#!/usr/bin/env node
// Unicode 17 default extended grapheme clusters (UAX #29), matching the
// pinned Node release. Normal builds use the checked-in tables and cases.
import { createHash } from "node:crypto";
import { mkdir, readFile, writeFile } from "node:fs/promises";
import { fileURLToPath } from "node:url";
import { join } from "node:path";

const root = fileURLToPath(new URL("..", import.meta.url));
const inputs = [
  ["auxiliary/GraphemeBreakProperty.txt", "d6b51d1d2ae5c33b451b7ed994b48f1f4dc62b2272a5831e7fd418514a6bae89"],
  ["DerivedCoreProperties.txt", "24c7fed1195c482faaefd5c1e7eb821c5ee1fb6de07ecdbaa64b56a99da22c08"],
  ["emoji/emoji-data.txt", "2cb2bb9455cda83e8481541ecf5b6dfda66a3bb89efa3fa7c5297eccf607b72b"],
  ["auxiliary/GraphemeBreakTest.txt", "e2d134d2c52919bace503ebb6a551c1855fe1a1faec18478c78fff254a1793ec"],
];
const files = await Promise.all(inputs.map(async ([path, hash]) => {
  const bytes = process.argv[2]
    ? await readFile(join(process.argv[2], path.split("/").at(-1)))
    : await (async () => {
        const response = await fetch(`https://www.unicode.org/Public/17.0.0/ucd/${path}`);
        if (!response.ok) throw new Error(`${path}: ${response.status}`);
        return Buffer.from(await response.arrayBuffer());
      })();
  if (createHash("sha256").update(bytes).digest("hex") !== hash) throw new Error(`${path}: checksum mismatch`);
  return bytes.toString("utf8");
}));

const names = ["Other", "CR", "LF", "Control", "Extend", "ZWJ", "Regional_Indicator", "Prepend", "SpacingMark", "L", "V", "T", "LV", "LVT"];
const data = new Uint8Array(0x110000);
function properties(text, select) {
  for (const line of text.split("\n")) {
    const fields = line.split("#")[0].trim().split(";").map((x) => x.trim());
    if (fields.length < 2) continue;
    const value = select(fields);
    if (!value) continue;
    const [start, end = start] = fields[0].split("..").map((x) => parseInt(x, 16));
    for (let cp = start; cp <= end; cp++) data[cp] |= value;
  }
}
properties(files[0], ([, value]) => names.indexOf(value));
properties(files[1], ([, property, value]) => property === "InCB" ? ["None", "Consonant", "Extend", "Linker"].indexOf(value) << 4 : 0);
properties(files[2], ([, property]) => property === "Extended_Pictographic" ? 64 : 0);
// Hangul syllables have an algorithmic LV/LVT classification.
data.fill(0, 0xac00, 0xd7a4);
const rows = [];
for (let start = 0; start < data.length;) {
  let end = start + 1;
  while (end < data.length && data[end] === data[start]) end++;
  if (data[start]) rows.push(`  { 0x${start.toString(16)}, 0x${(end - 1).toString(16)}, ${data[start]} },`);
  start = end;
}
const header = [
  "/* Generated by scripts/gen-grapheme-tables.mjs; Unicode 17.0.0.",
  " * Unicode data is licensed under vendor/unicode/LICENSE. Do not edit. */",
  "#ifndef SCR_GRAPHEME_DATA_H",
  "#define SCR_GRAPHEME_DATA_H",
  "enum { " + names.map((name, index) => `SCR_GCB_${name.toUpperCase()} = ${index}`).join(", ") + " };",
  "typedef struct { uint32_t start, end; uint8_t properties; } ScrGraphemeRange;",
  "static const ScrGraphemeRange scr_grapheme_ranges[] = {",
  ...rows,
  "};",
  "#endif",
  "",
].join("\n");
await writeFile(join(root, "packages/runtime/src/scr_grapheme_data.h"), header);

const cases = [];
for (const line of files[3].split("\n")) {
  const content = line.split("#")[0].trim();
  if (!content) continue;
  let input = "";
  const breaks = [];
  for (const token of content.split(/\s+/)) {
    if (token === "÷") breaks.push(input.length);
    else if (token !== "×") input += String.fromCodePoint(parseInt(token, 16));
  }
  cases.push([input, breaks.join(",")]);
}
const corpusDir = join(root, "tests/corpus/intl-grapheme-conformance");
await mkdir(corpusDir, { recursive: true });
// Escape non-ASCII source so control characters never corrupt the fixture.
const quote = (text) => JSON.stringify(text).replace(/[\u007f-\uffff]/g, (ch) => `\\u${ch.charCodeAt(0).toString(16).padStart(4, "0")}`);
await writeFile(join(corpusDir, "cases.ts"), [
  "// Generated from Unicode 17.0.0 GraphemeBreakTest.txt by scripts/gen-grapheme-tables.mjs.",
  "// Unicode data license: packages/runtime/vendor/unicode/LICENSE.",
  "export const cases: string[][] = [",
  ...cases.map(([input, breaks]) => `  [${quote(input)}, ${quote(breaks)}],`),
  "];",
  "",
].join("\n"));
console.log(`wrote ${rows.length} property ranges and ${cases.length} grapheme conformance cases`);