/*
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 * All rights reserved.
 *
 * This source code is licensed under both the BSD-style license (found in the
 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
 * in the COPYING file in the root directory of this source tree).
 * You may select, at your option, one or both of these licenses.
 */

/* The optimal parser is implemented in rust/src/zstd_opt.rs.  Keep the
 * private ZSTD_MatchState_t and entropy-table layouts on the C side: this
 * translation unit only projects the leaves Rust needs and preserves the
 * established C entry points. */
#include "zstd_compress_internal.h"
#include "zstd_opt.h"

#if !defined(ZSTD_EXCLUDE_BTLAZY2_BLOCK_COMPRESSOR) \
 || !defined(ZSTD_EXCLUDE_BTOPT_BLOCK_COMPRESSOR) \
 || !defined(ZSTD_EXCLUDE_BTULTRA_BLOCK_COMPRESSOR)

typedef struct {
    U32* hashTable;
    U32* chainTable;
    const BYTE* base;
    const BYTE* dictBase;
    U32 dictLimit;
    U32 lowLimit;
    U32 loadedDictEnd;
    U32* nextToUpdate;
    U32 hashLog;
    U32 chainLog;
    U32 searchLog;
    U32 windowLog;
    int useCPredict;
    U32* hashTable3;
    U32 hashLog3;
    const BYTE* nextSrc;
    U32 minMatch;
    U32 targetLength;
    optState_t* opt;
    const void* dictMatchState;
    const RawSeqStore_t* ldmSeqStore;
    const BYTE** windowBase;
    U32* windowDictLimit;
    U32* windowLowLimit;
    const size_t* hufCTable;
    int hufRepeatValid;
    const U32* fseLitLengthCTable;
    const U32* fseMatchLengthCTable;
    const U32* fseOffCodeCTable;
} ZSTD_RustOptState;

typedef char ZSTD_rust_opt_seqdef_layout[(sizeof(SeqDef) == 8) ? 1 : -1];
typedef char ZSTD_rust_opt_match_layout[(sizeof(ZSTD_match_t) == 8) ? 1 : -1];
typedef char ZSTD_rust_opt_rawseq_layout[(sizeof(rawSeq) == 12) ? 1 : -1];
typedef char ZSTD_rust_opt_seqstore_layout[
        (offsetof(SeqStore_t, longLengthPos) == 9 * sizeof(size_t) + 4) ? 1 : -1];
typedef char ZSTD_rust_optimal_layout[
        (sizeof(ZSTD_optimal_t) == 4 * sizeof(U32) + sizeof(U32) * ZSTD_REP_NUM) ? 1 : -1];
typedef char ZSTD_rust_opt_rep_count[(ZSTD_REP_NUM == 3) ? 1 : -1];

static void ZSTD_rustOptState_init(
        ZSTD_RustOptState* const out,
        ZSTD_MatchState_t* const ms,
        const ZSTD_RustOptState* const dms)
{
    out->hashTable = ms->hashTable;
    out->chainTable = ms->chainTable;
    out->base = ms->window.base;
    out->dictBase = ms->window.dictBase;
    out->dictLimit = ms->window.dictLimit;
    out->lowLimit = ms->window.lowLimit;
    out->loadedDictEnd = ms->loadedDictEnd;
    out->nextToUpdate = &ms->nextToUpdate;
    out->hashLog = ms->cParams.hashLog;
    out->chainLog = ms->cParams.chainLog;
    out->searchLog = ms->cParams.searchLog;
#ifdef ZSTD_C_PREDICT
    out->useCPredict = 1;
#else
    out->useCPredict = 0;
#endif
    out->windowLog = ms->cParams.windowLog;
    out->hashTable3 = ms->hashTable3;
    out->hashLog3 = ms->hashLog3;
    out->nextSrc = ms->window.nextSrc;
    out->minMatch = ms->cParams.minMatch;
    out->targetLength = ms->cParams.targetLength;
    out->opt = &ms->opt;
    out->dictMatchState = dms;
    out->ldmSeqStore = ms->ldmSeqStore;
    out->windowBase = &ms->window.base;
    out->windowDictLimit = &ms->window.dictLimit;
    out->windowLowLimit = &ms->window.lowLimit;
    out->hufCTable = NULL;
    out->hufRepeatValid = 0;
    out->fseLitLengthCTable = NULL;
    out->fseMatchLengthCTable = NULL;
    out->fseOffCodeCTable = NULL;
}

static void ZSTD_rustOptState_projectCosts(
        ZSTD_RustOptState* const out,
        ZSTD_MatchState_t* const ms)
{
    const ZSTD_entropyCTables_t* const costs = ms->opt.symbolCosts;
    out->hufCTable = costs ? costs->huf.CTable : NULL;
    out->hufRepeatValid = costs && costs->huf.repeatMode == HUF_repeat_valid;
    out->fseLitLengthCTable = costs ? costs->fse.litlengthCTable : NULL;
    out->fseMatchLengthCTable = costs ? costs->fse.matchlengthCTable : NULL;
    out->fseOffCodeCTable = costs ? costs->fse.offcodeCTable : NULL;
}

static void ZSTD_rustOptState_init_with_dict(
        ZSTD_RustOptState* const out,
        ZSTD_MatchState_t* const ms)
{
    ZSTD_rustOptState_init(out, ms, NULL);
}

static void ZSTD_rustOptState_init_with_costs(
        ZSTD_RustOptState* const out,
        ZSTD_MatchState_t* const ms,
        const ZSTD_RustOptState* const dms)
{
    ZSTD_rustOptState_init(out, ms, dms);
    ZSTD_rustOptState_projectCosts(out, ms);
}

void ZSTD_rust_opt_updateTree(
        ZSTD_RustOptState* state,
        const void* ip, const void* iend,
        U32 mls, int dictMode);

size_t ZSTD_rust_compressBlock_opt(
        ZSTD_RustOptState* state, void* seqStore, U32 rep[ZSTD_REP_NUM],
        const void* src, size_t srcSize, int optLevel, int dictMode);

void ZSTD_rust_initStats_ultra(
        ZSTD_RustOptState* state, void* seqStore, const U32 rep[ZSTD_REP_NUM],
        const void* src, size_t srcSize);

size_t ZSTD_rust_compressBlock_btultra2(
        ZSTD_RustOptState* state, void* seqStore, U32 rep[ZSTD_REP_NUM],
        const void* src, size_t srcSize);

enum {
    ZSTD_rust_dict_noDict = 0,
    ZSTD_rust_dict_extDict = 1,
    ZSTD_rust_dict_dictMatchState = 2,
};

void ZSTD_updateTree(ZSTD_MatchState_t* const ms, const BYTE* const ip,
                     const BYTE* const iend)
{
    ZSTD_RustOptState state;
    ZSTD_rustOptState_init_with_dict(&state, ms);
    ZSTD_rust_opt_updateTree(&state, ip, iend, ms->cParams.minMatch,
                             ZSTD_rust_dict_noDict);
}

#ifndef ZSTD_EXCLUDE_BTOPT_BLOCK_COMPRESSOR
size_t ZSTD_compressBlock_btopt(
        ZSTD_MatchState_t* const ms, SeqStore_t* const seqStore,
        U32 rep[ZSTD_REP_NUM], const void* const src, size_t const srcSize)
{
    ZSTD_RustOptState state;
    ZSTD_rustOptState_init_with_costs(&state, ms, NULL);
    return ZSTD_rust_compressBlock_opt(&state, seqStore, rep, src, srcSize,
                                       0, ZSTD_rust_dict_noDict);
}

size_t ZSTD_compressBlock_btopt_dictMatchState(
        ZSTD_MatchState_t* const ms, SeqStore_t* const seqStore,
        U32 rep[ZSTD_REP_NUM], const void* const src, size_t const srcSize)
{
    ZSTD_RustOptState state;
    ZSTD_RustOptState dictState;
    ZSTD_MatchState_t dictCopy = *ms->dictMatchState;
    ZSTD_rustOptState_init(&dictState, &dictCopy, NULL);
    ZSTD_rustOptState_init_with_costs(&state, ms, &dictState);
    return ZSTD_rust_compressBlock_opt(&state, seqStore, rep, src, srcSize,
                                       0, ZSTD_rust_dict_dictMatchState);
}

size_t ZSTD_compressBlock_btopt_extDict(
        ZSTD_MatchState_t* const ms, SeqStore_t* const seqStore,
        U32 rep[ZSTD_REP_NUM], const void* const src, size_t const srcSize)
{
    ZSTD_RustOptState state;
    ZSTD_rustOptState_init_with_costs(&state, ms, NULL);
    return ZSTD_rust_compressBlock_opt(&state, seqStore, rep, src, srcSize,
                                       0, ZSTD_rust_dict_extDict);
}
#endif

#ifndef ZSTD_EXCLUDE_BTULTRA_BLOCK_COMPRESSOR
size_t ZSTD_compressBlock_btultra(
        ZSTD_MatchState_t* const ms, SeqStore_t* const seqStore,
        U32 rep[ZSTD_REP_NUM], const void* const src, size_t const srcSize)
{
    ZSTD_RustOptState state;
    ZSTD_rustOptState_init_with_costs(&state, ms, NULL);
    return ZSTD_rust_compressBlock_opt(&state, seqStore, rep, src, srcSize,
                                       2, ZSTD_rust_dict_noDict);
}

size_t ZSTD_compressBlock_btultra_dictMatchState(
        ZSTD_MatchState_t* const ms, SeqStore_t* const seqStore,
        U32 rep[ZSTD_REP_NUM], const void* const src, size_t const srcSize)
{
    ZSTD_RustOptState state;
    ZSTD_RustOptState dictState;
    ZSTD_MatchState_t dictCopy = *ms->dictMatchState;
    ZSTD_rustOptState_init(&dictState, &dictCopy, NULL);
    ZSTD_rustOptState_init_with_costs(&state, ms, &dictState);
    return ZSTD_rust_compressBlock_opt(&state, seqStore, rep, src, srcSize,
                                       2, ZSTD_rust_dict_dictMatchState);
}

size_t ZSTD_compressBlock_btultra_extDict(
        ZSTD_MatchState_t* const ms, SeqStore_t* const seqStore,
        U32 rep[ZSTD_REP_NUM], const void* const src, size_t const srcSize)
{
    ZSTD_RustOptState state;
    ZSTD_rustOptState_init_with_costs(&state, ms, NULL);
    return ZSTD_rust_compressBlock_opt(&state, seqStore, rep, src, srcSize,
                                       2, ZSTD_rust_dict_extDict);
}

size_t ZSTD_compressBlock_btultra2(
        ZSTD_MatchState_t* const ms, SeqStore_t* const seqStore,
        U32 rep[ZSTD_REP_NUM], const void* const src, size_t const srcSize)
{
    ZSTD_RustOptState state;
    ZSTD_rustOptState_init_with_costs(&state, ms, NULL);
    return ZSTD_rust_compressBlock_btultra2(&state, seqStore, rep, src,
                                            srcSize);
}
#endif

#endif /* any optimal parser entry point is enabled */