feat: add main entry point with arg parsing

cmd/tz-snipe/main.go

@@ -0,0 +1,48 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"os"
+	"tz-snipe/internal/geodata"
+	"tz-snipe/internal/ui"
+
+	tea "github.com/charmbracelet/bubbletea"
+)
+
+func main() {
+	// 1. arg parsing
+
+	// go's flag package is the native arg parser for cmd line apps
+	// --tz mode, default val, usage string
+	tzFlag := flag.String("tz", "", "Timezone like +1000")
+	// --github mode
+	ghFlag := flag.String("github", "", "From a github username")
+
+	flag.Parse()
+
+	// 2. load tz data
+	db, err := geodata.Fetch()
+	if err != nil {
+		fmt.Printf("Error loading timezone data: %v\n", err)
+		os.Exit(1) // 1 is error code
+	}
+
+	// 3. checks
+	if *tzFlag != "" && *ghFlag != "" {
+		fmt.Println("Cannot use both --tz and --github modes")
+		os.Exit(1)
+	}
+	if *tzFlag == "" && *ghFlag == "" {
+		fmt.Println("Both args empty... exiting")
+		os.Exit(1)
+	}
+
+	// 4. exec
+	p := tea.NewProgram(ui.NewModel(db, *ghFlag, *tzFlag))
+	if _, err := p.Run(); err != nil {
+		// I keep on forgetting, fmt.ErrorF makes an error, does not print
+		fmt.Printf("Error: %v", err)
+		os.Exit(1)
+	}
+}