/**
 * One-off: tenant/company code = nombre(4) + YYMM; username = code lowercase.
 * Usage: deno run -A scripts/migrate-tenant-codes.ts
 */
import { Database } from "jsr:@db/sqlite@0.12";

const PLATFORM = new URL("../data/platform.db", import.meta.url).pathname;
const APP = new URL("../data/app.db", import.meta.url).pathname;

function shortFromName(name: string): string {
  const slug = (name ?? "")
    .toString()
    .normalize("NFD")
    .replace(/\p{M}/gu, "")
    .toUpperCase()
    .replace(/[^A-Z0-9]+/g, "")
    .slice(0, 4);
  return slug.length >= 2 ? slug : (slug || "EMP").padEnd(2, "X").slice(0, 4);
}

function stampFromCreated(createdAt: string): string {
  const m = createdAt.match(/^(\d{4})-(\d{2})/);
  if (!m) {
    const d = new Date();
    return `${String(d.getFullYear()).slice(-2)}${String(d.getMonth() + 1).padStart(2, "0")}`;
  }
  return `${m[1].slice(-2)}${m[2]}`;
}

const platform = new Database(PLATFORM);
const app = new Database(APP);
platform.exec("PRAGMA foreign_keys = ON;");
app.exec("PRAGMA foreign_keys = ON;");

const tenants = platform.prepare(
  "SELECT id, code, name, created_at FROM tenants ORDER BY id",
).all() as { id: number; code: string; name: string; created_at: string }[];

const used = new Set<string>([
  ...(app.prepare("SELECT code FROM companies").all() as { code: string }[]).map((r) => r.code),
  ...tenants.map((t) => t.code),
]);

function allocate(name: string, createdAt: string, oldCode: string): string {
  const base = shortFromName(name);
  const stamp = stampFromCreated(createdAt);
  let candidate = `${base}${stamp}`;
  if (candidate === oldCode || !used.has(candidate)) return candidate;
  for (let n = 2; n < 1000; n++) {
    const suffix = String(n);
    const head = base.slice(0, Math.max(2, 4 - suffix.length));
    candidate = `${head}${stamp}${suffix}`;
    if (candidate === oldCode || !used.has(candidate)) return candidate;
  }
  throw new Error(`No unique code for ${name}`);
}

type MapRow = {
  tenantId: number;
  oldCode: string;
  newCode: string;
  oldUser: string;
  newUser: string;
};

const mappings: MapRow[] = [];
for (const t of tenants) {
  const newCode = allocate(t.name, t.created_at, t.code);
  used.add(newCode);
  mappings.push({
    tenantId: t.id,
    oldCode: t.code,
    newCode,
    oldUser: `adm.${t.code.toLowerCase()}`,
    newUser: newCode.toLowerCase(),
  });
}

console.log("Migrating:", mappings);

for (const m of mappings) {
  if (m.oldCode !== m.newCode) {
    platform.prepare("UPDATE tenants SET code = ? WHERE id = ?").run(m.newCode, m.tenantId);

    const principal = app.prepare(
      "SELECT id, code FROM companies WHERE tenant_id = ? AND kind = 'principal' ORDER BY id LIMIT 1",
    ).get(m.tenantId) as { id: number; code: string } | undefined;

    if (principal && principal.code === m.oldCode) {
      app.prepare("UPDATE companies SET code = ? WHERE id = ?").run(m.newCode, principal.id);
      app.prepare("UPDATE workers SET hire_type = ? WHERE company_id = ? AND hire_type = ?")
        .run(m.newCode, principal.id, m.oldCode);
    }
  }

  const clash = app.prepare("SELECT id FROM users WHERE username = ?").get(m.newUser);
  if (!clash) {
    app.prepare(
      "UPDATE users SET username = ? WHERE tenant_id = ? AND username = ?",
    ).run(m.newUser, m.tenantId, m.oldUser);
    // also catch if username already equals old code lowercase without adm.
    app.prepare(
      "UPDATE users SET username = ? WHERE tenant_id = ? AND username = ? AND username != ?",
    ).run(m.newUser, m.tenantId, m.oldCode.toLowerCase(), m.newUser);
  } else {
    // ensure old adm.* row is renamed only if target not taken by another user
    const old = app.prepare(
      "SELECT id FROM users WHERE tenant_id = ? AND username = ?",
    ).get(m.tenantId, m.oldUser) as { id: number } | undefined;
    if (old && (clash as { id: number }).id === old.id) {
      // same row already correct
    } else if (old) {
      console.warn(`Skip user rename ${m.oldUser} → ${m.newUser}: target exists`);
    }
  }
}

console.log("TENANTS", platform.prepare("SELECT id, code, name FROM tenants").all());
console.log(
  "PRINCIPALS",
  app.prepare("SELECT id, code, tenant_id, kind FROM companies WHERE kind = 'principal'").all(),
);
console.log(
  "USERS",
  app.prepare("SELECT id, username, tenant_id, role FROM users").all(),
);

platform.close();
app.close();