export class CodexAppServerEventProjector {

private readonly assistantTextByItem = new Map<string, string>();

private readonly assistantItemOrder: string[] = [];

private readonly assistantPhaseByItem = new Map<string, string>();

private readonly lastCommentaryProgressTextByItem = new Map<string, string>();

private readonly reasoningTextByItem = new Map<string, string>();

private readonly planTextByItem = new Map<string, string>();

private readonly activeItemIds = new Set<string>();

this.rememberAssistantItem(itemId);

const text = `${this.assistantTextByItem.get(itemId) ?? ""}${delta}`;

this.assistantTextByItem.set(itemId, text);

if (this.isCommentaryAssistantItem(itemId)) {

this.emitCommentaryProgress({ itemId, text });

}

// Codex app-server can emit multiple agentMessage items per turn, including

// intermediate coordination/progress prose. Keep those deltas internal until

// turn completion chooses the last assistant item as the user-visible reply.

private async handleItemStarted(params: JsonObject): Promise<void> {

const item = readItem(params.item);

const itemId = item?.id ?? readString(params, "itemId") ?? readString(params, "id");

this.rememberAssistantPhase(item);

if (itemId) {

this.activeItemIds.add(itemId);

}

this.activeItemIds.delete(itemId);

this.completedItemIds.add(itemId);

}

this.rememberAssistantPhase(item);

if (item?.type === "agentMessage" && typeof item.text === "string" && item.text) {

this.rememberAssistantItem(item.id);

this.assistantTextByItem.set(item.id, item.text);

if (this.isCommentaryAssistantItem(item.id)) {

this.emitCommentaryProgress({ itemId: item.id, text: item.text });

}

}

this.recordNativeGeneratedMedia(item);

if (item?.type === "plan" && typeof item.text === "string" && item.text) {

this.promptErrorSource = "prompt";

}

for (const item of turn.items ?? []) {

this.rememberAssistantPhase(item);

if (item.type === "agentMessage" && typeof item.text === "string" && item.text) {

this.rememberAssistantItem(item.id);

this.assistantTextByItem.set(item.id, item.text);

});

}

private rememberAssistantPhase(item: CodexThreadItem | undefined): void {

if (item?.type !== "agentMessage") {

return;

}

const phase = readItemString(item, "phase");

if (phase) {

this.assistantPhaseByItem.set(item.id, phase);

}

}

private isCommentaryAssistantItem(itemId: string): boolean {

return this.assistantPhaseByItem.get(itemId) === "commentary";

}

private emitCommentaryProgress(params: { itemId: string; text: string }): void {

const progressText = params.text.replace(/\s+/g, " ").trim();

if (

!progressText ||

this.lastCommentaryProgressTextByItem.get(params.itemId) === progressText

) {

return;

}

this.lastCommentaryProgressTextByItem.set(params.itemId, progressText);

this.emitAgentEvent({

stream: "item",

data: {

itemId: params.itemId,

kind: "preamble",

title: "Preamble",

phase: "update",

progressText,

source: "codex-app-server",

},

});

}

private emitStandardItemEvent(params: {

phase: "start" | "end";

item: CodexThreadItem | undefined;

continue;

}

const text = this.assistantTextByItem.get(itemId)?.trim();

if (this.assistantPhaseByItem.get(itemId) === "commentary") {

continue;

}

if (text && !this.toolProgressTexts.has(text)) {

return text;

}