import { LLMError } from "./llm-error.js";
import type { LLMClient } from "./llm-client.js";

/**
 * Pi LLM Client — uses Pi's built-in `complete()` from `@mariozechner/pi-ai`.
 *
 * This runs inside the Pi extension runtime and calls Pi's internal AI layer,
 * which respects the user's configured model (/model) and auth (/login).
 * No external fetch() — Pi handles transport, retries, and token accounting.
 */
export class PiLLMClient implements LLMClient {
	constructor(private extensionContext?: unknown) {}

	async complete(prompt: string): Promise<string> {
		const ctx = this.extensionContext as any;

		if (!ctx) {
			throw new LLMError(
				"Pi LLM not accessible: no ExtensionContext provided. " +
					"This tool must run inside Pi.",
			);
		}

		// Get the active model from Pi's runtime
		const model = ctx.model ?? ctx.modelRegistry?.get?.();
		if (!model) {
			throw new LLMError(
				"Pi LLM not accessible: no model configured. " +
					"Set a model via /model before using project-map tools.",
			);
		}

		try {
			// Dynamically import Pi's AI module (available in the Pi runtime)
			const { complete } = await import("@mariozechner/pi-ai");

			const response = await complete(
				model,
				{
					systemPrompt:
						"You are a code analysis assistant. Analyze the provided file and respond with concise, structured information.",
					messages: [
						{
							role: "user",
							content: prompt,
							timestamp: Date.now(),
						},
					],
				},
				{
					temperature: 0.1,
					maxTokens: 256,
				},
			);

			if (response.errorMessage) {
				throw new LLMError(`Pi LLM error: ${response.errorMessage}`);
			}

			// Extract text content from AssistantMessage
			const text = response.content
				.filter((c: any) => c.type === "text")
				.map((c: any) => c.text)
				.join("")
				.trim();

			return text;
		} catch (err: any) {
			if (err instanceof LLMError) throw err;
			if (err.code === "MODULE_NOT_FOUND") {
				throw new LLMError(
					"Pi LLM not accessible: @mariozechner/pi-ai is not available. " +
						"This extension must run inside the Pi runtime.",
				);
			}
			throw new LLMError(
				`Pi LLM call failed: ${err.message || String(err)}`,
				err,
			);
		}
	}
}