#include "domain/active_register_repository.h"
#include "domain/register_monitor_model.h"
#include "domain/register_repository.h"
#include "domain/virtual_register_repository.h"
#include "services/register_monitor_service.h"
#include "support/test_support.h"

#include <iostream>
#include <cmath>
#include <limits>
#include <stdexcept>
#include <string>

namespace {

using TestSupport::require;

void testRangeManagement()
{
    VirtualRegisterRepository repository;
    RegisterMonitorService service(repository);
    int change_count = 0;
    service.setAddressesChangedCallback([&change_count] { ++change_count; });

    const RegisterMonitorResult added = service.addRange(" d10 ", 3);
    require(added.succeeded && added.affectedCount == 3
                && service.addresses().size() == 3U,
            "monitor service must expand a normalized continuous address range");
    require(service.addresses().front() == RegisterAddress{RegisterArea::D, 10}
                && service.addresses().back() == RegisterAddress{RegisterArea::D, 12},
            "monitor service must preserve expanded address order");
    const RegisterMonitorResult duplicate = service.addRange("D11", 2);
    require(!duplicate.succeeded && duplicate.error == RegisterMonitorError::NoChange,
            "monitor service must reject a fully duplicated range");
    require(!service.addRange("M4000", 2).succeeded,
            "monitor service must reject a range crossing address 4000");
    require(change_count == 1,
            "failed additions must not report a monitor address change");

    require(service.remove({RegisterAddress{RegisterArea::D, 11}}).succeeded
                && service.addresses().size() == 2U,
            "monitor service must remove selected addresses");
    require(service.clear().succeeded && service.addresses().empty(),
            "monitor service must clear the current monitor table");
    require(change_count == 3,
            "successful add, remove and clear operations must notify address changes");
}

void testSharedActiveRepositoryValues()
{
    VirtualRegisterRepository virtual_repository;
    VirtualRegisterRepository plc_repository;
    ActiveRegisterRepository active_repository(virtual_repository);
    RegisterMonitorService service(active_repository);
    require(service.addRange("M0", 1).succeeded
                && service.addRange("D0", 1).succeeded,
            "monitor service must accept one M and one D address");

    virtual_repository.writeBit({RegisterArea::M, 0}, true);
    virtual_repository.writeWord({RegisterArea::D, 0}, -123);
    std::vector<MonitorValue> values = service.values(false);
    require(values.size() == 2U && values[0].bitValue && values[1].wordValue == -123,
            "monitor values must reflect the active virtual repository");

    plc_repository.writeBit({RegisterArea::M, 0}, false);
    plc_repository.writeWord({RegisterArea::D, 0}, 456);
    active_repository.use(plc_repository);
    values = service.values(false);
    require(!values[0].bitValue && values[1].wordValue == 456,
            "monitor values must follow the active repository switch");
    values = service.values(true);
    require(values[0].state == MonitorValueState::CommunicationFault
                && values[1].state == MonitorValueState::CommunicationFault,
            "valid cached values must be marked stale during a communication fault");
}

void testRegisterWrites()
{
    VirtualRegisterRepository repository;
    RegisterMonitorService service(repository);
    const RegisterAddress m0{RegisterArea::M, 0};
    const RegisterAddress d0{RegisterArea::D, 0};

    const RegisterMonitorWriteResult bit_write = service.writeBit(m0, true);
    require(bit_write.succeeded && repository.readBit(m0).value,
            "monitor service must write M values through the active repository");

    const RegisterMonitorWriteResult word_write = service.writeWord(d0, -123);
    require(word_write.succeeded && repository.readWord(d0).value == -123,
            "monitor service must write signed D values through the active repository");

    const RegisterMonitorWriteResult wrong_bit = service.writeBit(d0, true);
    require(!wrong_bit.succeeded && wrong_bit.error == RegisterError::AreaMismatch,
            "monitor bit writes must reject D addresses");
    const RegisterMonitorWriteResult wrong_word = service.writeWord(m0, 123);
    require(!wrong_word.succeeded && wrong_word.error == RegisterError::AreaMismatch,
            "monitor word writes must reject M addresses");

    require(service.writeWord(d0, static_cast<std::int16_t>(-32768)).succeeded
                && repository.readWord(d0).value == -32768
                && service.writeWord(d0, static_cast<std::int16_t>(32767)).succeeded
                && repository.readWord(d0).value == 32767,
            "monitor word writes must preserve signed 16-bit boundary values");
}

void testOfflineInitialValueCapture()
{
    VirtualRegisterRepository virtual_repository;
    VirtualRegisterRepository initial_repository;
    ActiveRegisterRepository active_repository(virtual_repository);
    RegisterMonitorService service(active_repository);
    service.setOfflineInitialRepository(initial_repository);
    service.setOfflineInitialCaptureEnabled(true);

    require(service.writeBit({RegisterArea::M, 3}, true).succeeded
                && service.writeWord({RegisterArea::D, 10}, -456).succeeded
                && service.writeFloat({RegisterArea::D, 20}, 1.5f).succeeded,
            "editing monitor writes must succeed against the virtual repository");
    require(initial_repository.readBit({RegisterArea::M, 3}).value
                && initial_repository.readWord({RegisterArea::D, 10}).value == -456
                && std::fabs(Float32Codec::decode(
                    initial_repository.readWordPair({RegisterArea::D, 20}).values[0],
                    initial_repository.readWordPair({RegisterArea::D, 20}).values[1])
                        .value_or(0.0f) - 1.5f) < 0.000001f,
            "editing monitor writes must be captured as offline initial values");

    service.setOfflineInitialCaptureEnabled(false);
    require(service.writeBit({RegisterArea::M, 3}, false).succeeded
                && initial_repository.readBit({RegisterArea::M, 3}).value,
            "runtime writes must not overwrite the captured initial values");
}

void testFloat32Monitoring()
{
    VirtualRegisterRepository repository;
    RegisterMonitorService service(repository);
    const RegisterMonitorResult added = service.addRange(
        "D1", 3, RegisterDataType::Float32);
    require(added.succeeded && added.affectedCount == 3
                && service.points().size() == 3U
                && service.points()[0].address == RegisterAddress{RegisterArea::D, 1}
                && service.points()[1].address == RegisterAddress{RegisterArea::D, 3}
                && service.points()[2].address == RegisterAddress{RegisterArea::D, 5},
            "Float32 monitor batches must advance by two D words");
    require(service.float32Starts().size() == 3U
                && service.pollAddresses().size() == 6U,
            "Float32 monitor points must expose both words for polling");

    const RegisterMonitorResult duplicate = service.addRange(
        "D1", 1, RegisterDataType::Float32);
    require(!duplicate.succeeded && duplicate.error == RegisterMonitorError::NoChange,
            "identical Float32 monitor points must be rejected");
    const RegisterMonitorResult overlap = service.addRange(
        "D2", 1, RegisterDataType::Int16);
    require(overlap.succeeded && !overlap.message.empty(),
            "partially overlapping monitor points must be added with a warning");
    require(service.remove(std::vector<MonitorPoint>{
                MonitorPoint{{RegisterArea::D, 2}, RegisterDataType::Int16}}).succeeded
                && service.points().size() == 3U,
            "overlapping monitor removal must identify the point type");

    require(service.writeFloat({RegisterArea::D, 1}, -2.5f).succeeded,
            "Float32 monitor writes must use the pair write path");
    const std::vector<MonitorValue> values = service.values(false);
    require(values.front().state == MonitorValueState::Valid
                && std::fabs(values.front().floatValue - (-2.5f)) < 0.000001f,
            "Float32 monitor values must decode the pair correctly");
    require(!service.writeFloat({RegisterArea::D, 4000}, 1.0f).succeeded,
            "Float32 monitor writes at D4000 must be rejected");
}

} // namespace

int main()
{
    try
    {
        testRangeManagement();
        testSharedActiveRepositoryValues();
        testRegisterWrites();
        testOfflineInitialValueCapture();
        testFloat32Monitoring();
    }
    catch (const std::exception &error)
    {
        std::cerr << "register monitor service tests failed: " << error.what() << '\n';
        return 1;
    }
    std::cout << "register monitor service tests passed\n";
    return 0;
}