/**
 * Outbound HTTP to the Frappe `st.api.foundry.*` endpoints.
 *
 * All calls are POST with `X-Bridge-Secret` and `X-Bridge-World` headers.
 * Bodies are JSON. Errors include the Frappe server message when present.
 */

import { MODULE_ID } from "./constants.js";

function getConfig() {
	const baseUrl = (game.settings.get(MODULE_ID, "frappeBaseUrl") || "").replace(/\/+$/, "");
	const secret = game.settings.get(MODULE_ID, "sharedSecret") || "";
	const worldId = game.settings.get(MODULE_ID, "worldId") || game.world?.id || "";
	return { baseUrl, secret, worldId };
}

async function bridgeFetch(method, body) {
	const { baseUrl, secret, worldId } = getConfig();
	if (!baseUrl) throw new Error("Bridge not configured: set Frappe Base URL in module settings.");
	if (!secret) throw new Error("Bridge not configured: set Shared Secret in module settings.");
	if (!worldId) throw new Error("Bridge not configured: World ID could not be determined.");

	const url = `${baseUrl}/api/method/st.api.foundry.${method}`;
	const res = await fetch(url, {
		method: "POST",
		headers: {
			"Content-Type": "application/json",
			"X-Bridge-Secret": secret,
			"X-Bridge-World": worldId,
		},
		body: JSON.stringify(body),
	});

	if (!res.ok) {
		let detail = "";
		try {
			const json = await res.json();
			detail = json._server_messages || json.exception || JSON.stringify(json);
		} catch {
			detail = await res.text();
		}
		throw new Error(`Bridge ${method} failed: ${res.status} ${res.statusText} — ${detail}`);
	}
	return await res.json();
}

/**
 * Produce a player display name for an actor by inspecting Foundry's
 * ownership map. Returns the first non-GM user with OWNER permission, or
 * null if none exists. The Frappe side reads this from `_player_name`
 * during snapshot extraction (see `_actor_player_name` in foundry.py).
 */
function resolvePlayerName(actor) {
	const ownership = actor.ownership || {};
	for (const [userId, level] of Object.entries(ownership)) {
		if (userId === "default") continue;
		if (level < CONST.DOCUMENT_OWNERSHIP_LEVELS.OWNER) continue;
		const user = game.users.get(userId);
		if (user && !user.isGM) return user.name;
	}
	return null;
}

function buildManifest() {
	return game.actors
		.filter((a) => a.type === "character")
		.map((a) => ({
			id: a.id,
			name: a.name,
			player: resolvePlayerName(a),
		}));
}

export async function pushManifest() {
	const actors = buildManifest();
	console.log(`[${MODULE_ID}] pushing manifest with ${actors.length} actor(s)`);
	const result = await bridgeFetch("receive_actor_index", { actors });
	console.log(`[${MODULE_ID}] manifest result:`, result);
	return result;
}

/**
 * Push one actor's full data to the Frappe side. We send `toObject()`
 * (source data, pre-ActiveEffects) since the fields the Frappe extractor
 * currently reads — XP, HP, class levels, inventory — are stored, not
 * derived. If we later want effect-applied values (e.g. ability scores
 * with magic-item bonuses), we'll add a `_derived` block.
 *
 * `_player_name` is denormalized here because Foundry's ownership map
 * uses opaque user IDs that don't survive the trip to Frappe.
 */
export async function pushSnapshot(actor) {
	if (!actor) throw new Error("pushSnapshot called with no actor.");
	if (actor.type !== "character") {
		throw new Error(`Actor "${actor.name}" is not a PC (type=${actor.type}).`);
	}
	const payload = {
		...actor.toObject(),
		_player_name: resolvePlayerName(actor),
	};
	console.log(`[${MODULE_ID}] pushing snapshot for ${actor.name} (${actor.id})`);
	const result = await bridgeFetch("receive_actor_snapshot", payload);
	console.log(`[${MODULE_ID}] snapshot result:`, result);
	return result;
}

/**
 * Project each active Foundry module to a credit-only summary. Versions
 * are deliberately omitted: this list is intended for a public credits
 * page on the Frappe side and we don't want to leak dependency versions
 * if the site is ever indexed. The Frappe endpoint also strips any
 * version/compatibility fields server-side as defense-in-depth.
 */
function buildModuleInventory() {
	const out = [];
	for (const mod of game.modules.values()) {
		if (!mod.active) continue;
		const authors = (mod.authors || [])
			.map((a) => ({ name: a?.name, url: a?.url || null }))
			.filter((a) => a.name);
		out.push({
			id: mod.id,
			title: mod.title || mod.id,
			url: mod.url || null,
			authors,
		});
	}
	return out;
}

export async function pushModuleInventory() {
	const modules = buildModuleInventory();
	console.log(`[${MODULE_ID}] pushing module inventory (${modules.length} active)`);
	const result = await bridgeFetch("receive_module_inventory", { modules });
	console.log(`[${MODULE_ID}] module inventory result:`, result);
	return result;
}

export async function listScheduledSessions() {
	const result = await bridgeFetch("list_scheduled_sessions", {});
	return result?.message ?? [];
}

export async function completeSession(sessionId) {
	if (!sessionId) throw new Error("completeSession requires a session_id.");
	const result = await bridgeFetch("complete_session", { session_id: sessionId });
	return result?.message ?? {};
}

/**
 * Round-trip an empty manifest push to verify URL, secret, world ID, and
 * Frappe-side enablement. Surfaces the result in the Foundry UI.
 */
export async function testConnection() {
	console.log(`[${MODULE_ID}] testing connection...`);
	try {
		const result = await bridgeFetch("receive_actor_index", { actors: [] });
		const received = result?.message?.received ?? 0;
		ui.notifications.info(`Seitime Bridge OK — server accepted ${received} actor(s).`);
		return result;
	} catch (err) {
		ui.notifications.error(`Seitime Bridge: ${err.message}`);
		throw err;
	}
}