#include <doctest/doctest.h>

#include "fgc/Config.h"
#include "fgc/IniEdit.h"

#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <filesystem>
#include <fstream>

#include <unistd.h>

using namespace fgc;

namespace {
// How many times `needle` appears in `hay`. Used to assert that calibration
// history replaces itself rather than accumulating.
int countOccurrences(const std::string& hay, const std::string& needle) {
    int    n = 0;
    size_t i = hay.find(needle);
    while (i != std::string::npos) {
        ++n;
        i = hay.find(needle, i + needle.size());
    }
    return n;
}
}  // namespace

TEST_CASE("ConfigLoader maps and defaults typed values") {
    unsetenv("FGC_MQTT_USER");
    unsetenv("FGC_MQTT_PW");

    std::map<std::string, std::string> kv = {
        {"General.tower_name", "Staeffelsberg"},
        {"General.image_interval", "3"},
        {"General.debug", "1"},
        {"Network.zkms_server_ip", "10.0.0.5"},
        {"Network.mqtt_user", "fileuser"},
        {"Features.enable_mqtt", "false"},
    };
    AppConfig c = ConfigLoader::fromMap(kv);

    CHECK(c.general.tower_name == "Staeffelsberg");
    CHECK(c.general.image_interval == 3);
    CHECK(c.general.debug == true);
    CHECK(c.network.broker_ip == "10.0.0.5");
    CHECK(c.network.mqtt_user == "fileuser");
    CHECK(c.features.enable_mqtt == false);
    CHECK(!c.paths.output_dir.empty());        // defaulted
    CHECK(std::abs(c.image_rate() - 1.0 / 3.0) < 1e-9);
}

TEST_CASE("ConfigLoader maps [Env]/env feature flags") {
    AppConfig d = ConfigLoader::fromMap({});
    CHECK(d.features.enable_env == false);
    CHECK(d.features.mock_env == false);
    CHECK(d.env.i2c_device == "/dev/i2c-1");
    CHECK(d.env.i2c_addr == 0x44);
    CHECK(d.env.period_ms == 2000);

    std::map<std::string, std::string> kv = {
        {"Features.enable_env", "true"},
        {"Features.mock_env", "true"},
        {"Env.i2c_device", "/dev/i2c-3"},
        {"Env.i2c_addr", "68"},
        {"Env.period_ms", "5000"},
    };
    AppConfig c = ConfigLoader::fromMap(kv);
    CHECK(c.features.enable_env == true);
    CHECK(c.features.mock_env == true);
    CHECK(c.env.i2c_device == "/dev/i2c-3");
    CHECK(c.env.i2c_addr == 68);
    CHECK(c.env.period_ms == 5000);
}

TEST_CASE("Env.i2c_addr accepts the hex form every datasheet uses") {
    // Plain std::stoi() stops at the 'x' and returns 0, which would silently
    // configure address 0x00 — the sensor would then never answer.
    CHECK(ConfigLoader::fromMap({{"Env.i2c_addr", "0x44"}}).env.i2c_addr == 0x44);
    CHECK(ConfigLoader::fromMap({{"Env.i2c_addr", "0X44"}}).env.i2c_addr == 0x44);
    CHECK(ConfigLoader::fromMap({{"Env.i2c_addr", "68"}}).env.i2c_addr == 68);
    // Decimal stays decimal: no surprise octal for a leading zero.
    CHECK(ConfigLoader::fromMap({{"Env.i2c_addr", "010"}}).env.i2c_addr == 10);
    CHECK_THROWS(ConfigLoader::fromMap({{"Env.i2c_addr", "0x4g"}}));
}

TEST_CASE("environment overrides file credentials") {
    setenv("FGC_MQTT_USER", "envuser", 1);
    AppConfig c = ConfigLoader::fromMap({{"Network.mqtt_user", "fileuser"}});
    CHECK(c.network.mqtt_user == "envuser");
    unsetenv("FGC_MQTT_USER");
}

TEST_CASE("ConfigLoader validates input") {
    CHECK_THROWS(ConfigLoader::fromMap({{"General.image_interval", "0"}}));
    CHECK_THROWS(ConfigLoader::fromMap({{"General.image_interval", "abc"}}));
    CHECK_THROWS(ConfigLoader::fromMap({{"General.debug", "maybe"}}));
}

TEST_CASE("brokerUri builds a Paho serverURI from host + port") {
    // The port used to be whatever Paho defaulted to when handed a bare address.
    // It is now explicit, so these cases pin the whole resolution table.
    auto uri = [](const std::string& host, int port) {
        NetworkConfig n;
        n.broker_ip = host;
        n.mqtt_port = port;
        return n.brokerUri();
    };

    CHECK(uri("10.11.12.20", 1883) == "tcp://10.11.12.20:1883");
    CHECK(uri("broker.local", 8883) == "tcp://broker.local:8883");

    // A port already in the host wins - existing configs that smuggled one in
    // there must keep working.
    CHECK(uri("10.11.12.20:1884", 1883) == "tcp://10.11.12.20:1884");

    // A scheme means the operator owns the whole string: verbatim, port ignored.
    // Appending to a ws:// path would corrupt it.
    CHECK(uri("tcp://host:1883", 9999) == "tcp://host:1883");
    CHECK(uri("ws://host/mqtt", 9999) == "ws://host/mqtt");
    CHECK(uri("ssl://host:8883", 1883) == "ssl://host:8883");

    // IPv6: bracketed passes through, bare gets bracketed - otherwise Paho's
    // rightmost-colon parse reads the last hextet as the port.
    CHECK(uri("[::1]", 1883) == "tcp://[::1]:1883");
    CHECK(uri("[::1]:1884", 1883) == "tcp://[::1]:1884");
    CHECK(uri("::1", 1883) == "tcp://[::1]:1883");
    CHECK(uri("fe80::1234:5678", 1883) == "tcp://[fe80::1234:5678]:1883");

    // The default config resolves to the MQTT default port.
    CHECK(ConfigLoader::fromMap({}).network.brokerUri() == "tcp://127.0.0.1:1883");
    CHECK(ConfigLoader::fromMap({{"Network.zkms_server_ip", "10.0.0.5"},
                                 {"Network.mqtt_port", "8883"}})
              .network.brokerUri() == "tcp://10.0.0.5:8883");
}

TEST_CASE("[Startup] defaults to the idle start: no homing, manual") {
    AppConfig d = ConfigLoader::fromMap({});
    CHECK(d.startup.home == false);
    CHECK(d.startup.mode == Mode::Manual);

    AppConfig e = ConfigLoader::fromMap({{"Startup.home", ""}, {"Startup.mode", ""}});
    CHECK(e.startup.home == false);
    CHECK(e.startup.mode == Mode::Manual);
}

TEST_CASE("[Startup] home and mode are read") {
    AppConfig c = ConfigLoader::fromMap({{"Startup.home", "true"}, {"Startup.mode", "auto"}});
    CHECK(c.startup.home == true);
    CHECK(c.startup.mode == Mode::Auto);

    AppConfig m = ConfigLoader::fromMap({{"Startup.home", "false"}, {"Startup.mode", "manual"}});
    CHECK(m.startup.home == false);
    CHECK(m.startup.mode == Mode::Manual);
}

TEST_CASE("[Startup] refuses a mode it cannot start in") {
    CHECK_THROWS(ConfigLoader::fromMap({{"Startup.mode", "atuo"}}));
    CHECK_THROWS(ConfigLoader::fromMap({{"Startup.mode", "pan"}}));   // needs a spec
    CHECK_THROWS(ConfigLoader::fromMap({{"Startup.home", "maybe"}}));
}

TEST_CASE("the example config starts idle-but-homed, like a new tower") {
    const auto kv = parseIniString([] {
        std::ifstream f(std::string(FGC_SOURCE_DIR) + "/config/config.example.ini");
        return std::string(std::istreambuf_iterator<char>(f), {});
    }());
    AppConfig c = ConfigLoader::fromMap(kv);
    CHECK(c.startup.home == true);
    CHECK(c.startup.mode == Mode::Manual);
}

TEST_CASE("Network.mqtt_port is range-checked") {
    CHECK(ConfigLoader::fromMap({}).network.mqtt_port == 1883);
    CHECK(ConfigLoader::fromMap({{"Network.mqtt_port", "8883"}}).network.mqtt_port == 8883);
    CHECK_THROWS(ConfigLoader::fromMap({{"Network.mqtt_port", "0"}}));
    CHECK_THROWS(ConfigLoader::fromMap({{"Network.mqtt_port", "65536"}}));
    CHECK_THROWS(ConfigLoader::fromMap({{"Network.mqtt_port", "-1"}}));
    CHECK_THROWS(ConfigLoader::fromMap({{"Network.mqtt_port", "1883x"}}));
}

TEST_CASE("Cameras are declared explicitly, one block per camera") {
    // Identity is no longer positional: the block names the camera and `label`
    // names its output, so nothing is implied by the order of the keys.
    AppConfig c = ConfigLoader::fromMap({
        {"Camera.jxl_distance", "0.8"},
        {"Camera.rgb.id", "DEV_1"},
        {"Camera.rgb.label", "RGB"},
        {"Camera.rgb.profile_dir", "/tmp/profiles/rgb"},
        {"Camera.rgb.profile", "night"},
        {"Camera.rgb.rotation_deg", "180"},
        {"Camera.rgb.jxl_effort", "6"},
        {"Camera.nir.id", "DEV_2"},
        {"Camera.nir.profile_dir", "/tmp/profiles/nir"},
    });

    REQUIRE(c.camera.cameras.size() == 2);
    const CameraSpec* rgb = nullptr;
    const CameraSpec* nir = nullptr;
    for (const auto& s : c.camera.cameras) {
        if (s.name == "rgb") rgb = &s;
        if (s.name == "nir") nir = &s;
    }
    REQUIRE(rgb);
    REQUIRE(nir);

    CHECK(rgb->id == "DEV_1");
    CHECK(rgb->label == "RGB");
    CHECK(rgb->profile == "night");
    CHECK(rgb->rotation_deg == 180);
    CHECK(rgb->driver == "vimba");
    CHECK(rgb->enabled);

    // Per-camera override wins; anything not overridden falls back to [Camera].
    CHECK(rgb->jxl_effort == 6);
    CHECK(rgb->jxl_distance == doctest::Approx(0.8));

    // label defaults to the block name rather than to a position in a list.
    CHECK(nir->label == "nir");
    CHECK(nir->profile == "standard");
}

TEST_CASE("Per-profile timing is per camera, and the scheduler takes the longest") {
    AppConfig c = ConfigLoader::fromMap({
        {"Camera.rgb.id", "DEV_1"},
        {"Camera.rgb.profile_dir", "/tmp/p"},
        {"Camera.rgb.profile", "standard"},
        {"Camera.rgb.standard.settle_wait_ms", "1000"},
        {"Camera.rgb.standard.frame_timeout_ms", "2000"},
        {"Camera.nir.id", "DEV_2"},
        {"Camera.nir.profile_dir", "/tmp/p"},
        {"Camera.nir.profile", "standard"},
        {"Camera.nir.standard.settle_wait_ms", "2500"},
        {"Camera.nir.standard.frame_timeout_ms", "5000"},
    });

    // The gimbal must stand still long enough for EVERY camera, so the longest
    // wait wins - taking the first camera's would short-change the slower sensor.
    CHECK(c.camera.maxSettleWaitMs() == 2500);
    CHECK(c.camera.maxFrameTimeoutMs() == 5000);

    // A profile with no timing block falls back to the defaults.
    CHECK(c.camera.cameras[0].timingFor("night").settle_wait_ms == 1000);
}

TEST_CASE("A disabled camera is excluded from the active set and its timing") {
    AppConfig c = ConfigLoader::fromMap({
        {"Camera.rgb.id", "DEV_1"},
        {"Camera.rgb.profile_dir", "/tmp/p"},
        {"Camera.rgb.standard.settle_wait_ms", "1000"},
        {"Camera.slow.enabled", "false"},
        {"Camera.slow.profile_dir", "/tmp/p"},
        {"Camera.slow.standard.settle_wait_ms", "9000"},
    });
    CHECK(c.camera.cameras.size() == 2);
    CHECK(c.camera.active().size() == 1);
    CHECK(c.camera.maxSettleWaitMs() == 1000);   // the disabled camera does not slow the scan
}

TEST_CASE("Camera blocks reject what cannot work") {
    auto base = [](std::map<std::string, std::string> extra) {
        std::map<std::string, std::string> kv = {{"Camera.rgb.id", "DEV_1"},
                                                 {"Camera.rgb.profile_dir", "/tmp/p"}};
        for (auto& [k, v] : extra) kv[k] = v;
        return kv;
    };
    CHECK_NOTHROW(ConfigLoader::fromMap(base({})));

    // No second backend exists yet; accepting the key silently would be worse.
    CHECK_THROWS(ConfigLoader::fromMap(base({{"Camera.rgb.driver", "thermal"}})));
    // An enabled camera with no id cannot be opened.
    CHECK_THROWS(ConfigLoader::fromMap({{"Camera.rgb.profile_dir", "/tmp/p"}}));
    // Nothing to load settings from.
    CHECK_THROWS(ConfigLoader::fromMap({{"Camera.rgb.id", "DEV_1"}}));
    CHECK_THROWS(ConfigLoader::fromMap(base({{"Camera.rgb.rotation_deg", "45"}})));
    CHECK_THROWS(ConfigLoader::fromMap(base({{"Camera.rgb.jxl_distance", "-1"}})));
    CHECK_THROWS(ConfigLoader::fromMap(base({{"Camera.rgb.jxl_effort", "10"}})));
    // A typo'd timing key would otherwise be silently ignored.
    CHECK_THROWS(ConfigLoader::fromMap(base({{"Camera.rgb.standard.settle_wait", "500"}})));
}

TEST_CASE("updateIniSectionKeys replaces in-section keys, leaving others intact") {
    const std::string in =
        "[General]\n"
        "tower_name = Foo\n"
        "[Motor]\n"
        "; calibrate me\n"
        "yaw_counts_per_deg = 983.33\n"
        "yaw_center_count = 500000\n"
        "yaw_min_deg = -90\n"
        "[Scan]\n"
        "yaw_min_deg = -90\n";  // same key name, different section — must NOT change

    auto out = updateIniSectionKeys(in, "Motor",
                                    {{"yaw_counts_per_deg", "1000"}, {"yaw_center_count", "12345"}});

    CHECK(out.find("yaw_counts_per_deg = 1000") != std::string::npos);
    CHECK(out.find("yaw_center_count = 12345") != std::string::npos);
    CHECK(out.find("yaw_counts_per_deg = 983.33") == std::string::npos);  // replaced
    CHECK(out.find("; calibrate me") != std::string::npos);               // comment kept
    CHECK(out.find("tower_name = Foo") != std::string::npos);             // other section kept
    CHECK(out.find("[Motor]\nyaw_min_deg") == std::string::npos);         // Motor's other key kept in place
    CHECK(out.find("[Scan]\nyaw_min_deg = -90") != std::string::npos);    // Scan untouched
}

TEST_CASE("updateIniSectionKeys appends keys missing from the section") {
    const std::string in = "[Motor]\nyaw_counts_per_deg = 1\n";
    auto out = updateIniSectionKeys(in, "Motor", {{"pitch_center_count", "7"}});
    // re-parsing must see the appended key under [Motor]
    CHECK(out.find("pitch_center_count = 7") != std::string::npos);
}

TEST_CASE("a key the section lacks goes into that section, not a second block") {
    const std::string in = "[Hardware]\naxes = yaw\nenv = dht11\n\n; about pins\n[Pins]\n"
                           "yaw_cs = 8\n\n[Camera.rgb]\nid = X\n";
    auto out = updateIniSectionKeys(in, "Hardware", {{"cooling", "fan"}}, "t1, fan test");
    CHECK(out.find("[Hardware]") == out.rfind("[Hardware]"));          // still one block
    CHECK(out.find("env = dht11\n; added   ; t1, fan test\ncooling = fan\n") !=
          std::string::npos);                                            // right after its keys
    CHECK(out.find("cooling = fan") < out.find("; about pins"));       // before the next one's comment
    auto kv = parseIniString(out);
    CHECK(kv["Hardware.cooling"] == "fan");

    // A section the file does not have is still appended whole.
    auto out2 = updateIniSectionKeys(in, "Env", {{"i2c_device", "/dev/i2c-2"}});
    CHECK(out2.find("\n[Env]\ni2c_device = /dev/i2c-2\n") != std::string::npos);
}

TEST_CASE("updateIniSectionKeys keeps the superseded value as a ';prev' comment") {
    const std::string in =
        "[Motor]\n"
        "; the heading the gimbal points at when parked\n"
        "yaw_heading_at_center = 0.0\n"
        "yaw_center_count = 500000\n";

    auto out = updateIniSectionKeys(in, "Motor",
                                    {{"yaw_heading_at_center", "127.4"},
                                     {"yaw_center_count", "500000"}},  // unchanged
                                    "2026-09-11T14:32Z, gimbal heading setup");

    SUBCASE("the changed key keeps its old value, stamped") {
        CHECK(out.find(";prev yaw_heading_at_center = 0.0") != std::string::npos);
        CHECK(out.find("2026-09-11T14:32Z, gimbal heading setup") != std::string::npos);
        CHECK(out.find("yaw_heading_at_center = 127.4") != std::string::npos);
    }
    SUBCASE("the history sits directly above the value it superseded") {
        CHECK(out.find(";prev yaw_heading_at_center = 0.0   ; 2026-09-11T14:32Z, gimbal "
                       "heading setup\nyaw_heading_at_center = 127.4") != std::string::npos);
    }
    SUBCASE("an UNCHANGED key gets no history - otherwise every save adds noise") {
        CHECK(out.find(";prev yaw_center_count") == std::string::npos);
    }
    SUBCASE("hand-written comments survive") {
        CHECK(out.find("; the heading the gimbal points at when parked") != std::string::npos);
    }
}

TEST_CASE("updateIniSectionKeys keeps exactly one generation of history") {
    // Saving twice must REPLACE the marker, not stack markers up: the file has to
    // grow once and then hold steady however often the gimbal is recalibrated.
    std::string s = "[Motor]\nyaw_heading_at_center = 0.0\n";
    s = updateIniSectionKeys(s, "Motor", {{"yaw_heading_at_center", "10"}}, "t1, first");
    s = updateIniSectionKeys(s, "Motor", {{"yaw_heading_at_center", "20"}}, "t2, second");
    s = updateIniSectionKeys(s, "Motor", {{"yaw_heading_at_center", "30"}}, "t3, third");

    CHECK(countOccurrences(s, ";prev yaw_heading_at_center") == 1);
    CHECK(s.find(";prev yaw_heading_at_center = 20") != std::string::npos);  // the one before
    CHECK(s.find("yaw_heading_at_center = 30") != std::string::npos);
    CHECK(s.find("= 0.0") == std::string::npos);  // the oldest is gone
    CHECK(s.find("t3, third") != std::string::npos);
    CHECK(s.find("t1, first") == std::string::npos);
}

TEST_CASE("updateIniSectionKeys history respects inline comments and unchanged values") {
    // inih treats ' ;' as an inline comment, so the stored value is "983.33", not
    // "983.33   ; measured". Comparing raw text instead would call this key changed
    // on every save and bury the file in useless history.
    const std::string in = "[Motor]\nyaw_counts_per_deg = 983.33   ; measured on the rig\n";

    SUBCASE("same value behind an inline comment counts as unchanged") {
        auto out = updateIniSectionKeys(in, "Motor", {{"yaw_counts_per_deg", "983.33"}}, "t, c");
        CHECK(out.find(";prev") == std::string::npos);
    }
    SUBCASE("a real change records only the parsed value, not the comment") {
        auto out = updateIniSectionKeys(in, "Motor", {{"yaw_counts_per_deg", "1000"}}, "t, c");
        CHECK(out.find(";prev yaw_counts_per_deg = 983.33   ; t, c") != std::string::npos);
    }
}

TEST_CASE("updateIniSectionKeys writes no history without a provenance") {
    // The default keeps the old behaviour, so callers that have nothing useful to
    // say about where the values came from do not litter the file.
    const std::string in = "[Motor]\nyaw_center_count = 1\n";
    auto out = updateIniSectionKeys(in, "Motor", {{"yaw_center_count", "2"}});
    CHECK(out.find(";prev") == std::string::npos);
    CHECK(out.find("yaw_center_count = 2") != std::string::npos);
}

TEST_CASE("a ';prev' comment does not survive a reload as a real key") {
    // The marker has to be inert to inih, or reverting by uncommenting would be
    // pointless: the stale value would already be in force.
    std::string s = "[General]\ntower_name = T\n[Motor]\nyaw_center_count = 1\n";
    s = updateIniSectionKeys(s, "Motor", {{"yaw_center_count", "2"}}, "t, c");
    REQUIRE(s.find(";prev yaw_center_count = 1") != std::string::npos);

    const std::string path = "test_prev_marker_reload.ini";
    { std::ofstream(path) << s; }
    auto cfg = ConfigLoader::loadFromFile(path);
    CHECK(cfg.geometry.yaw.center_count == 2);
    std::filesystem::remove(path);
}

TEST_CASE("saveMotorGeometry round-trips the full per-axis map") {
    // Write a starting config, save a calibrated Geometry into it, reload, and
    // confirm every [Motor] parameter survives, while another section is left
    // untouched. min_deg/max_deg are deliberately NOT persisted - they come from
    // homing - so they must come back at their defaults, not at the saved values.
    const std::string path = "test_calib_roundtrip.ini";
    {
        std::ofstream f(path, std::ios::trunc);
        f << "[General]\ntower_name = rig7\n\n"
             "[Motor]\n"
             "yaw_counts_per_deg = 1.0\n"
             "yaw_center_count = 500000\n"
             "yaw_heading_at_center = 0\n"
             "pitch_counts_per_deg = 1.0\n"
             "pitch_center_count = 500000\n"
             "pitch_angle_at_center = 0\n";
    }

    Geometry geo;
    geo.yaw   = {983.33, 500123, 137.25, -88.0, 92.0};
    geo.pitch = {8333.33, 499000, 10.5, -2.0, 61.5};
    REQUIRE(saveMotorGeometry(path, geo, 4000, 6000));

    AppConfig cfg = ConfigLoader::loadFromFile(path);
    CHECK(cfg.general.tower_name == "rig7");  // unrelated section preserved
    CHECK(cfg.geometry.yaw.counts_per_deg == doctest::Approx(983.33));
    CHECK(cfg.geometry.yaw.center_count == 500123);
    CHECK(cfg.geometry.yaw.deg_at_center == doctest::Approx(137.25));
    CHECK(cfg.geometry.pitch.counts_per_deg == doctest::Approx(8333.33));
    CHECK(cfg.geometry.pitch.center_count == 499000);
    CHECK(cfg.geometry.pitch.deg_at_center == doctest::Approx(10.5));
    CHECK(cfg.yaw_soft_margin_counts == 4000);
    CHECK(cfg.pitch_soft_margin_counts == 6000);

    std::remove(path.c_str());
}

TEST_CASE("the [Motor] loader rejects values that would silently misaim the gimbal") {
    auto base = [] {
        return std::map<std::string, std::string>{
            {"Motor.yaw_counts_per_deg", "983.33"},   {"Motor.yaw_center_count", "500000"},
            {"Motor.pitch_counts_per_deg", "8333.33"}, {"Motor.pitch_center_count", "500000"}};
    };
    CHECK_NOTHROW(ConfigLoader::fromMap(base()));

    // A zero scale maps every degree to the centre: it would look calibrated.
    auto zero_scale = base();
    zero_scale["Motor.yaw_counts_per_deg"] = "0";
    CHECK_THROWS_AS(ConfigLoader::fromMap(zero_scale), std::runtime_error);

    // The centre count exists to keep the working range positive.
    auto neg_centre = base();
    neg_centre["Motor.pitch_center_count"] = "-1";
    CHECK_THROWS_AS(ConfigLoader::fromMap(neg_centre), std::runtime_error);

    auto neg_margin = base();
    neg_margin["Motor.yaw_soft_margin_counts"] = "-100";
    CHECK_THROWS_AS(ConfigLoader::fromMap(neg_margin), std::runtime_error);
}

TEST_CASE("keys from the old [Motor] layout are ignored, not silently honoured") {
    // A config still carrying yaw_zero_count must load (so an upgrade is not a
    // hard stop) but must not pick the stale origin up from anywhere.
    std::map<std::string, std::string> kv{
        {"Motor.yaw_counts_per_deg", "983.33"}, {"Motor.yaw_center_count", "500000"},
        {"Motor.yaw_heading_at_center", "42"},  {"Motor.yaw_zero_count", "851592"},
        {"Motor.yaw_min_deg", "0"},             {"Motor.yaw_max_deg", "319"},
        {"Motor.yaw_home_zero", "high"}};
    AppConfig cfg = ConfigLoader::fromMap(kv);
    CHECK(cfg.geometry.yaw.center_count == 500000);
    CHECK(cfg.geometry.yaw.deg_at_center == doctest::Approx(42.0));
    // The removed range keys must not have leaked into the derived window.
    CHECK(cfg.geometry.yaw.min_deg == doctest::Approx(-100000.0));
    CHECK(cfg.geometry.yaw.max_deg == doctest::Approx(100000.0));
}

TEST_CASE("loadFromFile anchors a relative profile_dir to the config file's directory") {
    // The config is found through a search path that has nothing to do with the
    // working directory, so a relative profile_dir must resolve next to the
    // config.ini itself. Resolving it against the cwd is how a profile directory
    // silently goes missing when the program is started from elsewhere.
    namespace fs = std::filesystem;
    const fs::path dir = fs::temp_directory_path() /
                         ("fgc_cfgdir_" + std::to_string(::getpid()));
    fs::remove_all(dir);
    fs::create_directories(dir / "config" / "camera_profiles" / "rgb");
    const fs::path path = dir / "config.ini";
    {
        std::ofstream f(path, std::ios::trunc);
        f << "[Camera.rgb]\n"
             "id = DEV_1\n"
             "profile_dir = config/camera_profiles/rgb\n"
             "[Camera.nir]\n"
             "id = DEV_2\n"
             "profile_dir = /opt/profiles/nir\n"
             "[Camera.swir]\n"
             "id = DEV_3\n"
             "profile_dir = ~/profiles/swir\n";
    }

    AppConfig cfg = ConfigLoader::loadFromFile(path.string());
    const CameraSpec* rgb  = nullptr;
    const CameraSpec* nir  = nullptr;
    const CameraSpec* swir = nullptr;
    for (const auto& c : cfg.camera.cameras) {
        if (c.name == "rgb")  rgb  = &c;
        if (c.name == "nir")  nir  = &c;
        if (c.name == "swir") swir = &c;
    }
    REQUIRE(rgb);
    REQUIRE(nir);
    REQUIRE(swir);

    CHECK(rgb->profile_dir == (dir / "config" / "camera_profiles" / "rgb").string());
    // An absolute path is the operator's explicit choice and is left alone.
    CHECK(nir->profile_dir == "/opt/profiles/nir");
    // ~ expands to the home directory, not to a literal "~" subdirectory.
    CHECK(swir->profile_dir.rfind("~", 0) != 0);
    CHECK(swir->profile_dir.find("/profiles/swir") != std::string::npos);

    fs::remove_all(dir);
}

TEST_CASE("[IMU] x/y/z describe the mount and default to no rotation") {
    // Absent keys must leave the identity, so an existing config.ini keeps
    // behaving exactly as it did before the mount existed.
    AppConfig none = ConfigLoader::fromMap({{"Camera.rgb.id", "D"},
                                            {"Camera.rgb.profile_dir", "/tmp/p"}});
    CHECK(none.imu.mount.identity());

    AppConfig c = ConfigLoader::fromMap({{"Camera.rgb.id", "D"},
                                         {"Camera.rgb.profile_dir", "/tmp/p"},
                                         {"IMU.x", "180"},
                                         {"IMU.y", "-0.5"},
                                         {"IMU.z", "-90"}});
    CHECK(c.imu.mount.x_deg == doctest::Approx(180.0));
    CHECK(c.imu.mount.y_deg == doctest::Approx(-0.5));
    CHECK(c.imu.mount.z_deg == doctest::Approx(-90.0));
    CHECK_FALSE(c.imu.mount.identity());
}

TEST_CASE("hardware.ini layers over config.ini and wins") {
    const std::string cfg_path = "test_hw_layer_config.ini";
    const std::string hw_path  = "test_hw_layer_hardware.ini";
    {
        std::ofstream c(cfg_path);
        c << "[General]\ntower_name = NorthRidge\nimage_interval = 3\n"
             "[Camera.rgb]\nid = OLD_ID\nprofile_dir = /tmp/p\n"
             "[Serial]\ndevice = /dev/ttyACM0\n";
        std::ofstream h(hw_path);
        h << "[Board]\nmodel = lattepanda-iota\nfirmware_env = iota_rp2040\n"
             "[Hardware]\naxes = yaw, pitch\nimu = none\nenv = sht41\ncameras = rgb\n"
             "[Serial]\ndevice = /dev/serial/by-id/usb-RP2040-if00\n"
             "[Camera.rgb]\nid = NEW_ID\n";
    }
    auto c = ConfigLoader::loadFromFile(cfg_path, hw_path);

    SUBCASE("assembly data arrives from hardware.ini") {
        CHECK(c.board.model == "lattepanda-iota");
        CHECK(c.board.firmware_env == "iota_rp2040");
        CHECK(c.hardware.axes == std::vector<std::string>{"yaw", "pitch"});
        CHECK(c.hardware.imu == "none");
        CHECK(c.hardware.env == "sht41");
        CHECK(c.hardware.cameras == std::vector<std::string>{"rgb"});
        CHECK(c.hardware.declared);
        CHECK(c.hardware.source_path == hw_path);
    }
    SUBCASE("bindings in hardware.ini override the ones left in config.ini") {
        CHECK(c.serial.device == "/dev/serial/by-id/usb-RP2040-if00");
        REQUIRE(c.camera.cameras.size() == 1);
        CHECK(c.camera.cameras[0].id == "NEW_ID");
    }
    SUBCASE("operational settings stay with config.ini") {
        CHECK(c.general.tower_name == "NorthRidge");
        CHECK(c.general.image_interval == 3);
    }
    std::filesystem::remove(cfg_path);
    std::filesystem::remove(hw_path);
}

TEST_CASE("without a hardware.ini nothing changes and nothing is declared") {
    // The migration guarantee: an un-migrated tower must behave exactly as before.
    const std::string path = "test_hw_absent.ini";
    {
        std::ofstream c(path);
        c << "[General]\ntower_name = Old\n"
             "[Camera.rgb]\nid = D\nprofile_dir = /tmp/p\n"
             "[Serial]\ndevice = /dev/ttyACM0\n";
    }
    auto c = ConfigLoader::loadFromFile(path);
    CHECK_FALSE(c.hardware.declared);
    CHECK(c.hardware.axes.empty());
    CHECK(c.serial.device == "/dev/ttyACM0");
    CHECK(c.general.tower_name == "Old");

    // An undeclared rig must not answer "no" to any axis, or every caller that
    // asks would start refusing work on towers that have not been migrated.
    CHECK(c.hardware.hasAxis("yaw"));
    CHECK(c.hardware.hasAxis("pitch"));
    std::filesystem::remove(path);
}

TEST_CASE("Hardware.axes parsing and membership") {
    auto c = ConfigLoader::fromMap({{"Camera.rgb.id", "D"},
                                    {"Camera.rgb.profile_dir", "/tmp/p"},
                                    {"Hardware.axes", " YAW ,, pitch ,"}});
    SUBCASE("case, spacing and stray commas are tolerated") {
        CHECK(c.hardware.axes == std::vector<std::string>{"yaw", "pitch"});
        CHECK(c.hardware.axesLabel() == "yaw, pitch");
    }
    SUBCASE("a declared yaw-only rig answers no to pitch") {
        auto y = ConfigLoader::fromMap({{"Camera.rgb.id", "D"},
                                        {"Camera.rgb.profile_dir", "/tmp/p"},
                                        {"Hardware.axes", "yaw"}});
        CHECK(y.hardware.hasAxis("yaw"));
        CHECK_FALSE(y.hardware.hasAxis("pitch"));
    }
    SUBCASE("an unknown axis is a typo worth refusing, not ignoring") {
        CHECK_THROWS(ConfigLoader::fromMap({{"Camera.rgb.id", "D"},
                                            {"Camera.rgb.profile_dir", "/tmp/p"},
                                            {"Hardware.axes", "yaw, roll"}}));
    }
}

TEST_CASE("[Pins] is read for comparison, and absent reads as undeclared") {
    auto c = ConfigLoader::fromMap({{"Camera.rgb.id", "D"},
                                    {"Camera.rgb.profile_dir", "/tmp/p"},
                                    {"Pins.yaw_cs", "1"},
                                    {"Pins.yaw_en", "4"},
                                    {"Pins.spi_sck", "2"},
                                    {"Pins.spi_miso", "0"}});
    CHECK(c.hardware.pins.declared());
    CHECK(c.hardware.pins.yaw_cs == 1);
    CHECK(c.hardware.pins.yaw_en == 4);
    CHECK(c.hardware.pins.spi_sck == 2);
    CHECK(c.hardware.pins.spi_miso == 0);    // GP0 is a pin, not "unset"
    CHECK(c.hardware.pins.pitch_cs == -1);

    auto none = ConfigLoader::fromMap({{"Camera.rgb.id", "D"},
                                       {"Camera.rgb.profile_dir", "/tmp/p"}});
    CHECK_FALSE(none.hardware.pins.declared());
}

TEST_CASE("A mount angle that cannot be a rotation is rejected") {
    auto with = [](const std::string& k, const std::string& v) {
        return ConfigLoader::fromMap({{"Camera.rgb.id", "D"},
                                      {"Camera.rgb.profile_dir", "/tmp/p"},
                                      {k, v}});
    };
    // Out of range is a typo far more often than an intent, and one accepted
    // silently is invisible afterwards - the readings just describe wrong axes.
    CHECK_THROWS(with("IMU.z", "900"));
    CHECK_THROWS(with("IMU.x", "-361"));
    CHECK_THROWS(with("IMU.y", "nan"));
    CHECK_NOTHROW(with("IMU.z", "-360"));
    CHECK_NOTHROW(with("IMU.z", "360"));
}

TEST_CASE("[Motor.<axis>] drivetrain keys are parsed per axis") {
    auto cfg = ConfigLoader::fromMap({
        {"General.tower_name", "t"},
        {"Motor.yaw.r_sense_ohm", "0.075"},
        {"Motor.yaw.run_current_ma", "756"},
        {"Motor.yaw.homing_current_ma", "200"},
        {"Motor.yaw.travel_deg", "340"},
    });
    CHECK(cfg.drivetrain.yaw.declared);
    CHECK(cfg.drivetrain.yaw.r_sense_ohm == doctest::Approx(0.075));
    CHECK(cfg.drivetrain.yaw.run_current_ma == doctest::Approx(756.0));
    CHECK(cfg.drivetrain.yaw.homing_current_ma == doctest::Approx(200.0));
    CHECK(cfg.drivetrain.yaw.travel_deg == doctest::Approx(340.0));
    CHECK(cfg.drivetrain.yaw.reducesForHoming());
    // The other axis stays undeclared, so nothing is sent for it.
    CHECK_FALSE(cfg.drivetrain.pitch.declared);
}

TEST_CASE("an axis that names only a run current is not asking for a reduction") {
    auto cfg = ConfigLoader::fromMap({
        {"General.tower_name", "t"},
        {"Motor.yaw.r_sense_ohm", "0.075"},
        {"Motor.yaw.run_current_ma", "756"},
    });
    CHECK(cfg.drivetrain.yaw.homing_current_ma == doctest::Approx(756.0));
    CHECK_FALSE(cfg.drivetrain.yaw.reducesForHoming());
}

TEST_CASE("[Motor.yaw] travel_deg does not shadow [Motor] yaw_counts_per_deg") {
    // The whole reason the travel angle is a separate key in a separate section:
    // hardware.ini is merged OVER config.ini and wins, so if the derived
    // calibration shared a key with the nameplate fact, every saved calibration
    // would be silently discarded on the next start.
    auto cfg = ConfigLoader::fromMap({
        {"General.tower_name", "t"},
        {"Motor.yaw_counts_per_deg", "3561.1"},   // calibration, from config.ini
        {"Motor.yaw.travel_deg", "340"},          // nameplate, from hardware.ini
    });
    CHECK(cfg.geometry.yaw.counts_per_deg == doctest::Approx(3561.1));
    CHECK(cfg.drivetrain.yaw.travel_deg == doctest::Approx(340.0));
}

TEST_CASE("a drivetrain current without its sense resistor is refused") {
    // Computing registers against a guessed resistor would silently deliver the
    // wrong current, which on a rig with a yielding endstop is the whole hazard.
    CHECK_THROWS(ConfigLoader::fromMap({
        {"General.tower_name", "t"},
        {"Motor.yaw.run_current_ma", "756"},
    }));
}

TEST_CASE("an undeclared drivetrain leaves every axis silent") {
    auto cfg = ConfigLoader::fromMap({{"General.tower_name", "t"}});
    CHECK_FALSE(cfg.drivetrain.yaw.declared);
    CHECK_FALSE(cfg.drivetrain.pitch.declared);
    CHECK(cfg.drivetrain.yaw.run_current_ma == 0.0);
    CHECK_FALSE(cfg.drivetrain.yaw.reducesForHoming());
}

TEST_CASE("a value that only changes spelling gets no history line") {
    // The writer formats doubles with %.10g, so a hand-written "0.0" comes back
    // as "0". That is the same number, and recording it as a change would spend
    // the single ";prev" generation on a value that never moved - displacing the
    // real previous value the mechanism exists to preserve.
    const std::string before = "[Motor]\nyaw_heading_at_center = 0.0\n";
    const std::string after =
        updateIniSectionKeys(before, "Motor", {{"yaw_heading_at_center", "0"}}, "a save");
    CHECK(after.find(";prev") == std::string::npos);
    CHECK(after.find("yaw_heading_at_center = 0") != std::string::npos);
}

TEST_CASE("differently spelled equal numbers are not changes") {
    for (auto [old_text, new_text] : std::vector<std::pair<std::string, std::string>>{
             {"1e3", "1000"}, {"500.0", "500"}, {"0.50", "0.5"}, {" 12 ", "12"}}) {
        const std::string out = updateIniSectionKeys("[Motor]\nk = " + old_text + "\n", "Motor",
                                                     {{"k", new_text}}, "a save");
        CHECK(out.find(";prev") == std::string::npos);
    }
}

TEST_CASE("a genuine numeric change still records its history") {
    const std::string out = updateIniSectionKeys("[Motor]\nyaw_counts_per_deg = 500\n", "Motor",
                                                 {{"yaw_counts_per_deg", "3552.867647"}},
                                                 "homed travel");
    CHECK(out.find(";prev yaw_counts_per_deg = 500") != std::string::npos);
    CHECK(out.find("homed travel") != std::string::npos);
    CHECK(out.find("yaw_counts_per_deg = 3552.867647") != std::string::npos);
}

TEST_CASE("non-numeric values still compare as text") {
    const std::string out = updateIniSectionKeys("[Serial]\ndevice = /dev/ttyACM0\n", "Serial",
                                                 {{"device", "/dev/ttyUSB0"}}, "a save");
    CHECK(out.find(";prev device = /dev/ttyACM0") != std::string::npos);
}

// --- [Hardware] imu/env retiring [Features] enable_imu/enable_env (plan A.12) ---

TEST_CASE("an undeclared rig still obeys the legacy flag exactly as before") {
    // Every tower until it is migrated. Behaviour must not change.
    auto on = resolveSensorEnable("", true, true);
    CHECK(on.enabled);
    CHECK(on.source == SensorEnableSource::Flag);
    CHECK_FALSE(on.conflict);

    auto off = resolveSensorEnable("", false, true);
    CHECK_FALSE(off.enabled);

    auto absent = resolveSensorEnable("", false, false);
    CHECK_FALSE(absent.enabled);
    CHECK(absent.source == SensorEnableSource::Default);
}

TEST_CASE("a declared sensor needs no second key agreeing with it") {
    // The trap this removes: declare the IMU, forget enable_imu, and presence
    // reconciliation reports missing HARDWARE for what is a missing flag.
    auto e = resolveSensorEnable("mti-630", /*flag_value=*/false, /*flag_present=*/false);
    CHECK(e.enabled);
    CHECK(e.source == SensorEnableSource::Declaration);
    CHECK_FALSE(e.conflict);
}

TEST_CASE("'none' cannot be contradicted into enabling a sensor") {
    auto e = resolveSensorEnable("none", /*flag_value=*/true, /*flag_present=*/true);
    CHECK_FALSE(e.enabled);
    CHECK(e.source == SensorEnableSource::Declaration);
    CHECK(e.conflict);  // named, so the stale key can be deleted
}

TEST_CASE("a declaration beats a flag that disagrees, and the clash is reported") {
    auto e = resolveSensorEnable("sht41", /*flag_value=*/false, /*flag_present=*/true);
    CHECK(e.enabled);
    CHECK(e.conflict);

    // Agreeing is not a conflict, merely redundant.
    auto agree = resolveSensorEnable("sht41", true, true);
    CHECK(agree.enabled);
    CHECK_FALSE(agree.conflict);
}

TEST_CASE("image saving and de-Bayer settings: defaults, sharing the cores, limits") {
    auto base = [](std::map<std::string, std::string> extra) {
        std::map<std::string, std::string> kv = {{"Camera.rgb.id", "DEV_1"},
                                                 {"Camera.rgb.profile_dir", "/tmp/p"}};
        for (auto& [k, v] : extra) kv[k] = v;
        return ConfigLoader::fromMap(kv);
    };

    AppConfig c = base({});
    CHECK(c.hardware.save_workers == 1);
    CHECK(c.hardware.jxl_threads == 4);       // 4 / save_workers
    CHECK(c.hardware.save_queue_max == 4);
    REQUIRE(c.camera.cameras.size() == 1);
    CHECK(c.camera.cameras[0].demosaic == "edge_aware");

    // Two workers share the four cores unless told otherwise (the 3 Delta).
    c = base({{"Hardware.save_workers", "2"}});
    CHECK(c.hardware.jxl_threads == 2);
    c = base({{"Hardware.save_workers", "2"}, {"Hardware.jxl_threads", "3"}});
    CHECK(c.hardware.jxl_threads == 3);

    // [Camera] default, overridden per camera; case does not matter.
    c = base({{"Camera.demosaic", "Bilinear"}});
    CHECK(c.camera.cameras[0].demosaic == "bilinear");
    c = base({{"Camera.demosaic", "bilinear"}, {"Camera.rgb.demosaic", "edge_aware"}});
    CHECK(c.camera.cameras[0].demosaic == "edge_aware");

    CHECK_THROWS(base({{"Camera.rgb.demosaic", "vng"}}));
    CHECK_THROWS(base({{"Hardware.save_workers", "0"}}));
    CHECK_THROWS(base({{"Hardware.save_workers", "5"}}));
    CHECK_THROWS(base({{"Hardware.jxl_threads", "9"}}));
    CHECK_THROWS(base({{"Hardware.save_queue_max", "0"}}));
    CHECK_THROWS(base({{"Hardware.save_queue_max", "33"}}));
}

TEST_CASE("each profile chooses its keep rule: fixed (default) or brightness") {
    auto c = ConfigLoader::fromMap({{"Camera.rgb.id", "DEV_1"},
                                    {"Camera.rgb.profile_dir", "/tmp/p"},
                                    {"Camera.rgb.standard.settle_rule", "Brightness"},
                                    {"Camera.rgb.standard.frame_timeout_ms", "5000"},
                                    {"Camera.rgb.night.settle_wait_ms", "2500"}});
    REQUIRE(c.camera.cameras.size() == 1);
    const auto& cam = c.camera.cameras[0];
    CHECK(cam.timingFor("standard").settle_rule == "brightness");
    CHECK(cam.timingFor("standard").frame_timeout_ms == 5000);
    CHECK(cam.timingFor("night").settle_rule == "fixed");
    CHECK(cam.timingFor("unnamed").settle_rule == "fixed");
    CHECK_THROWS(ConfigLoader::fromMap({{"Camera.rgb.id", "DEV_1"},
                                        {"Camera.rgb.profile_dir", "/tmp/p"},
                                        {"Camera.rgb.standard.settle_rule", "magic"}}));
}