/***********************************************************************************************************************************
IO Filter Interface
***********************************************************************************************************************************/
#include "build.auto.h"

#include "common/debug.h"
#include "common/io/filter/filter.h"
#include "common/log.h"
#include "common/memContext.h"

/***********************************************************************************************************************************
Object type
***********************************************************************************************************************************/
struct IoFilter
{
    IoFilterPub pub;                                                // Publicly accessible variables
    bool flushing;                                                  // Has the filter started flushing?
};

/***********************************************************************************************************************************
Allocations will be in the memory context of the caller.
***********************************************************************************************************************************/
FN_EXTERN IoFilter *
ioFilterNew(const StringId type, void *const driver, Pack *const paramList, const IoFilterInterface interface)
{
    FUNCTION_LOG_BEGIN(logLevelTrace);
        FUNCTION_LOG_PARAM(STRING_ID, type);
        FUNCTION_LOG_PARAM_P(VOID, driver);
        FUNCTION_LOG_PARAM(PACK, paramList);
        FUNCTION_LOG_PARAM(IO_FILTER_INTERFACE, interface);
    FUNCTION_LOG_END();

    ASSERT(type != 0);
    ASSERT(driver != NULL);
    // One of processIn or processInOut must be set
    ASSERT(interface.in != NULL || interface.inOut != NULL);
    // But not both of them
    ASSERT(!(interface.in != NULL && interface.inOut != NULL));
    // If the filter does not produce output then it should produce a result
    ASSERT(interface.in == NULL || (interface.result != NULL && interface.done == NULL && interface.inputSame == NULL));

    OBJ_NEW_BEGIN(IoFilter, .childQty = MEM_CONTEXT_QTY_MAX)
    {
        *this = (IoFilter)
        {
            .pub =
            {
                .type = type,
                .driver = objMoveToInterface(driver, this, memContextPrior()),
                .paramList = pckMove(paramList, objMemContext(this)),
                .interface = interface,
            },
        };
    }
    OBJ_NEW_END();

    FUNCTION_LOG_RETURN(IO_FILTER, this);
}

/**********************************************************************************************************************************/
FN_EXTERN void
ioFilterProcessIn(IoFilter *this, const Buffer *input)
{
    FUNCTION_TEST_BEGIN();
        FUNCTION_TEST_PARAM(IO_FILTER, this);
        FUNCTION_TEST_PARAM(BUFFER, input);
    FUNCTION_TEST_END();

    ASSERT(this != NULL);
    ASSERT(this->pub.interface.in != NULL);
    CHECK(AssertError, input == NULL || !bufEmpty(input), "expected data or flush");
    CHECK(AssertError, !this->flushing || input == NULL, "no data allowed after flush");

    if (input == NULL)
        this->flushing = true;
    else
        this->pub.interface.in(this->pub.driver, input);

    FUNCTION_TEST_RETURN_VOID();
}

/**********************************************************************************************************************************/
FN_EXTERN void
ioFilterProcessInOut(IoFilter *this, const Buffer *input, Buffer *output)
{
    FUNCTION_TEST_BEGIN();
        FUNCTION_TEST_PARAM(IO_FILTER, this);
        FUNCTION_TEST_PARAM(BUFFER, input);
        FUNCTION_TEST_PARAM(BUFFER, output);
    FUNCTION_TEST_END();

    ASSERT(this != NULL);
    ASSERT(output != NULL);
    ASSERT(this->pub.interface.inOut != NULL);
    CHECK(AssertError, input == NULL || !bufEmpty(input), "expected data or flush");
    CHECK(AssertError, !this->flushing || input == NULL, "no data allowed after flush");

    if (input == NULL && !this->flushing)
        this->flushing = true;

    if (!ioFilterDone(this))
        this->pub.interface.inOut(this->pub.driver, input, output);

    // If input same is requested then there must be some output otherwise there is no point in requesting the same input
    CHECK(AssertError, !ioFilterInputSame(this) || !bufEmpty(output), "expected input to be consumed or some output");

    FUNCTION_TEST_RETURN_VOID();
}

/***********************************************************************************************************************************
If done is not defined by the filter then check inputSame. If inputSame is true then the filter is not done. Even if the filter is
done the interface will not report done until the interface is flushing.
***********************************************************************************************************************************/
FN_EXTERN bool
ioFilterDone(const IoFilter *this)
{
    FUNCTION_TEST_BEGIN();
        FUNCTION_TEST_PARAM(IO_FILTER, this);
    FUNCTION_TEST_END();

    ASSERT(this != NULL);

    bool result = false;

    if (this->flushing)
        result = this->pub.interface.done != NULL ? this->pub.interface.done(this->pub.driver) : !ioFilterInputSame(this);

    FUNCTION_TEST_RETURN(BOOL, result);
}

/**********************************************************************************************************************************/
FN_EXTERN bool
ioFilterInputSame(const IoFilter *this)
{
    FUNCTION_TEST_BEGIN();
        FUNCTION_TEST_PARAM(IO_FILTER, this);
    FUNCTION_TEST_END();

    ASSERT(this != NULL);

    FUNCTION_TEST_RETURN(BOOL, this->pub.interface.inputSame != NULL ? this->pub.interface.inputSame(this->pub.driver) : false);
}

/**********************************************************************************************************************************/
FN_EXTERN Pack *
ioFilterResult(const IoFilter *this)
{
    FUNCTION_TEST_BEGIN();
        FUNCTION_TEST_PARAM(IO_FILTER, this);
    FUNCTION_TEST_END();

    ASSERT(this != NULL);

    FUNCTION_TEST_RETURN(PACK, this->pub.interface.result ? this->pub.interface.result(this->pub.driver) : NULL);
}

/**********************************************************************************************************************************/
FN_EXTERN void
ioFilterToLog(const IoFilter *const this, StringStatic *const debugLog)
{
    strStcCat(debugLog, "{type: ");
    strStcResultSizeInc(debugLog, strIdToLog(ioFilterType(this), strStcRemains(debugLog), strStcRemainsSize(debugLog)));
    strStcCatChr(debugLog, '}');
}
