1/*
2 * Copyright (c) 2026 DataPond D-Library Pty Ltd. ("The Sanctuary")
3 * Non-Profit Public Library — The World Library
4 * 
5 * D-SAFE Certification issued by POND Enterprise.
6 * Published under the D-Open Code Sovereign Licence v1.0 framework
7 * DataPond D-Library All exclusive Right reserved on modifiying the code - CC Attribution to data pond, Non modifiable, Non Commercial.
8 * https://registry.world.bibliotech.com/licence
9 * Source code donated to DataPond D-Library by it's author: data pond.
10 * 
11 * Technical Guardian ("The Shield"): Pond Enterprise Pty Ltd. (ACN 694 747 987)
12 * All liability claims about D-SAFE certification issues coming from the published D-Safe direction must be addressed with Pond Enterprise Pty Ltd.
13 * Code Modification automatically voids the certified liability protection provided by Pond Enterprise.
14 */
15import type { Lang, SidecarUrls } from "../../interfaces.ts";
16import type { StoredPatch } from "../../indexdb/patch_storage.ts";
17import { getAllPatches } from "../../indexdb/patch_storage.ts";
18import { parseSidecar, extractRecordCols, type ParsedSidecar } from "../../enriched-index.ts";
19
20export interface SidecarSet {
21    objectType: number;
22    lang: Lang;
23    slim?: ParsedSidecar;
24    extended?: ParsedSidecar;
25    prov?: ParsedSidecar;
26    /** uid -> array index, from the `ids` column of the slim tier. */
27    idIndex: Map<number, number>;
28}
29
30/** Worker-side retained sidecar data, for GetRecord re-hydration. */
31export const sidecarStore = new Map<number, Map<Lang, SidecarSet>>();
32
33let currentLangs: Lang[] = ['eng'];
34export const getCurrentLangs = (): Lang[] => currentLangs;
35
36const fetchAndParse = async (url: string): Promise<ParsedSidecar> => {
37    const response = await fetch(url);
38    if (!response.ok) {
39        throw new Error(`failed to fetch sidecar ${url}: ${response.status}`);
40    }
41    return parseSidecar(await response.arrayBuffer());
42}
43
44const buildIdIndex = (parsed: ParsedSidecar | undefined): Map<number, number> => {
45    const map = new Map<number, number>();
46    const ids = parsed?.columns.get('ids');
47    if (ids && !Array.isArray(ids)) {
48        for (let i = 0; i < ids.length; i++) {
49            map.set(ids[i], i);
50        }
51    }
52    return map;
53}
54
55/**
56 * Fetches and parses all sidecar tiers off the main thread, retains them in
57 * worker memory (for GetRecord), and returns the parsed structures plus all
58 * locally stored patches. Maps and TypedArrays survive the structured clone.
59 */
60export const initialLoad = async (sidecars: Array<SidecarUrls>, selectedLangs: Lang[]): Promise<{
61    sidecars: Array<SidecarSet>,
62    patches: { [user: string]: Array<StoredPatch> },
63}> => {
64    console.log(`[worker] initialLoad started: ${sidecars.length} sidecar set(s), langs=${selectedLangs.join(',')}`)
65    currentLangs = selectedLangs;
66    sidecarStore.clear();
67
68    const sets: Array<SidecarSet> = [];
69    for (const { objectType, lang, slimUrl, extendedUrl, provUrl } of sidecars) {
70        const [slim, extended, prov] = await Promise.all([
71            slimUrl ? fetchAndParse(slimUrl) : Promise.resolve(undefined),
72            extendedUrl ? fetchAndParse(extendedUrl) : Promise.resolve(undefined),
73            provUrl ? fetchAndParse(provUrl) : Promise.resolve(undefined),
74        ]);
75        const set: SidecarSet = {
76            objectType,
77            lang,
78            slim,
79            extended,
80            prov,
81            idIndex: buildIdIndex(slim ?? extended),
82        };
83        
84        let byLang = sidecarStore.get(objectType);
85        if (!byLang) {
86            byLang = new Map<Lang, SidecarSet>();
87            sidecarStore.set(objectType, byLang);
88        }
89        byLang.set(lang, set);
90        sets.push(set);
91    }
92
93    console.log(`[worker] fetching local patches...`)
94    const patches = await getAllPatches();
95
96    console.log(`[worker] initialLoad complete`)
97    return { sidecars: sets, patches };
98}
99
100/**
101 * Single-record extraction for LRU re-hydration (WorkerCommands.GetRecord).
102 * Returns cols objects whose arrays hold exactly one entry — the main thread
103 * merges them with `merge*(cols, 0, lang)`.
104 */
105export const getRecordCols = (objectType: number, id: number): Array<{
106    lang: Lang,
107    slim?: Record<string, any>,
108    extended?: Record<string, any>,
109    prov?: Record<string, any>,
110}> => {
111    const out: Array<{
112        lang: Lang,
113        slim?: Record<string, any>,
114        extended?: Record<string, any>,
115        prov?: Record<string, any>,
116    }> = [];
117
118    const byLang = sidecarStore.get(objectType);
119    if (!byLang) return out;
120
121    for (const lang of currentLangs) {
122        const set = byLang.get(lang);
123        if (!set) continue;
124
125        const index = set.idIndex.get(id);
126        if (typeof index === 'undefined') continue;
127
128        out.push({
129            lang,
130            slim: set.slim ? extractRecordCols(set.slim, index) : undefined,
131            extended: set.extended ? extractRecordCols(set.extended, index) : undefined,
132            prov: set.prov ? extractRecordCols(set.prov, index) : undefined,
133        });
134    }
135
136    return out;
137}
138