package org.openautonomousconnection.oac2web.frontend;

import org.openautonomousconnection.oac2web.utils.*;
import org.openautonomousconnection.protocol.packets.v1_0_0.beta.web.WebResponsePacket;
import org.openautonomousconnection.protocol.side.web.ProtocolWebServer;
import org.openautonomousconnection.protocol.side.web.managers.SessionManager;
import org.openautonomousconnection.protocol.versions.v1_0_0.beta.WebRequestMethod;
import org.openautonomousconnection.webserver.api.Route;
import org.openautonomousconnection.webserver.api.WebPage;
import org.openautonomousconnection.webserver.api.WebPageContext;
import org.openautonomousconnection.webserver.utils.Html;
import org.openautonomousconnection.webserver.utils.RequestParams;

import java.util.HashMap;
import java.util.Map;

/**
 * Login page.
 *
 * POST headers expected:
 * - username
 * - password
 *
 * Creates a session with SessionManager.
 */
@Route(path = "ins/login")
public final class login implements WebPage {

    @Override
    public WebResponsePacket handle(WebPageContext ctx) throws Exception {
        if (ctx.request.getMethod() != WebRequestMethod.POST) {
            return renderForm(null);
        }

        RequestParams p = new RequestParams(ctx.request);
        String username = p.get("username");
        String password = p.get("password");

        if (username == null || username.isBlank() || password == null || password.isBlank()) {
            return renderForm("Missing username/password (send via headers).");
        }

        Oac2WebApp app = Oac2WebApp.get();
        String usernameHash = Sha256.hex(username.trim());

        RegistrarDao.UserRow u = app.dao().findUserByUsernameHash(usernameHash).orElse(null);
        if (u == null) return renderForm("Invalid credentials.");

        boolean ok = app.passwordHasher().verify(password, u.passwordEncoded());
        if (!ok) return renderForm("Invalid credentials.");

        String ip = (ctx.client.getConnection().getSocket() != null && ctx.client.getConnection().getSocket().getInetAddress() != null)
                ? ctx.client.getConnection().getSocket().getInetAddress().getHostAddress()
                : "";

        String ua = ctx.request.getHeaders() != null ? ctx.request.getHeaders().getOrDefault("user-agent", "") : "";

        String session = SessionManager.create(String.valueOf(u.id()), ip, ua, (ProtocolWebServer) ctx.client.getServer());

        Map<String, String> headers = new HashMap<>();
        headers.put("session", session);
        headers.put("location", "/dashboard");
        return new WebResponsePacket(302, "text/plain", headers, new byte[0]);
    }

    private WebResponsePacket renderForm(String err) {
        String body = """
                <div class="card">
                  <h2>Login</h2>
                  %s
                  <p class="muted">Send a POST request with headers <code>username</code> and <code>password</code>.</p>
                  <div class="row">
                    <div class="col"><a href="/register">Register</a></div>
                    <div class="col"><a href="/">Home</a></div>
                  </div>
                </div>
                """.formatted(err == null ? "" : "<p class='err'>" + Html.esc(err) + "</p>");

        String html = Html.page("Login", body);
        return new WebResponsePacket(200, "text/html", new HashMap<>(), Html.utf8(html));
    }
}