import type { ExtensionAPI, ProviderModelConfig } from "@earendil-works/pi-coding-agent";
import {
	buildModelCatalog,
	parseModelListResponse,
	resolveBaseUrl,
	STATIC_FALLBACK_CATALOG,
} from "./helpers.ts";

const PROVIDER_ID = "bailian";

function sanitizeRemoteMessage(value: unknown, apiKey: string): string | undefined {
	if (typeof value !== "string") return undefined;
	let text = value.replaceAll(apiKey, "[redacted]").replace(/sk-[A-Za-z0-9_-]{8,}/g, "[redacted]");
	text = text.replace(/[\r\n\t]+/g, " ").trim();
	return text ? text.slice(0, 300) : undefined;
}

async function readErrorMessage(response: Response, apiKey: string): Promise<string | undefined> {
	try {
		const payload = (await response.json()) as { message?: unknown; error?: { message?: unknown } | string };
		const message = payload?.message ?? (typeof payload?.error === "string" ? payload.error : payload?.error?.message);
		return sanitizeRemoteMessage(message, apiKey);
	} catch {
		return undefined;
	}
}

async function discoverModels(baseUrl: string, apiKey: string, signal: AbortSignal): Promise<ProviderModelConfig[]> {
	if (!apiKey) throw new Error("DASHSCOPE_API_KEY is not set; Bailian model discovery cannot authenticate");

	let response: Response;
	try {
		response = await fetch(`${baseUrl}/models`, {
			headers: {
				Accept: "application/json",
				Authorization: `Bearer ${apiKey}`,
			},
			signal,
		});
	} catch (error) {
		if (signal.aborted) throw error;
		throw new Error(`Bailian model discovery request failed: ${error instanceof Error ? error.message : "network error"}`);
	}

	if (!response.ok) {
		const remoteMessage = await readErrorMessage(response, apiKey);
		const hint = response.status === 401 || response.status === 403 ? " Check that the API key matches the configured region." : "";
		throw new Error(
			`Bailian model discovery failed with HTTP ${response.status}${remoteMessage ? `: ${remoteMessage}` : ""}.${hint}`,
		);
	}

	let payload: unknown;
	try {
		payload = await response.json();
	} catch {
		throw new Error("Bailian model discovery returned invalid JSON");
	}
	return buildModelCatalog(parseModelListResponse(payload)) as ProviderModelConfig[];
}

export default function bailianExtension(pi: ExtensionAPI): void {
	const baseUrl = resolveBaseUrl(process.env);

	pi.registerProvider(PROVIDER_ID, {
		name: "Alibaba Cloud Bailian (API Key)",
		baseUrl,
		apiKey: "$DASHSCOPE_API_KEY",
		authHeader: true,
		api: "openai-completions",
		models: [...STATIC_FALLBACK_CATALOG] as ProviderModelConfig[],
		async refreshModels(context) {
			return discoverModels(baseUrl, process.env.DASHSCOPE_API_KEY?.trim() ?? "", context.signal);
		},
	});
}