aboutsummaryrefslogtreecommitdiff
path: root/mardown/ast_modifier.go
blob: bd04b2864c71c5fffae556ff762c42335889b97d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
package mardown

import (
	"encoding/json"
	"errors"
	"fmt"
	"html/template"
)

var (
	ErrInternalError         = errors.New("internal error")
	ErrInvalidModifier       = errors.Join(ErrInvalidParagraph, errors.New("invalid modifier organization"))
	ErrInvalidTypeInModifier = errors.Join(ErrInvalidParagraph, errors.New("invalid type in modifier"))
)

type modifierTag string

const (
	boldTag modifierTag = "b"
	emTag   modifierTag = "em"
)

type astModifier struct {
	symbols string
	tag     modifierTag
	content []block
	super   bool
}

func (a *astModifier) Eval() (template.HTML, error) {
	var content template.HTML
	for _, c := range a.content {
		ct, err := c.Eval()
		if err != nil {
			return "", err
		}
		content += ct
	}
	if a.super {
		return content, nil
	}
	return template.HTML(fmt.Sprintf("<%s>%s</%s>", a.tag, content, a.tag)), nil
}

func (a *astModifier) String() string {
	content := "["
	for _, c := range a.content {
		content += "\n\t"
		if v, ok := c.(fmt.Stringer); ok {
			content += v.String()
		} else {
			b, _ := json.MarshalIndent(a.content, "\t", "  ")
			content += string(b)
		}
		content += ",\n\t"
	}
	content += "]"
	return fmt.Sprintf("modifier{sym: %s, tag: %s, super: %v, content: %s\n}", a.symbols, a.tag, a.super, content)
}

func modifier(lxs *lexers) (*astModifier, error) {
	current := lxs.Current().Value
	mod, err := modifierDetect(current)
	if err != nil {
		return nil, err
	}
	var s string
	for lxs.Next() {
		switch lxs.Current().Type {
		case lexerLiteral, lexerHeader, lexerList:
			s += lxs.Current().Value
		case lexerModifier:
			if mod.super && []rune(mod.symbols)[0] == []rune(lxs.Current().Value)[0] &&
				len(mod.symbols) >= len(lxs.Current().Value) {
				mod.symbols = mod.symbols[len(lxs.Current().Value):]
				subMod, err := modifierDetect(lxs.Current().Value)
				if err != nil {
					return nil, err
				}
				if !subMod.super {
					subMod.content = append(subMod.content, astLiteral(s))
					mod, err = modifierDetect(mod.symbols) // this trick is so cool :D
					if err != nil {
						return nil, err
					}
				} else {
					subMod, _ = modifierDetect("**")
					subEm, _ := modifierDetect("*")
					subEm.content = append(subEm.content, astLiteral(s))
					subMod.content = append(subMod.content, subEm)
				}
				s = ""
				mod.content = append(mod.content, subMod)
				if len(mod.symbols) == 0 {
					return mod, nil
				}
			} else {
				if lxs.Current().Value == mod.symbols {
					mod.content = append(mod.content, astLiteral(s))
					return mod, nil
				} else if len(s) != 0 {
					mod.content = append(mod.content, astLiteral(s))
					s = ""
				}
				c, err := modifier(lxs)
				if err != nil {
					return nil, err
				}
				mod.content = append(mod.content, c)
			}
		case lexerBreak:
			lxs.Before() // because we did not use it
			if len(s) != 0 {
				return nil, ErrInvalidModifier
			}
			return mod, nil
		case lexerExternal:
			if lxs.Current().Value == "!" {
				s += lxs.Current().Value
			} else {
				ext, err := external(lxs)
				if err != nil {
					return nil, err
				}
				mod.content = append(mod.content, ext)
			}
		default:
			return nil, ErrInvalidTypeInModifier
		}
	}
	if len(s) != 0 {
		return nil, ErrInvalidModifier
	}
	return mod, nil
}

func modifierDetect(val string) (*astModifier, error) {
	mod := new(astModifier)
	mod.symbols = val
	switch len(val) {
	case 1:
		mod.tag = emTag
	case 2:
		mod.tag = boldTag
	case 3:
		mod.super = true
	default:
		return nil, ErrInvalidModifier
	}
	return mod, nil
}