#include "modbusino_tests.h"
#include "modbusino.h"
#include <assert.h>
#include <netinet/in.h>
#include <stdio.h>
#include <string.h>


int read_byte_empty(uint8_t* b, int32_t timeout) {
    return 0;
}


int write_byte_empty(uint8_t b, int32_t timeout) {
    return 0;
}


void test_server_create(mbsn_transport transport) {
    mbsn_t mbsn;
    mbsn_error err;

    mbsn_platform_conf platform_conf_empty = {.transport = transport,
                                              .read_byte = read_byte_empty,
                                              .write_byte = write_byte_empty,
                                              .sleep = platform_sleep};

    should("create a modbus server");
    reset(mbsn);
    err = mbsn_server_create(&mbsn, TEST_SERVER_ADDR, &platform_conf_empty, (mbsn_callbacks){});
    check(err);

    should("check parameters and fail to create a modbus server");
    reset(mbsn);
    err = mbsn_server_create(NULL, TEST_SERVER_ADDR, &platform_conf_empty, (mbsn_callbacks){});
    expect(err == MBSN_ERROR_INVALID_ARGUMENT);

    reset(mbsn);
    err = mbsn_server_create(&mbsn, 0, &platform_conf_empty, (mbsn_callbacks){});
    expect(err == MBSN_ERROR_INVALID_ARGUMENT);

    reset(mbsn);
    mbsn_platform_conf p = platform_conf_empty;
    p.transport = 3;
    err = mbsn_server_create(&mbsn, 0, &p, (mbsn_callbacks){});
    expect(err == MBSN_ERROR_INVALID_ARGUMENT);

    reset(mbsn);
    p = platform_conf_empty;
    p.read_byte = NULL;
    err = mbsn_server_create(&mbsn, 0, &p, (mbsn_callbacks){});
    expect(err == MBSN_ERROR_INVALID_ARGUMENT);

    reset(mbsn);
    p = platform_conf_empty;
    p.write_byte = NULL;
    err = mbsn_server_create(&mbsn, 0, &p, (mbsn_callbacks){});
    expect(err == MBSN_ERROR_INVALID_ARGUMENT);
}


int read_byte_timeout(uint8_t* b, int32_t timeout) {
    usleep(timeout * 1000);
    return 0;
}


int read_byte_timeout_third(uint8_t* b, int32_t timeout) {
    static int stage = 0;
    switch (stage) {
        case 0:
        case 1:
            *b = 1;
            stage++;
            return 1;
        case 2:
            assert(timeout > 0);
            usleep(timeout * 1000 + 100 * 1000);
            stage = 0;
            return 0;
        default:
            stage = 0;
            return -1;
    }
}


void test_server_receive_base(mbsn_transport transport) {
    mbsn_t server;
    mbsn_error err;
    mbsn_platform_conf platform_conf;


    should("honor read_timeout and return normally");
    reset(server);
    platform_conf.transport = transport;
    platform_conf.read_byte = read_byte_timeout;
    platform_conf.write_byte = write_byte_empty;
    platform_conf.sleep = platform_sleep;

    const int32_t read_timeout_ms = 250;

    err = mbsn_server_create(&server, TEST_SERVER_ADDR, &platform_conf, (mbsn_callbacks){});
    check(err);

    mbsn_set_read_timeout(&server, read_timeout_ms);
    mbsn_set_byte_timeout(&server, -1);

    const int polls = 5;
    for (int i = 0; i < polls; i++) {
        uint64_t start = now_ms();
        err = mbsn_server_receive(&server);
        check(err);

        uint64_t diff = now_ms() - start;

        assert(diff >= read_timeout_ms);
    }


    should("honor byte_timeout and return MBSN_ERROR_TIMEOUT");
    reset(server);
    platform_conf.transport = transport;
    platform_conf.read_byte = read_byte_timeout_third;
    platform_conf.write_byte = write_byte_empty;

    const int32_t byte_timeout_ms = 250;

    err = mbsn_server_create(&server, TEST_SERVER_ADDR, &platform_conf, (mbsn_callbacks){});
    check(err);

    mbsn_set_read_timeout(&server, 1000);
    mbsn_set_byte_timeout(&server, byte_timeout_ms);

    err = mbsn_server_receive(&server);
    expect(err == MBSN_ERROR_TIMEOUT);
}


mbsn_error read_discrete(uint16_t address, uint16_t quantity, mbsn_bitfield coils_out) {
    if (address == 1)
        return -1;

    if (address == 2)
        return MBSN_EXCEPTION_ILLEGAL_DATA_ADDRESS;

    if (address == 3)
        return MBSN_EXCEPTION_ILLEGAL_DATA_VALUE;

    if (address == 10 && quantity == 3) {
        mbsn_bitfield_write(coils_out, 0, 1);
        mbsn_bitfield_write(coils_out, 1, 0);
        mbsn_bitfield_write(coils_out, 2, 1);
    }

    return MBSN_ERROR_NONE;
}


void test_fc1(mbsn_transport transport) {
    uint8_t raw_res[260];

    start_client_and_server(transport, (mbsn_callbacks){});

    should("return MBSN_EXCEPTION_ILLEGAL_FUNCTION when callback is not registered server-side");
    assert(mbsn_read_coils(&CLIENT, 1, 1, NULL) == MBSN_EXCEPTION_ILLEGAL_FUNCTION);

    stop_client_and_server();

    start_client_and_server(transport, (mbsn_callbacks){.read_coils = read_discrete});

    should("immediately return MBSN_ERROR_INVALID_ARGUMENT when calling with quantity 0");
    assert(mbsn_read_coils(&CLIENT, 1, 0, NULL) == MBSN_ERROR_INVALID_ARGUMENT);

    should("immediately return MBSN_ERROR_INVALID_ARGUMENT when calling with quantity > 2000");
    assert(mbsn_read_coils(&CLIENT, 1, 2001, NULL) == MBSN_ERROR_INVALID_ARGUMENT);

    should("immediately return MBSN_ERROR_INVALID_ARGUMENT when calling with address + quantity > 65535");
    assert(mbsn_read_coils(&CLIENT, 65530, 7, NULL) == MBSN_ERROR_INVALID_ARGUMENT);

    should("return MBSN_EXCEPTION_ILLEGAL_DATA_VALUE from server when calling with quantity 0");
    check(mbsn_send_raw_pdu(&CLIENT, 1, (uint16_t[]){htons(1), htons(0)}, 4));
    assert(mbsn_receive_raw_pdu_response(&CLIENT, raw_res, 2) == MBSN_EXCEPTION_ILLEGAL_DATA_VALUE);

    should("return MBSN_EXCEPTION_ILLEGAL_DATA_VALUE from server when calling with quantity > 2000");
    check(mbsn_send_raw_pdu(&CLIENT, 1, (uint16_t[]){htons(1), htons(2001)}, 4));
    assert(mbsn_receive_raw_pdu_response(&CLIENT, raw_res, 2) == MBSN_EXCEPTION_ILLEGAL_DATA_VALUE);

    should("return MBSN_EXCEPTION_ILLEGAL_DATA_ADDRESS from server when calling with address + quantity > 65535");
    check(mbsn_send_raw_pdu(&CLIENT, 1, (uint16_t[]){htons(65530), htons(7)}, 4));
    assert(mbsn_receive_raw_pdu_response(&CLIENT, raw_res, 2) == MBSN_EXCEPTION_ILLEGAL_DATA_ADDRESS);

    should("return MBSN_EXCEPTION_SERVER_DEVICE_FAILURE when server handler returns any non-exception error");
    assert(mbsn_read_coils(&CLIENT, 1, 1, NULL) == MBSN_EXCEPTION_SERVER_DEVICE_FAILURE);

    should("return MBSN_EXCEPTION_ILLEGAL_DATA_ADDRESS if returned by server handler");
    assert(mbsn_read_coils(&CLIENT, 2, 1, NULL) == MBSN_EXCEPTION_ILLEGAL_DATA_ADDRESS);

    should("return MBSN_EXCEPTION_ILLEGAL_DATA_VALUE if returned by server handler");
    assert(mbsn_read_coils(&CLIENT, 3, 1, NULL) == MBSN_EXCEPTION_ILLEGAL_DATA_VALUE);

    should("read with no error");
    mbsn_bitfield bf;
    check(mbsn_read_coils(&CLIENT, 10, 3, bf));
    assert(mbsn_bitfield_read(bf, 0) == 1);
    assert(mbsn_bitfield_read(bf, 1) == 0);
    assert(mbsn_bitfield_read(bf, 2) == 1);

    stop_client_and_server();
}


void test_fc2(mbsn_transport transport) {
    uint8_t raw_res[260];

    start_client_and_server(transport, (mbsn_callbacks){});

    should("return MBSN_EXCEPTION_ILLEGAL_FUNCTION when callback is not registered server-side");
    assert(mbsn_read_discrete_inputs(&CLIENT, 1, 1, NULL) == MBSN_EXCEPTION_ILLEGAL_FUNCTION);

    stop_client_and_server();

    start_client_and_server(transport, (mbsn_callbacks){.read_discrete_inputs = read_discrete});

    should("immediately return MBSN_ERROR_INVALID_ARGUMENT when calling with quantity 0");
    assert(mbsn_read_discrete_inputs(&CLIENT, 1, 0, NULL) == MBSN_ERROR_INVALID_ARGUMENT);

    should("immediately return MBSN_ERROR_INVALID_ARGUMENT when calling with quantity > 2000");
    assert(mbsn_read_discrete_inputs(&CLIENT, 1, 2001, NULL) == MBSN_ERROR_INVALID_ARGUMENT);

    should("immediately return MBSN_ERROR_INVALID_ARGUMENT when calling with address + quantity > 65535");
    assert(mbsn_read_discrete_inputs(&CLIENT, 65530, 7, NULL) == MBSN_ERROR_INVALID_ARGUMENT);

    should("return MBSN_EXCEPTION_ILLEGAL_DATA_VALUE from server when calling with quantity 0");
    check(mbsn_send_raw_pdu(&CLIENT, 2, (uint16_t[]){htons(1), htons(0)}, 4));
    assert(mbsn_receive_raw_pdu_response(&CLIENT, raw_res, 2) == MBSN_EXCEPTION_ILLEGAL_DATA_VALUE);

    should("return MBSN_EXCEPTION_ILLEGAL_DATA_VALUE from server when calling with quantity > 2000");
    check(mbsn_send_raw_pdu(&CLIENT, 2, (uint16_t[]){htons(1), htons(2001)}, 4));
    assert(mbsn_receive_raw_pdu_response(&CLIENT, raw_res, 2) == MBSN_EXCEPTION_ILLEGAL_DATA_VALUE);

    should("return MBSN_EXCEPTION_ILLEGAL_DATA_ADDRESS from server when calling with address + quantity > 65535");
    check(mbsn_send_raw_pdu(&CLIENT, 2, (uint16_t[]){htons(65530), htons(7)}, 4));
    assert(mbsn_receive_raw_pdu_response(&CLIENT, raw_res, 2) == MBSN_EXCEPTION_ILLEGAL_DATA_ADDRESS);

    should("return MBSN_EXCEPTION_SERVER_DEVICE_FAILURE when server handler returns any non-exception error");
    assert(mbsn_read_discrete_inputs(&CLIENT, 1, 1, NULL) == MBSN_EXCEPTION_SERVER_DEVICE_FAILURE);

    should("return MBSN_EXCEPTION_ILLEGAL_DATA_ADDRESS if returned by server handler");
    assert(mbsn_read_discrete_inputs(&CLIENT, 2, 1, NULL) == MBSN_EXCEPTION_ILLEGAL_DATA_ADDRESS);

    should("return MBSN_EXCEPTION_ILLEGAL_DATA_VALUE if returned by server handler");
    assert(mbsn_read_discrete_inputs(&CLIENT, 3, 1, NULL) == MBSN_EXCEPTION_ILLEGAL_DATA_VALUE);

    should("read with no error");
    mbsn_bitfield bf;
    check(mbsn_read_discrete_inputs(&CLIENT, 10, 3, bf));
    assert(mbsn_bitfield_read(bf, 0) == 1);
    assert(mbsn_bitfield_read(bf, 1) == 0);
    assert(mbsn_bitfield_read(bf, 2) == 1);

    stop_client_and_server();
}


mbsn_transport transports[2] = {MBSN_TRANSPORT_TCP, MBSN_TRANSPORT_RTU};
const char* transports_str[2] = {"TCP", "RTU"};


void for_transports(void (*test_fn)(mbsn_transport), const char* should_str) {
    for (int t = 0; t < sizeof(transports) / sizeof(mbsn_transport); t++) {
        printf("Should %s on %s:\n", should_str, transports_str[t]);
        test(test_fn(transports[t]));
    }
}


int main() {

    for_transports(test_server_create, "create a modbus server");

    for_transports(test_server_receive_base, "receive no messages without failing");

    for_transports(test_fc1, "send and receive FC 01 (0x01) Read Coils");

    for_transports(test_fc2, "send and receive FC 02 (0x02) Read Discrete Inputs");


    return 0;
}