// Copyright © 2013 Steve Francia <spf@spf13.com>.

//

// Licensed under the Apache License, Version 2.0 (the "License");

// you may not use this file except in compliance with the License.

// You may obtain a copy of the License at

// http://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing, software

// distributed under the License is distributed on an "AS IS" BASIS,

// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

// See the License for the specific language governing permissions and

// limitations under the License.

// Commands similar to git, go tools and other modern CLI tools

// inspired by go, go-Commander, gh and subcommand

package cobra

import (

	"fmt"

	"io"

	"os"

	"reflect"

	"strconv"

	"strings"

	"text/template"

	"time"

	"unicode"

)

var templateFuncs = template.FuncMap{

	"trim":                    strings.TrimSpace,

	"trimRightSpace":          trimRightSpace,

	"trimTrailingWhitespaces": trimRightSpace,

	"appendIfNotPresent":      appendIfNotPresent,

	"rpad":                    rpad,

	"gt":                      Gt,

	"eq":                      Eq,

}

var initializers []func()

// EnablePrefixMatching allows to set automatic prefix matching. Automatic prefix matching can be a dangerous thing

// to automatically enable in CLI tools.

// Set this to true to enable it.

var EnablePrefixMatching = false

// EnableCommandSorting controls sorting of the slice of commands, which is turned on by default.

// To disable sorting, set it to false.

var EnableCommandSorting = true

// MousetrapHelpText enables an information splash screen on Windows

// if the CLI is started from explorer.exe.

// To disable the mousetrap, just set this variable to blank string ("").

// Works only on Microsoft Windows.

var MousetrapHelpText = `This is a command line tool.

You need to open cmd.exe and run it from there.

`

// MousetrapDisplayDuration controls how long the MousetrapHelpText message is displayed on Windows

// if the CLI is started from explorer.exe. Set to 0 to wait for the return key to be pressed.

// To disable the mousetrap, just set MousetrapHelpText to blank string ("").

// Works only on Microsoft Windows.

var MousetrapDisplayDuration = 5 * time.Second

// AddTemplateFunc adds a template function that's available to Usage and Help

// template generation.

func AddTemplateFunc(name string, tmplFunc interface{}) {

	templateFuncs[name] = tmplFunc

}

// AddTemplateFuncs adds multiple template functions that are available to Usage and

// Help template generation.

func AddTemplateFuncs(tmplFuncs template.FuncMap) {

	for k, v := range tmplFuncs {

		templateFuncs[k] = v

	}

}

// OnInitialize sets the passed functions to be run when each command's

// Execute method is called.

func OnInitialize(y ...func()) {

	initializers = append(initializers, y...)

}

// FIXME Gt is unused by cobra and should be removed in a version 2. It exists only for compatibility with users of cobra.

// Gt takes two types and checks whether the first type is greater than the second. In case of types Arrays, Chans,

// Maps and Slices, Gt will compare their lengths. Ints are compared directly while strings are first parsed as

// ints and then compared.

func Gt(a interface{}, b interface{}) bool {

	var left, right int64

	av := reflect.ValueOf(a)

	switch av.Kind() {

	case reflect.Array, reflect.Chan, reflect.Map, reflect.Slice:

		left = int64(av.Len())

	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:

		left = av.Int()

	case reflect.String:

		left, _ = strconv.ParseInt(av.String(), 10, 64)

	}

	bv := reflect.ValueOf(b)

	switch bv.Kind() {

	case reflect.Array, reflect.Chan, reflect.Map, reflect.Slice:

		right = int64(bv.Len())

	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:

		right = bv.Int()

	case reflect.String:

		right, _ = strconv.ParseInt(bv.String(), 10, 64)

	}

	return left > right

}

// FIXME Eq is unused by cobra and should be removed in a version 2. It exists only for compatibility with users of cobra.

// Eq takes two types and checks whether they are equal. Supported types are int and string. Unsupported types will panic.

func Eq(a interface{}, b interface{}) bool {

	av := reflect.ValueOf(a)

	bv := reflect.ValueOf(b)

	switch av.Kind() {

	case reflect.Array, reflect.Chan, reflect.Map, reflect.Slice:

		panic("Eq called on unsupported type")

	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:

		return av.Int() == bv.Int()

	case reflect.String:

		return av.String() == bv.String()

	}

	return false

}

func trimRightSpace(s string) string {

	return strings.TrimRightFunc(s, unicode.IsSpace)

}

// FIXME appendIfNotPresent is unused by cobra and should be removed in a version 2. It exists only for compatibility with users of cobra.

// appendIfNotPresent will append stringToAppend to the end of s, but only if it's not yet present in s.

func appendIfNotPresent(s, stringToAppend string) string {

	if strings.Contains(s, stringToAppend) {

		return s

	}

	return s + " " + stringToAppend

}

// rpad adds padding to the right of a string.

func rpad(s string, padding int) string {

	template := fmt.Sprintf("%%-%ds", padding)

	return fmt.Sprintf(template, s)

}

// tmpl executes the given template text on data, writing the result to w.

func tmpl(w io.Writer, text string, data interface{}) error {

	t := template.New("top")

	t.Funcs(templateFuncs)

	template.Must(t.Parse(text))

	return t.Execute(w, data)

}

// ld compares two strings and returns the levenshtein distance between them.

func ld(s, t string, ignoreCase bool) int {

	if ignoreCase {

		s = strings.ToLower(s)

		t = strings.ToLower(t)

	}

	d := make([][]int, len(s)+1)

	for i := range d {

		d[i] = make([]int, len(t)+1)

	}

	for i := range d {

		d[i][0] = i

	}

	for j := range d[0] {

		d[0][j] = j

	}

	for j := 1; j <= len(t); j++ {

		for i := 1; i <= len(s); i++ {

			if s[i-1] == t[j-1] {

				d[i][j] = d[i-1][j-1]

			} else {

				min := d[i-1][j]

				if d[i][j-1] < min {

					min = d[i][j-1]

				}

				if d[i-1][j-1] < min {

					min = d[i-1][j-1]

				}

				d[i][j] = min + 1

			}

		}

	}

	return d[len(s)][len(t)]

}

func stringInSlice(a string, list []string) bool {

	for _, b := range list {

		if b == a {

			return true

		}

	}

	return false

}

// CheckErr prints the msg with the prefix 'Error:' and exits with error code 1. If the msg is nil, it does nothing.

func CheckErr(msg interface{}) {

	if msg != nil {

		fmt.Fprintln(os.Stderr, "Error:", msg)

		os.Exit(1)

	}

}

// WriteStringAndCheck writes a string into a buffer, and checks if the error is not nil.

func WriteStringAndCheck(b io.StringWriter, s string) {

	_, err := b.WriteString(s)

	CheckErr(err)

}