#!/usr/bin/env node
import fs from "node:fs/promises";
import path from "node:path";
import process from "node:process";

const CWD = process.cwd();
const DIST_ROOT = path.join(CWD, "dist");
const ALIASES_PATH = path.join(CWD, "src", "anchors", "anchor-aliases.json");

const argv = process.argv.slice(2);
const DRY_RUN = argv.includes("--dry-run");
const STRICT = argv.includes("--strict");

function escRe(s) {
  return String(s).replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
}

function normalizeRoute(route) {
  let r = String(route || "").trim();
  if (!r.startsWith("/")) r = "/" + r;
  if (!r.endsWith("/")) r = r + "/";
  r = r.replace(/\/{2,}/g, "/");
  return r;
}

async function exists(p) {
  try {
    await fs.access(p);
    return true;
  } catch {
    return false;
  }
}

function hasId(html, id) {
  const re = new RegExp(`\\bid=(["'])${escRe(id)}\\1`, "i");
  return re.test(html);
}

function injectBeforeId(html, newId, injectHtml) {
  // insère juste avant la balise qui porte id="newId"
  const re = new RegExp(
    `(<[^>]+\\bid=(["'])${escRe(newId)}\\2[^>]*>)`,
    "i"
  );
  const m = html.match(re);
  if (!m || m.index == null) return { html, injected: false };
  const i = m.index;
  const out = html.slice(0, i) + injectHtml + "\n" + html.slice(i);
  return { html: out, injected: true };
}

async function main() {
  if (!(await exists(ALIASES_PATH))) {
    console.log("ℹ️  Aucun fichier d'aliases (src/anchors/anchor-aliases.json). Skip.");
    return;
  }

  const raw = await fs.readFile(ALIASES_PATH, "utf-8");
  /** @type {Record<string, Record<string,string>>} */
  const aliases = JSON.parse(raw);

  const routes = Object.keys(aliases || {});
  if (routes.length === 0) {
    console.log("ℹ️  Aliases vides. Rien à injecter.");
    return;
  }

  let changedFiles = 0;
  let injectedCount = 0;
  let warnCount = 0;

  for (const routeKey of routes) {
    const route = normalizeRoute(routeKey);
    const map = aliases[routeKey] || {};
    const entries = Object.entries(map);

    if (entries.length === 0) continue;

    const rel = route.replace(/^\/+|\/+$/g, ""); // sans slash
    const htmlPath = path.join(DIST_ROOT, rel, "index.html");

    if (!(await exists(htmlPath))) {
      const msg = `⚠️  dist introuvable pour route=${route} (${htmlPath})`;
      if (STRICT) throw new Error(msg);
      console.log(msg);
      warnCount++;
      continue;
    }

    let html = await fs.readFile(htmlPath, "utf-8");
    let fileChanged = false;

    for (const [oldId, newId] of entries) {
      if (!oldId || !newId) continue;

      if (hasId(html, oldId)) {
        // alias déjà présent → idempotent
        continue;
      }

      if (!hasId(html, newId)) {
        const msg = `⚠️  newId introuvable: ${route} old=${oldId} -> new=${newId}`;
        if (STRICT) throw new Error(msg);
        console.log(msg);
        warnCount++;
        continue;
      }

      const aliasSpan = `<span id="${oldId}" class="para-alias" aria-hidden="true"></span>`;
      const r = injectBeforeId(html, newId, aliasSpan);

      if (!r.injected) {
        const msg = `⚠️  injection impossible (pattern non trouvé) : ${route} new=${newId}`;
        if (STRICT) throw new Error(msg);
        console.log(msg);
        warnCount++;
        continue;
      }

      html = r.html;
      fileChanged = true;
      injectedCount++;
    }

    if (fileChanged) {
      changedFiles++;
      if (!DRY_RUN) await fs.writeFile(htmlPath, html, "utf-8");
    }
  }

  console.log(
    `✅ inject-anchor-aliases: files_changed=${changedFiles} aliases_injected=${injectedCount} warnings=${warnCount}` +
      (DRY_RUN ? " (dry-run)" : "")
  );

  if (STRICT && warnCount > 0) process.exit(2);
}

main().catch((e) => {
  console.error("💥 inject-anchor-aliases:", e?.message || e);
  process.exit(1);
});