| interface ForkTurnItem { | |
| readonly type: string; | |
| } | |
| interface ForkTurnMessage { | |
| readonly role: "user" | "assistant"; | |
| readonly forkable?: boolean; | |
| readonly steps?: readonly { | |
| readonly items: readonly ForkTurnItem[]; | |
| }[]; | |
| } | |
| /** Return the core's zero-based user-visible turn index for an assistant bubble. */ | |
| export function getForkTurnIndex( | |
| messages: readonly ForkTurnMessage[], | |
| messageIndex: number, | |
| ): number | undefined { | |
| const target = messages[messageIndex]; | |
| if (target?.role !== "assistant" || target.forkable === false) return undefined; | |
| let visibleTurns = 0; | |
| for (let index = 0; index <= messageIndex; index += 1) { | |
| const message = messages[index]; | |
| if (message === undefined) continue; | |
| if (message.role === "user" && message.forkable !== false) { | |
| visibleTurns += 1; | |
| continue; | |
| } | |
| if (message.role === "assistant") { | |
| visibleTurns += countSteers(message); | |
| } | |
| } | |
| return visibleTurns - 1; | |
| } | |
| function countSteers(message: ForkTurnMessage): number { | |
| return ( | |
| message.steps?.reduce( | |
| (count, step) => count + step.items.filter((item) => item.type === "steer").length, | |
| 0, | |
| ) ?? 0 | |
| ); | |
| } | |