nandi.uk
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1/**
2 * Shared island utilities: canonical ID, component types, BFS, DB access.
3 */
4
5import { resolve } from 'node:path';
6import { createHash } from 'node:crypto';
7import { Database } from 'bun:sqlite';
8
9const CARRY_DIR = process.env.CARRY_DIR ?? '/home/nandi/.local/share/carry-vault';
10const DB_PATH = process.env.ISLAND_DETECT_DB ?? resolve(CARRY_DIR, '.island-detect.db');
11
12export interface Component {
13 nodes: Set<string>;
14 dids: Set<string>;
15 lexmin: string;
16 islandId: string;
17}
18
19export interface EdgeRow {
20 source: string;
21 target: string;
22 relation: string | null;
23 did: string;
24 atUri: string | null;
25}
26
27// --- Canonical island ID: first 12 hex chars of SHA-256(lexmin) ---
28
29export function islandId(lexmin: string): string {
30 return createHash('sha256').update(lexmin).digest('hex').slice(0, 12);
31}
32
33// --- SQLite ---
34
35export function openDb(): Database {
36 return new Database(DB_PATH, { readonly: true });
37}
38
39// --- Connected components (BFS) ---
40
41export function findComponents(db: Database): Component[] {
42 const adj = new Map<string, Set<string>>();
43 const edgeDids = new Map<string, Set<string>>();
44
45 const rows = db.query('SELECT source, target, did FROM edges').all() as Array<{ source: string; target: string; did: string }>;
46 for (const row of rows) {
47 const s = row.source;
48 const t = row.target;
49 if (!adj.has(s)) adj.set(s, new Set());
50 if (!adj.has(t)) adj.set(t, new Set());
51 adj.get(s)!.add(t);
52 adj.get(t)!.add(s);
53 if (!edgeDids.has(s)) edgeDids.set(s, new Set());
54 if (!edgeDids.has(t)) edgeDids.set(t, new Set());
55 edgeDids.get(s)!.add(row.did);
56 edgeDids.get(t)!.add(row.did);
57 }
58
59 const visited = new Set<string>();
60 const components: Component[] = [];
61
62 for (const node of adj.keys()) {
63 if (visited.has(node)) continue;
64 const compNodes = new Set<string>();
65 const compDids = new Set<string>();
66 const queue = [node];
67 while (queue.length > 0) {
68 const current = queue.pop()!;
69 if (visited.has(current)) continue;
70 visited.add(current);
71 compNodes.add(current);
72 for (const did of edgeDids.get(current) ?? []) compDids.add(did);
73 for (const neighbor of adj.get(current) ?? []) {
74 if (!visited.has(neighbor)) queue.push(neighbor);
75 }
76 }
77 const lexmin = [...compNodes].sort()[0];
78 components.push({ nodes: compNodes, dids: compDids, lexmin, islandId: islandId(lexmin) });
79 }
80
81 return components.sort((a, b) => b.nodes.size - a.nodes.size);
82}
83
84/** Find a component by its island ID (lexmin hash). */
85export function findComponentById(db: Database, targetId: string): Component | undefined {
86 return findComponents(db).find((c) => c.islandId === targetId);
87}
88
89/** Fetch edges for a component from the DB. */
90export function fetchComponentEdges(db: Database, component: Component): EdgeRow[] {
91 const nodePlaceholders = [...component.nodes].map(() => '?').join(',');
92 const nodeValues = [...component.nodes];
93 const edges = db.query(
94 `SELECT source, target, relation, did, at_uri as atUri FROM edges WHERE source IN (${nodePlaceholders}) OR target IN (${nodePlaceholders})`,
95 ).all(...nodeValues, ...nodeValues) as EdgeRow[];
96
97 // Deduplicate (same source+target from multiple DIDs)
98 const seen = new Set<string>();
99 const unique: EdgeRow[] = [];
100 for (const e of edges) {
101 const key = `${e.source}::${e.target}`;
102 if (!seen.has(key)) {
103 seen.add(key);
104 unique.push(e);
105 }
106 }
107 return unique;
108}
109
110/** Resolve handles for a set of DIDs. */
111export function resolveDidHandles(db: Database, dids: Set<string>): Map<string, string | null> {
112 const handles = new Map<string, string | null>();
113 if (dids.size === 0) return handles;
114 const placeholders = [...dids].map(() => '?').join(',');
115 const rows = db.query(`SELECT did, handle FROM dids WHERE did IN (${placeholders})`).all(...dids) as Array<{ did: string; handle: string | null }>;
116 for (const r of rows) handles.set(r.did, r.handle);
117 return handles;
118}
119
120/** Extract domain from a URL for display. */
121export function domainFromUrl(url: string): string {
122 try {
123 return new URL(url).hostname.replace(/^www\./, '');
124 } catch {
125 return url;
126 }
127}