#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>

#include "trikke_transport.h"

typedef struct {
    trikke_transport_status_t begin_status;
    trikke_transport_status_t poll_status;
    unsigned int begin_calls;
    unsigned int poll_calls;
    const uint8_t *packet;
    size_t packet_size;
} mock_transport_t;

static int fail(int code, const char *message)
{
    fprintf(stderr, "transport fixture failure %d: %s\n", code, message);
    return code;
}

static trikke_transport_status_t mock_begin(
    void *context,
    const uint8_t *packet,
    size_t packet_size)
{
    mock_transport_t *mock = context;
    ++mock->begin_calls;
    mock->packet = packet;
    mock->packet_size = packet_size;
    return mock->begin_status;
}

static trikke_transport_status_t mock_poll(void *context)
{
    mock_transport_t *mock = context;
    ++mock->poll_calls;
    return mock->poll_status;
}

int main(void)
{
    const uint8_t packet[] = {0x54, 0x52, 0x4B, 0x31};
    mock_transport_t mock = {
        .begin_status = TRIKKE_TRANSPORT_RETRY,
        .poll_status = TRIKKE_TRANSPORT_PENDING,
    };
    const trikke_transport_t transport = {
        .context = &mock,
        .begin = mock_begin,
        .poll = mock_poll,
    };
    trikke_transport_sender_t sender;
    trikke_transport_sender_init(&sender);

    if (trikke_transport_sender_step(
            &sender, &transport, packet, sizeof(packet)) !=
            TRIKKE_TRANSPORT_RETRY ||
        sender.pending || mock.begin_calls != 1 || mock.poll_calls != 0 ||
        mock.packet != packet || mock.packet_size != sizeof(packet)) {
        return fail(1, "zero-accept submission must remain retryable");
    }

    mock.begin_status = TRIKKE_TRANSPORT_PENDING;
    if (trikke_transport_sender_step(
            &sender, &transport, packet, sizeof(packet)) !=
            TRIKKE_TRANSPORT_PENDING ||
        !sender.pending || mock.begin_calls != 2 || mock.poll_calls != 0) {
        return fail(2, "accepted submission must become pending");
    }

    if (trikke_transport_sender_step(
            &sender, &transport, packet, sizeof(packet)) !=
            TRIKKE_TRANSPORT_PENDING ||
        !sender.pending || mock.begin_calls != 2 || mock.poll_calls != 1) {
        return fail(3, "pending transfer must poll without resubmission");
    }

    mock.poll_status = TRIKKE_TRANSPORT_COMPLETE;
    if (trikke_transport_sender_step(
            &sender, &transport, packet, sizeof(packet)) !=
            TRIKKE_TRANSPORT_COMPLETE ||
        sender.pending || mock.begin_calls != 2 || mock.poll_calls != 2) {
        return fail(4, "completed transfer must return to idle");
    }

    mock.begin_status = TRIKKE_TRANSPORT_COMPLETE;
    if (trikke_transport_sender_step(
            &sender, &transport, packet, sizeof(packet)) !=
            TRIKKE_TRANSPORT_COMPLETE ||
        sender.pending || mock.begin_calls != 3) {
        return fail(5, "synchronous completion contract");
    }

    mock.begin_status = TRIKKE_TRANSPORT_PENDING;
    mock.poll_status = TRIKKE_TRANSPORT_RETRY;
    if (trikke_transport_sender_step(
            &sender, &transport, packet, sizeof(packet)) !=
            TRIKKE_TRANSPORT_PENDING ||
        trikke_transport_sender_step(
            &sender, &transport, packet, sizeof(packet)) !=
            TRIKKE_TRANSPORT_FATAL ||
        !sender.pending || mock.begin_calls != 4 || mock.poll_calls != 3 ||
        trikke_transport_sender_step(
            &sender, &transport, packet, sizeof(packet)) !=
            TRIKKE_TRANSPORT_FATAL ||
        mock.begin_calls != 4 || mock.poll_calls != 4) {
        return fail(6, "retry after acceptance must fail closed without resubmit");
    }

    trikke_transport_sender_init(&sender);
    if (trikke_transport_sender_step(
            NULL, &transport, packet, sizeof(packet)) !=
            TRIKKE_TRANSPORT_FATAL ||
        trikke_transport_sender_step(
            &sender, NULL, packet, sizeof(packet)) != TRIKKE_TRANSPORT_FATAL ||
        trikke_transport_sender_step(
            &sender, &transport, NULL, sizeof(packet)) !=
            TRIKKE_TRANSPORT_FATAL ||
        trikke_transport_sender_step(
            &sender, &transport, packet, 0) != TRIKKE_TRANSPORT_FATAL) {
        return fail(7, "invalid arguments must fail closed");
    }

    mock.begin_status = (trikke_transport_status_t)99;
    if (trikke_transport_sender_step(
            &sender, &transport, packet, sizeof(packet)) !=
            TRIKKE_TRANSPORT_FATAL ||
        sender.pending) {
        return fail(8, "unknown backend status must fail closed");
    }

    return 0;
}