Add configuration file support with organization list

- Create config package with JSON parsing support
- Define Organization struct with host and name
- Add config file auto-detection in common locations
- Add --config/-c flag for custom config path
- Add --list-orgs flag to display configured organizations
- Create example configuration file
- Add comprehensive .gitignore

Configuration supports multiple git organizations for future sync functionality.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

1 files changed, 73 insertions, 3 deletions

diff --git a/cmd/gitsyncer/main.go b/cmd/gitsyncer/main.go
index 3a38d32..d859747 100644
--- a/cmd/gitsyncer/main.go
+++ b/cmd/gitsyncer/main.go
@@ -3,23 +3,93 @@ package main
 import (
 	"flag"
 	"fmt"
+	"log"
 	"os"
+	"path/filepath"
 
+	"github.com/paul/gitsyncer/internal/config"
 	"github.com/paul/gitsyncer/internal/version"
 )
 
 func main() {
-	var versionFlag bool
+	var (
+		versionFlag bool
+		configPath  string
+		listOrgs    bool
+	)
+
+	// Define command line flags
 	flag.BoolVar(&versionFlag, "version", false, "print version information")
 	flag.BoolVar(&versionFlag, "v", false, "print version information (short)")
+	flag.StringVar(&configPath, "config", "", "path to configuration file")
+	flag.StringVar(&configPath, "c", "", "path to configuration file (short)")
+	flag.BoolVar(&listOrgs, "list-orgs", false, "list configured organizations")
 	flag.Parse()
 
+	// Handle version flag
 	if versionFlag {
 		fmt.Println(version.GetVersion())
 		os.Exit(0)
 	}
 
+	// Determine config file path
+	if configPath == "" {
+		// Try default locations
+		home, err := os.UserHomeDir()
+		if err != nil {
+			log.Fatal("Failed to get home directory:", err)
+		}
+
+		// Check common config locations
+		configLocations := []string{
+			filepath.Join(".", "gitsyncer.json"),
+			filepath.Join(home, ".config", "gitsyncer", "config.json"),
+			filepath.Join(home, ".gitsyncer.json"),
+		}
+
+		for _, loc := range configLocations {
+			if _, err := os.Stat(loc); err == nil {
+				configPath = loc
+				break
+			}
+		}
+
+		if configPath == "" {
+			fmt.Println("No configuration file found. Please create one of:")
+			for _, loc := range configLocations {
+				fmt.Printf("  - %s\n", loc)
+			}
+			fmt.Println("\nOr specify a config file with --config flag")
+			fmt.Println("\nExample configuration:")
+			fmt.Println(`{
+  "organizations": [
+    {"host": "git@github.com", "name": "myorg"},
+    {"host": "git@codeberg.org", "name": "myorg"}
+  ]
+}`)
+			os.Exit(1)
+		}
+	}
+
+	// Load configuration
+	cfg, err := config.Load(configPath)
+	if err != nil {
+		log.Fatal("Failed to load configuration:", err)
+	}
+
+	fmt.Printf("Loaded configuration from: %s\n", configPath)
+
+	// Handle list organizations flag
+	if listOrgs {
+		fmt.Println("\nConfigured organizations:")
+		for _, org := range cfg.Organizations {
+			fmt.Printf("  - %s\n", org.GetGitURL())
+		}
+		os.Exit(0)
+	}
+
 	// TODO: Implement main gitsyncer functionality
-	fmt.Println("gitsyncer - Git repository synchronization tool")
-	fmt.Println("Use --version to display version information")
+	fmt.Println("\ngitsyncer - Git repository synchronization tool")
+	fmt.Printf("Configured with %d organization(s)\n", len(cfg.Organizations))
+	fmt.Println("\nUse --list-orgs to display configured organizations")
 }
\ No newline at end of file