package main

import (
	"fmt"
	"runtime/debug"

	"github.com/alecthomas/kong"
	cfg "github.com/grmrgecko/repo-sync/config"
)

// VersionFlag prints build information and exits.
type VersionFlag bool

// Decode satisfies kong.MapperValue. The flag is treated as a boolean toggle.
func (v VersionFlag) Decode(ctx *kong.DecodeContext) error { return nil }

// IsBool reports the flag as a boolean for kong's parser.
func (v VersionFlag) IsBool() bool { return true }

// BeforeApply emits version information then exits before the rest of the
// command is executed.
func (v VersionFlag) BeforeApply(app *kong.Kong, vars kong.Vars) error {
	fmt.Printf("%s: %s (%s)\n", cfg.Name, cfg.Version, cfg.Mode)
	if cfg.Commit != "" {
		fmt.Printf("  commit: %s\n", cfg.Commit)
	}
	if cfg.Date != "" {
		fmt.Printf("  built:  %s\n", cfg.Date)
	}
	if cfg.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)
				}
			}
		}
	}
	app.Exit(0)
	return nil
}

// Flags is the root command line configuration.
type Flags struct {
	LogLevel string      `help:"Log level (debug, info, warn, error)." enum:"debug,info,warn,error" default:"info"`
	Version  VersionFlag `name:"version" help:"Print version information and quit"`

	RPM    RPMCmd    `cmd:"" name:"rpm" help:"Synchronize RPM (yum/dnf) repositories."`
	Deb    DebCmd    `cmd:"" name:"deb" help:"Synchronize DEB (apt) repositories."`
	Arch   ArchCmd   `cmd:"" name:"arch" help:"Synchronize Arch Linux (pacman) repositories."`
	Apk    ApkCmd    `cmd:"" name:"apk" help:"Synchronize Alpine Linux (apk) repositories."`
	Server ServerCmd `cmd:"" name:"server" help:"Run the caching mirror server."`
}

// flags holds the parsed command line configuration.
var flags Flags

// ParseFlags parses the command line, exiting with usage information on
// error.
func ParseFlags() *kong.Context {
	return kong.Parse(&flags,
		kong.Name(cfg.Name),
		kong.Description(cfg.Description),
		kong.UsageOnError(),
		kong.ConfigureHelp(kong.HelpOptions{
			Compact: true,
		}),
	)
}