///////////////////////////////////////////////////////////////////////////////
//
/// \file       filter_decoder.c
/// \brief      Filter ID mapping to filter-specific functions
//
//  Author:     Lasse Collin
//
//  This file has been put into the public domain.
//  You can do whatever you want with this file.
//
///////////////////////////////////////////////////////////////////////////////

#include "filter_encoder.h"
#include "filter_common.h"
#include "lzma_encoder.h"
#include "lzma2_encoder.h"
#include "simple_encoder.h"
#include "delta_encoder.h"


typedef struct {
    /// Filter ID
    lzma_vli id;

    /// Initializes the filter encoder and calls lzma_next_filter_init()
    /// for filters + 1.
    lzma_init_function init;

    /// Calculates memory usage of the encoder. If the options are
    /// invalid, UINT64_MAX is returned.
    uint64_t (*memusage)(const void *options);

    /// Calculates the recommended Uncompressed Size for .xz Blocks to
    /// which the input data can be split to make multithreaded
    /// encoding possible. If this is NULL, it is assumed that
    /// the encoder is fast enough with single thread.
    uint64_t (*block_size)(const void *options);

    /// Tells the size of the Filter Properties field. If options are
    /// invalid, UINT32_MAX is returned. If this is NULL, props_size_fixed
    /// is used.
    lzma_ret (*props_size_get)(uint32_t *size, const void *options);
    uint32_t props_size_fixed;

    /// Encodes Filter Properties.
    ///
    /// \return     - LZMA_OK: Properties encoded successfully.
    ///             - LZMA_OPTIONS_ERROR: Unsupported options
    ///             - LZMA_PROG_ERROR: Invalid options or not enough
    ///               output space
    lzma_ret (*props_encode)(const void *options, uint8_t *out);

} lzma_filter_encoder;


static const lzma_filter_encoder encoders[] = {
#ifdef HAVE_ENCODER_LZMA1
    {
        .id = LZMA_FILTER_LZMA1,
        .init = &lzma_lzma_encoder_init,
        .memusage = &lzma_lzma_encoder_memusage,
        .block_size = NULL, // FIXME
        .props_size_get = NULL,
        .props_size_fixed = 5,
        .props_encode = &lzma_lzma_props_encode,
    },
#endif
#ifdef HAVE_ENCODER_LZMA2
    {
        .id = LZMA_FILTER_LZMA2,
        .init = &lzma_lzma2_encoder_init,
        .memusage = &lzma_lzma2_encoder_memusage,
        .block_size = &lzma_lzma2_block_size, // FIXME
        .props_size_get = NULL,
        .props_size_fixed = 1,
        .props_encode = &lzma_lzma2_props_encode,
    },
#endif
#ifdef HAVE_ENCODER_X86
    {
        .id = LZMA_FILTER_X86,
        .init = &lzma_simple_x86_encoder_init,
        .memusage = NULL,
        .block_size = NULL,
        .props_size_get = &lzma_simple_props_size,
        .props_encode = &lzma_simple_props_encode,
    },
#endif
#ifdef HAVE_ENCODER_POWERPC
    {
        .id = LZMA_FILTER_POWERPC,
        .init = &lzma_simple_powerpc_encoder_init,
        .memusage = NULL,
        .block_size = NULL,
        .props_size_get = &lzma_simple_props_size,
        .props_encode = &lzma_simple_props_encode,
    },
#endif
#ifdef HAVE_ENCODER_IA64
    {
        .id = LZMA_FILTER_IA64,
        .init = &lzma_simple_ia64_encoder_init,
        .memusage = NULL,
        .block_size = NULL,
        .props_size_get = &lzma_simple_props_size,
        .props_encode = &lzma_simple_props_encode,
    },
#endif
#ifdef HAVE_ENCODER_ARM
    {
        .id = LZMA_FILTER_ARM,
        .init = &lzma_simple_arm_encoder_init,
        .memusage = NULL,
        .block_size = NULL,
        .props_size_get = &lzma_simple_props_size,
        .props_encode = &lzma_simple_props_encode,
    },
#endif
#ifdef HAVE_ENCODER_ARMTHUMB
    {
        .id = LZMA_FILTER_ARMTHUMB,
        .init = &lzma_simple_armthumb_encoder_init,
        .memusage = NULL,
        .block_size = NULL,
        .props_size_get = &lzma_simple_props_size,
        .props_encode = &lzma_simple_props_encode,
    },
#endif
#ifdef HAVE_ENCODER_SPARC
    {
        .id = LZMA_FILTER_SPARC,
        .init = &lzma_simple_sparc_encoder_init,
        .memusage = NULL,
        .block_size = NULL,
        .props_size_get = &lzma_simple_props_size,
        .props_encode = &lzma_simple_props_encode,
    },
#endif
#ifdef HAVE_ENCODER_DELTA
    {
        .id = LZMA_FILTER_DELTA,
        .init = &lzma_delta_encoder_init,
        .memusage = &lzma_delta_coder_memusage,
        .block_size = NULL,
        .props_size_get = NULL,
        .props_size_fixed = 1,
        .props_encode = &lzma_delta_props_encode,
    },
#endif
};


static const lzma_filter_encoder *
encoder_find(lzma_vli id)
{
    for (size_t i = 0; i < ARRAY_SIZE(encoders); ++i)
        if (encoders[i].id == id)
            return encoders + i;

    return NULL;
}


extern LZMA_API(lzma_bool)
lzma_filter_encoder_is_supported(lzma_vli id)
{
    return encoder_find(id) != NULL;
}


extern LZMA_API(lzma_ret)
lzma_filters_update(lzma_stream *strm, const lzma_filter *filters)
{
    if (strm->internal->next.update == NULL)
        return LZMA_PROG_ERROR;

    // Validate the filter chain.
    if (lzma_raw_encoder_memusage(filters) == UINT64_MAX)
        return LZMA_OPTIONS_ERROR;

    // The actual filter chain in the encoder is reversed. Some things
    // still want the normal order chain, so we provide both.
    size_t count = 1;
    while (filters[count].id != LZMA_VLI_UNKNOWN)
        ++count;

    lzma_filter reversed_filters[LZMA_FILTERS_MAX + 1];
    for (size_t i = 0; i < count; ++i)
        reversed_filters[count - i - 1] = filters[i];

    reversed_filters[count].id = LZMA_VLI_UNKNOWN;

    return strm->internal->next.update(strm->internal->next.coder,
            strm->allocator, filters, reversed_filters);
}


extern lzma_ret
lzma_raw_encoder_init(lzma_next_coder *next, const lzma_allocator *allocator,
        const lzma_filter *options)
{
    return lzma_raw_coder_init(next, allocator,
            options, (lzma_filter_find)(&encoder_find), true);
}


extern LZMA_API(lzma_ret)
lzma_raw_encoder(lzma_stream *strm, const lzma_filter *options)
{
    lzma_next_strm_init(lzma_raw_coder_init, strm, options,
            (lzma_filter_find)(&encoder_find), true);

    strm->internal->supported_actions[LZMA_RUN] = true;
    strm->internal->supported_actions[LZMA_SYNC_FLUSH] = true;
    strm->internal->supported_actions[LZMA_FINISH] = true;

    return LZMA_OK;
}


extern LZMA_API(uint64_t)
lzma_raw_encoder_memusage(const lzma_filter *filters)
{
    return lzma_raw_coder_memusage(
            (lzma_filter_find)(&encoder_find), filters);
}


extern uint64_t
lzma_mt_block_size(const lzma_filter *filters)
{
    uint64_t max = 0;

    for (size_t i = 0; filters[i].id != LZMA_VLI_UNKNOWN; ++i) {
        const lzma_filter_encoder *const fe
                = encoder_find(filters[i].id);
        if (fe->block_size != NULL) {
            const uint64_t size
                    = fe->block_size(filters[i].options);
            if (size == 0)
                return 0;

            if (size > max)
                max = size;
        }
    }

    return max;
}


extern LZMA_API(lzma_ret)
lzma_properties_size(uint32_t *size, const lzma_filter *filter)
{
    const lzma_filter_encoder *const fe = encoder_find(filter->id);
    if (fe == NULL) {
        // Unknown filter - if the Filter ID is a proper VLI,
        // return LZMA_OPTIONS_ERROR instead of LZMA_PROG_ERROR,
        // because it's possible that we just don't have support
        // compiled in for the requested filter.
        return filter->id <= LZMA_VLI_MAX
                ? LZMA_OPTIONS_ERROR : LZMA_PROG_ERROR;
    }

    if (fe->props_size_get == NULL) {
        // No props_size_get() function, use props_size_fixed.
        *size = fe->props_size_fixed;
        return LZMA_OK;
    }

    return fe->props_size_get(size, filter->options);
}


extern LZMA_API(lzma_ret)
lzma_properties_encode(const lzma_filter *filter, uint8_t *props)
{
    const lzma_filter_encoder *const fe = encoder_find(filter->id);
    if (fe == NULL)
        return LZMA_PROG_ERROR;

    if (fe->props_encode == NULL)
        return LZMA_OK;

    return fe->props_encode(filter->options, props);
}
