/**
 * rSpace Unified Server
 *
 * Hono-based HTTP router + Bun WebSocket handler.
 * Mounts module routes under /:space/:moduleId.
 * Preserves backward-compatible subdomain routing and /api/communities/* API.
 */

import { resolve } from "node:path";
import { Hono } from "hono";
import { cors } from "hono/cors";
import type { ServerWebSocket } from "bun";
import {
	addShapes,
	clearShapes,
	communityExists,
	createCommunity,
	forgetShape,
	rememberShape,
	generateSyncMessageForPeer,
	getDocumentData,
	loadCommunity,
	receiveSyncMessage,
	removePeerSyncState,
	updateShape,
	updateShapeFields,
} from "./community-store";
import { ensureDemoCommunity } from "./seed-demo";
import { ensureCampaignDemo } from "./seed-campaign";
import type { SpaceVisibility } from "./community-store";
import {
	verifyEncryptIDToken,
	evaluateSpaceAccess,
	extractToken,
	authenticateWSUpgrade,
} from "@encryptid/sdk/server";
import type { EncryptIDClaims, SpaceAuthConfig } from "@encryptid/sdk/server";

// ── Module system ──
import { registerModule, getAllModules, getModuleInfoList } from "../shared/module";
import { canvasModule } from "../modules/canvas/mod";
import { spaces } from "./spaces";
import { renderShell } from "./shell";

// Register modules
registerModule(canvasModule);

// ── Config ──
const PORT = Number(process.env.PORT) || 3000;
const INTERNAL_API_KEY = process.env.INTERNAL_API_KEY || "";
const DIST_DIR = resolve(import.meta.dir, "../dist");

// ── Hono app ──
const app = new Hono();

// CORS for API routes
app.use("/api/*", cors());

// ── .well-known/webauthn (WebAuthn Related Origins) ──
app.get("/.well-known/webauthn", (c) => {
	return c.json(
		{
			origins: [
				"https://rwallet.online",
				"https://rvote.online",
				"https://rmaps.online",
				"https://rfiles.online",
				"https://rnotes.online",
			],
		},
		200,
		{
			"Access-Control-Allow-Origin": "*",
			"Cache-Control": "public, max-age=3600",
		}
	);
});

// ── Space registry API ──
app.route("/api/spaces", spaces);

// ── Existing /api/communities/* routes (backward compatible) ──

/** Resolve a community slug to SpaceAuthConfig for the SDK guard */
async function getSpaceConfig(slug: string): Promise<SpaceAuthConfig | null> {
	let doc = getDocumentData(slug);
	if (!doc) {
		await loadCommunity(slug);
		doc = getDocumentData(slug);
	}
	if (!doc) return null;
	return {
		spaceSlug: slug,
		visibility: (doc.meta.visibility || "public_read") as SpaceVisibility,
		ownerDID: doc.meta.ownerDID || undefined,
		app: "rspace",
	};
}

// Demo reset rate limiter
let lastDemoReset = 0;
const DEMO_RESET_COOLDOWN = 5 * 60 * 1000;

// POST /api/communities — create community
app.post("/api/communities", async (c) => {
	const token = extractToken(c.req.raw.headers);
	if (!token) return c.json({ error: "Authentication required to create a community" }, 401);

	let claims: EncryptIDClaims;
	try {
		claims = await verifyEncryptIDToken(token);
	} catch {
		return c.json({ error: "Invalid or expired authentication token" }, 401);
	}

	const body = await c.req.json<{ name?: string; slug?: string; visibility?: SpaceVisibility }>();
	const { name, slug, visibility = "public_read" } = body;

	if (!name || !slug) return c.json({ error: "Name and slug are required" }, 400);
	if (!/^[a-z0-9-]+$/.test(slug)) return c.json({ error: "Slug must contain only lowercase letters, numbers, and hyphens" }, 400);

	const validVisibilities: SpaceVisibility[] = ["public", "public_read", "authenticated", "members_only"];
	if (!validVisibilities.includes(visibility)) return c.json({ error: `Invalid visibility` }, 400);
	if (await communityExists(slug)) return c.json({ error: "Community already exists" }, 409);

	await createCommunity(name, slug, claims.sub, visibility);

	// Notify modules
	for (const mod of getAllModules()) {
		if (mod.onSpaceCreate) {
			try { await mod.onSpaceCreate(slug); } catch (e) { console.error(`Module ${mod.id} onSpaceCreate:`, e); }
		}
	}

	return c.json({ url: `https://${slug}.rspace.online`, slug, name, visibility, ownerDID: claims.sub }, 201);
});

// POST /api/communities/demo/reset
app.post("/api/communities/demo/reset", async (c) => {
	const now = Date.now();
	if (now - lastDemoReset < DEMO_RESET_COOLDOWN) {
		const remaining = Math.ceil((DEMO_RESET_COOLDOWN - (now - lastDemoReset)) / 1000);
		return c.json({ error: `Demo reset on cooldown. Try again in ${remaining}s` }, 429);
	}
	lastDemoReset = now;
	await loadCommunity("demo");
	clearShapes("demo");
	await ensureDemoCommunity();
	broadcastAutomergeSync("demo");
	broadcastJsonSnapshot("demo");
	return c.json({ ok: true, message: "Demo community reset to seed data" });
});

// POST /api/communities/campaign-demo/reset
app.post("/api/communities/campaign-demo/reset", async (c) => {
	const now = Date.now();
	if (now - lastDemoReset < DEMO_RESET_COOLDOWN) {
		const remaining = Math.ceil((DEMO_RESET_COOLDOWN - (now - lastDemoReset)) / 1000);
		return c.json({ error: `Reset on cooldown. Try again in ${remaining}s` }, 429);
	}
	lastDemoReset = now;
	await loadCommunity("campaign-demo");
	clearShapes("campaign-demo");
	await ensureCampaignDemo();
	broadcastAutomergeSync("campaign-demo");
	broadcastJsonSnapshot("campaign-demo");
	return c.json({ ok: true, message: "Campaign demo reset to seed data" });
});

// GET /api/communities/:slug/shapes
app.get("/api/communities/:slug/shapes", async (c) => {
	const slug = c.req.param("slug");
	const token = extractToken(c.req.raw.headers);
	const access = await evaluateSpaceAccess(slug, token, "GET", { getSpaceConfig });

	if (!access.allowed) return c.json({ error: access.reason }, access.claims ? 403 : 401);

	await loadCommunity(slug);
	const data = getDocumentData(slug);
	if (!data) return c.json({ error: "Community not found" }, 404);

	return c.json({ shapes: data.shapes || {} });
});

// POST /api/communities/:slug/shapes
app.post("/api/communities/:slug/shapes", async (c) => {
	const slug = c.req.param("slug");
	const internalKey = c.req.header("X-Internal-Key");
	const isInternalCall = INTERNAL_API_KEY && internalKey === INTERNAL_API_KEY;

	if (!isInternalCall) {
		const token = extractToken(c.req.raw.headers);
		const access = await evaluateSpaceAccess(slug, token, "POST", { getSpaceConfig });
		if (!access.allowed) return c.json({ error: access.reason }, access.claims ? 403 : 401);
		if (access.readOnly) return c.json({ error: "Write access required to add shapes" }, 403);
	}

	await loadCommunity(slug);
	const data = getDocumentData(slug);
	if (!data) return c.json({ error: "Community not found" }, 404);

	const body = await c.req.json<{ shapes?: Record<string, unknown>[] }>();
	if (!body.shapes || !Array.isArray(body.shapes) || body.shapes.length === 0) {
		return c.json({ error: "shapes array is required and must not be empty" }, 400);
	}

	const ids = addShapes(slug, body.shapes);
	broadcastAutomergeSync(slug);
	broadcastJsonSnapshot(slug);

	return c.json({ ok: true, ids }, 201);
});

// PATCH /api/communities/:slug/shapes/:shapeId
app.patch("/api/communities/:slug/shapes/:shapeId", async (c) => {
	const slug = c.req.param("slug");
	const shapeId = c.req.param("shapeId");
	const internalKey = c.req.header("X-Internal-Key");
	const isInternalCall = INTERNAL_API_KEY && internalKey === INTERNAL_API_KEY;

	if (!isInternalCall) {
		const token = extractToken(c.req.raw.headers);
		const access = await evaluateSpaceAccess(slug, token, "PATCH", { getSpaceConfig });
		if (!access.allowed) return c.json({ error: access.reason }, access.claims ? 403 : 401);
	}

	await loadCommunity(slug);
	const body = await c.req.json<Record<string, unknown>>();
	const updated = updateShapeFields(slug, shapeId, body);
	if (!updated) return c.json({ error: "Shape not found" }, 404);

	broadcastAutomergeSync(slug);
	broadcastJsonSnapshot(slug);

	return c.json({ ok: true });
});

// GET /api/communities/:slug — community info
app.get("/api/communities/:slug", async (c) => {
	const slug = c.req.param("slug");
	const token = extractToken(c.req.raw.headers);
	const access = await evaluateSpaceAccess(slug, token, "GET", { getSpaceConfig });

	if (!access.allowed) return c.json({ error: access.reason }, access.claims ? 403 : 401);

	let data = getDocumentData(slug);
	if (!data) {
		await loadCommunity(slug);
		data = getDocumentData(slug);
	}
	if (!data) return c.json({ error: "Community not found" }, 404);

	return c.json({ meta: data.meta, readOnly: access.readOnly });
});

// ── Module info API (for app switcher) ──
app.get("/api/modules", (c) => {
	return c.json({ modules: getModuleInfoList() });
});

// ── Mount module routes under /:space/:moduleId ──
for (const mod of getAllModules()) {
	app.route(`/:space/${mod.id}`, mod.routes);
}

// ── Page routes ──

// Landing page: rspace.online/
app.get("/", async (c) => {
	const file = Bun.file(resolve(DIST_DIR, "index.html"));
	if (await file.exists()) {
		return new Response(file, { headers: { "Content-Type": "text/html" } });
	}
	return c.text("rSpace", 200);
});

// Create new space page
app.get("/new", async (c) => {
	const file = Bun.file(resolve(DIST_DIR, "index.html"));
	if (await file.exists()) {
		return new Response(file, { headers: { "Content-Type": "text/html" } });
	}
	return c.text("Create space", 200);
});

// Space root: /:space → redirect to /:space/canvas
app.get("/:space", (c) => {
	const space = c.req.param("space");
	// Don't redirect for static file paths
	if (space.includes(".")) return c.notFound();
	return c.redirect(`/${space}/canvas`);
});

// ── WebSocket types ──
interface WSData {
	communitySlug: string;
	peerId: string;
	claims: EncryptIDClaims | null;
	readOnly: boolean;
	mode: "automerge" | "json";
}

// Track connected clients per community
const communityClients = new Map<string, Map<string, ServerWebSocket<WSData>>>();

function generatePeerId(): string {
	return `peer-${Date.now()}-${Math.random().toString(36).substr(2, 9)}`;
}

function getClient(slug: string, peerId: string): ServerWebSocket<WSData> | undefined {
	return communityClients.get(slug)?.get(peerId);
}

function broadcastJsonSnapshot(slug: string, excludePeerId?: string): void {
	const clients = communityClients.get(slug);
	if (!clients) return;
	const docData = getDocumentData(slug);
	if (!docData) return;
	const snapshotMsg = JSON.stringify({ type: "snapshot", shapes: docData.shapes || {} });
	for (const [clientPeerId, client] of clients) {
		if (client.data.mode === "json" && clientPeerId !== excludePeerId && client.readyState === WebSocket.OPEN) {
			client.send(snapshotMsg);
		}
	}
}

function broadcastAutomergeSync(slug: string, excludePeerId?: string): void {
	const clients = communityClients.get(slug);
	if (!clients) return;
	for (const [clientPeerId, client] of clients) {
		if (client.data.mode === "automerge" && clientPeerId !== excludePeerId && client.readyState === WebSocket.OPEN) {
			const syncMsg = generateSyncMessageForPeer(slug, clientPeerId);
			if (syncMsg) {
				client.send(JSON.stringify({ type: "sync", data: Array.from(syncMsg) }));
			}
		}
	}
}

// ── Subdomain parsing (backward compat) ──
const RESERVED_SUBDOMAINS = ["www", "rspace", "create", "new", "start", "auth"];

function getSubdomain(host: string | null): string | null {
	if (!host) return null;
	if (host.includes("localhost") || host.includes("127.0.0.1")) return null;
	const parts = host.split(".");
	if (parts.length >= 3 && parts.slice(-2).join(".") === "rspace.online") {
		const sub = parts[0];
		if (!RESERVED_SUBDOMAINS.includes(sub)) return sub;
	}
	return null;
}

// ── Static file serving ──
function getContentType(path: string): string {
	if (path.endsWith(".html")) return "text/html";
	if (path.endsWith(".js")) return "application/javascript";
	if (path.endsWith(".css")) return "text/css";
	if (path.endsWith(".json")) return "application/json";
	if (path.endsWith(".svg")) return "image/svg+xml";
	if (path.endsWith(".wasm")) return "application/wasm";
	if (path.endsWith(".png")) return "image/png";
	if (path.endsWith(".jpg") || path.endsWith(".jpeg")) return "image/jpeg";
	if (path.endsWith(".gif")) return "image/gif";
	if (path.endsWith(".ico")) return "image/x-icon";
	return "application/octet-stream";
}

async function serveStatic(path: string): Promise<Response | null> {
	const filePath = resolve(DIST_DIR, path);
	const file = Bun.file(filePath);
	if (await file.exists()) {
		return new Response(file, { headers: { "Content-Type": getContentType(path) } });
	}
	return null;
}

// ── Bun.serve: WebSocket + fetch delegation ──
const server = Bun.serve<WSData>({
	port: PORT,

	async fetch(req, server) {
		const url = new URL(req.url);
		const host = req.headers.get("host");
		const subdomain = getSubdomain(host);

		// ── WebSocket upgrade ──
		if (url.pathname.startsWith("/ws/")) {
			const communitySlug = url.pathname.split("/")[2];
			if (communitySlug) {
				const spaceConfig = await getSpaceConfig(communitySlug);
				const claims = await authenticateWSUpgrade(req);
				let readOnly = false;

				if (spaceConfig) {
					const vis = spaceConfig.visibility;
					if (vis === "authenticated" || vis === "members_only") {
						if (!claims) return new Response("Authentication required", { status: 401 });
					} else if (vis === "public_read") {
						readOnly = !claims;
					}
				}

				const peerId = generatePeerId();
				const mode = url.searchParams.get("mode") === "json" ? "json" : "automerge";
				const upgraded = server.upgrade(req, {
					data: { communitySlug, peerId, claims, readOnly, mode } as WSData,
				});
				if (upgraded) return undefined;
			}
			return new Response("WebSocket upgrade failed", { status: 400 });
		}

		// ── Static assets (before Hono routing) ──
		if (url.pathname !== "/" && !url.pathname.startsWith("/api/") && !url.pathname.startsWith("/ws/")) {
			const assetPath = url.pathname.slice(1);
			// Serve files with extensions directly
			if (assetPath.includes(".")) {
				const staticResponse = await serveStatic(assetPath);
				if (staticResponse) return staticResponse;
			}
		}

		// ── Subdomain backward compat: redirect to path-based routing ──
		if (subdomain) {
			const pathSegments = url.pathname.split("/").filter(Boolean);

			// If visiting subdomain root, redirect to /:subdomain/canvas
			if (pathSegments.length === 0) {
				// First, ensure the community exists
				const community = await loadCommunity(subdomain);
				if (community) {
					// Serve canvas.html directly for backward compat
					const canvasHtml = await serveStatic("canvas.html");
					if (canvasHtml) return canvasHtml;
				}
				return new Response("Community not found", { status: 404 });
			}

			// Subdomain with path: serve canvas.html
			const slug = pathSegments.join("-");
			const community = await loadCommunity(slug) || await loadCommunity(subdomain);
			if (community) {
				const canvasHtml = await serveStatic("canvas.html");
				if (canvasHtml) return canvasHtml;
			}
			return new Response("Community not found", { status: 404 });
		}

		// ── Hono handles everything else ──
		const response = await app.fetch(req);

		// If Hono returns 404, try serving canvas.html as SPA fallback
		if (response.status === 404 && !url.pathname.startsWith("/api/")) {
			// Check if this looks like a /:space/:module path
			const parts = url.pathname.split("/").filter(Boolean);
			if (parts.length >= 1 && !parts[0].includes(".")) {
				// Could be a space/module path — try canvas.html fallback
				const canvasHtml = await serveStatic("canvas.html");
				if (canvasHtml) return canvasHtml;

				const indexHtml = await serveStatic("index.html");
				if (indexHtml) return indexHtml;
			}
		}

		return response;
	},

	// ── WebSocket handlers (unchanged) ──
	websocket: {
		open(ws: ServerWebSocket<WSData>) {
			const { communitySlug, peerId, mode } = ws.data;

			if (!communityClients.has(communitySlug)) {
				communityClients.set(communitySlug, new Map());
			}
			communityClients.get(communitySlug)!.set(peerId, ws);

			console.log(`[WS] Client ${peerId} connected to ${communitySlug} (mode: ${mode})`);

			loadCommunity(communitySlug).then((doc) => {
				if (!doc) return;

				if (mode === "json") {
					const docData = getDocumentData(communitySlug);
					if (docData) {
						ws.send(JSON.stringify({ type: "snapshot", shapes: docData.shapes || {} }));
					}
				} else {
					const syncMessage = generateSyncMessageForPeer(communitySlug, peerId);
					if (syncMessage) {
						ws.send(JSON.stringify({ type: "sync", data: Array.from(syncMessage) }));
					}
				}
			});
		},

		message(ws: ServerWebSocket<WSData>, message: string | Buffer) {
			const { communitySlug, peerId } = ws.data;

			try {
				const msg = JSON.parse(message.toString());

				if (msg.type === "sync" && Array.isArray(msg.data)) {
					if (ws.data.readOnly) {
						ws.send(JSON.stringify({ type: "error", message: "Authentication required to edit this space" }));
						return;
					}
					const syncMessage = new Uint8Array(msg.data);
					const result = receiveSyncMessage(communitySlug, peerId, syncMessage);

					if (result.response) {
						ws.send(JSON.stringify({ type: "sync", data: Array.from(result.response) }));
					}

					for (const [targetPeerId, targetMessage] of result.broadcastToPeers) {
						const targetClient = getClient(communitySlug, targetPeerId);
						if (targetClient && targetClient.data.mode === "automerge" && targetClient.readyState === WebSocket.OPEN) {
							targetClient.send(JSON.stringify({ type: "sync", data: Array.from(targetMessage) }));
						}
					}

					if (result.broadcastToPeers.size > 0) {
						broadcastJsonSnapshot(communitySlug, peerId);
					}
				} else if (msg.type === "ping") {
					ws.send(JSON.stringify({ type: "pong", timestamp: msg.timestamp }));
				} else if (msg.type === "presence") {
					const clients = communityClients.get(communitySlug);
					if (clients) {
						const presenceMsg = JSON.stringify({ type: "presence", peerId, ...msg });
						for (const [clientPeerId, client] of clients) {
							if (clientPeerId !== peerId && client.readyState === WebSocket.OPEN) {
								client.send(presenceMsg);
							}
						}
					}
				} else if (msg.type === "update" && msg.id && msg.data) {
					if (ws.data.readOnly) {
						ws.send(JSON.stringify({ type: "error", message: "Authentication required to edit" }));
						return;
					}
					updateShape(communitySlug, msg.id, msg.data);
					broadcastJsonSnapshot(communitySlug, peerId);
					broadcastAutomergeSync(communitySlug, peerId);
				} else if (msg.type === "delete" && msg.id) {
					if (ws.data.readOnly) {
						ws.send(JSON.stringify({ type: "error", message: "Authentication required to delete" }));
						return;
					}
					forgetShape(communitySlug, msg.id, ws.data.claims?.sub);
					broadcastJsonSnapshot(communitySlug, peerId);
					broadcastAutomergeSync(communitySlug, peerId);
				} else if (msg.type === "forget" && msg.id) {
					if (ws.data.readOnly) {
						ws.send(JSON.stringify({ type: "error", message: "Authentication required to forget" }));
						return;
					}
					forgetShape(communitySlug, msg.id, ws.data.claims?.sub);
					broadcastJsonSnapshot(communitySlug, peerId);
					broadcastAutomergeSync(communitySlug, peerId);
				} else if (msg.type === "remember" && msg.id) {
					if (ws.data.readOnly) {
						ws.send(JSON.stringify({ type: "error", message: "Authentication required to remember" }));
						return;
					}
					rememberShape(communitySlug, msg.id);
					broadcastJsonSnapshot(communitySlug, peerId);
					broadcastAutomergeSync(communitySlug, peerId);
				}
			} catch (e) {
				console.error("[WS] Failed to parse message:", e);
			}
		},

		close(ws: ServerWebSocket<WSData>) {
			const { communitySlug, peerId } = ws.data;
			const clients = communityClients.get(communitySlug);
			if (clients) {
				clients.delete(peerId);
				if (clients.size === 0) communityClients.delete(communitySlug);
			}
			removePeerSyncState(communitySlug, peerId);
			console.log(`[WS] Client ${peerId} disconnected from ${communitySlug}`);
		},
	},
});

// ── Startup ──
ensureDemoCommunity().then(() => console.log("[Demo] Demo community ready")).catch((e) => console.error("[Demo] Failed:", e));
ensureCampaignDemo().then(() => console.log("[Campaign] Campaign demo ready")).catch((e) => console.error("[Campaign] Failed:", e));

console.log(`rSpace unified server running on http://localhost:${PORT}`);
console.log(`Modules: ${getAllModules().map((m) => `${m.icon} ${m.name}`).join(", ")}`);