package cmd

import (
	"errors"
	"flag"
	"fmt"
	"os"
	"strings"

	"github.com/golang/glog"
	"github.com/spf13/pflag"

	"github.com/spf13/cobra"
	"github.com/spf13/viper"
)

var cfgFile string

// rootCmd represents the base command when called without any subcommands
var rootCmd = &cobra.Command{
	Use:   "model-registry",
	Short: "A go server for recording and retrieving metadata associated with ML developer and data scientist workflows",
	Long: `The model-registry is a rest server that stores metadata
for ML applications.

This go server is an alternative to the CPP gRPC service provided by the
ml-metadata project. It's meant to provide extra features such as loading
custom metadata libraries, exposing a higher level API, RBAC, etc.`,
	// Uncomment the following line if your bare application
	// has an action associated with it:
	// Run: func(cmd *cobra.Command, args []string) { },
	PersistentPreRunE: func(cmd *cobra.Command, args []string) error {
		return initConfig(cmd)
	},
}

// Execute adds all child commands to the root command and sets flags appropriately.
// This is called by main.main(). It only needs to happen once to the rootCmd.
func Execute() {
	err := rootCmd.Execute()
	if err != nil {
		glog.Exitf("error: %v", err)
	}
}

func init() {
	//cobra.OnInitialize(initConfig)

	// Here you will define your flags and configuration settings.
	// Cobra supports persistent flags, which, if defined here,
	// will be global for your application.

	rootCmd.PersistentFlags().StringVarP(&cfgFile, "config", "c", "", "config file (default is $HOME/.model-registry.yaml)")

	// default to logging to stderr
	_ = flag.Set("logtostderr", "true")
	// also add standard glog flags
	rootCmd.PersistentFlags().AddGoFlagSet(flag.CommandLine)

	// Cobra also supports local flags, which will only run
	// when this action is called directly.
	//rootCmd.Flags().BoolP("toggle", "t", false, "Help message for toggle")

}

// initConfig reads in config file and ENV variables if set.
func initConfig(cmd *cobra.Command) error {
	if cfgFile != "" {
		// Use config file from the flag.
		viper.SetConfigFile(cfgFile)
	} else {
		// Find home directory.
		home, err := os.UserHomeDir()
		if err != nil {
			return err
		}

		// Search config in home directory with name ".model-registry" (without extension).
		viper.AddConfigPath(home)
		viper.SetConfigType("yaml")
		viper.SetConfigName(".model-registry")
	}

	viper.SetEnvPrefix(EnvPrefix)
	viper.SetEnvKeyReplacer(strings.NewReplacer("-", "_"))
	viper.AutomaticEnv() // read in environment variables that match

	// If a config file is found, read it in.
	if err := viper.ReadInConfig(); err == nil {
		glog.Info("Using config file: ", viper.ConfigFileUsed())
	} else {
		var configFileNotFoundError viper.ConfigFileNotFoundError
		ok := errors.As(err, &configFileNotFoundError)
		// ignore if it's a file not found error for default config file
		if cfgFile != "" || !ok {
			return fmt.Errorf("reading config %s: %v", viper.ConfigFileUsed(), err)
		}
	}

	// bind flags to config
	if err := viper.BindPFlags(cmd.Flags()); err != nil {
		return err
	}
	var err error
	cmd.Flags().VisitAll(func(f *pflag.Flag) {
		name := f.Name
		if err == nil && !f.Changed && viper.IsSet(name) {
			value := viper.Get(name)
			err = cmd.Flags().Set(name, fmt.Sprintf("%v", value))
		}
	})

	return err
}