Update Build Code parsing for SotO

package.json

@@ -17,14 +17,14 @@
     "url": "https://github.com/gw2efficiency/chat-codes"
   },
   "dependencies": {
-    "base64-js": "^1.1.2"
+    "base64-js": "^1.5.1"
   },
   "devDependencies": {
-    "@types/base64-js": "^1.2.5",
-    "@types/jest": "^24.9.0",
-    "jest": "^24.9.0",
-    "prettier": "^1.19.1",
-    "ts-jest": "^24.3.0",
-    "typescript": "^3.7.5"
+    "@types/base64-js": "^1.3.0",
+    "@types/jest": "^29.5.4",
+    "jest": "^29.6.4",
+    "prettier": "^3.0.3",
+    "ts-jest": "^29.1.1",
+    "typescript": "^5.2.2"
   }
 }

src/ChatCodeStruct.ts

@@ -29,11 +29,25 @@ export class ChatCodeStruct {
     this.bytes.push((value >> 0x10) & 0xff)
   }
 
-  writeTraitSelection([trait1, trait2, trait3]: Array<number>) {
+  write4Bytes(value: number) {
+    this.bytes.push((value >> 0x00) & 0xff)
+    this.bytes.push((value >> 0x08) & 0xff)
+    this.bytes.push((value >> 0x10) & 0xff)
+    this.bytes.push((value >> 0x18) & 0xff)
+  }
+
+  writeTraitSelection([trait1, trait2, trait3]: [number, number, number]) {
     const value = ((trait3 & 3) << 4) | ((trait2 & 3) << 2) | ((trait1 & 3) << 0)
     this.write1Byte(value)
   }
 
+  writeDynamicArray(values: number[], bytesPerValue: 2 | 4) {
+    this.write1Byte(values.length)
+    for (const value of values) {
+      bytesPerValue === 2 ? this.write2Bytes(value) : this.write4Bytes(value)
+    }
+  }
+
   // -- DECODING --
 
   decodeFromChatCode(chatCode: string) {
@@ -60,11 +74,40 @@ export class ChatCodeStruct {
     )
   }
 
-  readTraitSelection(): Array<number> {
+  read4Bytes() {
+    return (
+      this.bytes[this.offset++] |
+      (this.bytes[this.offset++] << 8) |
+      (this.bytes[this.offset++] << 16) |
+      (this.bytes[this.offset++] << 24)
+    )
+  }
+
+  readTraitSelection(): [number, number, number] {
     return [
       this.bytes[this.offset] & 3,
       (this.bytes[this.offset] >> 2) & 3,
-      (this.bytes[this.offset++] >> 4) & 3
+      (this.bytes[this.offset++] >> 4) & 3,
     ]
   }
+
+  readDynamicArray(bytesPerValue: 2 | 4): undefined | number[] {
+    const length = this.read1Byte()
+
+    if (length === 0) {
+      return undefined
+    }
+
+    const values: number[] = []
+
+    for (let i = 0; i < length; i++) {
+      values.push(bytesPerValue === 2 ? this.read2Bytes() : this.read4Bytes())
+    }
+
+    return values
+  }
+
+  atEnd(): boolean {
+    return this.offset >= this.bytes.length
+  }
 }

src/decode/decode.ts

@@ -18,7 +18,7 @@ export function decode(chatCode: string) {
   // The header describing the type of the chat code is encoded as the first byte
   const typeHeader = struct.read1Byte()
   const codeType = Object.keys(TYPE_HEADERS).find(
-    (key) => TYPE_HEADERS[key as CodeType] === typeHeader
+    (key) => TYPE_HEADERS[key as CodeType] === typeHeader,
   )
 
   switch (codeType) {

src/decode/decodeBuildLink.ts

@@ -1,9 +1,7 @@
-import { CodeType, PROFESSION_FLAGS } from '../static'
+import { PROFESSION_FLAGS } from '../static'
 import { ChatCodeStruct } from '../ChatCodeStruct'
 
 export function decodeBuildLink(struct: ChatCodeStruct) {
-  const type = 'build' as CodeType
-
   const profession = struct.read1Byte()
 
   const specialization1 = struct.read1Byte()
@@ -48,8 +46,24 @@ export function decodeBuildLink(struct: ChatCodeStruct) {
     aquaticLegend2 = struct.read1Byte()
   }
 
+  // skip inactive legends
+  struct.read2Bytes()
+  struct.read2Bytes()
+  struct.read2Bytes()
+  struct.read2Bytes()
+  struct.read2Bytes()
+  struct.read2Bytes()
+
+  // check if we are at the end of the build code already,
+  // selectedWeapons and selectedSkillVariants were added with SotO,
+  // and old chat codes generated before SotO don't contain these yet.
+  const legacyChatCode = struct.atEnd()
+
+  const selectedWeapons = legacyChatCode ? undefined : struct.readDynamicArray(2)
+  const selectedSkillVariants = legacyChatCode ? undefined : struct.readDynamicArray(4)
+
   return {
-    type,
+    type: 'build' as const,
 
     profession,
 
@@ -80,6 +94,9 @@ export function decodeBuildLink(struct: ChatCodeStruct) {
     terrestrialLegend1,
     terrestrialLegend2,
     aquaticLegend1,
-    aquaticLegend2
+    aquaticLegend2,
+
+    selectedWeapons,
+    selectedSkillVariants,
   }
 }

src/decode/decodeIdLink.ts

@@ -1,7 +1,10 @@
 import { CodeType } from '../static'
 import { ChatCodeStruct } from '../ChatCodeStruct'
 
-export function decodeIdLink(type: CodeType, struct: ChatCodeStruct) {
+export function decodeIdLink(
+  type: Exclude<CodeType, 'item' | 'objective' | 'build'>,
+  struct: ChatCodeStruct,
+) {
   const id = struct.read3Bytes()
   return { type, id }
 }

src/decode/decodeItemLink.ts

@@ -1,9 +1,7 @@
-import { CodeType, ITEM_FLAGS } from '../static'
+import { ITEM_FLAGS } from '../static'
 import { ChatCodeStruct } from '../ChatCodeStruct'
 
 export function decodeItemLink(struct: ChatCodeStruct) {
-  const type = 'item' as CodeType
-
   const quantity = struct.read1Byte()
   const id = struct.read3Bytes()
   const flags = struct.read1Byte()
@@ -16,18 +14,18 @@ export function decodeItemLink(struct: ChatCodeStruct) {
   }
 
   // Upgrade slot 1
-  let upgrades
+  let upgrades: undefined | [number] | [number, number]
   if (hasFlag(flags, ITEM_FLAGS.upgrade1)) {
     upgrades = [struct.read3Bytes()]
     struct.read1Byte() // Skip the next byte (always 0x00)
   }
 
   // Upgrade slot 2
   if (hasFlag(flags, ITEM_FLAGS.upgrade2)) {
-    ;(upgrades as Array<number>).push(struct.read3Bytes())
+    upgrades!.push(struct.read3Bytes())
   }
 
-  return { type, quantity, id, skin, upgrades }
+  return { type: 'item' as const, quantity, id, skin, upgrades }
 }
 
 function hasFlag(flags: number, flag: number) {

src/decode/decodeObjectiveLink.ts

@@ -1,12 +1,9 @@
-import { CodeType } from '../static'
 import { ChatCodeStruct } from '../ChatCodeStruct'
 
 export function decodeObjectiveLink(struct: ChatCodeStruct) {
-  const type = 'objective' as CodeType
-
   const id = struct.read3Bytes()
   struct.read1Byte() // Skip the next byte (always 0x00)
   const map = struct.read3Bytes()
 
-  return { type, id: `${map}-${id}` }
+  return { type: 'objective' as const, id: `${map}-${id}` }
 }

src/encode/encode.ts

@@ -4,13 +4,23 @@ import { encodeObjectiveLink, ObjectiveLinkMeta } from './encodeObjectiveLink'
 import { encodeItemLink, ItemLinkMeta } from './encodeItemLink'
 import { BuildLinkMeta, encodeBuildLink } from './encodeBuildLink'
 
-type MetaOrId = string | number | IdLinkMeta | ItemLinkMeta | ObjectiveLinkMeta | BuildLinkMeta
+type TypeMeta = {
+  item: ItemLinkMeta | ItemLinkMeta['id']
+  map: IdLinkMeta | IdLinkMeta['id']
+  skill: IdLinkMeta | IdLinkMeta['id']
+  trait: IdLinkMeta | IdLinkMeta['id']
+  recipe: IdLinkMeta | IdLinkMeta['id']
+  skin: IdLinkMeta | IdLinkMeta['id']
+  outfit: IdLinkMeta | IdLinkMeta['id']
+  objective: ObjectiveLinkMeta | ObjectiveLinkMeta['id']
+  build: BuildLinkMeta
+}
 
-export function encode(type: CodeType, metaOrId: MetaOrId): string | false {
+export function encode<Type extends CodeType>(type: Type, data: TypeMeta[Type]): string | false {
   const codeType = type.trim().toLowerCase() as CodeType
 
   // Normalize into a meta object if only the ID was passed
-  const meta = typeof metaOrId !== 'object' ? { id: metaOrId } : metaOrId
+  const meta = typeof data !== 'object' ? { id: data } : data
 
   switch (codeType) {
     case 'map':

src/encode/encodeBuildLink.ts

@@ -5,11 +5,11 @@ export type BuildLinkMeta = {
   profession: number
 
   specialization1: number
-  traitChoices1: Array<number>
+  traitChoices1: [number, number, number]
   specialization2: number
-  traitChoices2: Array<number>
+  traitChoices2: [number, number, number]
   specialization3: number
-  traitChoices3: Array<number>
+  traitChoices3: [number, number, number]
 
   terrestrialHealSkill: number
   terrestrialUtilitySkill1: number
@@ -32,6 +32,9 @@ export type BuildLinkMeta = {
   terrestrialLegend2?: number
   aquaticLegend1?: number
   aquaticLegend2?: number
+
+  selectedWeapons?: number[]
+  selectedSkillVariants?: number[]
 }
 
 export function encodeBuildLink(meta: BuildLinkMeta): string | false {
@@ -103,5 +106,8 @@ export function encodeBuildLink(meta: BuildLinkMeta): string | false {
     struct.write2Bytes(0x00)
   }
 
+  struct.writeDynamicArray(meta.selectedWeapons ?? [], 2)
+  struct.writeDynamicArray(meta.selectedSkillVariants ?? [], 4)
+
   return struct.encodeToChatCode()
 }

src/static.ts

@@ -18,16 +18,16 @@ export const TYPE_HEADERS: { [key in CodeType]: number } = {
   skin: 0x0a,
   outfit: 0x0b,
   objective: 0x0c,
-  build: 0x0d
+  build: 0x0d,
 }
 
 export const ITEM_FLAGS = {
   skin: 0x80,
   upgrade1: 0x40,
-  upgrade2: 0x20
+  upgrade2: 0x20,
 }
 
 export const PROFESSION_FLAGS = {
   ranger: 0x04,
-  revenant: 0x09
+  revenant: 0x09,
 }