package cmd

import (
	"fmt"
	"os"
	"strings"

	"github.com/spf13/cobra"
)

var rootCmd = &cobra.Command{
	Use:   "nib",
	Short: "capture and crystallize notes, todos, and events",
	Args:  cobra.ArbitraryArgs,
	RunE: func(cmd *cobra.Command, args []string) error {
		if len(args) == 0 {
			return cmd.Help()
		}
		return runAdd(cmd, args)
	},
	SilenceUsage: true,
}

func Execute() error {
	if len(os.Args) > 1 {
		first := os.Args[1]
		isFlag := strings.HasPrefix(first, "-") && !strings.Contains(first, " ")
		if first != "help" && first != "completion" &&
			!isFlag && !isSubcommand(first) {
			if near := nearSubcommand(first); near != "" {
				fmt.Fprintf(os.Stderr, "unknown command %q — did you mean %q?\n", first, near)
				os.Exit(1)
			}
			// "--" stops cobra from parsing glyph prefixes like "-" as flags
			rootCmd.SetArgs(append([]string{"add", "--"}, os.Args[1:]...))
		}
	}
	return rootCmd.Execute()
}

func isSubcommand(name string) bool {
	for _, c := range rootCmd.Commands() {
		if c.Name() == name {
			return true
		}
		for _, alias := range c.Aliases {
			if alias == name {
				return true
			}
		}
	}
	return false
}

func nearSubcommand(name string) string {
	for _, c := range rootCmd.Commands() {
		if d := editDist(name, c.Name()); d > 0 && d <= 2 {
			return c.Name()
		}
		for _, alias := range c.Aliases {
			if d := editDist(name, alias); d > 0 && d <= 2 {
				return alias
			}
		}
	}
	return ""
}

func editDist(a, b string) int {
	la, lb := len(a), len(b)
	if la == 0 {
		return lb
	}
	if lb == 0 {
		return la
	}
	prev := make([]int, lb+1)
	for j := range prev {
		prev[j] = j
	}
	for i := 1; i <= la; i++ {
		curr := make([]int, lb+1)
		curr[0] = i
		for j := 1; j <= lb; j++ {
			cost := 1
			if a[i-1] == b[j-1] {
				cost = 0
			}
			ins := curr[j-1] + 1
			del := prev[j] + 1
			sub := prev[j-1] + cost
			curr[j] = ins
			if del < curr[j] {
				curr[j] = del
			}
			if sub < curr[j] {
				curr[j] = sub
			}
		}
		prev = curr
	}
	return prev[lb]
}

func init() {
	rootCmd.AddCommand(addCmd)
	rootCmd.AddCommand(lsCmd)
}