1 files changed, 99 insertions, 0 deletions
diff --git a/cmd/cetus/app.go b/cmd/cetus/app.go
new file mode 100644
index 0000000..c82fb29
--- /dev/null
+++ b/cmd/cetus/app.go
@@ -0,0 +1,99 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"math/rand"
+	"os"
+	"time"
+)
+
+var (
+	version string = "v0.6.3"
+	dump    bool
+	random  bool
+	notify  bool
+	print   bool
+
+	err     error
+	body    string
+	file    string
+	reqInfo map[string]string
+
+	apodDate string
+)
+
+func app() {
+	// Early Check: If command was not passed then print usage and
+	// exit. Later command & service both are checked, this check
+	// is for version command. If not checked then running cetus
+	// without any args will fail because os.Args[1] will panic
+	// the program & produce runtime error.
+	if len(os.Args) == 1 {
+		printUsage()
+		os.Exit(0)
+	}
+
+	parseArgs()
+}
+
+// parseArgs will be parsing the arguments, it will verify if they are
+// correct. Flag values are also set by parseArgs.
+func parseArgs() {
+	// Running just `cetus` would've paniced the program if length
+	// of os.Args was not checked beforehand because there would
+	// be no os.Args[1].
+	switch os.Args[1] {
+	case "version", "-version", "--version", "-v":
+		fmt.Printf("Cetus %s\n", version)
+		os.Exit(0)
+
+	case "help", "-help", "--help", "-h":
+		// If help was passed then the program shouldn't exit
+		// with non-zero error code.
+		printUsage()
+		os.Exit(0)
+
+	case "set", "fetch":
+		// If command & service was not passed then print
+		// usage and exit.
+		if len(os.Args) < 3 {
+			printUsage()
+			os.Exit(1)
+		}
+
+	default:
+		fmt.Printf("Invalid command: %q\n", os.Args[1])
+		printUsage()
+		os.Exit(1)
+	}
+
+	rand.Seed(time.Now().Unix())
+
+	// If the program has reached this far then that means a valid
+	// command was passed & now we should check if a valid service
+	// was passed and parse the flags.
+	cetus := flag.NewFlagSet("cetus", flag.ExitOnError)
+
+	// We first declare common flags then service specific flags.
+	cetus.BoolVar(&dump, "dump", false, "Dump the response")
+	cetus.BoolVar(&notify, "notify", false, "Send a desktop notification with info")
+	cetus.BoolVar(&print, "print", false, "Print information")
+	cetus.BoolVar(&random, "random", false, "Choose a random image")
+
+	switch os.Args[2] {
+	case "apod", "nasa":
+		defDate := time.Now().UTC().Format("2006-01-02")
+		cetus.StringVar(&apodDate, "date", defDate, "Date of NASA APOD to retrieve")
+		cetus.Parse(os.Args[3:])
+
+		execAPOD()
+	case "bpod", "bing":
+		cetus.Parse(os.Args[3:])
+		execBPOD()
+	default:
+		fmt.Printf("Invalid service: %q\n", os.Args[2])
+		printUsage()
+		os.Exit(1)
+	}
+}