e4.0.0 Refactored, file watcher and improved builder, doc update

discovery.go

@@ -0,0 +1,128 @@
+// FILE: lixenwraith/config/discovery.go
+package config
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+// FileDiscoveryOptions configures automatic config file discovery
+type FileDiscoveryOptions struct {
+	// Base name of config file (without extension)
+	Name string
+
+	// Extensions to try (in order)
+	Extensions []string
+
+	// Custom search paths (in addition to defaults)
+	Paths []string
+
+	// Environment variable to check for explicit path
+	EnvVar string
+
+	// CLI flag to check (e.g., "--config" or "-c")
+	CLIFlag string
+
+	// Whether to search in XDG config directories
+	UseXDG bool
+
+	// Whether to search in current directory
+	UseCurrentDir bool
+}
+
+// DefaultDiscoveryOptions returns sensible defaults
+func DefaultDiscoveryOptions(appName string) FileDiscoveryOptions {
+	return FileDiscoveryOptions{
+		Name:          appName,
+		Extensions:    []string{".toml", ".conf", ".config"},
+		EnvVar:        strings.ToUpper(appName) + "_CONFIG",
+		CLIFlag:       "--config",
+		UseXDG:        true,
+		UseCurrentDir: true,
+	}
+}
+
+// WithFileDiscovery enables automatic config file discovery
+func (b *Builder) WithFileDiscovery(opts FileDiscoveryOptions) *Builder {
+	// Check CLI args first (highest priority)
+	if opts.CLIFlag != "" && len(b.args) > 0 {
+		for i, arg := range b.args {
+			if arg == opts.CLIFlag && i+1 < len(b.args) {
+				b.file = b.args[i+1]
+				return b
+			}
+			if strings.HasPrefix(arg, opts.CLIFlag+"=") {
+				b.file = strings.TrimPrefix(arg, opts.CLIFlag+"=")
+				return b
+			}
+		}
+	}
+
+	// Check environment variable
+	if opts.EnvVar != "" {
+		if path := os.Getenv(opts.EnvVar); path != "" {
+			b.file = path
+			return b
+		}
+	}
+
+	// Build search paths
+	var searchPaths []string
+
+	// Custom paths first
+	searchPaths = append(searchPaths, opts.Paths...)
+
+	// Current directory
+	if opts.UseCurrentDir {
+		if cwd, err := os.Getwd(); err == nil {
+			searchPaths = append(searchPaths, cwd)
+		}
+	}
+
+	// XDG paths
+	if opts.UseXDG {
+		searchPaths = append(searchPaths, getXDGConfigPaths(opts.Name)...)
+	}
+
+	// Search for config file
+	for _, dir := range searchPaths {
+		for _, ext := range opts.Extensions {
+			path := filepath.Join(dir, opts.Name+ext)
+			if _, err := os.Stat(path); err == nil {
+				b.file = path
+				return b
+			}
+		}
+	}
+
+	// No file found is not an error - app can run with defaults/env
+	return b
+}
+
+// getXDGConfigPaths returns XDG-compliant config search paths
+func getXDGConfigPaths(appName string) []string {
+	var paths []string
+
+	// XDG_CONFIG_HOME
+	if xdgHome := os.Getenv("XDG_CONFIG_HOME"); xdgHome != "" {
+		paths = append(paths, filepath.Join(xdgHome, appName))
+	} else if home := os.Getenv("HOME"); home != "" {
+		paths = append(paths, filepath.Join(home, ".config", appName))
+	}
+
+	// XDG_CONFIG_DIRS
+	if xdgDirs := os.Getenv("XDG_CONFIG_DIRS"); xdgDirs != "" {
+		for _, dir := range filepath.SplitList(xdgDirs) {
+			paths = append(paths, filepath.Join(dir, appName))
+		}
+	} else {
+		// Default system paths
+		paths = append(paths,
+			filepath.Join("/etc/xdg", appName),
+			filepath.Join("/etc", appName),
+		)
+	}
+
+	return paths
+}