parent
b8fcac6ae2
commit
70383bee12
@ -0,0 +1,165 @@
|
||||
package formatter
|
||||
|
||||
import (
|
||||
"sort"
|
||||
|
||||
log "github.com/sirupsen/logrus"
|
||||
"github.com/zelenin/go-tdlib/client"
|
||||
)
|
||||
|
||||
// Insertion is a piece of text in given position
|
||||
type Insertion struct {
|
||||
Offset int32
|
||||
Runes []rune
|
||||
}
|
||||
|
||||
// InsertionStack contains the sequence of insertions
|
||||
// from the start or from the end
|
||||
type InsertionStack []*Insertion
|
||||
|
||||
var boldRunes = []rune("**")
|
||||
var italicRunes = []rune("_")
|
||||
var codeRunes = []rune("\n```\n")
|
||||
var urlRuneL = []rune("[")
|
||||
|
||||
// rebalance pumps all the values at given offset to current stack (growing
|
||||
// from start) from given stack (growing from end); should be called
|
||||
// before any insertions to the current stack at the given offset
|
||||
func (s InsertionStack) rebalance(s2 InsertionStack, offset int32) (InsertionStack, InsertionStack) {
|
||||
for len(s2) > 0 && s2[len(s2)-1].Offset <= offset {
|
||||
s = append(s, s2[len(s2)-1])
|
||||
s2 = s2[:len(s2)-1]
|
||||
}
|
||||
|
||||
return s, s2
|
||||
}
|
||||
|
||||
// NewIterator is a second order function that sequentially scans and returns
|
||||
// stack elements; starts returning nil when elements are ended
|
||||
func (s InsertionStack) NewIterator() func() *Insertion {
|
||||
i := -1
|
||||
|
||||
return func() *Insertion {
|
||||
i++
|
||||
if i < len(s) {
|
||||
return s[i]
|
||||
}
|
||||
return nil
|
||||
}
|
||||
}
|
||||
|
||||
// SortEntities arranges the entities in traversal-ready order
|
||||
func SortEntities(entities []*client.TextEntity) []*client.TextEntity {
|
||||
sortedEntities := make([]*client.TextEntity, len(entities))
|
||||
copy(sortedEntities, entities)
|
||||
|
||||
sort.Slice(sortedEntities, func(i int, j int) bool {
|
||||
entity1 := entities[i]
|
||||
entity2 := entities[j]
|
||||
if entity1.Offset < entity2.Offset {
|
||||
return true
|
||||
} else if entity1.Offset == entity2.Offset {
|
||||
return entity1.Length > entity2.Length
|
||||
}
|
||||
return false
|
||||
})
|
||||
return sortedEntities
|
||||
}
|
||||
|
||||
func markupBraces(entity *client.TextEntity, lbrace, rbrace []rune) (*Insertion, *Insertion) {
|
||||
return &Insertion{
|
||||
Offset: entity.Offset,
|
||||
Runes: lbrace,
|
||||
}, &Insertion{
|
||||
Offset: entity.Offset + entity.Length,
|
||||
Runes: rbrace,
|
||||
}
|
||||
}
|
||||
|
||||
// EntityToMarkdown generates the wrapping Markdown tags
|
||||
func EntityToMarkdown(entity *client.TextEntity) (*Insertion, *Insertion) {
|
||||
switch entity.Type.TextEntityTypeType() {
|
||||
case client.TypeTextEntityTypeBold:
|
||||
return markupBraces(entity, boldRunes, boldRunes)
|
||||
case client.TypeTextEntityTypeItalic:
|
||||
return markupBraces(entity, italicRunes, italicRunes)
|
||||
case client.TypeTextEntityTypeCode, client.TypeTextEntityTypePre:
|
||||
return markupBraces(entity, codeRunes, codeRunes)
|
||||
case client.TypeTextEntityTypePreCode:
|
||||
preCode, _ := entity.Type.(*client.TextEntityTypePreCode)
|
||||
return markupBraces(entity, []rune("\n```"+preCode.Language+"\n"), codeRunes)
|
||||
case client.TypeTextEntityTypeTextUrl:
|
||||
textURL, _ := entity.Type.(*client.TextEntityTypeTextUrl)
|
||||
return markupBraces(entity, urlRuneL, []rune("]("+textURL.Url+")"))
|
||||
}
|
||||
|
||||
return nil, nil
|
||||
}
|
||||
|
||||
// Format traverses an already sorted list of entities and wraps the text in Markdown
|
||||
func Format(
|
||||
sourceText string,
|
||||
entities []*client.TextEntity,
|
||||
entityToMarkup func(*client.TextEntity) (*Insertion, *Insertion),
|
||||
) string {
|
||||
if len(entities) == 0 {
|
||||
return sourceText
|
||||
}
|
||||
|
||||
startStack := make(InsertionStack, 0, len(sourceText))
|
||||
endStack := make(InsertionStack, 0, len(sourceText))
|
||||
|
||||
// convert entities to a stack of brackets
|
||||
var maxEndOffset int32
|
||||
for _, entity := range entities {
|
||||
log.Debugf("%#v", entity)
|
||||
if entity.Length <= 0 {
|
||||
continue
|
||||
}
|
||||
|
||||
endOffset := entity.Offset + entity.Length
|
||||
if endOffset > maxEndOffset {
|
||||
maxEndOffset = endOffset
|
||||
}
|
||||
|
||||
startStack, endStack = startStack.rebalance(endStack, entity.Offset)
|
||||
|
||||
startInsertion, endInsertion := entityToMarkup(entity)
|
||||
if startInsertion != nil {
|
||||
startStack = append(startStack, startInsertion)
|
||||
}
|
||||
if endInsertion != nil {
|
||||
endStack = append(endStack, endInsertion)
|
||||
}
|
||||
}
|
||||
// flush the closing brackets that still remain in endStack
|
||||
startStack, endStack = startStack.rebalance(endStack, maxEndOffset)
|
||||
|
||||
// merge brackets into text
|
||||
markupRunes := make([]rune, 0, len(sourceText))
|
||||
|
||||
nextInsertion := startStack.NewIterator()
|
||||
insertion := nextInsertion()
|
||||
var runeI int32
|
||||
|
||||
for _, cp := range sourceText {
|
||||
for insertion != nil && insertion.Offset <= runeI {
|
||||
markupRunes = append(markupRunes, insertion.Runes...)
|
||||
insertion = nextInsertion()
|
||||
}
|
||||
|
||||
markupRunes = append(markupRunes, cp)
|
||||
// skip two UTF-16 code units (not points actually!) if needed
|
||||
if cp > 0x0000ffff {
|
||||
runeI += 2
|
||||
} else {
|
||||
runeI++
|
||||
}
|
||||
}
|
||||
for insertion != nil {
|
||||
markupRunes = append(markupRunes, insertion.Runes...)
|
||||
insertion = nextInsertion()
|
||||
}
|
||||
|
||||
return string(markupRunes)
|
||||
}
|
||||
Loading…
Reference in new issue