/**
 * Space registry — CRUD for rSpace spaces.
 *
 * Spaces are stored as Automerge CRDT documents (extending the existing
 * community-store pattern). This module provides Hono routes for listing,
 * creating, and managing spaces.
 */

import { Hono } from "hono";
import { stat } from "node:fs/promises";
import {
	communityExists,
	createCommunity,
	loadCommunity,
	getDocumentData,
	listCommunities,
	addNestedSpace,
	updateNestedSpace,
	removeNestedSpace,
	getNestPolicy,
	updateNestPolicy,
	capPermissions,
	findNestedIn,
	DEFAULT_COMMUNITY_NEST_POLICY,
} from "./community-store";
import type {
	SpaceVisibility,
	NestPermissions,
	NestPolicy,
	SpaceRef,
	PendingNestRequest,
	NestRequestStatus,
} from "./community-store";
import {
	verifyEncryptIDToken,
	extractToken,
} from "@encryptid/sdk/server";
import type { EncryptIDClaims } from "@encryptid/sdk/server";
import { getAllModules } from "../shared/module";

// ── In-memory pending nest requests (move to DB later) ──
const nestRequests = new Map<string, PendingNestRequest>();
let nestRequestCounter = 0;

const spaces = new Hono();

// ── List spaces (public + user's own/member spaces) ──

spaces.get("/", async (c) => {
	const slugs = await listCommunities();

	// Check if user is authenticated
	const token = extractToken(c.req.raw.headers);
	let claims: EncryptIDClaims | null = null;
	if (token) {
		try {
			claims = await verifyEncryptIDToken(token);
		} catch {
			// Invalid token — treat as unauthenticated
		}
	}

	const spacesList = [];
	for (const slug of slugs) {
		await loadCommunity(slug);
		const data = getDocumentData(slug);
		if (data?.meta) {
			const vis = data.meta.visibility || "public_read";
			const isOwner = !!(claims && data.meta.ownerDID === claims.sub);
			const memberEntry = claims ? data.members?.[claims.sub] : undefined;
			const isMember = !!memberEntry;

			// Include if: public/public_read OR user is owner OR user is member
			if (vis === "public" || vis === "public_read" || isOwner || isMember) {
				spacesList.push({
					slug: data.meta.slug,
					name: data.meta.name,
					visibility: vis,
					createdAt: data.meta.createdAt,
					role: isOwner ? "owner" : memberEntry?.role || undefined,
				});
			}
		}
	}

	return c.json({ spaces: spacesList });
});

// ── Create a new space (requires auth) ──

spaces.post("/", async (c) => {
	const token = extractToken(c.req.raw.headers);
	if (!token) {
		return c.json({ error: "Authentication required" }, 401);
	}

	let claims: EncryptIDClaims;
	try {
		claims = await verifyEncryptIDToken(token);
	} catch {
		return c.json({ error: "Invalid or expired 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. Must be one of: ${validVisibilities.join(", ")}` }, 400);
	}

	if (await communityExists(slug)) {
		return c.json({ error: "Space already exists" }, 409);
	}

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

	// Notify all modules about the new space
	for (const mod of getAllModules()) {
		if (mod.onSpaceCreate) {
			try {
				await mod.onSpaceCreate(slug);
			} catch (e) {
				console.error(`[Spaces] Module ${mod.id} onSpaceCreate failed:`, e);
			}
		}
	}

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

// ── Get space info ──

spaces.get("/:slug", async (c) => {
	const slug = c.req.param("slug");
	await loadCommunity(slug);
	const data = getDocumentData(slug);

	if (!data) {
		return c.json({ error: "Space not found" }, 404);
	}

	return c.json({
		slug: data.meta.slug,
		name: data.meta.name,
		visibility: data.meta.visibility,
		createdAt: data.meta.createdAt,
		ownerDID: data.meta.ownerDID,
		memberCount: Object.keys(data.members || {}).length,
	});
});

// ── Admin: list ALL spaces with detailed stats ──

spaces.get("/admin", async (c) => {
	const STORAGE_DIR = process.env.STORAGE_DIR || "./data/communities";
	const slugs = await listCommunities();

	const spacesList = [];
	for (const slug of slugs) {
		await loadCommunity(slug);
		const data = getDocumentData(slug);
		if (!data?.meta) continue;

		const shapes = data.shapes || {};
		const members = data.members || {};
		const shapeCount = Object.keys(shapes).length;
		const memberCount = Object.keys(members).length;

		// Get file size on disk
		let fileSizeBytes = 0;
		try {
			const s = await stat(`${STORAGE_DIR}/${slug}.automerge`);
			fileSizeBytes = s.size;
		} catch {
			try {
				const s = await stat(`${STORAGE_DIR}/${slug}.json`);
				fileSizeBytes = s.size;
			} catch { /* not on disk yet */ }
		}

		// Count shapes by type
		const shapeTypes: Record<string, number> = {};
		for (const shape of Object.values(shapes)) {
			const t = (shape as Record<string, unknown>).type as string || "unknown";
			shapeTypes[t] = (shapeTypes[t] || 0) + 1;
		}

		spacesList.push({
			slug: data.meta.slug,
			name: data.meta.name,
			visibility: data.meta.visibility || "public_read",
			createdAt: data.meta.createdAt,
			ownerDID: data.meta.ownerDID,
			shapeCount,
			memberCount,
			fileSizeBytes,
			shapeTypes,
		});
	}

	// Sort by creation date descending (newest first)
	spacesList.sort((a, b) => {
		const da = a.createdAt ? new Date(a.createdAt).getTime() : 0;
		const db = b.createdAt ? new Date(b.createdAt).getTime() : 0;
		return db - da;
	});

	return c.json({ spaces: spacesList, total: spacesList.length });
});

// ══════════════════════════════════════════════════════════════════════════════
// NESTING API
// ══════════════════════════════════════════════════════════════════════════════

// ── Get nest policy for a space ──

spaces.get("/:slug/nest-policy", async (c) => {
	const slug = c.req.param("slug");
	await loadCommunity(slug);
	const policy = getNestPolicy(slug);
	if (!policy) return c.json({ error: "Space not found" }, 404);
	return c.json({ nestPolicy: policy });
});

// ── Update nest policy (admin only) ──

spaces.patch("/:slug/nest-policy", async (c) => {
	const slug = c.req.param("slug");
	const token = extractToken(c.req.raw.headers);
	if (!token) return c.json({ error: "Authentication required" }, 401);

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

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

	// Must be admin or owner
	const member = data.members?.[claims.sub];
	const isOwner = data.meta.ownerDID === claims.sub;
	if (!isOwner && member?.role !== 'admin') {
		return c.json({ error: "Admin access required" }, 403);
	}

	const body = await c.req.json<Partial<NestPolicy>>();
	updateNestPolicy(slug, body);

	return c.json({ ok: true, nestPolicy: getNestPolicy(slug) });
});

// ── List nested spaces in a space ──

spaces.get("/:slug/nest", async (c) => {
	const slug = c.req.param("slug");
	await loadCommunity(slug);
	const data = getDocumentData(slug);
	if (!data) return c.json({ error: "Space not found" }, 404);

	const refs = Object.values(data.nestedSpaces || {});
	return c.json({ nestedSpaces: refs });
});

// ── Nest a space (create SpaceRef) — respects source space's NestPolicy ──

spaces.post("/:slug/nest", async (c) => {
	const targetSlug = c.req.param("slug");
	const token = extractToken(c.req.raw.headers);
	if (!token) return c.json({ error: "Authentication required" }, 401);

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

	const body = await c.req.json<{
		sourceSlug: string;
		permissions?: Partial<NestPermissions>;
		filter?: SpaceRef['filter'];
		x?: number; y?: number;
		width?: number; height?: number;
		rotation?: number;
		label?: string;
		collapsed?: boolean;
		message?: string;
	}>();

	const { sourceSlug } = body;
	if (!sourceSlug) return c.json({ error: "sourceSlug is required" }, 400);

	// Load both spaces
	await loadCommunity(targetSlug);
	await loadCommunity(sourceSlug);
	const targetData = getDocumentData(targetSlug);
	const sourceData = getDocumentData(sourceSlug);
	if (!targetData) return c.json({ error: "Target space not found" }, 404);
	if (!sourceData) return c.json({ error: "Source space not found" }, 404);

	// Check: requester must be admin or moderator in the TARGET space
	const targetMember = targetData.members?.[claims.sub];
	const isTargetOwner = targetData.meta.ownerDID === claims.sub;
	if (!isTargetOwner && targetMember?.role !== 'admin' && targetMember?.role !== 'moderator') {
		return c.json({ error: "Admin or moderator role required in the target space" }, 403);
	}

	// Get source space's nest policy
	const policy = sourceData.meta.nestPolicy || DEFAULT_COMMUNITY_NEST_POLICY;

	// Check blocklist
	if (policy.blocklist?.includes(targetSlug)) {
		return c.json({ error: "Source space has blocked nesting into this space" }, 403);
	}

	// Check consent level
	const isOnAllowlist = policy.allowlist?.includes(targetSlug);

	if (policy.consent === 'closed' && !isOnAllowlist) {
		return c.json({ error: "Source space does not allow nesting" }, 403);
	}

	if (policy.consent === 'members' && !isOnAllowlist) {
		const sourceMember = sourceData.members?.[claims.sub];
		const isSourceOwner = sourceData.meta.ownerDID === claims.sub;
		if (!isSourceOwner && !sourceMember) {
			return c.json({ error: "Must be a member of the source space to nest it" }, 403);
		}
	}

	// Build requested permissions, capped by source policy's ceiling
	const requestedPerms: NestPermissions = {
		read: body.permissions?.read ?? true,
		write: body.permissions?.write ?? false,
		addShapes: body.permissions?.addShapes ?? false,
		deleteShapes: body.permissions?.deleteShapes ?? false,
		reshare: body.permissions?.reshare ?? false,
		expiry: body.permissions?.expiry,
	};
	const cappedPerms = capPermissions(requestedPerms, policy.defaultPermissions);

	// If consent is 'approval' and not on allowlist, create a pending request
	if (policy.consent === 'approval' && !isOnAllowlist) {
		const reqId = `nest-req-${++nestRequestCounter}`;
		const request: PendingNestRequest = {
			id: reqId,
			sourceSlug,
			targetSlug,
			requestedBy: claims.sub,
			requestedPermissions: cappedPerms,
			message: body.message,
			status: 'pending',
			createdAt: Date.now(),
		};
		nestRequests.set(reqId, request);

		return c.json({
			status: 'pending',
			requestId: reqId,
			message: 'Nest request created. Awaiting source space admin approval.',
			cappedPermissions: cappedPerms,
		}, 202);
	}

	// Consent is 'open', 'members' (passed), or allowlisted — create immediately
	const refId = `ref-${Date.now()}-${Math.random().toString(36).slice(2, 8)}`;
	const ref: SpaceRef = {
		id: refId,
		sourceSlug,
		sourceDID: claims.sub,
		filter: body.filter,
		x: body.x ?? 100,
		y: body.y ?? 100,
		width: body.width ?? 600,
		height: body.height ?? 400,
		rotation: body.rotation ?? 0,
		permissions: cappedPerms,
		collapsed: body.collapsed ?? false,
		label: body.label,
		createdAt: Date.now(),
		createdBy: claims.sub,
	};

	addNestedSpace(targetSlug, ref);

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

// ── Get a specific nested space ref ──

spaces.get("/:slug/nest/:refId", async (c) => {
	const slug = c.req.param("slug");
	const refId = c.req.param("refId");
	await loadCommunity(slug);
	const data = getDocumentData(slug);
	if (!data) return c.json({ error: "Space not found" }, 404);

	const ref = data.nestedSpaces?.[refId];
	if (!ref) return c.json({ error: "Nested space ref not found" }, 404);

	return c.json({ ref });
});

// ── Update a nested space ref (permissions, filter, position) ──

spaces.patch("/:slug/nest/:refId", async (c) => {
	const slug = c.req.param("slug");
	const refId = c.req.param("refId");
	const token = extractToken(c.req.raw.headers);
	if (!token) return c.json({ error: "Authentication required" }, 401);

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

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

	const ref = data.nestedSpaces?.[refId];
	if (!ref) return c.json({ error: "Nested space ref not found" }, 404);

	// Must be admin/moderator in the nesting space OR the creator of this ref
	const member = data.members?.[claims.sub];
	const isOwner = data.meta.ownerDID === claims.sub;
	const isRefCreator = ref.createdBy === claims.sub;
	if (!isOwner && member?.role !== 'admin' && member?.role !== 'moderator' && !isRefCreator) {
		return c.json({ error: "Insufficient permissions" }, 403);
	}

	const body = await c.req.json<Partial<SpaceRef>>();
	updateNestedSpace(slug, refId, body);

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

// ── Remove a nested space ref (un-nest) ──

spaces.delete("/:slug/nest/:refId", async (c) => {
	const slug = c.req.param("slug");
	const refId = c.req.param("refId");
	const token = extractToken(c.req.raw.headers);
	if (!token) return c.json({ error: "Authentication required" }, 401);

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

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

	const ref = data.nestedSpaces?.[refId];
	if (!ref) return c.json({ error: "Nested space ref not found" }, 404);

	// Can be removed by:
	// 1. Admin/owner of the nesting (target) space
	// 2. Creator of this ref
	// 3. Admin/owner of the SOURCE space (sovereignty guarantee)
	const member = data.members?.[claims.sub];
	const isOwner = data.meta.ownerDID === claims.sub;
	const isRefCreator = ref.createdBy === claims.sub;

	let isSourceAdmin = false;
	await loadCommunity(ref.sourceSlug);
	const sourceData = getDocumentData(ref.sourceSlug);
	if (sourceData) {
		const sourceMember = sourceData.members?.[claims.sub];
		isSourceAdmin = sourceData.meta.ownerDID === claims.sub || sourceMember?.role === 'admin';
	}

	if (!isOwner && member?.role !== 'admin' && !isRefCreator && !isSourceAdmin) {
		return c.json({ error: "Insufficient permissions" }, 403);
	}

	removeNestedSpace(slug, refId);

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

// ── Reverse lookup: where is this space nested? ──

spaces.get("/:slug/nested-in", async (c) => {
	const slug = c.req.param("slug");
	const token = extractToken(c.req.raw.headers);
	if (!token) return c.json({ error: "Authentication required" }, 401);

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

	// Must be admin/owner of the space to see where it's nested
	await loadCommunity(slug);
	const data = getDocumentData(slug);
	if (!data) return c.json({ error: "Space not found" }, 404);

	const member = data.members?.[claims.sub];
	const isOwner = data.meta.ownerDID === claims.sub;
	if (!isOwner && member?.role !== 'admin') {
		return c.json({ error: "Admin access required" }, 403);
	}

	const nestedIn = await findNestedIn(slug);
	return c.json({ nestedIn });
});

// ══════════════════════════════════════════════════════════════════════════════
// NEST REQUEST API (approval flow)
// ══════════════════════════════════════════════════════════════════════════════

// ── List pending nest requests for a space (admin only) ──

spaces.get("/:slug/nest-requests", async (c) => {
	const slug = c.req.param("slug");
	const token = extractToken(c.req.raw.headers);
	if (!token) return c.json({ error: "Authentication required" }, 401);

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

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

	const member = data.members?.[claims.sub];
	const isOwner = data.meta.ownerDID === claims.sub;
	if (!isOwner && member?.role !== 'admin') {
		return c.json({ error: "Admin access required" }, 403);
	}

	// Find requests where this space is the SOURCE (someone wants to nest us)
	const requests = Array.from(nestRequests.values())
		.filter(r => r.sourceSlug === slug);

	return c.json({ requests });
});

// ── Approve or deny a nest request ──

spaces.patch("/:slug/nest-requests/:reqId", async (c) => {
	const slug = c.req.param("slug");
	const reqId = c.req.param("reqId");
	const token = extractToken(c.req.raw.headers);
	if (!token) return c.json({ error: "Authentication required" }, 401);

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

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

	const member = data.members?.[claims.sub];
	const isOwner = data.meta.ownerDID === claims.sub;
	if (!isOwner && member?.role !== 'admin') {
		return c.json({ error: "Admin access required" }, 403);
	}

	const request = nestRequests.get(reqId);
	if (!request || request.sourceSlug !== slug) {
		return c.json({ error: "Nest request not found" }, 404);
	}
	if (request.status !== 'pending') {
		return c.json({ error: `Request already ${request.status}` }, 400);
	}

	const body = await c.req.json<{
		action: 'approve' | 'deny';
		modifiedPermissions?: NestPermissions;
	}>();

	if (body.action === 'deny') {
		request.status = 'denied';
		request.resolvedAt = Date.now();
		request.resolvedBy = claims.sub;
		return c.json({ ok: true, status: 'denied' });
	}

	if (body.action === 'approve') {
		const finalPerms = body.modifiedPermissions || request.requestedPermissions;
		request.status = 'approved';
		request.resolvedAt = Date.now();
		request.resolvedBy = claims.sub;
		request.modifiedPermissions = body.modifiedPermissions;

		// Create the actual SpaceRef in the TARGET space
		await loadCommunity(request.targetSlug);
		const refId = `ref-${Date.now()}-${Math.random().toString(36).slice(2, 8)}`;
		const ref: SpaceRef = {
			id: refId,
			sourceSlug: request.sourceSlug,
			sourceDID: request.requestedBy,
			x: 100,
			y: 100,
			width: 600,
			height: 400,
			rotation: 0,
			permissions: finalPerms,
			collapsed: false,
			createdAt: Date.now(),
			createdBy: request.requestedBy,
		};

		addNestedSpace(request.targetSlug, ref);

		return c.json({ ok: true, status: 'approved', ref });
	}

	return c.json({ error: "action must be 'approve' or 'deny'" }, 400);
});

export { spaces };