([]byte(str)))
+	returns = append(returns, arg{Type: t})
+	return returns
+}
+
+func (obj *golangPackage) getHelp(function, internalName string) (string, error) {
+	cmd := exec.Command("go", "doc", fmt.Sprintf("%s.%s", obj.Name, function))
+	var out bytes.Buffer
+	cmd.Stdout = &out
+	err := cmd.Run()
+	if err != nil {
+		return "", err
+	}
+	var doc string
+	for i, line := range strings.Split(strings.TrimSpace(out.String()), "\n") {
+		if i > 0 {
+			s := strings.TrimSpace(line)
+			if i == 1 {
+				docs := strings.Split(s, " ")
+				docs[0] = internalName
+				s = strings.Join(docs, " ")
+			}
+			doc = fmt.Sprintf("%s// %s is an autogenerated function.\n", doc, s)
+		}
+	}
+	return doc, nil
+}