package main

import (
	"flag"
	"fmt"
	"os"
	"runtime/debug"
)

// Flags supplied to the cli.
type Flags struct {
	ConfigPath string
	Discover   bool
	Verbose    bool
}

// printVersion emits version and build information to stdout.
func printVersion() {
	fmt.Printf("%s: %s (%s)\n", Name, Version, Mode)
	if Commit != "" {
		fmt.Printf("  commit: %s\n", Commit)
	}
	if Date != "" {
		fmt.Printf("  built:  %s\n", Date)
	}
	// Without build stamps, a module-aware build still records the revision
	// it was built from, so fall back to what the toolchain embedded.
	if Commit == "" {
		if bi, ok := debug.ReadBuildInfo(); ok {
			for _, s := range bi.Settings {
				switch s.Key {
				case "vcs.revision":
					fmt.Printf("  commit: %s\n", s.Value)
				case "vcs.time":
					fmt.Printf("  built:  %s\n", s.Value)
				}
			}
		}
	}
}

// ParseFlags parses the supplied command-line flags.
func (a *App) ParseFlags() {
	app.flags = new(Flags)
	flag.Usage = func() {
		fmt.Printf(Name + ": " + Description + ".\n\nUsage:\n")
		flag.PrintDefaults()
	}

	// Print the version and exit when requested.
	var showVersion bool
	usage := "Print version information and quit"
	flag.BoolVar(&showVersion, "version", false, usage)
	flag.BoolVar(&showVersion, "v", false, usage+" (shorthand)")

	// Override the configuration path.
	usage = "Load configuration from `FILE`"
	flag.StringVar(&app.flags.ConfigPath, "config", "", usage)
	flag.StringVar(&app.flags.ConfigPath, "c", "", usage+" (shorthand)")

	// Query each configured device for its integration IDs and exit.
	usage = "Connect to each device, print its integration IDs, and exit"
	flag.BoolVar(&app.flags.Discover, "discover", false, usage)
	flag.BoolVar(&app.flags.Discover, "d", false, usage+" (shorthand)")

	// Force debug-level logging to the console, overriding the configured log level.
	usage = "Force debug-level logging to the console, overriding the config"
	flag.BoolVar(&app.flags.Verbose, "verbose", false, usage)
	flag.BoolVar(&app.flags.Verbose, "V", false, usage+" (shorthand)")

	flag.Parse()

	if showVersion {
		printVersion()
		os.Exit(0)
	}
}