Show issue reactions (#421)

```
$ tea issue 230

   #230 issue/pull details: show reactions (open)

  @6543 created 2020-10-22 16:39

  since reactions are utf8 now and most terminals too, we can display them nicely :)

  https://gitea.com/api/v1/repos/gitea/tea/issues/230/reactions

  --------

  1x 🎉  |  1x 👀  |  1x   |  1x 👍  |  1x 👎  |  1x 😆  |  1x 😕  |  1x ❤️
```

caveats:
- reactions are not returned as UTF8 (as was claimed in #230), so they need to be parsed. the library I use doesn't (and can't → ) support all reactions available in gitea
- currently only for issues, as reactions for comments mean an additional API request for each comment..

fixes #230

Co-authored-by: Norwin <git@nroo.de>
Reviewed-on: https://gitea.com/gitea/tea/pulls/421
Reviewed-by: Lunny Xiao <xiaolunwen@gmail.com>
Reviewed-by: techknowlogick <techknowlogick@gitea.io>
Co-authored-by: Norwin <noerw@noreply.gitea.io>
Co-committed-by: Norwin <noerw@noreply.gitea.io>

vendor/github.com/enescakir/emoji/.gitignore

@@ -0,0 +1,15 @@
+# Binaries for programs and plugins
+*.exe
+*.exe~
+*.dll
+*.so
+*.dylib
+
+# Test binary, built with `go test -c`
+*.test
+
+# Output of the go coverage tool, specifically when used with LiteIDE
+*.out
+
+# Dependency directories (remove the comment below to include it)
+# vendor/

vendor/github.com/enescakir/emoji/LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2020 Enes Çakır
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

vendor/github.com/enescakir/emoji/README.md

@@ -0,0 +1,99 @@
+# emoji :rocket: :school_satchel: :tada:
+[![Build Status](https://github.com/enescakir/emoji/workflows/build/badge.svg?branch=master)](https://github.com/enescakir/emoji/actions)
+[![godoc](https://godoc.org/github.com/enescakir/emoji?status.svg)](https://godoc.org/github.com/enescakir/emoji)
+[![Go Report Card](https://goreportcard.com/badge/github.com/enescakir/emoji)](https://goreportcard.com/report/github.com/enescakir/emoji)
+[![Codecov](https://img.shields.io/codecov/c/github/enescakir/emoji)](https://codecov.io/gh/enescakir/emoji)
+[![MIT License](https://img.shields.io/github/license/enescakir/emoji)](https://github.com/enescakir/emoji/blob/master/LICENSE)
+
+`emoji` is a minimalistic emoji library for Go. It lets you use emoji characters in strings.
+
+Inspired by [spatie/emoji](https://github.com/spatie/emoji)
+
+## Install :floppy_disk:
+``` bash
+go get github.com/enescakir/emoji
+```
+
+## Usage :surfer:
+```go
+package main
+
+import (
+    "fmt"
+
+    "github.com/enescakir/emoji"
+)
+
+func main() {
+	fmt.Printf("Hello %v\n", emoji.WavingHand)
+	fmt.Printf("I am %v from %v\n",
+		emoji.ManTechnologist,
+		emoji.FlagForTurkey,
+	)
+	fmt.Printf("Different skin tones.\n  default: %v light: %v dark: %v\n",
+		emoji.ThumbsUp,
+		emoji.OkHand.Tone(emoji.Light),
+		emoji.CallMeHand.Tone(emoji.Dark),
+	)
+	fmt.Printf("Emojis with multiple skin tones.\n  both medium: %v light and dark: %v\n",
+		emoji.PeopleHoldingHands.Tone(emoji.Medium),
+		emoji.PeopleHoldingHands.Tone(emoji.Light, emoji.Dark),
+	)
+	fmt.Println(emoji.Parse("Emoji aliases are :sunglasses:"))
+	emoji.Println("Use fmt wrappers :+1: with emoji support :tada:")
+}
+
+/* OUTPUT
+
+    Hello 👋
+    I am 👨‍💻 from 🇹🇷
+    Different skin tones.
+      default: 👍 light: 👌🏻 dark: 🤙🏿
+    Emojis with multiple skin tones.
+      both medium: 🧑🏽‍🤝‍🧑🏽 light and dark: 🧑🏻‍🤝‍🧑🏿
+    Emoji aliases are 😎
+    Use fmt wrappers 👍 with emoji support 🎉
+*/
+```
+
+This package contains emojis constants based on [Full Emoji List v13.0](https://unicode.org/Public/emoji/13.0/emoji-test.txt).
+```go
+emoji.CallMeHand // 🤙
+emoji.CallMeHand.Tone(emoji.Dark) // 🤙🏿
+```
+Also, it has additional emoji aliases from [github/gemoji](https://github.com/github/gemoji).
+```go
+emoji.Parse(":+1:") // 👍
+emoji.Parse(":100:") // 💯
+```
+
+You can generate country flag emoji with [ISO 3166 Alpha2](https://en.wikipedia.org/wiki/ISO_3166-1_alpha-2) codes:
+```go
+emoji.CountryFlag("tr") // 🇹🇷
+emoji.CountryFlag("US") // 🇺🇸
+emoji.Parse("country flag alias :flag-gb:") // country flag alias 🇬🇧
+```
+
+All constants are generated by `internal/generator`.
+
+## Testing :hammer:
+``` bash
+go test
+```
+
+## Todo :pushpin:
+* Add examples to `godoc`
+
+## Contributing :man_technologist:
+I am accepting PRs that add aliases to the package.
+You have to add it to `customEmojis` list at `internal/generator/main`.
+
+If you think an emoji constant is not correct, open an issue.
+Please use [this list](http://unicode.org/emoji/charts/full-emoji-list.html)
+to look up the correct unicode value and the name of the character.
+
+## Credits :star:
+- [Enes Çakır](https://github.com/enescakir)
+
+## License :scroll:
+The MIT License (MIT). Please see [License File](LICENSE.md) for more information.

vendor/github.com/enescakir/emoji/doc.go

@@ -0,0 +1,4 @@
+/*
+Package emoji makes working with emojis easier.
+*/
+package emoji

vendor/github.com/enescakir/emoji/emoji.go

@@ -0,0 +1,124 @@
+package emoji
+
+import (
+	"fmt"
+	"strings"
+)
+
+// Base attributes
+const (
+	TonePlaceholder = "@"
+	flagBaseIndex   = '\U0001F1E6' - 'a'
+)
+
+// Skin tone colors
+const (
+	Default     Tone = ""
+	Light       Tone = "\U0001F3FB"
+	MediumLight Tone = "\U0001F3FC"
+	Medium      Tone = "\U0001F3FD"
+	MediumDark  Tone = "\U0001F3FE"
+	Dark        Tone = "\U0001F3FF"
+)
+
+// Emoji defines an emoji object with no skin variations.
+type Emoji string
+
+// String returns string representation of the simple emoji.
+func (e Emoji) String() string {
+	return string(e)
+}
+
+// EmojiWithTone defines an emoji object that has skin tone options.
+type EmojiWithTone struct {
+	oneTonedCode string
+	twoTonedCode string
+	defaultTone  Tone
+}
+
+// newEmojiWithTone constructs a new emoji object that has skin tone options.
+func newEmojiWithTone(codes ...string) EmojiWithTone {
+	if len(codes) == 0 {
+		return EmojiWithTone{}
+	}
+
+	one := codes[0]
+	two := codes[0]
+
+	if len(codes) > 1 {
+		two = codes[1]
+	}
+
+	return EmojiWithTone{
+		oneTonedCode: one,
+		twoTonedCode: two,
+	}
+}
+
+// withDefaultTone sets default tone for an emoji and returns it.
+func (e EmojiWithTone) withDefaultTone(tone string) EmojiWithTone {
+	e.defaultTone = Tone(tone)
+
+	return e
+}
+
+// String returns string representation of the emoji with default skin tone.
+func (e EmojiWithTone) String() string {
+	return strings.ReplaceAll(e.oneTonedCode, TonePlaceholder, e.defaultTone.String())
+}
+
+// Tone returns string representation of the emoji with given skin tone.
+func (e EmojiWithTone) Tone(tones ...Tone) string {
+	// if no tone given, return with default skin tone
+	if len(tones) == 0 {
+		return e.String()
+	}
+
+	str := e.twoTonedCode
+	replaceCount := 1
+
+	// if one tone given or emoji doesn't have twoTonedCode, use oneTonedCode
+	// Also, replace all with one tone
+	if len(tones) == 1 {
+		str = e.oneTonedCode
+		replaceCount = -1
+	}
+
+	// replace tone one by one
+	for _, t := range tones {
+		// use emoji's default tone
+		if t == Default {
+			t = e.defaultTone
+		}
+
+		str = strings.Replace(str, TonePlaceholder, t.String(), replaceCount)
+	}
+
+	return str
+}
+
+// Tone defines skin tone options for emojis.
+type Tone string
+
+// String returns string representation of the skin tone.
+func (t Tone) String() string {
+	return string(t)
+}
+
+// CountryFlag returns a country flag emoji from given country code.
+// Full list of country codes: https://en.wikipedia.org/wiki/ISO_3166-1_alpha-2
+func CountryFlag(code string) (Emoji, error) {
+	if len(code) != 2 {
+		return "", fmt.Errorf("not valid country code: %q", code)
+	}
+
+	code = strings.ToLower(code)
+	flag := countryCodeLetter(code[0]) + countryCodeLetter(code[1])
+
+	return Emoji(flag), nil
+}
+
+// countryCodeLetter shifts given letter byte as flagBaseIndex.
+func countryCodeLetter(l byte) string {
+	return string(rune(l) + flagBaseIndex)
+}

vendor/github.com/enescakir/emoji/fmt.go

@@ -0,0 +1,56 @@
+package emoji
+
+import (
+	"fmt"
+	"io"
+)
+
+// Sprint wraps fmt.Sprint with emoji support
+func Sprint(a ...interface{}) string {
+	return Parse(fmt.Sprint(a...))
+}
+
+// Sprintf wraps fmt.Sprintf with emoji support
+func Sprintf(format string, a ...interface{}) string {
+	return Parse(fmt.Sprintf(format, a...))
+}
+
+// Sprintln wraps fmt.Sprintln with emoji support
+func Sprintln(a ...interface{}) string {
+	return Parse(fmt.Sprintln(a...))
+}
+
+// Print wraps fmt.Print with emoji support
+func Print(a ...interface{}) (n int, err error) {
+	return fmt.Print(Sprint(a...))
+}
+
+// Println wraps fmt.Println with emoji support
+func Println(a ...interface{}) (n int, err error) {
+	return fmt.Println(Sprint(a...))
+}
+
+// Printf wraps fmt.Printf with emoji support
+func Printf(format string, a ...interface{}) (n int, err error) {
+	return fmt.Print(Sprintf(format, a...))
+}
+
+// Fprint wraps fmt.Fprint with emoji support
+func Fprint(w io.Writer, a ...interface{}) (n int, err error) {
+	return fmt.Fprint(w, Sprint(a...))
+}
+
+// Fprintf wraps fmt.Fprintf with emoji support
+func Fprintf(w io.Writer, format string, a ...interface{}) (n int, err error) {
+	return fmt.Fprint(w, Sprintf(format, a...))
+}
+
+// Fprintln wraps fmt.Fprintln with emoji support
+func Fprintln(w io.Writer, a ...interface{}) (n int, err error) {
+	return fmt.Fprintln(w, Sprint(a...))
+}
+
+// Errorf wraps fmt.Errorf with emoji support
+func Errorf(format string, a ...interface{}) error {
+	return fmt.Errorf(Sprintf(format, a...))
+}

vendor/github.com/enescakir/emoji/go.mod

@@ -0,0 +1,3 @@
+module github.com/enescakir/emoji
+
+go 1.13

vendor/github.com/enescakir/emoji/parser.go

@@ -0,0 +1,127 @@
+package emoji
+
+import (
+	"fmt"
+	"regexp"
+	"strings"
+	"unicode"
+)
+
+var (
+	flagRegex = regexp.MustCompile(`^:flag-([a-zA-Z]{2}):$`)
+)
+
+// Parse replaces emoji aliases (:pizza:) with unicode representation.
+func Parse(input string) string {
+	var matched strings.Builder
+	var output strings.Builder
+
+	for _, r := range input {
+		// when it's not `:`, it might be inner or outer of the emoji alias
+		if r != ':' {
+			// if matched is empty, it's the outer of the emoji alias
+			if matched.Len() == 0 {
+				output.WriteRune(r)
+				continue
+			}
+
+			matched.WriteRune(r)
+
+			// if it's space, the alias's not valid.
+			// reset matched for breaking the emoji alias
+			if unicode.IsSpace(r) {
+				output.WriteString(matched.String())
+				matched.Reset()
+			}
+			continue
+		}
+
+		// r is `:` now
+		// if matched is empty, it's the beginning of the emoji alias
+		if matched.Len() == 0 {
+			matched.WriteRune(r)
+			continue
+		}
+
+		// it's the end of the emoji alias
+		match := matched.String()
+		alias := match + ":"
+
+		// check for emoji alias
+		if code, ok := Find(alias); ok {
+			output.WriteString(code)
+			matched.Reset()
+			continue
+		}
+
+		// not found any emoji
+		output.WriteString(match)
+		// it might be the beginning of the another emoji alias
+		matched.Reset()
+		matched.WriteRune(r)
+
+	}
+
+	// if matched not empty, add it to output
+	if matched.Len() != 0 {
+		output.WriteString(matched.String())
+		matched.Reset()
+	}
+
+	return output.String()
+}
+
+// Map returns the emojis map.
+// Key is the alias of the emoji.
+// Value is the code of the emoji.
+func Map() map[string]string {
+	return emojiMap
+}
+
+// AppendAlias adds new emoji pair to the emojis map.
+func AppendAlias(alias, code string) error {
+	if c, ok := emojiMap[alias]; ok {
+		return fmt.Errorf("emoji already exist: %q => %+q", alias, c)
+	}
+
+	for _, r := range alias {
+		if unicode.IsSpace(r) {
+			return fmt.Errorf("emoji alias is not valid: %q", alias)
+		}
+	}
+
+	emojiMap[alias] = code
+
+	return nil
+}
+
+// Exist checks existence of the emoji by alias.
+func Exist(alias string) bool {
+	_, ok := Find(alias)
+
+	return ok
+}
+
+// Find returns the emoji code by alias.
+func Find(alias string) (string, bool) {
+	if code, ok := emojiMap[alias]; ok {
+		return code, true
+	}
+
+	if flag := checkFlag(alias); len(flag) > 0 {
+		return flag, true
+	}
+
+	return "", false
+}
+
+// checkFlag finds flag emoji for `flag-[CODE]` pattern
+func checkFlag(alias string) string {
+	if matches := flagRegex.FindStringSubmatch(alias); len(matches) == 2 {
+		flag, _ := CountryFlag(matches[1])
+
+		return flag.String()
+	}
+
+	return ""
+}