#include "llama-batch.h"

#include "llama-impl.h"
#include "llama-vocab.h"
#include "llama-memory.h"
#include "llama-hparams.h"
#include "llama-model.h"
#include "llama-context.h"

#include <cassert>
#include <cstring>
#include <algorithm>
#include <sstream>

llama_batch_allocr::llama_batch_allocr(uint32_t n_pos_per_embd) : n_pos_per_embd(n_pos_per_embd) {
    const char * LLAMA_BATCH_DEBUG = getenv("LLAMA_BATCH_DEBUG");
    debug = LLAMA_BATCH_DEBUG ? atoi(LLAMA_BATCH_DEBUG) : 0;

    seq_pos.resize(LLAMA_MAX_SEQ);
    seq_cpl.resize(LLAMA_MAX_SEQ);
    for (auto & cur : seq_cpl) {
        cur.resize(LLAMA_MAX_SEQ);
    }

    seq_idx.resize(LLAMA_MAX_SEQ, -1);
}

bool llama_batch_allocr::init(
        const llama_batch_ext & batch_inp,
        const llama_vocab & vocab,
        bool output_all) {
    clear();

    this->vocab     = &vocab;
    this->n_embd    = batch_inp.n_embd > 0 ? batch_inp.n_embd : batch_inp.n_embd_inp;
    this->n_seq_max = batch_inp.n_seq_max;

    const int32_t n_tok = (int32_t) batch_inp.tokens.size();

    GGML_ASSERT(n_tok > 0);

    if ((uint32_t) n_seq_max > LLAMA_MAX_SEQ) {
        LLAMA_LOG_ERROR("%s: n_seq_max = %d > %d\n", __func__, n_seq_max, LLAMA_MAX_SEQ);
        return false;
    }

    const llama_memory_i * mem = batch_inp.mem;

    //
    // determine the content types of the batch
    // an entry can carry a token id, a token embedding, or both (e.g. MTP hook batches)
    // all entries must carry the same combination
    //

    const bool has_token = batch_inp.tokens[0].id != LLAMA_TOKEN_NULL;
    const bool has_embd  = batch_inp.tokens[0].has_embd;

    for (int32_t i = 1; i < n_tok; ++i) {
        if ((batch_inp.tokens[i].id != LLAMA_TOKEN_NULL) != has_token ||
             batch_inp.tokens[i].has_embd                != has_embd) {
            LLAMA_LOG_ERROR("%s: all entries in the batch must have the same content types\n", __func__);
            return false;
        }
    }

    if (!has_token && !has_embd) {
        LLAMA_LOG_ERROR("%s: batch has neither token ids nor embeddings\n", __func__);
        return false;
    }

    //
    // build flat token/embd array
    //

    if (has_token) {
        token_vec.resize(n_tok);
        for (int32_t i = 0; i < n_tok; ++i) {
            const llama_token id = batch_inp.tokens[i].id;
            if (id < 0 || id >= batch_inp.n_vocab) {
                LLAMA_LOG_ERROR("%s: invalid token[%d] = %d\n", __func__, i, id);
                return false;
            }
            token_vec[i] = id;
        }
    }

    if (has_embd) {
        embd_vec = batch_inp.embd;
    }

    //
    // build flat pos array
    // token batch:     pos[i]            = tokens[i].pos[0]
    // embedding batch: pos[j*n_tok + i]  = tokens[i].pos[j]  (section-major)
    //

    {
        const int32_t n_pos_total = has_token ? n_tok : n_tok * (int32_t) n_pos_per_embd;
        pos.resize(n_pos_total);
        if (has_token) {
            for (int32_t i = 0; i < n_tok; ++i) {
                pos[i] = batch_inp.tokens[i].pos[0];
            }
        } else {
            for (int32_t i = 0; i < n_tok; ++i) {
                for (uint32_t j = 0; j < n_pos_per_embd; ++j) {
                    pos[(int32_t) j * n_tok + i] = batch_inp.tokens[i].pos[j];
                }
            }
        }
    }

    //
    // build n_seq_id / seq_id arrays
    //

    n_seq_id.resize(n_tok);
    seq_id.resize(n_tok + 1);
    seq_id[n_tok] = nullptr;

    {
        size_t total = 0;
        for (int32_t i = 0; i < n_tok; ++i) {
            total += batch_inp.tokens[i].seq_ids.size();
        }
        seq_id_data.reserve(total);

        for (int32_t i = 0; i < n_tok; ++i) {
            for (auto sid : batch_inp.tokens[i].seq_ids) {
                seq_id_data.push_back(sid);
            }
        }

        size_t off = 0;
        for (int32_t i = 0; i < n_tok; ++i) {
            n_seq_id[i] = (int32_t) batch_inp.tokens[i].seq_ids.size();
            seq_id[i]   = seq_id_data.data() + off;
            off += n_seq_id[i];

            for (int32_t s = 0; s < n_seq_id[i]; ++s) {
                if (seq_id[i][s] < 0 || seq_id[i][s] >= (llama_seq_id) n_seq_max) {
                    LLAMA_LOG_ERROR("%s: invalid seq_id[%d][%d] = %d >= %d\n", __func__, i, s, seq_id[i][s], (llama_seq_id) n_seq_max);
                    return false;
                }
            }
        }
    }

    //
    // build output/logits array
    //

    {
        output.resize(n_tok, 0);
        for (int32_t i = 0; i < n_tok; ++i) {
            output[i] = batch_inp.tokens[i].output ? 1 : 0;
        }

        if (output_all) {
            bool warn = false;
            for (int32_t i = 0; i < n_tok; ++i) {
                if (!output[i]) { warn = true; break; }
            }
            if (warn) {
                LLAMA_LOG_WARN("%s: embeddings required but some input tokens were not marked as outputs -> overriding\n", __func__);
                std::fill(output.begin(), output.end(), 1);
            }
        }
    }

    //
    // set up the internal llama_batch to point to our owned arrays
    //

    batch.n_tokens = n_tok;
    batch.token    = has_token ? token_vec.data() : nullptr;
    batch.embd     = has_embd  ? embd_vec.data()  : nullptr;
    batch.pos      = pos.data();
    batch.n_seq_id = n_seq_id.data();
    batch.seq_id   = seq_id.data();
    batch.logits   = output.data();

    //
    // compute stats
    //

    // count the outputs in this batch
    for (int32_t i = 0; i < batch.n_tokens; ++i) {
        n_outputs += batch.logits[i] != 0;
    }

    has_cpl = false;

    // determine coupled sequences
    // these are pairs of sequences that have at least one token in the input batch that is assigned to both of them
    for (int32_t i = 0; i < batch.n_tokens; ++i) {
        const llama_seq_id s0 = batch.seq_id[i][0];

        for (int32_t s = 0; s < batch.n_seq_id[i]; ++s) {
            const llama_seq_id s1 = batch.seq_id[i][s];

            seq_pos[s1].insert(batch.pos[i]);

            if (s > 0) {
                // mark that sequence s1 is coupled to s0
                seq_cpl[s1][s0] = true;

                // note: tracking the other way around is not necessary for now
                //seq_cpl[s0][s1] = true;

                has_cpl = true;
            }
        }
    }

    // precompute the sequence sets for each token and determine the unique sequence ids that participate in the batch
    {
        seq_set_t seq_set_unq;

        for (int32_t i = 0; i < batch.n_tokens; ++i) {
            seq_set_t cur;
            for (int32_t s = 0; s < batch.n_seq_id[i]; ++s) {
                const llama_seq_id seq_id = batch.seq_id[i][s];

                cur        .set(seq_id);
                seq_set_unq.set(seq_id);
            }

            seq_set.push_back(cur);
            seq_set_map[cur].push_back(i);
        }

        for (uint32_t s = 0; s < n_seq_max; ++s) {
            if (seq_set_unq.test(s)) {
                seq_idx[s] = seq_id_unq.size();
                seq_id_unq.push_back(s);
            }
        }
    }

    if (debug > 0) {
        LLAMA_LOG_DEBUG("%s: input batch info:\n", __func__);

        llama_ubatch ubatch {
            /*.b_equal_seqs =*/ false,
            /*.n_tokens     =*/ (uint32_t) batch.n_tokens,
            /*.n_seq_tokens =*/ (uint32_t) 1,
            /*.n_seqs       =*/ (uint32_t) batch.n_tokens,
            /*.n_seqs_unq   =*/ (uint32_t) this->seq_id_unq.size(),
            /*.n_pos        =*/ n_pos_per_embd,
            /*.token        =*/ batch.token,
            /*.embd         =*/ batch.embd,
            /*.pos          =*/ batch.pos,
            /*.n_seq_id     =*/ batch.n_seq_id,
            /*.seq_id       =*/ batch.seq_id,
            /*.seq_id_unq   =*/ this->seq_id_unq.data(),
            /*.seq_idx      =*/ this->seq_idx.data(),
            /*.output       =*/ batch.logits,
            /*.data         =*/ {},
        };

        ubatch_print(ubatch, debug);

        LLAMA_LOG_DEBUG("%s:   seq       = [\n", __func__);
        for (int s0 = 0; s0 < (int) seq_pos.size(); ++s0) {
            if (seq_pos[s0].empty()) {
                continue;
            }

            std::stringstream ss;
            for (int s1 = 0; s1 < (int) seq_cpl[s0].size(); ++s1) {
                if (seq_cpl[s0][s1]) {
                    ss << s1 << " ";
                }
            }

            LLAMA_LOG_DEBUG("%s:  %4d: pos = [%4d, %4d], cpl = %s\n",
                    __func__, s0, seq_pos_min(s0), seq_pos_max(s0), ss.str().empty() ? "-" : ss.str().c_str());
        }
        LLAMA_LOG_DEBUG("%s:   ]\n", __func__);
    }

    //
    // consistency checks
    //

    if (n_pos_per_embd > 1) {
        // M-RoPE case: allow position to "jump" forward only (non-continuous positions are allowed)
        for (uint32_t s = 0; s < n_seq_max; ++s) {
            if (seq_pos[s].empty()) {
                continue;
            }

            const llama_pos p0 = mem ? mem->seq_pos_max(s) : -1;

            if (batch.token) {
                if (p0 >= 0 && p0 >= seq_pos_min(s)) {
                    LLAMA_LOG_ERROR(
                            "%s: the tokens of sequence %d in the input batch have inconsistent sequence positions:\n"
                            " - the last position stored in the memory module of the context (i.e. the KV cache) for sequence %d is X = %d\n"
                            " - the tokens for sequence %d in the input batch have a starting position of Y = %d\n"
                            " for M-RoPE, it is required that the position satisfies: X < Y\n",
                            __func__, s, s, p0, s, seq_pos_min(s));

                    return false;
                }
            } else {
                // embedding inputs can have overlapping positions
                if (p0 >= 0 && p0 > seq_pos_min(s)) {
                    LLAMA_LOG_ERROR(
                            "%s: the tokens of sequence %d in the input batch have inconsistent sequence positions:\n"
                            " - the last position stored in the memory module of the context (i.e. the KV cache) for sequence %d is X = %d\n"
                            " - the tokens for sequence %d in the input batch have a starting position of Y = %d\n"
                            " for M-RoPE, it is required that the position satisfies: X <= Y\n",
                            __func__, s, s, p0, s, seq_pos_min(s));

                    return false;
                }
            }
        }
    } else {
        for (uint32_t s = 0; s < n_seq_max; ++s) {
            if (seq_pos[s].empty()) {
                continue;
            }

            const llama_pos p0 = mem ? mem->seq_pos_max(s) : -1;

            if (p0 >= 0) {
                bool ok = true;

                if (seq_pos_min(s) != p0 + 1) {
                    ok = false;
                }

                if (!ok) {
                    LLAMA_LOG_ERROR(
                            "%s: the tokens of sequence %d in the input batch have inconsistent sequence positions:\n"
                            " - the last position stored in the memory module of the context (i.e. the KV cache) for sequence %d is X = %d\n"
                            " - the tokens for sequence %d in the input batch have a starting position of Y = %d\n"
                            " it is required that the sequence positions remain consecutive: Y = X + 1\n",
                            __func__, s, s, p0, s, seq_pos_min(s));

                    return false;
                }
            }

            if (seq_pos_max(s) - seq_pos_min(s) + 1 > (int) seq_pos[s].size()) {
                LLAMA_LOG_ERROR("%s: sequence %d positions are not continuous\n", __func__, s);
                return false;
            }
        }
    }

    if (mem) {
        for (uint32_t s0 = 0; s0 < n_seq_max; ++s0) {
            for (uint32_t s1 = 0; s1 < n_seq_max; ++s1) {
                if (seq_cpl[s0][s1]) {
                    if (mem->seq_pos_min(s0) != mem->seq_pos_min(s1) ||
                        mem->seq_pos_max(s0) != mem->seq_pos_max(s1)) {
                        LLAMA_LOG_ERROR("%s: sequence %d is coupled to %d in the input batch, but have divereged\n", __func__, s0, s1);
                        return false;
                    }
                }
            }
        }
    }

    // disallow partial sequence sub-sets:
    //
    // invalid:          x
    //            i: 0 1 2 ...
    // ---------------------------------------
    // seq_id[i][0]: 0 0 1
    // seq_id[i][1]: 1 1 2
    // seq_id[i][2]: 2
    //
    // disallow decreasing sequence positions:
    //
    // invalid:                  x
    //            i: 0 1 2 3 4 5 6 ...
    // ---------------------------------------
    //       pos[i]: 4 5 0 1 6 2 3
    // seq_id[i][0]: 0 0 1 1 0 1 0
    //
    {
        seq_set_t cur_seq_set[LLAMA_MAX_SEQ];
        for (uint32_t s = 0; s < n_seq_max; ++s) {
            cur_seq_set[s].set();
        }

        llama_pos cur_seq_pos[LLAMA_MAX_SEQ];
        for (uint32_t s = 0; s < n_seq_max; ++s) {
            cur_seq_pos[s] = -1;
        }

        for (int32_t i = 0; i < batch.n_tokens; ++i) {
            const llama_pos pos = batch.pos[i];

            for (int32_t s = 0; s < batch.n_seq_id[i]; ++s) {
                const llama_seq_id seq_id = batch.seq_id[i][s];

                cur_seq_set[seq_id] &= seq_set[i];

                if (cur_seq_set[seq_id].none()) {
                    LLAMA_LOG_ERROR("%s: sequence %d belongs to incompatible sequence sets (not allowed)\n", __func__, seq_id);
                    return false;
                }

                if (pos < cur_seq_pos[seq_id]) {
                    LLAMA_LOG_ERROR("%s: sequence %d positions are decreasing (not allowed)\n", __func__, seq_id);
                    return false;
                }

                cur_seq_pos[seq_id] = pos;
            }
        }
    }

    split_reset();

    return true;
}

llama_ubatch llama_batch_allocr::ubatch_reserve(uint32_t n_seq_tokens, uint32_t n_seqs) {
    const uint32_t n_tokens = n_seq_tokens*n_seqs;

    clear();
    split_reset();

    const int64_t n_pos_all = (int64_t) n_tokens*n_pos_per_embd;

    auto udata = std::make_shared<llama_ubatch::data_t>();

    udata->token     .resize(n_tokens);
    udata->embd      .clear();
    udata->pos       .resize(n_pos_all);
    udata->n_seq_id  .resize(n_tokens);
    udata->seq_id    .resize(n_tokens);
    udata->seq_id_unq.resize(0);
    udata->seq_idx   .resize(LLAMA_MAX_SEQ, -1);
    udata->output    .resize(n_tokens);

    for (uint32_t s = 0; s < n_seqs; ++s) {
        udata->seq_idx[s] = s;
        udata->seq_id_unq.push_back(s);
    }

    llama_ubatch res {
        /*.b_equal_seqs =*/ true,
        /*.n_tokens     =*/ n_tokens,
        /*.n_seq_tokens =*/ n_seq_tokens,
        /*.n_seqs       =*/ n_seqs,
        /*.n_seqs_unq   =*/ n_seqs,
        /*.n_pos        =*/ n_pos_per_embd,

        /*.token        =*/ udata->token.data(),
        /*.embd         =*/ nullptr,
        /*.pos          =*/ udata->pos.data(),
        /*.n_seq_id     =*/ udata->n_seq_id.data(),
        /*.seq_id       =*/ udata->seq_id.data(),
        /*.seq_id_unq   =*/ udata->seq_id_unq.data(),
        /*.seq_idx      =*/ udata->seq_idx.data(),
        /*.output       =*/ udata->output.data(),
        /*.data         =*/ std::move(udata),
    };

    return res;
}

const llama_batch & llama_batch_allocr::get_batch() const {
    return batch;
}

uint32_t llama_batch_allocr::get_n_tokens() const {
    return batch.n_tokens;
}

uint32_t llama_batch_allocr::get_n_outputs() const {
    return n_outputs;
}

uint32_t llama_batch_allocr::get_n_used() const {
    return n_used;
}

std::vector<int32_t> & llama_batch_allocr::get_out_ids() {
    return out_ids;
}

llama_pos llama_batch_allocr::seq_pos_min(llama_seq_id seq_id) const {
    return seq_pos[seq_id].empty() ? -1 : *seq_pos[seq_id].begin();
}

llama_pos llama_batch_allocr::seq_pos_max(llama_seq_id seq_id) const {
    return seq_pos[seq_id].empty() ? -1 : *seq_pos[seq_id].rbegin();
}

void llama_batch_allocr::split_reset() {
    out_ids.clear();

    n_used = 0;

    used.clear();
    used.resize(get_n_tokens(), false);
}

llama_ubatch llama_batch_allocr::split_simple(uint32_t n_ubatch) {
    // find the first unused token
    uint32_t cur_idx = 0;
    while (cur_idx < used.size() && used[cur_idx]) {
        ++cur_idx;
    }

    // we are done
    if (cur_idx >= used.size()) {
        return {};
    }

    std::vector<int32_t> idxs;

    while (true) {
        idxs.push_back(cur_idx);

        used[cur_idx] = true;
        ++n_used;

        ++cur_idx;

        if (cur_idx >= used.size()) {
            break;
        }

        if (idxs.size() >= n_ubatch) {
            break;
        }
    }

    return ubatch_add(idxs, idxs.size(), false);
}

llama_ubatch llama_batch_allocr::split_equal(uint32_t n_ubatch, bool sequential, uint32_t n_keep_tail) {
    if (sequential && has_cpl) {
        LLAMA_LOG_ERROR("%s: sequential split is not supported when there are coupled sequences in the input batch (you may need to use the -kvu flag)\n", __func__);

        return {};
    }

    std::vector<seq_set_t> cur_seq_set;

    llama_seq_id last_seq_id = -1;

    // determine the non-overlapping sequence sets participating in this ubatch
    for (int32_t i = 0; i < batch.n_tokens; ++i) {
        if (used[i]) {
            continue;
        }

        bool add = true;

        for (uint32_t s = 0; s < cur_seq_set.size(); ++s) {
            // no overlap with existing sequence sets:
            if (!(cur_seq_set[s] & seq_set[i]).none()) {
                add = false;
                break;
            }
        }

        // accept only increasing sequence ids
        if (sequential) {
            add = add && (cur_seq_set.empty() || batch.seq_id[i][0] == last_seq_id + 1);
        }

        if (add) {
            cur_seq_set.push_back(seq_set[i]);

            last_seq_id = batch.seq_id[i][0];

            if (cur_seq_set.size() > n_ubatch) {
                break;
            }
        }
    }

    uint32_t n_seqs = cur_seq_set.size();

    // we are done
    if (n_seqs == 0) {
        return {};
    }

    // the current batch index of each sequence set
    std::vector<int32_t> cur_idx(n_seqs, 0);

    for (uint32_t s = 0; s < n_seqs; ++s) {
        while (used[seq_set_map[cur_seq_set[s]][cur_idx[s]]]) {
            ++cur_idx[s];
        }
    }

    // the list of batch indices for each sequence set
    // at the end we will concat these to get the final ubatch
    std::vector<idx_vec_t> idxs_per_seq(n_seqs);

    while (true) {
        // we can only add new n_seq_tokens tokens if all the sequence sets have at least 1 more unused tokens and
        //   if we haven't reached n_ubatch
        bool can_expand = true;

        for (uint32_t s = 0; s < n_seqs; ++s) {
            if (cur_idx[s] >= (int32_t) seq_set_map[cur_seq_set[s]].size()) {
                can_expand = false;
                break;
            }
        }

        if (!can_expand) {
            break;
        }

        for (uint32_t s = 0; s < n_seqs; ++s) {
            const int32_t idx = seq_set_map[cur_seq_set[s]][cur_idx[s]];

            idxs_per_seq[s].push_back(idx);

            used[idx] = true;
            ++n_used;

            ++cur_idx[s];
        }

        if  ((idxs_per_seq[0].size() + 1)*n_seqs > n_ubatch) {
            break;
        }
    }

    // if n_keep_tail > 0, keep only the seqs that either finish in this ubatch or have at least
    //   n_keep_tail tokens remaining for a future ubatch, so that the trailing n_keep_tail tokens
    //   of each seq are never split across ubatches
    if (n_keep_tail > 0) {
        GGML_ASSERT(n_ubatch > n_keep_tail);

        auto n_remaining = [&](uint32_t s) {
            return (uint32_t) (seq_set_map[cur_seq_set[s]].size() - cur_idx[s]);
        };

        // keep the longest prefix of seqs that satisfy the constraint, to preserve sequential seq ids
        uint32_t n_keep = 0;
        while (n_keep < n_seqs) {
            const uint32_t remaining = n_remaining(n_keep);

            if (remaining != 0 && remaining < n_keep_tail) {
                break;
            }

            n_keep++;
        }

        // all seqs violate the constraint - resolve the first one directly and emit it alone
        if (n_keep == 0) {
            auto & idxs = idxs_per_seq[0];

            const auto & seq_idxs = seq_set_map[cur_seq_set[0]];

            if (idxs.size() + n_remaining(0) <= n_ubatch) {
                // extend the seq to completion
                while (n_remaining(0) > 0) {
                    const int32_t idx = seq_idxs[cur_idx[0]];

                    idxs.push_back(idx);

                    used[idx] = true;
                    ++n_used;

                    ++cur_idx[0];
                }
            } else {
                // truncate the seq so that at least n_keep_tail tokens remain
                while (n_remaining(0) < n_keep_tail) {
                    used[idxs.back()] = false;
                    --n_used;

                    idxs.pop_back();

                    --cur_idx[0];
                }
            }

            n_keep = 1;
        }

        // return the tokens of the deferred seqs back to the pool
        for (uint32_t s = n_keep; s < n_seqs; ++s) {
            for (const int32_t idx : idxs_per_seq[s]) {
                used[idx] = false;
                --n_used;
            }
        }

        n_seqs = n_keep;
    }

    // concat the per-sequence-set lists
    std::vector<int32_t> idxs;

    for (uint32_t s = 0; s < n_seqs; ++s) {
        idxs.insert(idxs.end(), idxs_per_seq[s].begin(), idxs_per_seq[s].end());
    }

    return ubatch_add(idxs, n_seqs, true);
}

llama_ubatch llama_batch_allocr::split_seq(uint32_t n_ubatch) {
    // find the first unused token
    uint32_t cur_idx = 0;
    while (cur_idx < used.size() && used[cur_idx]) {
        ++cur_idx;
    }

    // we are done
    if (cur_idx >= used.size()) {
        return {};
    }

    // this is the starting sequence set
    // we allow adding tokens only if their sequence set is a subset of the current sequence set
    auto cur_seq_set = seq_set[cur_idx];

    std::vector<int32_t> idxs;

    while (true) {
        idxs.push_back(cur_idx);

        used[cur_idx] = true;
        ++n_used;

        if (idxs.size() >= n_ubatch) {
            break;
        }

        do {
            ++cur_idx;
        } while (cur_idx < get_n_tokens() && (used[cur_idx] || ((cur_seq_set & seq_set[cur_idx]) != seq_set[cur_idx])));

        if (cur_idx == get_n_tokens()) {
            break;
        }

        cur_seq_set = seq_set[cur_idx];
    }

    return ubatch_add(idxs, 1, true);
}

void llama_batch_allocr::clear() {
    n_outputs = 0;

    batch = {};

    token_vec   .clear();
    embd_vec    .clear();
    seq_id_data .clear();
    pos         .clear();
    n_seq_id    .clear();
    seq_id      .clear();
    seq_id_unq  .clear();
    output      .clear();

    for (auto & cur : seq_pos) {
        cur.clear();
    }

    for (auto & cur : seq_cpl) {
        std::fill(cur.begin(), cur.end(), false);
    }

    seq_set.clear();

    seq_set_map.clear();

    std::fill(seq_idx.begin(), seq_idx.end(), -1);
}

llama_ubatch llama_batch_allocr::ubatch_add(const std::vector<int32_t> & idxs, uint32_t n_seqs, bool equal_seqs) {
    const uint32_t n_tokens = idxs.size();

    assert(n_tokens%n_seqs == 0);

    auto udata = std::make_shared<llama_ubatch::data_t>();

    const int64_t n_embd_all = batch.embd ? (int64_t) n_tokens*n_embd : 0;
    const int64_t n_pos_all  =              (int64_t) n_tokens*n_pos_per_embd;

    udata->token     .resize(n_tokens);
    udata->embd      .resize(n_embd_all);
    udata->pos       .resize(n_pos_all);
    udata->n_seq_id  .resize(n_tokens);
    udata->seq_id    .resize(n_tokens);
    udata->seq_id_unq.resize(0);
    udata->seq_idx   .resize(LLAMA_MAX_SEQ, -1);
    udata->output    .resize(n_tokens);

    udata->seq_id_data.reserve(n_tokens);

    seq_set_t seq_set_unq;

    for (size_t i = 0; i < idxs.size(); ++i) {
        if (batch.token) {
            udata->token[i] = batch.token[idxs[i]];
        }

        if (batch.embd) {
            memcpy(udata->embd.data() + i*n_embd, batch.embd + (int64_t) idxs[i]*n_embd, n_embd*sizeof(float));
        }

        for (size_t j = 0; j < (size_t)n_pos_per_embd; ++j) {
            // if we are using M-RoPE
            //     if the current batch is text, we need to broadcast the same position across all RoPE sections
            //     otherwise, the input batch is image embeddings, we copy the positions as-is
            // if we are not using M-RoPE, there is only one position per token (this loop runs only once)
            size_t src_off = batch.token ? 0 : j*batch.n_tokens;
            udata->pos[j*n_tokens + i] = batch.pos[src_off + idxs[i]];
        }

        udata->n_seq_id[i] = batch.n_seq_id[idxs[i]];
        udata->output[i]   = batch.logits[idxs[i]];

        for (int s = 0; s < udata->n_seq_id[i]; ++s) {
            const llama_seq_id seq_id = batch.seq_id[idxs[i]][s];

            udata->seq_id_data.push_back(seq_id);
            seq_set_unq.set(seq_id);
        }

        if (udata->output[i]) {
            out_ids.push_back(idxs[i]);
        }
    }

    llama_seq_id * seq_id_ptr = udata->seq_id_data.data();
    for (size_t i = 0; i < idxs.size(); ++i) {
        udata->seq_id[i] = seq_id_ptr;
        seq_id_ptr += udata->n_seq_id[i];
    }

    for (uint32_t s = 0; s < n_seq_max; ++s) {
        if (seq_set_unq.test(s)) {
            udata->seq_idx[s] = udata->seq_id_unq.size();
            udata->seq_id_unq.push_back(s);
        }
    }

    llama_ubatch res {
        /*.b_equal_seqs =*/ equal_seqs,
        /*.n_tokens     =*/ n_tokens,
        /*.n_seq_tokens =*/ n_tokens/n_seqs,
        /*.n_seqs       =*/ n_seqs,
        /*.n_seqs_unq   =*/ (uint32_t) udata->seq_id_unq.size(),
        /*.n_pos        =*/ n_pos_per_embd,

        /*.token        =*/ batch.token ? udata->token.data() : nullptr,
        /*.embd         =*/ batch.embd ? udata->embd.data() : nullptr,
        /*.pos          =*/ udata->pos.data(),
        /*.n_seq_id     =*/ udata->n_seq_id.data(),
        /*.seq_id       =*/ udata->seq_id.data(),
        /*.seq_id_unq   =*/ udata->seq_id_unq.data(),
        /*.seq_idx      =*/ udata->seq_idx.data(),
        /*.output       =*/ udata->output.data(),
        /*.data         =*/ std::move(udata),
    };

    if (debug > 0) {
        LLAMA_LOG_DEBUG("%s: added ubatch to split:\n", __func__);

        ubatch_print(res, debug);
    }

    return res;
}

void llama_batch_allocr::ubatch_print(const llama_ubatch & ubatch, int debug) {
    if (debug > 0) {
        LLAMA_LOG_DEBUG("%s:   equal_seqs   = %d\n", __func__, ubatch.equal_seqs());
        LLAMA_LOG_DEBUG("%s:   n_tokens     = %d\n", __func__, ubatch.n_tokens);
        LLAMA_LOG_DEBUG("%s:   n_seq_tokens = %d\n", __func__, ubatch.n_seq_tokens);
        LLAMA_LOG_DEBUG("%s:   n_seqs       = %d\n", __func__, ubatch.n_seqs);
        LLAMA_LOG_DEBUG("%s:   n_seqs_unq   = %d\n", __func__, ubatch.n_seqs_unq);

        std::stringstream ss_seq_id_unq;
        std::stringstream ss_seq_idx;

        ss_seq_id_unq << "[ ";
        ss_seq_idx << "[";

        for (uint32_t s = 0; s < ubatch.n_seqs_unq; ++s) {
            ss_seq_id_unq << ubatch.seq_id_unq[s] << " ";
        }

        for (uint32_t s = 0; s < LLAMA_MAX_SEQ; ++s) {
            if (ubatch.seq_idx[s] >= 0) {
                ss_seq_idx << ubatch.seq_idx[s]%10;
            } else {
                ss_seq_idx << ".";
            }
        }

        ss_seq_id_unq << "]";
        ss_seq_idx    << "]";

        LLAMA_LOG_DEBUG("%s:   token      = %p\n", __func__, (void *) ubatch.token);
        LLAMA_LOG_DEBUG("%s:   embd       = %p\n", __func__, (void *) ubatch.embd);
        LLAMA_LOG_DEBUG("%s:   pos        = %p\n", __func__, (void *) ubatch.pos);
        LLAMA_LOG_DEBUG("%s:   n_seq_id   = %p\n", __func__, (void *) ubatch.n_seq_id);
        LLAMA_LOG_DEBUG("%s:   seq_id     = %p\n", __func__, (void *) ubatch.seq_id);
        LLAMA_LOG_DEBUG("%s:   seq_id_unq = %s\n", __func__, ss_seq_id_unq.str().c_str());
        LLAMA_LOG_DEBUG("%s:   seq_idx    = %s\n", __func__, ss_seq_idx.str().c_str());
        LLAMA_LOG_DEBUG("%s:   output     = %p\n", __func__, (void *) ubatch.output);
        LLAMA_LOG_DEBUG("%s:   n_outputs  = %d\n", __func__, n_outputs);

        if (debug > 0) {
            int seq_id_max = 0;
            for (uint32_t i = 0; i < ubatch.n_tokens; ++i) {
                for (int s = 0; s < ubatch.n_seq_id[i]; ++s) {
                    for (int s = 0; s < ubatch.n_seq_id[i]; ++s) {
                        seq_id_max = std::max(seq_id_max, ubatch.seq_id[i][s]);
                    }
                }
            }
            ++seq_id_max;

            LLAMA_LOG_DEBUG("%s:   token     = [\n", __func__);
            for (uint32_t i = 0; i < ubatch.n_tokens; ++i) {
                std::vector<int8_t> seq_id(seq_id_max);

                for (int s = 0; s < ubatch.n_seq_id[i]; ++s) {
                    seq_id[ubatch.seq_id[i][s]] = 1;
                }

                std::stringstream ss;
                for (int s = 0; s < seq_id_max; ++s) {
                    if (seq_id[s]) {
                        ss << s%10;
                    } else {
                        ss << ".";
                    }
                }

                if (ubatch.token) {
                    LLAMA_LOG_DEBUG("%s:  %4d: id = %6d (%16s), pos = %4d, n_seq_id = %2d, seq_id = [%s], output = %d\n",
                            __func__, i, ubatch.token[i], vocab->token_to_piece(ubatch.token[i]).c_str(),
                            ubatch.pos[i], ubatch.n_seq_id[i], ss.str().c_str(), ubatch.output[i]);
                } else {
                    LLAMA_LOG_DEBUG("%s:  %4d: [embd], pos = %4d, n_seq_id = %2d, seq_id = [%s], output = %d\n",
                            __func__, i, ubatch.pos[i], ubatch.n_seq_id[i], ss.str().c_str(), ubatch.output[i]);
                }
            }
            LLAMA_LOG_DEBUG("%s:   ]\n", __func__);
        }
    }
}

//
// interface implementation
//

struct llama_batch llama_batch_get_one(
             llama_token * tokens,
                 int32_t   n_tokens) {
    return {
        /*n_tokens =*/ n_tokens,
        /*tokens   =*/ tokens,
        /*embd     =*/ nullptr,
        /*pos      =*/ nullptr,
        /*n_seq_id =*/ nullptr,
        /*seq_id   =*/ nullptr,
        /*logits   =*/ nullptr,
    };
}

struct llama_batch llama_batch_init(int32_t n_tokens_alloc, int32_t embd, int32_t n_seq_max) {
    llama_batch batch = {
        /*n_tokens =*/ 0,
        /*tokens   =*/ nullptr,
        /*embd     =*/ nullptr,
        /*pos      =*/ nullptr,
        /*n_seq_id =*/ nullptr,
        /*seq_id   =*/ nullptr,
        /*logits   =*/ nullptr,
    };

    if (embd) {
        batch.embd = (float *) malloc(sizeof(float) * n_tokens_alloc * embd);
    } else {
        batch.token = (llama_token *) malloc(sizeof(llama_token) * n_tokens_alloc);
    }

    batch.pos      = (llama_pos *)     malloc(sizeof(llama_pos)      * n_tokens_alloc);
    batch.n_seq_id = (int32_t *)       malloc(sizeof(int32_t)        * n_tokens_alloc);
    batch.seq_id   = (llama_seq_id **) malloc(sizeof(llama_seq_id *) * (n_tokens_alloc + 1));
    for (int i = 0; i < n_tokens_alloc; ++i) {
        batch.seq_id[i] = (llama_seq_id *) malloc(sizeof(llama_seq_id) * n_seq_max);
    }
    batch.seq_id[n_tokens_alloc] = nullptr;

    batch.logits   = (int8_t *)        malloc(sizeof(int8_t)         * n_tokens_alloc);

    return batch;
}

void llama_batch_free(struct llama_batch batch) {
    if (batch.token)    free(batch.token);
    if (batch.embd)     free(batch.embd);
    if (batch.pos)      free(batch.pos);
    if (batch.n_seq_id) free(batch.n_seq_id);
    if (batch.seq_id) {
        for (int i = 0; batch.seq_id[i] != nullptr; ++i) {
            free(batch.seq_id[i]);
        }
        free(batch.seq_id);
    }
    if (batch.logits)   free(batch.logits);
}


// llama_batch_ext

size_t llama_batch_ext_select_n_embd_inp(llama_context_type ctx_type, llm_arch arch, const llama_hparams & hparams) {
    if (ctx_type == LLAMA_CONTEXT_TYPE_MTP) {
        return hparams.n_embd_out();
    }
    if (arch == LLM_ARCH_DFLASH) {
        return hparams.n_embd_inp_enc();
    }
    return hparams.n_embd_inp();
}

llama_batch_ext::llama_batch_ext(llama_context * ctx) :
        n_tokens_max(llama_n_batch(ctx)),
        n_embd_inp(llama_batch_ext_select_n_embd_inp(ctx->get_cparams().ctx_type, llama_get_model(ctx)->arch, llama_get_model(ctx)->hparams)),
        n_embd_inp_enc(llama_get_model(ctx)->hparams.n_embd_inp_enc()),
        n_seq_max(llama_n_seq_max(ctx)),
        mem(llama_get_memory(ctx)),
        n_vocab(llama_vocab_n_tokens(llama_model_get_vocab(llama_get_model(ctx)))),
        n_pos_per_embd(llama_get_model(ctx)->hparams.n_pos_per_embd()) {
    clear();
}

llama_batch_ext::llama_batch_ext(
        size_t n_tokens_max,
        size_t n_embd_inp,
        size_t n_embd_inp_enc,
        llama_seq_id n_seq_max,
        llama_memory_i * mem,
        llama_token n_vocab,
        size_t n_pos_per_embd) :
        n_tokens_max(n_tokens_max),
        n_embd_inp(n_embd_inp),
        n_embd_inp_enc(n_embd_inp_enc),
        n_seq_max(n_seq_max),
        mem(mem),
        n_vocab(n_vocab),
        n_pos_per_embd(n_pos_per_embd) {
    clear();
}

void llama_batch_ext::clear() {
    tokens.clear();
    embd  .clear();
    n_embd = 0;
}

int32_t llama_batch_ext::add_token(llama_seq_id seq_id) {
    if (tokens.size() >= n_tokens_max) {
        return -1; // size limit reached
    }
    if (seq_id < 0 || seq_id >= n_seq_max) {
        return -3; // invalid sequence id
    }

    // position is left undefined; call set_token_pos() before decoding
    token t;
    t.seq_ids.insert(seq_id);

    tokens.push_back(t);

    return (int32_t)(tokens.size() - 1);
}

bool llama_batch_ext::add_seq(int32_t idx, llama_seq_id seq_id) {
    if (idx < 0 || idx >= (int32_t) tokens.size()) {
        return false;
    }
    if (seq_id < 0 || seq_id >= n_seq_max) {
        return false;
    }

    token & t = tokens[idx];

    t.seq_ids.insert(seq_id);

    return true;
}

bool llama_batch_ext::set_token_id(int32_t idx, llama_token id) {
    if (idx < 0 || idx >= (int32_t) tokens.size()) {
        return false;
    }
    if (id < 0 || id >= n_vocab) {
        return false;
    }
    tokens[idx].id = id;
    return true;
}

bool llama_batch_ext::set_token_embd(int32_t idx, llama_embd embd_in) {
    if (idx < 0 || idx >= (int32_t) tokens.size()) {
        return false;
    }
    if (!embd_in.data) {
        return false;
    }

    const size_t n_total = embd_in.n_rows * embd_in.n_embd;
    if (n_embd == 0) {
        if (n_total != n_embd_inp && n_total != n_embd_inp_enc) {
            LLAMA_LOG_ERROR("%s: embedding size mismatch, got %zu rows x %zu = %zu, expected %zu or %zu\n",
                    __func__, embd_in.n_rows, embd_in.n_embd, n_total, n_embd_inp, n_embd_inp_enc);
            return false;
        }
        n_embd = n_total;
    } else if (n_total != n_embd) {
        LLAMA_LOG_ERROR("%s: embedding size mismatch, got %zu rows x %zu = %zu, expected %zu\n",
                __func__, embd_in.n_rows, embd_in.n_embd, n_total, n_embd);
        return false;
    }

    token & t = tokens[idx];

    if (t.has_embd) {
        LLAMA_LOG_ERROR("%s: embedding for token %d is already set\n", __func__, idx);
        return false;
    }

    t.has_embd = true;
    t.embd_off = embd.size();
    embd.insert(embd.end(), embd_in.data, embd_in.data + n_total);

    return true;
}

bool llama_batch_ext::set_token_pos(int32_t idx, const llama_pos * pos_in) {
    if (idx < 0 || idx >= (int32_t) tokens.size()) {
        return false;
    }
    if (!pos_in) {
        return false;
    }

    token & t = tokens[idx];

    size_t n_pos = t.id != LLAMA_TOKEN_NULL ? 1 : n_pos_per_embd;
    for (size_t i = 0; i < n_pos; ++i) {
        t.pos[i] = pos_in[i];
    }

    return true;
}

bool llama_batch_ext::set_output(int32_t idx, bool output_last) {
    if (idx < 0 || idx >= (int32_t) tokens.size()) {
        return false;
    }
    tokens[idx].output = output_last;
    return true;
}

// llama_batch_ext C API

llama_batch_ext * llama_batch_ext_init(llama_context * ctx) {
    return new llama_batch_ext(ctx);
}

void llama_batch_ext_free(llama_batch_ext * batch) {
    delete batch;
}

void llama_batch_ext_clear(llama_batch_ext * batch) {
    batch->clear();
}

int32_t llama_batch_ext_add(llama_batch_ext * batch, llama_seq_id seq_id) {
    return batch->add_token(seq_id);
}

int32_t llama_batch_ext_add_token(llama_batch_ext * batch, llama_seq_id seq_id, llama_token id) {
    int32_t idx = batch->add_token(seq_id);
    if (idx < 0) {
        return idx;
    }
    if (!batch->set_token_id(idx, id)) {
        return -2;
    }
    return idx;
}

int32_t llama_batch_ext_add_embd(llama_batch_ext * batch, llama_seq_id seq_id, llama_embd embd) {
    int32_t idx = batch->add_token(seq_id);
    if (idx < 0) {
        return idx;
    }
    if (!batch->set_token_embd(idx, embd)) {
        return -2;
    }
    return idx;
}

bool llama_batch_ext_add_seq(llama_batch_ext * batch, int32_t idx, llama_seq_id seq_id) {
    return batch->add_seq(idx, seq_id);
}

bool llama_batch_ext_set_pos(llama_batch_ext * batch, int32_t idx, const llama_pos * pos) {
    return batch->set_token_pos(idx, pos);
}

bool llama_batch_ext_set_embd_token(llama_batch_ext * batch, int32_t idx, llama_embd embd) {
    return batch->set_token_embd(idx, embd);
}

bool llama_batch_ext_set_embd_state(llama_batch_ext * batch, int32_t idx, llama_embd embd) {
    // TODO
    GGML_UNUSED(batch);
    GGML_UNUSED(idx);
    GGML_UNUSED(embd);
    return false;
}

bool llama_batch_ext_set_output_embd(llama_batch_ext * batch, int32_t idx, bool value) {
    return batch->set_output(idx, value);
}

bool llama_batch_ext_set_output_logits(llama_batch_ext * batch, int32_t idx, bool value) {
    return batch->set_output(idx, value);
}

// llama_batch_compat

void llama_batch_compat::init(llama_batch_ext & dst, const llama_batch & batch_inp, size_t n_embd_row) {
    llama_batch_ext * batch_ext = &dst;

    if (n_embd_row == 0) {
        n_embd_row = batch_ext->n_embd_inp;
    }

    // a batch can carry both, for example the MTP hook batches
    const bool has_token = batch_inp.token != nullptr;
    const bool has_embd  = batch_inp.embd  != nullptr;

    static const llama_seq_id default_seq_id    = 0;
    static const int32_t      default_n_seq_id  = 1;

    // auto-generates positions locally when batch_inp.pos is null, continuing from memory
    std::vector<llama_pos> pos_next(batch_ext->n_seq_max);
    for (llama_seq_id s = 0; s < (llama_seq_id) batch_ext->n_seq_max; ++s) {
        pos_next[s] = llama_memory_seq_pos_max(batch_ext->mem, s) + 1; // assume next pos
    }

    for (int32_t i = 0; i < batch_inp.n_tokens; ++i) {
        const int32_t      n_sid = batch_inp.n_seq_id ? batch_inp.n_seq_id[i]    : default_n_seq_id;
        const llama_seq_id * sids = batch_inp.seq_id  ? batch_inp.seq_id[i]      : &default_seq_id;

        llama_batch_ext::token t;

        // seq_ids
        for (int32_t s = 0; s < n_sid; ++s) {
            t.seq_ids.insert(sids[s]);
        }

        // position(s)
        if (batch_inp.pos) {
            if (has_token) {
                // token batch: one position per token
                t.pos[0] = batch_inp.pos[i];
            } else {
                // embedding batch (M-RoPE): section-major layout pos[j*n_tokens + i]
                for (uint32_t j = 0; j < batch_ext->n_pos_per_embd; ++j) {
                    t.pos[j] = batch_inp.pos[(int32_t) j * batch_inp.n_tokens + i];
                }
            }
        } else {
            // auto-generate position from the first seq_id
            t.pos[0] = pos_next[sids[0]]++;
        }

        // token id and/or embeddings
        if (has_token) {
            t.id = batch_inp.token[i];
        }

        if (has_embd) {
            t.has_embd = true;
            t.embd_off = batch_ext->embd.size();
            const float * src = batch_inp.embd + (size_t) i * n_embd_row;
            batch_ext->embd.insert(batch_ext->embd.end(), src, src + n_embd_row);
            batch_ext->n_embd = n_embd_row;
        }

        // output flag
        // if no logits array is given, default to only the last token being an output
        t.output = batch_inp.logits
            ? (batch_inp.logits[i] != 0)
            : (i == batch_inp.n_tokens - 1);

        batch_ext->tokens.push_back(t);
    }
}

llama_batch_compat::llama_batch_compat(llama_context * ctx, const llama_batch & batch_inp, size_t n_embd_row) {
    batch_ext = new llama_batch_ext(ctx);
    init(*batch_ext, batch_inp, n_embd_row);
}

llama_batch_compat::~llama_batch_compat() {
    delete batch_ext;
}