git.r.bdr.sh - rbdr/mobius/blob - hotline/field.go

   1 package hotline
   2
   3 import (
   4         "encoding/binary"
   5         "io"
   6         "slices"
   7 )
   8
   9 // List of Hotline protocol field types taken from the official 1.9 protocol document
  10 const (
  11         FieldError               = 100
  12         FieldData                = 101
  13         FieldUserName            = 102
  14         FieldUserID              = 103
  15         FieldUserIconID          = 104
  16         FieldUserLogin           = 105
  17         FieldUserPassword        = 106
  18         FieldRefNum              = 107
  19         FieldTransferSize        = 108
  20         FieldChatOptions         = 109
  21         FieldUserAccess          = 110
  22         FieldUserAlias           = 111 // TODO: implement
  23         FieldUserFlags           = 112
  24         FieldOptions             = 113
  25         FieldChatID              = 114
  26         FieldChatSubject         = 115
  27         FieldWaitingCount        = 116
  28         FieldBannerType          = 152
  29         FieldNoServerAgreement   = 152
  30         FieldVersion             = 160
  31         FieldCommunityBannerID   = 161
  32         FieldServerName          = 162
  33         FieldFileNameWithInfo    = 200
  34         FieldFileName            = 201
  35         FieldFilePath            = 202
  36         FieldFileResumeData      = 203
  37         FieldFileTransferOptions = 204
  38         FieldFileTypeString      = 205
  39         FieldFileCreatorString   = 206
  40         FieldFileSize            = 207
  41         FieldFileCreateDate      = 208
  42         FieldFileModifyDate      = 209
  43         FieldFileComment         = 210
  44         FieldFileNewName         = 211
  45         FieldFileNewPath         = 212
  46         FieldFileType            = 213
  47         FieldQuotingMsg          = 214
  48         FieldAutomaticResponse   = 215
  49         FieldFolderItemCount     = 220
  50         FieldUsernameWithInfo    = 300
  51         FieldNewsArtListData     = 321
  52         FieldNewsCatName         = 322
  53         FieldNewsCatListData15   = 323
  54         FieldNewsPath            = 325
  55         FieldNewsArtID           = 326
  56         FieldNewsArtDataFlav     = 327
  57         FieldNewsArtTitle        = 328
  58         FieldNewsArtPoster       = 329
  59         FieldNewsArtDate         = 330
  60         FieldNewsArtPrevArt      = 331
  61         FieldNewsArtNextArt      = 332
  62         FieldNewsArtData         = 333
  63         FieldNewsArtFlags        = 334 // TODO: what is this used for?
  64         FieldNewsArtParentArt    = 335
  65         FieldNewsArt1stChildArt  = 336
  66         FieldNewsArtRecurseDel   = 337 // TODO: implement news article recusive deletion
  67 )
  68
  69 type Field struct {
  70         ID        [2]byte // Type of field
  71         FieldSize [2]byte // Size of the data part
  72         Data      []byte  // Actual field content
  73
  74         readOffset int // Internal offset to track read progress
  75 }
  76
  77 type requiredField struct {
  78         ID     int
  79         minLen int
  80 }
  81
  82 func NewField(id uint16, data []byte) Field {
  83         f := Field{Data: data}
  84         binary.BigEndian.PutUint16(f.ID[:], id)
  85         binary.BigEndian.PutUint16(f.FieldSize[:], uint16(len(data)))
  86
  87         return f
  88 }
  89
  90 // fieldScanner implements bufio.SplitFunc for parsing byte slices into complete tokens
  91 func fieldScanner(data []byte, _ bool) (advance int, token []byte, err error) {
  92         if len(data) < minFieldLen {
  93                 return 0, nil, nil
  94         }
  95
  96         // tranLen represents the length of bytes that are part of the transaction
  97         neededSize := minFieldLen + int(binary.BigEndian.Uint16(data[2:4]))
  98         if neededSize > len(data) {
  99                 return 0, nil, nil
 100         }
 101
 102         return neededSize, data[0:neededSize], nil
 103 }
 104
 105 // Read implements io.Reader for Field
 106 func (f *Field) Read(p []byte) (int, error) {
 107         buf := slices.Concat(f.ID[:], f.FieldSize[:], f.Data)
 108
 109         if f.readOffset >= len(buf) {
 110                 return 0, io.EOF // All bytes have been read
 111         }
 112
 113         n := copy(p, buf[f.readOffset:])
 114         f.readOffset += n
 115
 116         return n, nil
 117 }
 118
 119 // Write implements io.Writer for Field
 120 func (f *Field) Write(p []byte) (int, error) {
 121         f.ID = [2]byte(p[0:2])
 122         f.FieldSize = [2]byte(p[2:4])
 123
 124         i := int(binary.BigEndian.Uint16(f.FieldSize[:]))
 125         f.Data = p[4 : 4+i]
 126
 127         return minFieldLen + i, nil
 128 }
 129
 130 func getField(id int, fields *[]Field) *Field {
 131         for _, field := range *fields {
 132                 if id == int(binary.BigEndian.Uint16(field.ID[:])) {
 133                         return &field
 134                 }
 135         }
 136         return nil
 137 }