github.com/oNaiPs/go-generate-fast@v0.3.0/src/plugins/go-bindata/main.go

// from https://github.com/go-bindata/go-bindata/blob/master/go-bindata/main.go
package plugin_go_bindata

import (
	"flag"
	"fmt"
	"os"
	"path/filepath"
	"regexp"
	"sort"
	"strings"
	"unicode"

	"github.com/go-bindata/go-bindata"
)

// parseArgs create s a new, filled configuration instance
// by reading and parsing command line options.
//
// This function exits the program with an error, if
// any of the command line options are incorrect.
func parseArgs(args []string) *bindata.Config {
	flag := flag.NewFlagSet("Gobindata", flag.ContinueOnError)

	var version bool

	c := bindata.NewConfig()

	flag.Usage = func() {
		fmt.Printf("Usage: %s [options] <input directories>\n\n", os.Args[0])
		flag.PrintDefaults()
	}

	flag.BoolVar(&c.Debug, "debug", c.Debug, "Do not embed the assets, but provide the embedding API. Contents will still be loaded from disk.")
	flag.BoolVar(&c.Dev, "dev", c.Dev, "Similar to debug, but does not emit absolute paths. Expects a rootDir variable to already exist in the generated code's package.")
	flag.StringVar(&c.Tags, "tags", c.Tags, "Optional set of build tags to include.")
	flag.StringVar(&c.Prefix, "prefix", c.Prefix, "Optional path prefix to strip off asset names.")
	flag.StringVar(&c.Package, "pkg", c.Package, "Package name to use in the generated code.")
	flag.BoolVar(&c.NoMemCopy, "nomemcopy", c.NoMemCopy, "Use a .rodata hack to get rid of unnecessary memcopies. Refer to the documentation to see what implications this carries.")
	flag.BoolVar(&c.NoCompress, "nocompress", c.NoCompress, "Assets will *not* be GZIP compressed when this flag is specified.")
	flag.BoolVar(&c.NoMetadata, "nometadata", c.NoMetadata, "Assets will not preserve size, mode, and modtime info.")
	flag.BoolVar(&c.HttpFileSystem, "fs", c.HttpFileSystem, "Whether generate instance http.FileSystem interface code.")
	flag.UintVar(&c.Mode, "mode", c.Mode, "Optional file mode override for all files.")
	flag.Int64Var(&c.ModTime, "modtime", c.ModTime, "Optional modification unix timestamp override for all files.")
	flag.StringVar(&c.Output, "o", c.Output, "Optional name of the output file to be generated.")
	flag.BoolVar(&version, "version", false, "Displays version information.")

	ignore := make([]string, 0)
	flag.Var((*AppendSliceValue)(&ignore), "ignore", "Regex pattern to ignore")

	err := flag.Parse(args)
	if err != nil {
		return nil
	}

	patterns := make([]*regexp.Regexp, 0)
	for _, pattern := range ignore {
		patterns = append(patterns, regexp.MustCompile(pattern))
	}
	c.Ignore = patterns

	if version {
		return nil
	}

	// Make sure we have input paths.
	if flag.NArg() == 0 {
		return nil
	}

	// Create input configurations.
	c.Input = make([]bindata.InputConfig, flag.NArg())
	for i := range c.Input {
		c.Input[i] = parseInput(flag.Arg(i))
	}

	return c
}

// parseRecursive determines whether the given path has a recursive indicator and
// returns a new path with the recursive indicator chopped off if it does.
//
//	ex:
//	    /path/to/foo/...    -> (/path/to/foo, true)
//	    /path/to/bar        -> (/path/to/bar, false)
func parseInput(path string) bindata.InputConfig {
	if strings.HasSuffix(path, "/...") {
		return bindata.InputConfig{
			Path:      filepath.Clean(path[:len(path)-4]),
			Recursive: true,
		}
	} else {
		return bindata.InputConfig{
			Path:      filepath.Clean(path),
			Recursive: false,
		}
	}
}

// ByName implements sort.Interface for []os.FileInfo based on Name()
type ByName []os.FileInfo

func (v ByName) Len() int           { return len(v) }
func (v ByName) Swap(i, j int)      { v[i], v[j] = v[j], v[i] }
func (v ByName) Less(i, j int) bool { return v[i].Name() < v[j].Name() }

// findFiles recursively finds all the file paths in the given directory tree.
// They are added to the given map as keys. Values will be safe function names
// for each file, which will be used when generating the output code.
func findFiles(dir, prefix string, recursive bool, toc *[]bindata.Asset, ignore []*regexp.Regexp, knownFuncs map[string]int, visitedPaths map[string]bool) error {
	dirpath := dir
	if len(prefix) > 0 {
		dirpath, _ = filepath.Abs(dirpath)
		prefix, _ = filepath.Abs(prefix)
		prefix = filepath.ToSlash(prefix)
	}

	fi, err := os.Stat(dirpath)
	if err != nil {
		return err
	}

	var list []os.FileInfo

	if !fi.IsDir() {
		dirpath = filepath.Dir(dirpath)
		list = []os.FileInfo{fi}
	} else {
		visitedPaths[dirpath] = true
		fd, err := os.Open(dirpath)
		if err != nil {
			return err
		}

		defer fd.Close()

		list, err = fd.Readdir(0)
		if err != nil {
			return err
		}

		// Sort to make output stable between invocations
		sort.Sort(ByName(list))
	}

	for _, file := range list {
		var asset bindata.Asset
		asset.Path = filepath.Join(dirpath, file.Name())
		asset.Name = filepath.ToSlash(asset.Path)

		ignoring := false
		for _, re := range ignore {
			if re.MatchString(asset.Path) {
				ignoring = true
				break
			}
		}
		if ignoring {
			continue
		}

		if file.IsDir() {
			if recursive {
				recursivePath := filepath.Join(dir, file.Name())
				visitedPaths[asset.Path] = true
				_ = findFiles(recursivePath, prefix, recursive, toc, ignore, knownFuncs, visitedPaths)
			}
			continue
		} else if file.Mode()&os.ModeSymlink == os.ModeSymlink {
			var linkPath string
			if linkPath, err = os.Readlink(asset.Path); err != nil {
				return err
			}
			if !filepath.IsAbs(linkPath) {
				if linkPath, err = filepath.Abs(dirpath + "/" + linkPath); err != nil {
					return err
				}
			}
			if _, ok := visitedPaths[linkPath]; !ok {
				visitedPaths[linkPath] = true
				_ = findFiles(asset.Path, prefix, recursive, toc, ignore, knownFuncs, visitedPaths)
			}
			continue
		}

		if strings.HasPrefix(asset.Name, prefix) {
			asset.Name = asset.Name[len(prefix):]
		} else {
			asset.Name = filepath.Join(dir, file.Name())
		}

		// If we have a leading slash, get rid of it.
		if len(asset.Name) > 0 && asset.Name[0] == '/' {
			asset.Name = asset.Name[1:]
		}

		// This shouldn't happen.
		if len(asset.Name) == 0 {
			return fmt.Errorf("invalid file: %v", asset.Path)
		}

		asset.Func = safeFunctionName(asset.Name, knownFuncs)
		asset.Path, _ = filepath.Abs(asset.Path)
		*toc = append(*toc, asset)
	}

	return nil
}

var regFuncName = regexp.MustCompile(`[^a-zA-Z0-9_]`)

// safeFunctionName converts the given name into a name
// which qualifies as a valid function identifier. It
// also compares against a known list of functions to
// prevent conflict based on name translation.
func safeFunctionName(name string, knownFuncs map[string]int) string {
	var inBytes, outBytes []byte
	var toUpper bool

	name = strings.ToLower(name)
	inBytes = []byte(name)

	for i := 0; i < len(inBytes); i++ {
		if regFuncName.Match([]byte{inBytes[i]}) {
			toUpper = true
		} else if toUpper {
			outBytes = append(outBytes, []byte(strings.ToUpper(string(inBytes[i])))...)
			toUpper = false
		} else {
			outBytes = append(outBytes, inBytes[i])
		}
	}

	name = string(outBytes)

	// Identifier can't start with a digit.
	if unicode.IsDigit(rune(name[0])) {
		name = "_" + name
	}

	if num, ok := knownFuncs[name]; ok {
		knownFuncs[name] = num + 1
		name = fmt.Sprintf("%s%d", name, num)
	} else {
		knownFuncs[name] = 2
	}

	return name
}