#include "xhci.h"
#include "commands.h"
#include "controller.h"
#include "trbRing.h"
#include <hlib.h>
#include <usb.h>

// see https://www.intel.com/content/dam/www/public/us/en/documents/technical-specifications/extensible-host-controler-interface-usb-xhci.pdf

XHCIInputContext *createInputContext(SlotXHCI *slot) {
    XHCIInputContext *inputContext = requestMemory(1, 0, 0);
    inputContext->inputControl.addContextFlags = 3;
    inputContext->deviceContext.slot.rootHubPort = slot->portIndex;
    inputContext->deviceContext.slot.interrupterTarget = 0;
    inputContext->deviceContext.slot.multiTT = 0;
    inputContext->deviceContext.slot.deviceAddress = 0;
    inputContext->deviceContext.slot.contextEntryCount = 1;
    inputContext->deviceContext.slot.speed = (slot->port->status >> 10) & 3;
    inputContext->deviceContext.endpoints[0].endpointType = 4;
    inputContext->deviceContext.endpoints[0].maxPacketSize = 8; // TODO
    inputContext->deviceContext.endpoints[0].maxBurstSize = 0;
    inputContext->deviceContext.endpoints[0].interval = 0;
    inputContext->deviceContext.endpoints[0].maxPrimaryStreams = 0;
    inputContext->deviceContext.endpoints[0].multiplier = 0;
    inputContext->deviceContext.endpoints[0].errorCount = 3;
    inputContext->deviceContext.endpoints[0].averageTRBLength = 1024;
    return inputContext;
}

UsbHostControllerInterface xhci;

void *resetSlot(XHCIController *controller, uint32_t portIndex) {
    SlotXHCI *slot = malloc(sizeof(SlotXHCI));
    slot->portIndex = portIndex;
    slot->controller = controller;
    slot->slotIndex = requestSlotIndex(controller);
    slot->port = &controller->operational->ports[portIndex - 1];

    slot->port->status |= 1 << 4;
    awaitCode(serviceId, xhciEvent, slot->portIndex << 24);
    if (!(slot->port->status & 1 << 1)) {
        printf("port %i reset not succesful, aborting\n", portIndex);
        return NULL;
    }
    slot->inputContext = createInputContext(slot);
    slot->controlRing = createSlotTRB(slot);
    controller->deviceContexts[slot->slotIndex] = malloc(sizeof(XHCIDevice));
    slot->controller->deviceContextBaseAddressArray[slot->slotIndex] =
        U32(getPhysicalAddress(
            (void *)controller->deviceContexts[slot->slotIndex]));
    addressDevice(slot, true);
    addressDevice(slot, false);
    UsbSlot *result = malloc(sizeof(UsbSlot));
    result->data = slot;
    result->interface = &xhci;
    result->portIndex = portIndex;
    return result;
}

void *init(uint32_t deviceId, uint32_t bar0, uint32_t interrupt) {
    UsbHostController *host = malloc(sizeof(UsbHostController));
    XHCIController *controller = xhciSetup(deviceId, bar0, interrupt);
    host->data = controller;
    for (uint32_t i = 0; i < controller->portCount; i++) {
        if (!(controller->operational->ports[i].status & 1 << 0)) {
            continue;
        }
        listAdd(&host->slots, resetSlot(controller, i + 1));
    }
    return host;
}

void xhciNormal(SlotXHCI *slot, void *bufferPhysical, uint32_t endpointIndex) {
    XHCINormalTRB normal = {0};
    normal.type = 1;
    normal.interrupterTarget = 0;
    normal.interruptOnCompletion = 1;
    normal.interruptOnShortPacket = 1;
    normal.dataBuffer[0] = U32(bufferPhysical);
    normal.dataBuffer[1] = 0;
    normal.transferSize = 4;
    uint32_t commandAddress = U32(enqueueCommand(
        slot->endpointRings[endpointIndex], (void *)&normal));
    slot->controller->doorbells[slot->slotIndex] = endpointIndex + 1;
    awaitCode(serviceId, xhciEvent, commandAddress);
}

void doXhciWriteNormal(SlotXHCI * slot, void *bufferPhysical, uint32_t endpointIndex, uint32_t transferSize) {
    // incidentally, this also works for reading from the XHCI device. nice!
    XHCINormalTRB normal = {0};
    normal.dataBuffer[0] = U32(bufferPhysical);
    normal.dataBuffer[1] = 0;
    normal.interrupterTarget = 0;
    normal.interruptOnCompletion = 1;
    normal.interruptOnShortPacket = 1;
    normal.transferSize = transferSize;
    normal.type = 1;
    uint32_t commandAddress = U32(enqueueCommand(
        slot->endpointRings[endpointIndex], (void *)&normal));
    slot->controller->doorbells[slot->slotIndex] = endpointIndex + 1;
    awaitCode(serviceId, xhciEvent, commandAddress);
}

void doXhciCommand(SlotXHCI *slot, uint8_t requestType, uint8_t request, uint16_t value, uint8_t direction) {
    XHCISetupStageTRB setup = {0};
    setup.requestType = requestType;
    setup.request = request;
    setup.value = value;
    setup.index = 0;
    setup.length = 0;
    setup.transferLength = 8;
    setup.interruptOnCompletion = 0;
    setup.interrupterTarget = 0;
    setup.type = 2;
    setup.transferType = 3;
    setup.immediateData = 1;
    enqueueCommand(slot->controlRing, (void *)&setup);

    XHCIStatusStageTRB status = {0};
    status.inDirection = direction;
    status.evaluateNext = 0;
    status.interruptOnCompletion = 1;
    status.type = 4;
    uint32_t commandAddress =
        U32(enqueueCommand(slot->controlRing, (void *)&status));

    slot->controller->doorbells[slot->slotIndex] = 1;
    awaitCode(serviceId, xhciEvent, commandAddress);
}

void xhciSetupEndpointsStart(SlotXHCI *slot, uint32_t configValue) {
    XHCIController *controller = slot->controller;
    XHCIInputContext *inputContext = slot->inputContext;
    memcpy((void *)controller->deviceContexts[slot->slotIndex],
           (void *)&inputContext->deviceContext, sizeof(XHCIDevice));
    inputContext->inputControl.addContextFlags = 1;
    printf("slot context state: %x, address: %x\n",
           inputContext->deviceContext.slot.slotState,
           inputContext->deviceContext.slot.deviceAddress);
}

void xhciSetupEndpointsEnd(SlotXHCI *slot, uint32_t configValue) {
    XHCIController *controller = slot->controller;
    XHCIInputContext *inputContext = slot->inputContext;
    uint32_t control = COMMAND_TYPE(12) | COMMAND_SLOT_ID(slot->slotIndex);
    xhciCommand(controller, U32(getPhysicalAddress((void *)inputContext)), 0, 0,
                control);
    doXhciCommand(slot, 0x00, 9, configValue, 0);
}

uint32_t xhciConfigureEndpoint(SlotXHCI *slot, UsbEndpointDescriptor *endpoint) {
    uint8_t endpointNumber = endpoint->address & 0xF; // never 0
    uint8_t direction = endpoint->address >> 7;
    uint8_t endpointIndex = (endpointNumber)*2 - 1 + direction;
    XHCIInputContext *inputContext = slot->inputContext;
    XHCIEndpointContext *endpointContext =
        &inputContext->deviceContext.endpoints[endpointIndex];
    endpointContext->maxPrimaryStreams = 0;
    endpointContext->interval = endpoint->interval;
    endpointContext->errorCount = 3;
    endpointContext->endpointType =
        direction << 2 | endpoint->attributes & 3;
    endpointContext->maxPacketSize = endpoint->maxPacketSize;
    slot->endpointRings[endpointIndex] = malloc(sizeof(TrbRing));
    setupTrbRing(slot->endpointRings[endpointIndex], 255);
    endpointContext->transferDequeuePointerLow =
        U32(slot->endpointRings[endpointIndex]->physical) | 1;
    endpointContext->transferDequeuePointerHigh = 0;
    endpointContext->averageTRBLength = 2048;
    inputContext->inputControl.addContextFlags |= 1 << (endpointIndex + 1);
    inputContext->deviceContext.slot.contextEntryCount = MAX(
        inputContext->deviceContext.slot.contextEntryCount, endpointIndex);
    return (1 << endpointContext->interval) / 8;
}

UsbHostControllerInterface xhci = {
    .initialize = init,
    .getDescriptor = (void *)xhciGetDescriptor,
    .setupEndpointsStart = (void *)xhciSetupEndpointsStart,
    .setupEndpointsEnd = (void *)xhciSetupEndpointsEnd,
    .configureEndpoint = (void *)xhciConfigureEndpoint,
    .pciClass = 0x0C0330,
    .doNormal = (void *)xhciNormal,
    .command = (void *)doXhciCommand,
    .writeNormal = (void *)doXhciWriteNormal,
    .readNormal = (void *)doXhciWriteNormal,
};