package ins.frontend;

import ins.frontend.utils.RegistrarDao;
import ins.frontend.utils.WebApp;
import org.openautonomousconnection.protocol.packets.v1_0_0.beta.web.WebResponsePacket;
import org.openautonomousconnection.protocol.side.web.ProtocolWebServer;
import org.openautonomousconnection.webserver.api.Route;
import org.openautonomousconnection.webserver.api.SessionContext;
import org.openautonomousconnection.webserver.api.WebPage;
import org.openautonomousconnection.webserver.api.WebPageContext;
import org.openautonomousconnection.webserver.utils.Html;
import org.openautonomousconnection.webserver.utils.MergedRequestParams;
import org.openautonomousconnection.webserver.utils.QuerySupport;

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

/**
 * INS registrar ins.frontend (TLN / InfoName / Records) with proper POST parameter parsing.
 *
 * <p>Supported actions (POST recommended for mutations):</p>
 * <ul>
 *   <li>create_tln</li>
 *   <li>update_tln</li>
 *   <li>delete_tln</li>
 *   <li>create_infoname</li>
 *   <li>delete_infoname</li>
 *   <li>add_record</li>
 * </ul>
 *
 * <p>Important: Listing/editing/deleting records requires DAO methods that are not part of the provided snippet.
 * This page currently supports adding records only.</p>
 */
@Route(path = "dashboard.html")
public final class dashboard implements WebPage {

    private static Integer normalizeNullableInt(String s) {
        if (s == null) return null;
        String t = s.trim();
        if (t.isEmpty()) return null;
        try {
            return Integer.parseInt(t);
        } catch (Exception ignored) {
            return null;
        }
    }

    @Override
    public WebResponsePacket handle(WebPageContext ctx) throws Exception {
        WebApp.init();

        SessionContext session = SessionContext.from(
                ctx.client,
                (ProtocolWebServer) ctx.client.getServer(),
                ctx.request.getHeaders()
        );

        if (!session.isValid() || session.getUser() == null) {
            return plain(401, "Authentication required (session).");
        }

        int userId;
        try {
            userId = Integer.parseInt(session.getUser());
        } catch (Exception e) {
            return plain(401, "Invalid session user.");
        }

        RegistrarDao dao = WebApp.get().dao();

        // Raw target and merged params (GET + POST).
        String rawTarget = org.openautonomousconnection.webserver.utils.QuerySupport.extractRawTarget(ctx.request);
        Map<String, String> headers = ctx.request.getHeaders();
        byte[] body = ctx.request.getBody();

        MergedRequestParams p = MergedRequestParams.from(rawTarget, headers, body);

        String msg = null;
        String err = null;

        String action = p.getOr("action", "").trim();
        if (!action.isBlank()) {
            try {
                ActionResult r = executeAction(action, p, userId, dao);
                msg = r.msg();
                err = r.err();
            } catch (Exception e) {
                err = "Action failed: " + safeMsg(e);
            }
        }

        return render(userId, msg, err, dao);
    }

    private ActionResult executeAction(String action, MergedRequestParams p, int userId, RegistrarDao dao) throws Exception {
        String a = action.trim().toLowerCase(Locale.ROOT);

        if ("create_tln".equals(a)) {
            String name = p.get("name");
            String info = p.getOr("info", "");
            boolean isPublic = p.getBool("is_public");
            boolean allowSubs = p.getBool("allow_subdomains");

            if (name == null || name.isBlank()) return ActionResult.err("Missing TLN name.");

            int id = dao.createTln(name.trim(), info, userId, isPublic, allowSubs);
            return ActionResult.ok("Created TLN id=" + id + " (" + name.trim() + ")");
        }

        if ("update_tln".equals(a)) {
            int id = p.getInt("id", -1);
            String info = p.getOr("info", "");
            boolean isPublic = p.getBool("is_public");
            boolean allowSubs = p.getBool("allow_subdomains");

            if (id <= 0) return ActionResult.err("Invalid TLN id.");

            boolean ok = dao.updateTlnOwned(id, userId, info, isPublic, allowSubs);
            return ActionResult.ok(ok ? ("Updated TLN id=" + id) : "Not owner / not found.");
        }

        if ("delete_tln".equals(a)) {
            int id = p.getInt("id", -1);
            if (id <= 0) return ActionResult.err("Invalid TLN id.");

            boolean ok = dao.deleteTlnOwned(id, userId);
            return ActionResult.ok(ok ? ("Deleted TLN id=" + id) : "Not owner / not found.");
        }

        if ("create_infoname".equals(a)) {
            String tlnName = p.get("tln");
            String info = p.get("info");

            if (tlnName == null || tlnName.isBlank() || info == null || info.isBlank()) {
                return ActionResult.err("Missing tln / info.");
            }

            RegistrarDao.TlnRow tln = dao.findTlnByName(tlnName.trim()).orElse(null);
            if (tln == null) return ActionResult.err("Unknown TLN: " + tlnName);

            if (!RegistrarDao.canUseTln(tln, userId)) {
                return ActionResult.err("TLN not public and not owned by you.");
            }

            int id = dao.createInfoName(tln, info.trim(), userId);
            return ActionResult.ok("Created infoname id=" + id + " (" + info.trim() + "." + tln.name() + ")");
        }

        if ("delete_infoname".equals(a)) {
            int id = p.getInt("id", -1);
            if (id <= 0) return ActionResult.err("Invalid infoname id.");

            boolean ok = dao.deleteInfoNameOwned(id, userId);
            return ActionResult.ok(ok ? ("Deleted infoname id=" + id) : "Not owner / not found.");
        }

        if ("add_record".equals(a)) {
            int infonameId = p.getInt("infoname_id", -1);
            String sub = p.get("sub");
            String type = p.getOr("type", "").trim().toUpperCase(Locale.ROOT);
            String value = p.get("value");

            int ttl = p.getInt("ttl", 3600);

            Integer priority = normalizeNullableInt(p.get("priority"));
            Integer port = normalizeNullableInt(p.get("port"));
            Integer weight = normalizeNullableInt(p.get("weight"));

            if (infonameId <= 0) return ActionResult.err("Invalid infoname_id.");
            if (!dao.isOwnerOfInfoName(infonameId, userId)) return ActionResult.err("Not owner of this infoname.");
            if (type.isBlank() || value == null || value.isBlank()) return ActionResult.err("Missing type/value.");

            // Validate allow_subdomains against TLN of this infoname (owned list contains TLN metadata).
            RegistrarDao.InfoNameRow[] owned = dao.listOwnedInfoNames(userId);
            RegistrarDao.InfoNameRow row = null;
            for (RegistrarDao.InfoNameRow r : owned) {
                if (r.id() == infonameId) {
                    row = r;
                    break;
                }
            }
            if (row == null) return ActionResult.err("Infoname not found in your ownership list.");

            if (!RegistrarDao.canUseSubname(row.tln(), userId, sub)) {
                return ActionResult.err("Subnames are not allowed for this TLN (allow_subdomains=0) unless you own the TLN.");
            }

            Integer subId = dao.ensureSubname(infonameId, sub);
            int rid = dao.addRecord(infonameId, subId, type, value.trim(), ttl, priority, port, weight);
            return ActionResult.ok("Added record id=" + rid + " type=" + type);
        }

        return ActionResult.err("Unknown action: " + action);
    }

    private WebResponsePacket render(int userId, String msg, String err, RegistrarDao dao) throws Exception {
        RegistrarDao.TlnRow[] tlns = dao.listVisibleTlns(userId);
        RegistrarDao.InfoNameRow[] owned = dao.listOwnedInfoNames(userId);

        String tlnHtml = renderTlnSection(tlns, userId);
        String infoHtml = renderInfoNamesSection(owned);

        String body = """
                <div class="card">
                  <h2>INS Registrar</h2>
                  %s
                  %s
                
                  <h3>Create TLN</h3>
                  <form method="post" action="dashboard.html" class="form">
                    <input type="hidden" name="action" value="create_tln">
                    <label><span class="muted">name</span><input type="text" name="name" placeholder="com" required></label>
                    <label><span class="muted">info</span><input type="text" name="info" required placeholder="ip[:port]"></label>
                    <label><span class="muted">is_public</span><input type="text" name="is_public" value="1" required></label>
                    <label><span class="muted">allow_subdomains</span><input type="text" name="allow_subdomains" value="1" required></label>
                    <button type="submit">Create TLN</button>
                  </form>
                
                  <h3>TLNs (public + owned)</h3>
                  %s
                
                  <h3>Create InfoName</h3>
                  <p class="muted">Allowed if TLN is public or owned by you.</p>
                  <form method="post" action="dashboard.html" class="form">
                    <input type="hidden" name="action" value="create_infoname">
                    <label><span class="muted">tln</span><input type="text" name="tln" placeholder="com" required></label>
                    <label><span class="muted">info</span><input type="text" name="info" placeholder="example" required></label>
                    <button type="submit">Create InfoName</button>
                  </form>
                
                  <h3>Add Record</h3>
                  <p class="muted">Subname requires allow_subdomains=1 unless you own the TLN. Root (no sub) always allowed.</p>
                  <form method="post" action="dashboard.html" class="form">
                    <input type="hidden" name="action" value="add_record">
                    <label><span class="muted">infoname_id</span><input type="number" name="infoname_id" min="1" required></label>
                    <label><span class="muted">sub (optional)</span><input type="text" name="sub" placeholder="www"></label>
                    <label><span class="muted">type</span><input type="text" name="type" placeholder="A/AAAA/TXT/CNAME/MX/SRV/NS" required></label>
                    <label><span class="muted">value</span><input type="text" name="value" required></label>
                    <label><span class="muted">ttl</span><input type="number" name="ttl" value="3600"></label>
                    <label><span class="muted">priority (MX/SRV)</span><input type="number" name="priority"></label>
                    <label><span class="muted">port (SRV)</span><input type="number" placeholder="Default: 1028" value="1028" name="port"></label>
                    <label><span class="muted">weight (SRV)</span><input type="number" name="weight"></label>
                    <button type="submit">Add Record</button>
                  </form>
                
                  <h3>Your InfoNames</h3>
                  %s
                
                  <div class="row">
                    <div class="col"><a href="index.html">Home</a></div>
                  </div>
                </div>
                """.formatted(
                msg == null ? "" : "<p class='ok'>" + Html.esc(msg) + "</p>",
                err == null ? "" : "<p class='err'>" + Html.esc(err) + "</p>",
                tlnHtml,
                infoHtml
        );

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

    private String renderTlnSection(RegistrarDao.TlnRow[] tlns, int userId) {
        if (tlns == null || tlns.length == 0) {
            return "<p class='muted'>No TLNs available.</p>";
        }

        StringBuilder sb = new StringBuilder();
        sb.append("<ul>");
        for (RegistrarDao.TlnRow t : tlns) {
            boolean ownedByMe = (t.ownerId() != null && t.ownerId() == userId);

            sb.append("<li>")
                    .append("<code>").append(Html.esc(t.name())).append("</code>")
                    .append(" <span class='muted'>(id=").append(t.id()).append(")</span> ")
                    .append(ownedByMe ? "<span class='muted'>(owner)</span>" : "<span class='muted'>(public)</span>")
                    .append(" <span class='muted'>is_public=").append(t.isPublic() ? "1" : "0")
                    .append(", allow_subdomains=").append(t.allowSubdomains() ? "1" : "0")
                    .append("</span>");

            if (ownedByMe) {
                sb.append("""
                        <div class="row" style="margin-top:8px; gap:10px; flex-wrap:wrap;">
                          <form method="post" action="dashboard.html" class="form" style="margin:0;">
                            <input type="hidden" name="action" value="update_tln">
                            <input type="hidden" name="id" value="%d">
                            <label>
                              <span class="muted">info</span>
                              <input type="text" name="info" value="%s">
                            </label>
                            <label>
                              <span class="muted">is_public</span>
                              <input type="text" name="is_public" value="%s" style="width:70px;">
                            </label>
                            <label>
                              <span class="muted">allow_subdomains</span>
                              <input type="text" name="allow_subdomains" value="%s" style="width:70px;">
                            </label>
                            <button type="submit">Update</button>
                          </form>
                        
                          <form method="post" action="dashboard.html" style="margin:0;">
                            <input type="hidden" name="action" value="delete_tln">
                            <input type="hidden" name="id" value="%d">
                            <button type="submit" class="muted">Delete</button>
                          </form>
                        </div>
                        """.formatted(
                        t.id(),
                        Html.esc(t.info() == null ? "" : t.info()),
                        t.isPublic() ? "1" : "0",
                        t.allowSubdomains() ? "1" : "0",
                        t.id()
                ));
            }

            sb.append("</li>");
        }
        sb.append("</ul>");
        return sb.toString();
    }

    private String renderInfoNamesSection(RegistrarDao.InfoNameRow[] owned) {
        if (owned == null || owned.length == 0) {
            return "<p class='muted'>No infonames yet.</p>";
        }

        StringBuilder sb = new StringBuilder();
        sb.append("<ul>");
        for (RegistrarDao.InfoNameRow r : owned) {
            sb.append("<li>")
                    .append("<code>")
                    .append(Html.esc(r.info())).append(".").append(Html.esc(r.tln().name()))
                    .append("</code>")
                    .append(" <span class='muted'>(id=").append(r.id()).append(")</span>")
                    .append("""
                            <form method="post" action="dashboard.html" style="display:inline; margin-left:10px;">
                              <input type="hidden" name="action" value="delete_infoname">
                              <input type="hidden" name="id" value="%d">
                              <button type="submit" class="muted">Delete</button>
                            </form>
                            """.formatted(r.id()))
                    .append("</li>");
        }
        sb.append("</ul>");
        return sb.toString();
    }

    private WebResponsePacket plain(int code, String text) {
        return new WebResponsePacket(code, "text/plain", new HashMap<>(), Html.utf8(text));
    }

    private String safeMsg(Exception e) {
        String m = e.getMessage();
        if (m == null || m.isBlank()) return e.getClass().getSimpleName();
        return m;
    }

    private record ActionResult(String msg, String err) {
        static ActionResult ok(String msg) {
            return new ActionResult(msg, null);
        }

        static ActionResult err(String err) {
            return new ActionResult(null, err);
        }
    }
}