// SPDX-FileCopyrightText: 2026 Filip Leonarski, Paul Scherrer Institute <filip.leonarski@psi.ch>
// SPDX-License-Identifier: GPL-3.0-only

#include <catch2/catch_all.hpp>
#include <httplib.h>
#include <nlohmann/json.hpp>
#include <mutex>
#include <set>
#include <thread>

#include "../detector_control/DectrisSimplonClient.h"

// A minimal SIMPLON server: the detector state and error list, and a disarm command that fails.
TEST_CASE("DectrisSimplonClient_MockServer", "[detector]") {
    httplib::Server server;
    std::mutex m;
    std::set<int> client_ports;
    std::string state = "idle";

    server.Get("/detector/api/1.8.0/status/state", [&](const httplib::Request &req, httplib::Response &res) {
        std::lock_guard lg(m);
        client_ports.insert(req.remote_port);
        if (state == "unavailable") {
            res.status = 503;
            res.set_content("DCU busy", "text/plain");
        } else
            res.set_content(nlohmann::json{{"value", state}}.dump(), "application/json");
    });
    server.Get("/detector/api/1.8.0/status/error", [&](const httplib::Request &, httplib::Response &res) {
        res.set_content(nlohmann::json{{"value", {"overheating"}}}.dump(), "application/json");
    });
    server.Post("/detector/api/1.8.0/command/disarm", [&](const httplib::Request &, httplib::Response &res) {
        res.status = 500;
        res.set_content("disarm refused", "text/plain");
    });

    const int port = server.bind_to_any_port("127.0.0.1");
    REQUIRE(port > 0);
    struct ServerThread {
        httplib::Server &server;
        std::thread thread;
        explicit ServerThread(httplib::Server &s) : server(s), thread([&s] { s.listen_after_bind(); }) {}
        ~ServerThread() { server.stop(); thread.join(); }
    } server_thread(server);
    server.wait_until_ready();

    DectrisSimplonClient client("127.0.0.1", port);

    // Repeated polling reuses one connection instead of opening a new one per request
    for (int i = 0; i < 10; i++)
        REQUIRE(client.GetState() == SimplonState::Idle);
    CHECK(client_ports.size() == 1);

    CHECK(client.GetErrorStatus() == R"(["overheating"])");

    // Failures carry the HTTP status and the body the DCU sent
    {
        std::lock_guard lg(m);
        state = "unavailable";
    }
    REQUIRE_THROWS_WITH(client.GetState(), Catch::Matchers::ContainsSubstring("HTTP503")
                                           && Catch::Matchers::ContainsSubstring("DCU busy"));
    REQUIRE_THROWS_WITH(client.EndAcquisitionFinished(), Catch::Matchers::ContainsSubstring("HTTP500")
                                                         && Catch::Matchers::ContainsSubstring("disarm refused"));
}