/**
 * Antigravity wire constants and header spoofing.
 * Copied from oh-my-pi's pi-catalog wire/gemini-headers module.
 */
import type { GoogleThinkingConfig, GoogleThinkingLevel } from "./helpers.js";

export const ANTIGRAVITY_DAILY_ENDPOINT = "https://daily-cloudcode-pa.googleapis.com";
export const ANTIGRAVITY_SANDBOX_ENDPOINT = "https://daily-cloudcode-pa.sandbox.googleapis.com";
export const ANTIGRAVITY_ENDPOINT_FALLBACKS = [ANTIGRAVITY_DAILY_ENDPOINT, ANTIGRAVITY_SANDBOX_ENDPOINT] as const;

export const CLAUDE_THINKING_BETA_HEADER = "interleaved-thinking-2025-05-14";

/**
 * User agent format captured from the real antigravity/hub client:
 * `antigravity/hub/2.8.0 (aidev_client; os_type=darwin; arch=arm64; cl=963137146)`.
 * The backend gates newer models on the client version. os_type/arch are pinned
 * to the darwin/arm64 reference client, independent of the host platform.
 */
export const DEFAULT_ANTIGRAVITY_VERSION = "2.8.0";

const ANTIGRAVITY_VERSION_MANIFEST_URL =
	"https://antigravity-hub-auto-updater-974169037036.us-central1.run.app/manifest/latest-arm64-mac.yml";
const ANTIGRAVITY_VERSION_FETCH_TIMEOUT_MS = 5_000;

let discoveredAntigravityVersion: string | null = null;
let antigravityVersionFetch: Promise<void> | null = null;

export function getAntigravityVersion(): string {
	return process.env.PI_AI_ANTIGRAVITY_VERSION || discoveredAntigravityVersion || DEFAULT_ANTIGRAVITY_VERSION;
}

export function parseAntigravityManifestVersion(yamlText: string): string | null {
	for (const line of yamlText.split(/\r?\n/)) {
		const match = /^\s*version\s*:\s*(?:"([^"]*)"|'([^']*)'|([^\s#]+))\s*(?:#.*)?$/.exec(line);
		if (!match) continue;
		const version = (match[1] ?? match[2] ?? match[3] ?? "").trim();
		return /^\d+\.\d+\.\d+$/.test(version) ? version : null;
	}
	return null;
}

export function ensureAntigravityVersion(fetcher: typeof fetch = fetch, signal?: AbortSignal): Promise<void> {
	if (process.env.PI_AI_ANTIGRAVITY_VERSION || discoveredAntigravityVersion) return Promise.resolve();
	if (antigravityVersionFetch) return antigravityVersionFetch;

	antigravityVersionFetch = (async () => {
		try {
			const timeoutSignal = AbortSignal.timeout(ANTIGRAVITY_VERSION_FETCH_TIMEOUT_MS);
			const response = await fetcher(ANTIGRAVITY_VERSION_MANIFEST_URL, {
				headers: { "Cache-Control": "no-cache", "User-Agent": "electron-builder" },
				signal: signal ? AbortSignal.any([signal, timeoutSignal]) : timeoutSignal,
			});
			if (response.ok) {
				discoveredAntigravityVersion = parseAntigravityManifestVersion(await response.text());
			}
		} catch {
			// Silent: the pinned fallback remains valid when version discovery fails.
		} finally {
			if (!discoveredAntigravityVersion) antigravityVersionFetch = null;
		}
	})();
	return antigravityVersionFetch;
}

export function getAntigravityUserAgent(): string {
	const version = getAntigravityVersion();
	// The backend does not validate `cl`; only the version gates models.
	const cl = process.env.PI_AI_ANTIGRAVITY_CL || "963137146";
	const os = process.env.PI_AI_ANTIGRAVITY_OS || "darwin";
	const arch = process.env.PI_AI_ANTIGRAVITY_ARCH || "arm64";
	return `antigravity/hub/${version} (aidev_client; os_type=${os}; arch=${arch}; cl=${cl})`;
}

export interface AntigravityModelWireProfile {
	modelEnum?: string;
	maxOutputTokens: number;
}

/**
 * Per-wire-id Antigravity request constants, captured from the real
 * antigravity/hub client. `modelEnum` is the opaque labels.model_enum token;
 * Anthropic-backed wire ids are accepted without one.
 */
export const ANTIGRAVITY_MODEL_WIRE_PROFILES: Readonly<Record<string, AntigravityModelWireProfile>> = {
	"gemini-3.5-flash-extra-low": { modelEnum: "MODEL_PLACEHOLDER_M187", maxOutputTokens: 65536 },
	"gemini-3.5-flash-low": { modelEnum: "MODEL_PLACEHOLDER_M20", maxOutputTokens: 65536 },
	"gemini-3-flash-agent": { modelEnum: "MODEL_PLACEHOLDER_M132", maxOutputTokens: 65536 },
	"gemini-3.1-pro-low": { modelEnum: "MODEL_PLACEHOLDER_M36", maxOutputTokens: 65535 },
	"gemini-pro-agent": { modelEnum: "MODEL_PLACEHOLDER_M16", maxOutputTokens: 65535 },
	"claude-sonnet-4-6": { maxOutputTokens: 64000 },
	"claude-opus-4-6-thinking": { maxOutputTokens: 64000 },
};

export function getAntigravityModelWireProfile(wireModelId: string): AntigravityModelWireProfile | undefined {
	return ANTIGRAVITY_MODEL_WIRE_PROFILES[wireModelId];
}

export interface AntigravityThinkingOptions {
	enabled: boolean;
	budgetTokens?: number;
	level?: GoogleThinkingLevel;
	suppress?: { level: GoogleThinkingLevel } | { budget: number };
}

export interface AntigravityWireGenerationConfig {
	maxOutputTokens?: number;
	temperature?: number;
	topP?: number;
	topK?: number;
	minP?: number;
	presencePenalty?: number;
	repetitionPenalty?: number;
	thinkingConfig?: GoogleThinkingConfig;
}