package cli

import (
	"fmt"
	"math"
	"os"
	"os/user"
	"path/filepath"
	"time"

	"git.cryptic.systems/volker.raschek/flucky/cli/completion"
	"git.cryptic.systems/volker.raschek/flucky/cli/daemon"
	imp "git.cryptic.systems/volker.raschek/flucky/cli/imp"
	"git.cryptic.systems/volker.raschek/flucky/cli/sensor"
	"git.cryptic.systems/volker.raschek/flucky/cli/temperature"
	"git.cryptic.systems/volker.raschek/flucky/pkg/config"

	uuid "github.com/satori/go.uuid"
	"github.com/spf13/cobra"
)

// Execute a
func Execute(version string) error {
	rootCmd := &cobra.Command{
		Use:               "flucky",
		PersistentPreRunE: preRunError,
		Version:           version,
	}

	defaultConfigFile, err := getDefaultConfigFile()
	if err != nil {
		return err
	}

	rootCmd.PersistentFlags().String("config", defaultConfigFile, "Config file")
	rootCmd.PersistentFlags().String("loglevel", "info", "Set the Loglevel. Possible values: debug, info, warn, error, fatal")

	subCommands := []func(cmd *cobra.Command) error{
		completion.InitCmd,
		daemon.InitCmd,
		imp.InitCmd,
		sensor.InitCmd,
		temperature.InitCmd,
	}

	for _, subCommand := range subCommands {
		if err := subCommand(rootCmd); err != nil {
			return err
		}
	}

	err = rootCmd.Execute()
	if err != nil {
		return err
	}

	return nil
}

func preRunError(cmd *cobra.Command, args []string) error {
	configFile := cmd.Flag("config").Value.String()

	// check if config file exists
	if _, err := os.Stat(configFile); os.IsNotExist(err) {
		// Time must be truncated for postgres. Postgres currently does not support
		// nanoseconds which is automatically include into the go time object
		postgresTimeStamp := time.Now()
		location, err := time.LoadLocation("Europe/Berlin")
		if err != nil {
			return err
		}
		postgresTimeStamp = time.Date(postgresTimeStamp.Year(), postgresTimeStamp.Month(), postgresTimeStamp.Day(), postgresTimeStamp.Hour(), postgresTimeStamp.Minute(), postgresTimeStamp.Second(), int(math.Round(float64(postgresTimeStamp.Nanosecond())/1000000)*1000000), location)

		// default cache directory
		defaultCacheDir, err := getDefaultCacheDir()
		if err != nil {
			return err
		}

		// Default configuration
		dsn := fmt.Sprintf("sqlite3://%v/sqlite.db?cache=shared&mode=memory&foreign_keys=on", defaultCacheDir)
		cnf := config.Config{
			DeviceID: uuid.NewV4().String(),
			DSN:      dsn,
		}

		err = config.Write(&cnf, configFile)
		if err != nil {
			return err
		}
	}

	return nil
}

// getDefaultConfigFile returns the default path to the configuration file of
// flucky
func getDefaultConfigFile() (string, error) {
	u, err := user.Current()
	if err != nil {
		return "", fmt.Errorf("Can not read current user: %v", err)
	}

	switch u.Uid {
	case "0":
		return "/etc/flucky/config.json", nil
	default:
		return filepath.Join(u.HomeDir, ".config/flucky/config.json"), nil
	}
}

// getDefaultCacheDir returns the default path to the cache directory where
// flucky stores his measured values.
func getDefaultCacheDir() (string, error) {
	u, err := user.Current()
	if err != nil {
		return "", fmt.Errorf("Can not read current user: %v", err)
	}

	switch u.Uid {
	case "0":
		return "/var/cache/flucky", nil
	default:
		return filepath.Join(u.HomeDir, ".cache/flucky"), nil
	}
}