/* =====================================================================
   lib/supporter-auth.js — Registrierung, E-Mail-Code-Login, Sessions für
   den öffentlichen Supporter-Bereich. 1:1 portiert, D1 → better-sqlite3.
   ===================================================================== */
import { db } from "../db.js";
import { sha256Hex, generateSessionToken, generateId, nowIso } from "./crypto.js";

const CODE_TTL_MS = 15 * 60 * 1000;
const SESSION_MAX_AGE_MS = 30 * 24 * 60 * 60 * 1000;
const INACTIVITY_MS = 14 * 24 * 60 * 60 * 1000;

export function normalizeTikTokUsername(input) {
  if (!input) return null;
  return String(input).trim().replace(/^@+/, "").toLowerCase() || null;
}

export function normalizeEmail(input) {
  return String(input || "").trim().toLowerCase();
}

function generateNumericCode() {
  const n = crypto.getRandomValues(new Uint32Array(1))[0] % 1_000_000;
  return String(n).padStart(6, "0");
}

export async function issueAuthCode(supporterId, purpose) {
  const code = generateNumericCode();
  const codeHash = await sha256Hex(code);
  db.prepare(
    `INSERT INTO supporter_auth_codes (id, supporter_id, purpose, code_hash, expires_at, created_at) VALUES (?, ?, ?, ?, ?, ?)`
  ).run(generateId(), supporterId, purpose, codeHash, new Date(Date.now() + CODE_TTL_MS).toISOString(), nowIso());
  return code;
}

export async function verifyAuthCode(supporterId, purpose, code) {
  const codeHash = await sha256Hex(String(code || "").trim());
  const row = db
    .prepare(
      `SELECT id, expires_at, used_at FROM supporter_auth_codes
       WHERE supporter_id = ? AND purpose = ? AND code_hash = ? ORDER BY created_at DESC LIMIT 1`
    )
    .get(supporterId, purpose, codeHash);
  if (!row) return false;
  if (row.used_at) return false;
  if (new Date(row.expires_at).getTime() < Date.now()) return false;
  db.prepare(`UPDATE supporter_auth_codes SET used_at = ? WHERE id = ?`).run(nowIso(), row.id);
  return true;
}

export async function createSupporterSession(supporterId) {
  const token = generateSessionToken();
  const tokenHash = await sha256Hex(token);
  const now = new Date();
  db.prepare(
    `INSERT INTO supporter_sessions (token_hash, supporter_id, created_at, last_active_at, expires_at) VALUES (?, ?, ?, ?, ?)`
  ).run(tokenHash, supporterId, now.toISOString(), now.toISOString(), new Date(now.getTime() + SESSION_MAX_AGE_MS).toISOString());
  return token;
}

export async function resolveSupporterSession(token) {
  if (!token) return null;
  const tokenHash = await sha256Hex(token);
  const session = db.prepare(`SELECT * FROM supporter_sessions WHERE token_hash = ?`).get(tokenHash);
  if (!session) return null;

  const now = Date.now();
  if (new Date(session.expires_at).getTime() < now || now - new Date(session.last_active_at).getTime() > INACTIVITY_MS) {
    db.prepare(`DELETE FROM supporter_sessions WHERE token_hash = ?`).run(tokenHash);
    return null;
  }
  db.prepare(`UPDATE supporter_sessions SET last_active_at = ? WHERE token_hash = ?`).run(nowIso(), tokenHash);

  const supporter = db.prepare(`SELECT * FROM supporter_users WHERE id = ? AND status = 'active'`).get(session.supporter_id);
  return supporter || null;
}

export async function endSupporterSession(token) {
  if (!token) return;
  db.prepare(`DELETE FROM supporter_sessions WHERE token_hash = ?`).run(await sha256Hex(token));
}

export async function requireSupporterSession(req) {
  const auth = req.headers["authorization"] || "";
  const token = auth.startsWith("Bearer ") ? auth.slice(7) : null;
  return resolveSupporterSession(token);
}