1. 1
2. 2
3. 3
4. 4
5. 5
6. 6
7. 7
8. 8
9. 9
10. 10
11. 11
12. 12
13. 13
14. 14
15. 15
16. 16
17. 17
18. 18
19. 19
20. 20
21. 21
22. 22
23. 23
24. 24
25. 25
26. 26
27. 27
28. 28
29. 29
30. 30
31. 31
32. 32
33. 33
34. 34
35. 35
36. 36
37. 37
38. 38
39. 39
40. 40
41. 41
42. 42
43. 43
44. 44
45. 45
46. 46
47. 47
48. 48
49. 49
50. 50
51. 51
52. 52
53. 53
54. 54
55. 55
56. 56
57. 57
58. 58
59. 59
60. 60
61. 61
62. 62
63. 63
64. 64
65. 65
66. 66
67. 67
68. 68
69. 69
70. 70
71. 71
72. 72
73. 73
74. 74
75. 75
76. 76
77. 77
78. 78
79. 79
80. 80
81. 81
82. 82
83. 83
84. 84
85. 85
86. 86
87. 87
88. 88
89. 89
90. 90
91. 91
92. 92
93. 93
94. 94
95. 95
96. 96
97. 97
98. 98
99. 99
100. 100
101. 101
102. 102
103. 103
104. 104
105. 105
106. 106
107. 107
108. 108
109. 109
110. 110
111. 111
112. 112
113. 113
114. 114
115. 115
116. 116
117. 117
118. 118
119. 119
120. 120
121. 121
122. 122
123. 123
124. 124
125. 125
126. 126
127. 127
128. 128
129. 129
130. 130
131. 131
132. 132
133. 133
134. 134
135. 135
136. 136
137. 137
138. 138
139. 139
140. 140
141. 141
142. 142
143. 143
144. 144
145. 145
146. 146
147. 147
148. 148
149. 149
150. 150
151. 151
152. 152
153. 153
154. 154
155. 155
156. 156
157. 157
158. 158
159. 159
160. 160
161. 161
162. 162
163. 163
164. 164
165. 165
166. 166
167. 167
168. 168
169. 169
170. 170
171. 171
172. 172
173. 173
174. 174
175. 175
176. 176
177. 177
178. 178
179. 179
180. 180
181. 181
182. 182
183. 183
184. 184

package cli

import (
	"flag"
	"fmt"
	"strings"
)

// StringSlice is an opaque type for []string to satisfy flag.Value and flag.Getter
type StringSlice []string

// Set appends the string value to the list of values
func (f *StringSlice) Set(value string) error {
	*f = append(*f, value)
	return nil
}

// String returns a readable representation of this value (for usage defaults)
func (f *StringSlice) String() string {
	return strings.Join(*f, ",")
}

// Value returns the slice of strings set by this flag
func (f *StringSlice) Value() []string {
	return *f
}

// Get returns the slice of strings set by this flag
func (f *StringSlice) Get() interface{} {
	return *f
}

// StringSliceFlag is a flag with type *StringSlice
type StringSliceFlag struct {
	Name      string
	Usage     string
	EnvVar    string
	FilePath  string
	Required  bool
	Hidden    bool
	TakesFile bool
	Value     *StringSlice
}

// String returns a readable representation of this value
// (for usage defaults)
func (f StringSliceFlag) String() string {
	return FlagStringer(f)
}

// GetName returns the name of the flag
func (f StringSliceFlag) GetName() string {
	return f.Name
}

// IsRequired returns whether or not the flag is required
func (f StringSliceFlag) IsRequired() bool {
	return f.Required
}

// TakesValue returns true of the flag takes a value, otherwise false
func (f StringSliceFlag) TakesValue() bool {
	return true
}

// GetUsage returns the usage string for the flag
func (f StringSliceFlag) GetUsage() string {
	return f.Usage
}

// GetValue returns the flags value as string representation and an empty
// string if the flag takes no value at all.
func (f StringSliceFlag) GetValue() string {
	if f.Value != nil {
		return f.Value.String()
	}
	return ""
}

// Apply populates the flag given the flag set and environment
// Ignores errors
func (f StringSliceFlag) Apply(set *flag.FlagSet) {
	_ = f.ApplyWithError(set)
}

// ApplyWithError populates the flag given the flag set and environment
func (f StringSliceFlag) ApplyWithError(set *flag.FlagSet) error {
	if envVal, ok := flagFromFileEnv(f.FilePath, f.EnvVar); ok {
		newVal := &StringSlice{}
		for _, s := range strings.Split(envVal, ",") {
			s = strings.TrimSpace(s)
			if err := newVal.Set(s); err != nil {
				return fmt.Errorf("could not parse %s as string value for flag %s: %s", envVal, f.Name, err)
			}
		}
		if f.Value == nil {
			f.Value = newVal
		} else {
			*f.Value = *newVal
		}
	}

	eachName(f.Name, func(name string) {
		if f.Value == nil {
			f.Value = &StringSlice{}
		}
		set.Var(f.Value, name, f.Usage)
	})

	return nil
}

// StringSlice looks up the value of a local StringSliceFlag, returns
// nil if not found
func (c *Context) StringSlice(name string) []string {
	return lookupStringSlice(name, c.flagSet)
}

// GlobalStringSlice looks up the value of a global StringSliceFlag, returns
// nil if not found
func (c *Context) GlobalStringSlice(name string) []string {
	if fs := lookupGlobalFlagSet(name, c); fs != nil {
		return lookupStringSlice(name, fs)
	}
	return nil
}

func lookupStringSlice(name string, set *flag.FlagSet) []string {
	f := set.Lookup(name)
	if f != nil {
		value, ok := f.Value.(*StringSlice)
		if !ok {
			return nil
		}
		// extract the slice from asserted value
		slice := value.Value()

		// extract default value from the flag
		var defaultVal []string
		for _, v := range strings.Split(f.DefValue, ",") {
			defaultVal = append(defaultVal, v)
		}

		// if the current value is not equal to the default value
		// remove the default values from the flag
		if !isStringSliceEqual(slice, defaultVal) {
			for _, v := range defaultVal {
				slice = removeFromStringSlice(slice, v)
			}
		}
		return slice
	}
	return nil
}

func removeFromStringSlice(slice []string, val string) []string {
	for i, v := range slice {
		if v == val {
			ret := append([]string{}, slice[:i]...)
			ret = append(ret, slice[i+1:]...)
			return ret
		}
	}
	return slice
}

func isStringSliceEqual(newValue, defaultValue []string) bool {
	// If one is nil, the other must also be nil.
	if (newValue == nil) != (defaultValue == nil) {
		return false
	}

	if len(newValue) != len(defaultValue) {
		return false
	}

	for i, v := range newValue {
		if v != defaultValue[i] {
			return false
		}
	}

	return true
}