import "dotenv/config";
import express from "express";
import helmet from "helmet";
import path from "node:path";
import { fileURLToPath } from "node:url";
import pg from "pg";
import { createRemoteJWKSet, jwtVerify } from "jose";

const __filename = fileURLToPath(import.meta.url);
const __dirname = path.dirname(__filename);

function env(name, fallback = "") {
  return (process.env[name] ?? fallback).toString();
}

function must(name) {
  const v = env(name).trim();
  if (!v) throw new Error(`Missing env: ${name}`);
  return v;
}

function safeIdent(s) {
  const v = String(s || "").trim();
  if (!/^[a-zA-Z_][a-zA-Z0-9_]*$/.test(v)) throw new Error("Invalid TABLE identifier");
  return v;
}

function parseCsv(s) {
  return String(s || "")
    .split(",")
    .map((x) => x.trim())
    .filter(Boolean);
}

function parseEmailCsv(s) {
  return parseCsv(s).map((x) => x.toLowerCase());
}

const PORT = Number(env("PORT", "8000")) || 8000;
const DB_HOST = must("DB_HOST");
const DB_PORT = Number(env("DB_PORT", "5432")) || 5432;
const DB_NAME = must("DB_NAME");
const DB_USER = must("DB_USER");
const DB_PASSWORD = must("DB_PASSWORD");
const TABLE = safeIdent(env("TABLE", "ncue_user") || "ncue_user");
const CONFIG_TABLE = "ncue_app_config";
const CONFIG_TOKEN = env("CONFIG_TOKEN", "").trim();
const ADMIN_EMAILS = new Set(parseEmailCsv(env("ADMIN_EMAILS", "")));

// Auth0 config via .env (preferred)
const AUTH0_DOMAIN = env("AUTH0_DOMAIN", "").trim();
const AUTH0_CLIENT_ID = env("AUTH0_CLIENT_ID", "").trim();
const AUTH0_GOOGLE_CONNECTION = env("AUTH0_GOOGLE_CONNECTION", "").trim();

const pool = new pg.Pool({
  host: DB_HOST,
  port: DB_PORT,
  database: DB_NAME,
  user: DB_USER,
  password: DB_PASSWORD,
  ssl: false,
  max: 10,
});

const app = express();

app.use(
  helmet({
    contentSecurityPolicy: false, // keep simple for static + Auth0
  })
);
app.use(express.json({ limit: "256kb" }));

app.get("/healthz", async (_req, res) => {
  try {
    await pool.query("select 1 as ok");
    res.json({ ok: true });
  } catch (e) {
    res.status(500).json({ ok: false });
  }
});

function getBearer(req) {
  const h = req.headers.authorization || "";
  const m = /^Bearer\s+(.+)$/i.exec(h);
  return m ? m[1].trim() : "";
}

async function verifyIdToken(idToken, { issuer, audience }) {
  const jwks = createRemoteJWKSet(new URL(`${issuer}.well-known/jwks.json`));
  const { payload } = await jwtVerify(idToken, jwks, {
    issuer,
    audience,
  });
  return payload;
}

async function ensureUserTable() {
  // Create table if missing + add columns for upgrades
  await pool.query(`
    create table if not exists public.${TABLE} (
      sub            text primary key,
      email          text,
      name           text,
      picture        text,
      provider       text,
      first_login_at timestamptz,
      last_login_at  timestamptz,
      last_logout_at timestamptz,
      is_admin       boolean not null default false,
      can_manage     boolean not null default false,
      created_at     timestamptz not null default now(),
      updated_at     timestamptz not null default now()
    )
  `);
  await pool.query(`create index if not exists idx_${TABLE}_email on public.${TABLE} (email)`);
  await pool.query(`alter table public.${TABLE} add column if not exists first_login_at timestamptz`);
  await pool.query(`alter table public.${TABLE} add column if not exists last_logout_at timestamptz`);
  await pool.query(`alter table public.${TABLE} add column if not exists is_admin boolean not null default false`);
  // Backward-compat: previously can_manage was used as admin flag. Preserve existing admins.
  await pool.query(`update public.${TABLE} set is_admin = true where can_manage = true and is_admin = false`);
  // Keep can_manage consistent with is_admin going forward.
  await pool.query(`update public.${TABLE} set can_manage = is_admin where can_manage is distinct from is_admin`);
}

async function ensureConfigTable() {
  await pool.query(`
    create table if not exists public.${CONFIG_TABLE} (
      key        text primary key,
      value      jsonb not null,
      updated_at timestamptz not null default now()
    )
  `);
}

app.post("/api/auth/sync", async (req, res) => {
  try {
    await ensureUserTable();
    const idToken = getBearer(req);
    if (!idToken) return res.status(401).json({ ok: false, error: "missing_token" });

    const issuer = String(req.headers["x-auth0-issuer"] || "").trim();
    const audience = String(req.headers["x-auth0-clientid"] || "").trim();
    if (!issuer || !audience) return res.status(400).json({ ok: false, error: "missing_auth0_headers" });

    const payload = await verifyIdToken(idToken, { issuer, audience });

    const sub = String(payload.sub || "").trim();
    const email = payload.email ? String(payload.email).trim().toLowerCase() : null;
    const name = payload.name ? String(payload.name).trim() : null;
    const picture = payload.picture ? String(payload.picture).trim() : null;
    const provider = sub.includes("|") ? sub.split("|", 1)[0] : null;

    if (!sub) return res.status(400).json({ ok: false, error: "missing_sub" });

    const bootstrapAdmin = Boolean(email && ADMIN_EMAILS.has(email));

    const q = `
      insert into public.${TABLE}
        (sub, email, name, picture, provider, first_login_at, last_login_at, is_admin, can_manage, updated_at)
      values
        ($1, $2, $3, $4, $5, now(), now(), $6, $6, now())
      on conflict (sub) do update set
        email = excluded.email,
        name = excluded.name,
        picture = excluded.picture,
        provider = excluded.provider,
        first_login_at = coalesce(public.${TABLE}.first_login_at, excluded.first_login_at),
        last_login_at = now(),
        is_admin = (public.${TABLE}.is_admin or public.${TABLE}.can_manage or $6),
        can_manage = (public.${TABLE}.is_admin or public.${TABLE}.can_manage or $6),
        updated_at = now()
      returning is_admin, can_manage, first_login_at, last_login_at, last_logout_at
    `;
    const r = await pool.query(q, [sub, email, name, picture, provider, bootstrapAdmin]);
    const isAdmin = Boolean(r.rows?.[0]?.is_admin);

    res.json({ ok: true, canManage: isAdmin, user: r.rows?.[0] || null });
  } catch (e) {
    res.status(401).json({ ok: false, error: "verify_failed" });
  }
});

app.post("/api/auth/logout", async (req, res) => {
  try {
    await ensureUserTable();
    const idToken = getBearer(req);
    if (!idToken) return res.status(401).json({ ok: false, error: "missing_token" });

    const issuer = String(req.headers["x-auth0-issuer"] || "").trim();
    const audience = String(req.headers["x-auth0-clientid"] || "").trim();
    if (!issuer || !audience) return res.status(400).json({ ok: false, error: "missing_auth0_headers" });

    const payload = await verifyIdToken(idToken, { issuer, audience });
    const sub = String(payload.sub || "").trim();
    if (!sub) return res.status(400).json({ ok: false, error: "missing_sub" });

    const q = `
      update public.${TABLE}
      set last_logout_at = now(),
          updated_at = now()
      where sub = $1
      returning last_logout_at
    `;
    const r = await pool.query(q, [sub]);
    res.json({ ok: true, last_logout_at: r.rows?.[0]?.last_logout_at || null });
  } catch (e) {
    res.status(401).json({ ok: false, error: "verify_failed" });
  }
});

// Shared auth config for all browsers (read-only public)
app.get("/api/config/auth", async (_req, res) => {
  try {
    // Prefer .env config (no UI needed)
    if (AUTH0_DOMAIN && AUTH0_CLIENT_ID && AUTH0_GOOGLE_CONNECTION) {
      return res.json({
        ok: true,
        value: {
          auth0: { domain: AUTH0_DOMAIN, clientId: AUTH0_CLIENT_ID },
          connections: { google: AUTH0_GOOGLE_CONNECTION },
          // Deprecated: admin is stored per-user in DB (ncue_user.is_admin)
          adminEmails: [],
        },
        updated_at: null,
        source: "env",
      });
    }

    await ensureConfigTable();
    const r = await pool.query(`select value, updated_at from public.${CONFIG_TABLE} where key = $1`, ["auth"]);
    if (!r.rows?.length) return res.status(404).json({ ok: false, error: "not_set" });
    const v = r.rows[0].value || {};
    // legacy: allowedEmails -> adminEmails
    if (v && typeof v === "object" && !v.adminEmails && Array.isArray(v.allowedEmails)) {
      v.adminEmails = v.allowedEmails;
    }
    res.json({ ok: true, value: v, updated_at: r.rows[0].updated_at, source: "db" });
  } catch (e) {
    res.status(500).json({ ok: false, error: "server_error" });
  }
});

// Write auth config (protected by CONFIG_TOKEN)
app.post("/api/config/auth", async (req, res) => {
  try {
    await ensureConfigTable();
    if (!CONFIG_TOKEN) return res.status(403).json({ ok: false, error: "config_token_not_set" });
    const token = String(req.headers["x-config-token"] || "").trim();
    if (token !== CONFIG_TOKEN) return res.status(403).json({ ok: false, error: "forbidden" });

    const body = req.body && typeof req.body === "object" ? req.body : {};
    const auth0 = body.auth0 && typeof body.auth0 === "object" ? body.auth0 : {};
    const connections = body.connections && typeof body.connections === "object" ? body.connections : {};
    // legacy: allowedEmails -> adminEmails
    const adminEmails = Array.isArray(body.adminEmails)
      ? body.adminEmails
      : Array.isArray(body.allowedEmails)
        ? body.allowedEmails
        : [];

    const domain = String(auth0.domain || "").trim();
    const clientId = String(auth0.clientId || "").trim();
    const googleConn = String(connections.google || "").trim();
    const emails = adminEmails.map((x) => String(x).trim().toLowerCase()).filter(Boolean);

    if (!domain || !clientId || !googleConn) {
      return res.status(400).json({ ok: false, error: "missing_fields" });
    }

    const value = {
      auth0: { domain, clientId },
      connections: { google: googleConn },
      adminEmails: emails,
    };

    await pool.query(
      `insert into public.${CONFIG_TABLE} (key, value, updated_at)
       values ($1, $2::jsonb, now())
       on conflict (key) do update set value = excluded.value, updated_at = now()`,
      ["auth", JSON.stringify(value)]
    );
    res.json({ ok: true });
  } catch (e) {
    res.status(500).json({ ok: false, error: "server_error" });
  }
});

// CONFIG_TOKEN-protected: set per-user admin flag in DB
app.post("/api/admin/users/set_admin", async (req, res) => {
  try {
    await ensureUserTable();
    if (!CONFIG_TOKEN) return res.status(403).json({ ok: false, error: "config_token_not_set" });
    const token = String(req.headers["x-config-token"] || "").trim();
    if (token !== CONFIG_TOKEN) return res.status(403).json({ ok: false, error: "forbidden" });

    const body = req.body && typeof req.body === "object" ? req.body : {};
    const sub = String(body.sub || "").trim();
    const email = String(body.email || "").trim().toLowerCase();
    const isAdmin = typeof body.isAdmin === "boolean" ? body.isAdmin : typeof body.admin === "boolean" ? body.admin : null;
    if (typeof isAdmin !== "boolean") return res.status(400).json({ ok: false, error: "missing_isAdmin" });
    if (!sub && !email) return res.status(400).json({ ok: false, error: "missing_identifier" });

    const q = sub
      ? `update public.${TABLE} set is_admin = $1, can_manage = $1, updated_at = now() where sub = $2 returning sub, email, is_admin`
      : `update public.${TABLE} set is_admin = $1, can_manage = $1, updated_at = now() where email = $2 returning sub, email, is_admin`;
    const r = await pool.query(q, [isAdmin, sub ? sub : email]);
    if (!r.rows?.length) return res.status(404).json({ ok: false, error: "not_found" });
    res.json({ ok: true, user: r.rows[0] });
  } catch {
    res.status(500).json({ ok: false, error: "server_error" });
  }
});

// Serve static site
app.use(express.static(__dirname, { extensions: ["html"] }));

app.listen(PORT, () => {
  // eslint-disable-next-line no-console
  console.log(`listening on http://localhost:${PORT}`);
});