// Copyright (C) 2026 Dcntrlized
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published
// by the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.

package web

import (
	"bytes"
	"context"
	"encoding/json"
	"io"
	"net/http"
	"time"

	"git.dcntrlized.org/dcntrlized/dcntrlized-auth/authproxy"
)

const maxHubBody = 1 << 20 // 1 MiB

// hubClient is the outbound hub transport. Contract rev 9 removed the mTLS
// identity layer fleet-wide, so this is a plain HTTP client — no client
// certificate and no custom TLS configuration. The timeout bounds the whole
// hub exchange so a stalled hub cannot pin a browser request.
var hubClient = &http.Client{Timeout: 10 * time.Second}

// callHub performs one fixed hub /auth/* call over the plaintext internal
// network. It deliberately does NOT use authproxy.Proxy: that helper copies
// every inbound header (including Cookie and X-Access-Token) to the hub, which
// is forbidden on the browser edge.
func callHub(ctx context.Context, method, path string, payload any) (int, []byte, error) {
	var body io.Reader
	if payload != nil {
		raw, err := json.Marshal(payload)
		if err != nil {
			return 0, nil, err
		}
		body = bytes.NewReader(raw)
	}
	req, err := http.NewRequestWithContext(ctx, method, authproxy.Target()+"/auth/"+path, body)
	if err != nil {
		return 0, nil, err
	}
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("Accept", "application/json")
	resp, err := hubClient.Do(req)
	if err != nil {
		return 0, nil, err
	}
	defer resp.Body.Close()
	out, err := io.ReadAll(io.LimitReader(resp.Body, maxHubBody))
	if err != nil {
		return 0, nil, err
	}
	return resp.StatusCode, out, nil
}