初始提交：短剧库源码（含转码优化 ultrafast）

internal/app/paths.go

@@ -0,0 +1,109 @@
+package app
+
+import (
+	"errors"
+	"flag"
+	"fmt"
+	"os"
+	"path/filepath"
+	"runtime"
+	"strings"
+)
+
+func portableFFmpeg(configured string) string {
+	if candidates := ffmpegCandidates(configured, ffmpegManagedDirectory()); len(candidates) > 0 {
+		return candidates[0]
+	}
+	if automaticFFmpeg(configured) {
+		return ffmpegExecutableName()
+	}
+	return normalizedFFmpegSetting(configured)
+}
+
+func normalizedOutputDirectory(raw string) (string, error) {
+	raw = strings.TrimSpace(raw)
+	if raw == "" {
+		return "", errors.New("下载目录不能为空")
+	}
+	if strings.ContainsAny(raw, "\x00\r\n") {
+		return "", errors.New("下载目录包含无效字符")
+	}
+	if strings.Contains(raw, "://") {
+		return "", errors.New("下载目录必须是本机文件夹路径，不是网址")
+	}
+	if runtime.GOOS != "windows" && (strings.HasPrefix(raw, `\\`) || len(raw) > 1 && raw[1] == ':') {
+		return "", errors.New("当前系统不支持 Windows 盘符或 UNC 路径")
+	}
+	return filepath.Clean(raw), nil
+}
+
+func checkOutputDirectory(directory string) error {
+	if err := os.MkdirAll(directory, 0o755); err != nil {
+		return fmt.Errorf("无法创建下载目录: %w", err)
+	}
+	file, err := os.CreateTemp(directory, ".juku-write-check-*")
+	if err != nil {
+		return fmt.Errorf("下载目录不可写: %w", err)
+	}
+	name := file.Name()
+	closeErr := file.Close()
+	removeErr := os.Remove(name)
+	if closeErr != nil {
+		return closeErr
+	}
+	return removeErr
+}
+
+func sameDirectory(first, second string) bool {
+	firstAbsolute, firstErr := filepath.Abs(first)
+	secondAbsolute, secondErr := filepath.Abs(second)
+	if firstErr != nil || secondErr != nil {
+		return first == second
+	}
+	if runtime.GOOS == "windows" {
+		return strings.EqualFold(firstAbsolute, secondAbsolute)
+	}
+	return firstAbsolute == secondAbsolute
+}
+
+func (cfg Config) runtimeSettingsDirectory() string {
+	return cfg.dataDirectory()
+}
+
+func (cfg Config) dataDirectory() string {
+	return firstNonEmpty(cfg.dataDir, "data")
+}
+
+func flagWasSet(name string) bool {
+	found := false
+	flag.Visit(func(option *flag.Flag) {
+		if option.Name == name {
+			found = true
+		}
+	})
+	return found
+}
+
+func isProjectDirectory(directory string) bool {
+	body, err := os.ReadFile(filepath.Join(directory, "go.mod"))
+	fields := strings.Fields(string(body))
+	return err == nil && len(fields) >= 2 && fields[0] == "module" && fields[1] == "juku"
+}
+
+func preparePortableWorkingDirectory() error {
+	if isProjectDirectory(".") {
+		return nil
+	}
+	executable, err := os.Executable()
+	if err != nil {
+		return err
+	}
+	directory := filepath.Dir(executable)
+	if filepath.Base(directory) == "dist" && isProjectDirectory(filepath.Dir(directory)) {
+		directory = filepath.Dir(directory)
+	}
+	if strings.HasPrefix(filepath.Base(filepath.Dir(directory)), "go-build") || strings.HasPrefix(filepath.Base(directory), "go-build") {
+		return nil
+	}
+	return os.Chdir(directory)
+}