// Copyright (C) 2026 Viorel Munteanu
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License along
// with this program; if not, write to the Free Software Foundation, Inc.,
// 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

// [integration][root][net]: exercises the full -u/--up -> -d/--down
// lifecycle against the real, checked-in test-compose/compose.yaml
// skeleton and its worker/server scripts -- not a scratch-written
// snippet, since the whole point is to test this project's own
// hand-maintained "does the orchestrator actually work end to end"
// fixture. Needs root (real bridges/namespaces/iptables/port-forwarding)
// and a real busybox fixture (find_busybox_fixture()) -- SKIPs cleanly on
// either missing.
//
// Deliberately does NOT use ScratchXdgDirs (unlike every other
// [root][net] test in this suite): test-compose/compose.yaml's own
// `test-preexisting-net` is an `external: true` network, meaning it's
// explicitly the *user's own* responsibility to create ahead of time --
// real Compose's own convention for that field -- so this test creates it
// once against the real, persistent config (if it isn't already there)
// and leaves it standing afterward, exactly like a real user would set it
// up once and keep reusing it, rather than tearing it down and recreating
// it on every run. Every *managed* resource this test's own -u/--up run
// creates (test-compose_test-intern-net, test-compose_test-extern-net,
// test-compose_test-server-log) is already "test-"-prefixed by
// compose_project_name(), matching this project's own established test-
// naming convention, so there's no realistic collision risk with a real
// (non-test) invocation either way -- and this test's own -d/--down plus
// an explicit final volume deletion leave no managed residue behind.

#include <arpa/inet.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <time.h>
#include <unistd.h>

#include <algorithm>
#include <fstream>
#include <optional>
#include <sstream>
#include <string>
#include <vector>

#include <catch2/catch_test_macros.hpp>

#include "cli_args.h"
#include "commands.h"
#include "compose_orchestrator.h"
#include "config_file.h"
#include "fixtures.h"
#include "pid_file.h"
#include "process.h"

namespace {

// Mirrors exactly what a real CLI invocation would see: main()'s own merge
// of the effective global config (g_test_app_config, fixtures.h) with
// persistent.yaml's own current volumes/networks, freshly reloaded from
// disk -- same pattern test_network_join_scenarios.cpp's own reload_config()
// already uses, needed since create_network_command()/compose_up_command()
// etc. always read/write persistent_file_path() directly.
AppConfig reload_config() {
    AppConfig config = g_test_app_config;
    if (auto persistent = load_persistent_config(persistent_file_path())) {
        config.volumes = persistent->volumes;
        config.networks = persistent->networks;
    }
    return config;
}

bool has_network(const AppConfig& config, const std::string& name) {
    return std::any_of(config.networks.begin(), config.networks.end(),
                        [&](const NetworkEntry& n) { return n.name == name; });
}

bool has_volume(const AppConfig& config, const std::string& name) {
    return std::any_of(config.volumes.begin(), config.volumes.end(),
                        [&](const VolumeEntry& v) { return v.name == name; });
}

// Creates the real, persistent "test-preexisting-net" (--intern, an
// explicit test-range subnet) if it doesn't already exist -- see this
// file's own top comment for why this one network is deliberately not
// scratch-isolated or torn down at the end.
bool ensure_test_preexisting_network() {
    AppConfig config = reload_config();
    if (has_network(config, "test-preexisting-net")) {
        return true;
    }
    ParsedArgs args;
    args.mode = Mode::network;
    args.network_specs = {"test-preexisting-net"};
    args.network_intern_flag = true;
    args.network_with_ipv6_flag = false;
    args.network_subnet_flag = "10.169.20.0/24";
    CapturedStdout capture;
    return dispatch_command(args, "/nonexistent/unused-config.yaml", config) == 0;
}

// Best-effort delete of a managed volume by name, via the real
// --delete-volume-full CLI path -- used at the end of this test to remove
// the volume -u/--up created, so a later run can exercise its creation
// again from scratch.
void delete_test_volume(const std::string& name) {
    ParsedArgs args;
    args.mode = Mode::delete_volume_full;
    args.mode_arg = name;
    AppConfig config = reload_config();
    CapturedStdout capture;
    dispatch_command(args, "/nonexistent/unused-config.yaml", config);
}

// Plain nanosleep()-based bounded poll, matching this project's existing
// direct-POSIX style elsewhere (kill_session.cpp's own poll_until()) rather
// than <chrono>/<thread>.
template <typename Predicate>
bool wait_until(int timeout_ms, int interval_ms, Predicate predicate) {
    for (int waited = 0; waited < timeout_ms; waited += interval_ms) {
        if (predicate()) {
            return true;
        }
        struct timespec ts {
            interval_ms / 1000, (interval_ms % 1000) * 1000000L
        };
        nanosleep(&ts, nullptr);
    }
    return predicate();
}

// Whether `path`'s current content contains `needle` -- used to poll a
// daemonized service's own log file for its startup echo lines, since
// -u/--up's own dispatch_command() call can return before the sandboxed
// script has actually started running: report_daemon_started() fires the
// instant bwrap's own pid is known, not once the sandboxed command itself
// has produced any output (daemonize.h/bwrap.cpp).
bool log_contains(const std::filesystem::path& path, const std::string& needle) {
    std::ifstream in(path);
    if (!in) {
        return false;
    }
    std::ostringstream contents;
    contents << in.rdbuf();
    return contents.str().find(needle) != std::string::npos;
}

// Discovers the host's own real, externally-reachable IPv4 address --
// needed because connecting to a -p-forwarded port via 127.0.0.1 doesn't
// work (a documented, known limitation of this project's own port
// forwarding -- NAT hairpinning, see port_forward.h's own doc comment): the
// DNAT rewrite leaves the packet's source address as 127.0.0.1, which the
// container's own kernel then drops as a martian source arriving on a
// non-loopback interface. Parses `ip -4 -o addr show scope global`'s own
// output (the same technique this project's own uplink code,
// network_bridge.cpp, already uses to discover real routing state rather
// than hardcoding it) and returns the first address found.
std::optional<std::string> host_global_ipv4() {
    auto result = run_process({"ip", "-4", "-o", "addr", "show", "scope", "global"});
    if (result.exit_code != 0) {
        return std::nullopt;
    }
    std::istringstream lines(result.stdout_output);
    std::string line;
    while (std::getline(lines, line)) {
        std::istringstream fields(line);
        std::string index;
        std::string ifname;
        std::string family;
        std::string addr_with_prefix;
        if (!(fields >> index >> ifname >> family >> addr_with_prefix)) {
            continue;
        }
        auto slash = addr_with_prefix.find('/');
        if (slash != std::string::npos) {
            return addr_with_prefix.substr(0, slash);
        }
    }
    return std::nullopt;
}

// Connects to host:port, reads until the peer closes the connection (or
// `timeout_ms` elapses with nothing received), and returns whatever was
// read -- a small hand-rolled TCP client, matching this project's own
// precedent of writing minimal raw network code directly rather than
// pulling in a library for it (self_test.cpp's own DNS query helpers).
// nullopt if the connection itself couldn't even be established.
std::optional<std::string> tcp_request(const std::string& host, int port, int timeout_ms) {
    int fd = socket(AF_INET, SOCK_STREAM, 0);
    if (fd < 0) {
        return std::nullopt;
    }
    struct timeval tv {
        timeout_ms / 1000, (timeout_ms % 1000) * 1000
    };
    setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv));
    setsockopt(fd, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof(tv));

    struct sockaddr_in addr {};
    addr.sin_family = AF_INET;
    addr.sin_port = htons(static_cast<uint16_t>(port));
    if (inet_pton(AF_INET, host.c_str(), &addr.sin_addr) != 1) {
        close(fd);
        return std::nullopt;
    }
    if (connect(fd, reinterpret_cast<struct sockaddr*>(&addr), sizeof(addr)) != 0) {
        close(fd);
        return std::nullopt;
    }

    std::string result;
    char buf[256];
    ssize_t n;
    while ((n = read(fd, buf, sizeof(buf))) > 0) {
        result.append(buf, static_cast<size_t>(n));
    }
    close(fd);
    return result;
}

}  // namespace

TEST_CASE("compose lifecycle: test-compose/compose.yaml up, verify, down", "[integration][root][net]") {
    if (geteuid() != 0) {
        SKIP("requires root");
    }

    auto busybox = find_busybox_fixture();
    if (!busybox) {
        SKIP("no busybox fixture (see tests/setup-tests.py)");
    }

    auto compose_path =
        std::filesystem::absolute(std::filesystem::path("test-compose") / "compose.yaml").lexically_normal();
    if (!std::filesystem::exists(compose_path)) {
        SKIP("test-compose/compose.yaml not found relative to cwd");
    }
    auto images_dir = busybox->parent_path();

    REQUIRE(ensure_test_preexisting_network());

    ParsedArgs up_args;
    up_args.mode = Mode::compose_up;
    up_args.compose_images_directory = images_dir.string();
    up_args.compose_file_name = compose_path.string();
    AppConfig up_config = reload_config();
    int up_result = 1;
    {
        CapturedStdout capture;
        up_result = dispatch_command(up_args, "/nonexistent/unused-config.yaml", up_config);
    }
    CHECK(up_result == 0);

    auto containers = list_compose_containers();
    auto find_container = [&](const std::string& service_name) -> const ComposeContainerInfo* {
        for (const auto& container : containers) {
            if (container.compose_path == compose_path && container.service_name == service_name) {
                return &container;
            }
        }
        return nullptr;
    };
    const ComposeContainerInfo* worker = find_container("test-worker");
    const ComposeContainerInfo* server = find_container("test-server");
    CHECK(worker != nullptr);
    CHECK(server != nullptr);

    // Both env-var sources (environment: and env_file:) should be visible,
    // printed by each service's own listen.sh at startup.
    if (worker) {
        auto log_path = session_log_file_path(worker->container_name, worker->pid);
        CHECK(wait_until(10000, 200,
                          [&] { return log_contains(log_path, "WORKER_GREETING=Hello from environment"); }));
        CHECK(log_contains(log_path, "WORKER_ENV_FILE_VAR=set-from-worker-env-file"));
    }
    if (server) {
        auto log_path = session_log_file_path(server->container_name, server->pid);
        CHECK(wait_until(10000, 200, [&] { return log_contains(log_path, "SERVER_ROLE=proxy"); }));
        CHECK(log_contains(log_path, "SERVER_ENV_FILE_VAR=set-from-server-env-file"));
    }

    // test-server's own -p 18080:80 should relay to test-worker1's own
    // "Hello from test-worker" reply.
    auto host_ip = host_global_ipv4();
    CHECK(host_ip.has_value());
    if (host_ip) {
        std::optional<std::string> reply;
        CHECK(wait_until(15000, 500, [&] {
            reply = tcp_request(*host_ip, 18080, 2000);
            return reply.has_value() && !reply->empty();
        }));
        REQUIRE(reply.has_value());
        CHECK(reply->find("Hello from test-worker") != std::string::npos);
    }

    ParsedArgs down_args;
    down_args.mode = Mode::compose_down;
    down_args.compose_file_name = compose_path.string();
    AppConfig down_config = reload_config();
    int down_result = 1;
    {
        CapturedStdout capture;
        down_result = dispatch_command(down_args, "/nonexistent/unused-config.yaml", down_config);
    }
    CHECK(down_result == 0);

    AppConfig after_down = reload_config();
    CHECK_FALSE(has_network(after_down, "test-compose_test-intern-net"));
    CHECK_FALSE(has_network(after_down, "test-compose_test-extern-net"));
    CHECK(has_network(after_down, "test-preexisting-net"));  // external -- never touched
    CHECK(has_volume(after_down, "test-compose_test-server-log"));  // volumes always persist

    // Remove the volume too, so a later run of this same test (or a manual
    // -u/--up) can exercise its creation again from scratch.
    delete_test_volume("test-compose_test-server-log");
    AppConfig final_config = reload_config();
    CHECK_FALSE(has_volume(final_config, "test-compose_test-server-log"));
}