import type { ExtensionContext } from "@earendil-works/pi-coding-agent";
import { isAdapterRuntime, resolveCodexRuntimePlan } from "../adapter/activation/runtime-plan.ts";
import type { CodeModeRegistration } from "../tools/code-mode/tools.ts";
import type { CodexExtensionRuntime } from "../extension/runtime.ts";
import { CANCELLED, interruptible } from "./cancellation.ts";
import type { PreparedVoiceDelegation } from "./session-messages.ts";

export async function prepareVoiceDelegation(
	runtime: CodexExtensionRuntime,
	codeMode: CodeModeRegistration,
	ctx: ExtensionContext,
	signal: AbortSignal,
): Promise<PreparedVoiceDelegation | undefined> {
	const { state } = runtime;
	const buildCurrent = () => {
		if (!isAdapterRuntime(resolveCodexRuntimePlan(ctx, state.config))) return undefined;
		const basePrompt = state.activeProviderSystemPrompt ?? ctx.getSystemPrompt();
		const promptOptions = state.config.prompt.heavySystemPromptOverwrite
			? { cwd: ctx.cwd }
			: undefined;
		const systemPrompt = runtime.codexSystemPrompt(
			codeMode.refreshPromptTools(basePrompt, ctx),
			ctx,
			undefined,
			promptOptions,
		);
		return {
			systemPrompt,
			prewarmIdentity: runtime.prewarmIdentity(ctx, systemPrompt),
		};
	};
	for (;;) {
		signal.throwIfAborted();
		const prepared = buildCurrent();
		if (!prepared) {
			state.voiceSystemPromptOverride = undefined;
			return undefined;
		}
		const prewarmOperation = runtime.waitForPrewarm(ctx, prepared.systemPrompt);
		const prewarm = prewarmOperation
			? await interruptible(prewarmOperation, signal)
			: undefined;
		if (prewarm === CANCELLED) {
			signal.throwIfAborted();
			throw new Error("Voice delegation preflight was cancelled");
		}
		if (prewarm?.status === "aborted") continue;
		if (prewarm?.status === "failed") throw prewarm.error;
		const current = buildCurrent();
		if (
			!current ||
			current.systemPrompt !== prepared.systemPrompt ||
			current.prewarmIdentity !== prepared.prewarmIdentity
		) continue;
		let committed = false;
		let previous: Pick<typeof state, "activeProviderSystemPrompt" | "voiceSystemPromptOverride" | "pendingActiveProviderPromptCapture"> | undefined;
		return {
			commit() {
				const commit = buildCurrent();
				if (
					!commit ||
					commit.systemPrompt !== prepared.systemPrompt ||
					commit.prewarmIdentity !== prepared.prewarmIdentity
				) return false;
				previous = {
					activeProviderSystemPrompt: state.activeProviderSystemPrompt,
					voiceSystemPromptOverride: state.voiceSystemPromptOverride,
					pendingActiveProviderPromptCapture: state.pendingActiveProviderPromptCapture,
				};
				state.activeProviderSystemPrompt = prepared.systemPrompt;
				state.voiceSystemPromptOverride = prepared.systemPrompt;
				state.pendingActiveProviderPromptCapture = true;
				committed = true;
				return true;
			},
			rollback() {
				if (!committed || !previous) return;
				if (state.activeProviderSystemPrompt === prepared.systemPrompt)
					state.activeProviderSystemPrompt = previous.activeProviderSystemPrompt;
				if (state.voiceSystemPromptOverride === prepared.systemPrompt)
					state.voiceSystemPromptOverride = previous.voiceSystemPromptOverride;
				if (state.pendingActiveProviderPromptCapture === true)
					state.pendingActiveProviderPromptCapture = previous.pendingActiveProviderPromptCapture;
				committed = false;
			},
		};
	}
}