wip: fluent setup, locale compiler & typechecker, markdown parser

apps/vdn-static/src/new-i18n/setup.ts

@@ -0,0 +1,179 @@
+import type { Result } from "@/utils/types";
+import {
+	FluentBundle,
+	FluentResource,
+	type FluentVariable,
+} from "@fluent/bundle";
+import { unsafeAsync } from "@/utils/unsafe";
+import type { Literal, Message, Pattern } from "@fluent/bundle/esm/ast";
+
+export async function loadFluentBundle(
+	localeId: string,
+	src: string,
+): Promise<Result<FluentBundle, string>> {
+	const ftlFileResponseRes = await unsafeAsync(() => fetch(src));
+	if (ftlFileResponseRes.type === "err") {
+		return { type: "err", err: `Failed to fetch locale from src: ${src}` };
+	}
+
+	const ftlFileResponse = ftlFileResponseRes.ok;
+	const ftlFileTextRes = await unsafeAsync(() => ftlFileResponse.text());
+	if (ftlFileTextRes.type === "err") {
+		return {
+			type: "err",
+			err: `Failed to fetch text content of FTL file from src: ${src}`,
+		};
+	}
+
+	const ftlFileText = ftlFileTextRes.ok;
+	console.log(ftlFileText);
+	const resource = new FluentResource(ftlFileText);
+
+	console.log(resource.body);
+
+	const bundle = new FluentBundle(localeId);
+	const errors = bundle.addResource(resource);
+	if (errors.length > 0) {
+		return {
+			type: "err",
+			err: `Failed to add Fluent resource to bundle:\n${errors.join("\n")}`,
+		};
+	}
+
+	return { type: "ok", ok: bundle };
+}
+
+export type L10nRecord = {
+	[id: string]:
+		| { type: "message"; message: Message }
+		| { type: "subrecord"; subrecord: L10nRecord };
+};
+
+export interface UncompiledLocale {
+	bundle: FluentBundle;
+	record: L10nRecord;
+}
+
+export function bundleToUncompiledLocale(
+	bundle: FluentBundle,
+): Result<UncompiledLocale, string> {
+	const record: L10nRecord = {};
+	for (const [id, message] of bundle._messages) {
+		const idChain = id.split("-");
+		let subrecord = record;
+
+		while (true) {
+			const subId = idChain.shift();
+			if (subId === undefined) {
+				return {
+					type: "err",
+					err: `Reached end of message ID chain before terminating for message ID: ${id}`,
+				};
+			}
+
+			if (idChain.length === 0) {
+				subrecord[subId] = { type: "message", message };
+				break;
+			} else {
+				const maybeSubrecord = (subrecord[subId] ??= {
+					type: "subrecord",
+					subrecord: {},
+				});
+
+				if (maybeSubrecord.type === "subrecord") {
+					subrecord = maybeSubrecord.subrecord;
+				} else {
+					return {
+						type: "err",
+						err: `Found message when expected subrecord for message ID: ${id} @ subId: ${subId}`,
+					};
+				}
+			}
+		}
+	}
+
+	return { type: "ok", ok: { bundle, record } };
+}
+
+type SelectionChain = (Literal | SelectionChain)[];
+
+interface PatternVariant {
+	selectionChain: SelectionChain;
+	string: string;
+}
+
+export function computeAllVariants(
+	pattern: Pattern,
+): Result<PatternVariant[], string> {
+	if (typeof pattern === "string") {
+		return { type: "ok", ok: [{ selectionChain: [], string: pattern }] };
+	}
+
+	let variants: PatternVariant[] = [{ selectionChain: [], string: "" }];
+	for (const element of pattern) {
+		if (typeof element === "string") {
+			variants = variants.map((variant) => ({
+				selectionChain: variant.selectionChain,
+				string: variant.string + element,
+			}));
+
+			continue;
+		}
+
+		switch (element.type) {
+			case "select": {
+				const selectVariants: PatternVariant[] = [];
+				for (const selectVariant of element.variants) {
+					const variantComputedRes = computeAllVariants(
+						selectVariant.value,
+					);
+
+					if (variantComputedRes.type === "err") {
+						return {
+							type: "err",
+							err: `Failed to compute select variants:\n${variantComputedRes.err}`,
+						};
+					}
+
+					const variantComputed = variantComputedRes.ok;
+					selectVariants.push(
+						...variantComputed.map(
+							(v): PatternVariant => ({
+								selectionChain: [
+									selectVariant.key,
+									...v.selectionChain,
+								],
+								string: v.string,
+							}),
+						),
+					);
+				}
+
+				variants = variants.flatMap((variant) =>
+					selectVariants.map(
+						(selectVariant): PatternVariant => ({
+							selectionChain: [
+								...variant.selectionChain,
+								selectVariant.selectionChain,
+							],
+							string: variant.string + selectVariant.string,
+						}),
+					),
+				);
+
+				break;
+			}
+			case "var": {
+				continue;
+			}
+			default: {
+				return {
+					type: "err",
+					err: `Unhandled PatternElement type: ${element.type}`,
+				};
+			}
+		}
+	}
+
+	return { type: "ok", ok: variants };
+}