feat: add chains page, update pipeline usage

web/src/lib/chains.svelte.ts

@@ -0,0 +1,153 @@
+import { formatStamp } from "./core/datefmt";
+import type { OutputMime } from "./core/io";
+import type { PixelImage } from "./core/types";
+import { t } from "./i18n/t";
+import {
+	CHAIN_VERSION,
+	parseChain,
+	serializeSteps,
+	type ChainStep,
+} from "./pipeline.svelte";
+
+export interface NamedChain {
+	id: string;
+	name: string;
+	updatedAt: number;
+	steps: ChainStep[];
+}
+
+const STORE_KEY = "chains:named";
+
+function storage(): Storage | null {
+	return typeof localStorage === "undefined" ? null : localStorage;
+}
+
+export function autoChainName(date = new Date()): string {
+	return t("savedChains.autoName", {
+		stamp: formatStamp(date, "YYYY-MM-DD hh:mm"),
+	});
+}
+
+/**
+ * Lenient per entry: one broken chain must not kill the rest of the list.
+ * Steps reuse the same serialized shape and validation as parseChain.
+ */
+export function parseNamedChains(data: unknown): NamedChain[] {
+	if (
+		!data ||
+		typeof data !== "object" ||
+		(data as { version?: unknown }).version !== CHAIN_VERSION ||
+		!Array.isArray((data as { chains?: unknown }).chains)
+	) {
+		return [];
+	}
+	const out: NamedChain[] = [];
+	for (const raw of (data as { chains: unknown[] }).chains) {
+		if (!raw || typeof raw !== "object") continue;
+		const { id, name, updatedAt, steps } = raw as {
+			id?: unknown;
+			name?: unknown;
+			updatedAt?: unknown;
+			steps?: unknown;
+		};
+		if (typeof id !== "string" || typeof name !== "string") continue;
+		const parsed = parseChain({ version: CHAIN_VERSION, steps });
+		if (!parsed) continue;
+		out.push({
+			id,
+			name,
+			updatedAt:
+				typeof updatedAt === "number" && Number.isFinite(updatedAt)
+					? updatedAt
+					: 0,
+			steps: parsed,
+		});
+	}
+	return out;
+}
+
+export function serializeNamedChains(
+	chains: NamedChain[],
+): Record<string, unknown> {
+	return {
+		version: CHAIN_VERSION,
+		chains: chains.map((c) => ({
+			id: c.id,
+			name: c.name,
+			updatedAt: c.updatedAt,
+			steps: serializeSteps(c.steps),
+		})),
+	};
+}
+
+function readAll(): NamedChain[] {
+	const raw = storage()?.getItem(STORE_KEY);
+	if (!raw) return [];
+	try {
+		return parseNamedChains(JSON.parse(raw));
+	} catch {
+		return [];
+	}
+}
+
+function writeAll(chains: NamedChain[]): void {
+	storage()?.setItem(STORE_KEY, JSON.stringify(serializeNamedChains(chains)));
+}
+
+/** Newest first. */
+export function listChains(): NamedChain[] {
+	return readAll().sort((a, b) => b.updatedAt - a.updatedAt);
+}
+
+export function getChain(id: string): NamedChain | undefined {
+	return readAll().find((c) => c.id === id);
+}
+
+export function createNamedChain(name: string, steps: ChainStep[]): NamedChain {
+	const chain: NamedChain = {
+		id: crypto.randomUUID(),
+		name: name.trim() || autoChainName(),
+		updatedAt: Date.now(),
+		steps,
+	};
+	writeAll([...readAll(), chain]);
+	return chain;
+}
+
+export function updateChainSteps(id: string, steps: ChainStep[]): void {
+	writeAll(
+		readAll().map((c) =>
+			c.id === id ? { ...c, steps, updatedAt: Date.now() } : c,
+		),
+	);
+}
+
+export function renameChain(id: string, name: string): void {
+	const trimmed = name.trim();
+	if (!trimmed) return;
+	writeAll(readAll().map((c) => (c.id === id ? { ...c, name: trimmed } : c)));
+}
+
+export function deleteChain(id: string): void {
+	writeAll(readAll().filter((c) => c.id !== id));
+}
+
+/** State that cannot persist across the tool -> pipeline route swap. */
+export interface ChainHandoff {
+	source: PixelImage | null;
+	textSource: string;
+	format: OutputMime;
+	limitKb: number | undefined;
+}
+
+const handoffs = new Map<string, ChainHandoff>();
+
+export function stashHandoff(id: string, handoff: ChainHandoff): void {
+	handoffs.set(id, handoff);
+}
+
+export function takeHandoff(id: string): ChainHandoff | undefined {
+	const handoff = handoffs.get(id);
+	handoffs.delete(id);
+	return handoff;
+}