#include "models.h"

#include "llama-impl.h"
#include "llama-kv-cache.h"
#include "llama-kv-cache-iswa.h"

void llama_model_dflash::load_arch_hparams(llama_model_loader & ml) {

    ml.get_key(LLM_KV_ATTENTION_LAYERNORM_RMS_EPS, hparams.f_norm_rms_eps);

    if (!ml.get_arr(LLM_KV_TARGET_LAYERS, target_layer_ids, false)) {
        throw std::runtime_error("DFlash model requires 'target_layers' in GGUF metadata");
    }

    hparams.n_embd_inp_enc_impl = (uint32_t) target_layer_ids.size() * hparams.n_embd;

    LLAMA_LOG_INFO("%s: DFlash extract_layers = [", __func__);
    for (size_t i = 0; i < target_layer_ids.size(); ++i) {
        LLAMA_LOG_INFO("%d%s", target_layer_ids[i], i + 1 < target_layer_ids.size() ? ", " : "");
    }
    LLAMA_LOG_INFO("]\n");

    // optional interleaved sliding-window attention with per-layer pattern array.
    // DFlash has a single rope, so the SWA rope == main rope.
    if (ml.get_key(LLM_KV_ATTENTION_SLIDING_WINDOW, hparams.n_swa, false) && hparams.n_swa > 0) {
        hparams.swa_type = LLAMA_SWA_TYPE_STANDARD;
        ml.get_key_or_arr(LLM_KV_ATTENTION_SLIDING_WINDOW_PATTERN, hparams.is_swa_impl, hparams.n_layer());
        hparams.rope_freq_base_train_swa  = hparams.rope_freq_base_train;
        hparams.rope_freq_scale_train_swa = hparams.rope_freq_scale_train;
    }

    type = LLM_TYPE_UNKNOWN;
}

void llama_model_dflash::load_arch_tensors(llama_model_loader &) {
    LLAMA_LOAD_LOCALS;

    const int64_t n_embd_inp = hparams.n_embd_inp_enc();

    // DSpark = DFlash + a semi-autoregressive Markov head and Confidence head
    //
    // TODO: only Qwen3-style backbones are supported for now; other backbones (e.g. Gemma4)
    //       need their own conversion path and graph tweaks
    const struct ggml_tensor * markov_meta = ml->get_tensor_meta("markov_w1.weight");
    if (markov_meta) {
        const int64_t dspark_markov_rank = markov_meta->ne[0];

        dspark_markov_w1 = create_tensor(tn(LLM_TENSOR_DSPARK_MARKOV_W1, "weight"), { dspark_markov_rank, n_vocab }, 0);
        dspark_markov_w2 = create_tensor(tn(LLM_TENSOR_DSPARK_MARKOV_W2, "weight"), { dspark_markov_rank, n_vocab }, 0);

        dspark_conf_proj   = create_tensor(tn(LLM_TENSOR_DSPARK_CONF_PROJ, "weight"), { n_embd + dspark_markov_rank, 1 }, 0);
        dspark_conf_proj_b = create_tensor(tn(LLM_TENSOR_DSPARK_CONF_PROJ, "bias"),   { 1 },             TENSOR_NOT_REQUIRED);

        LLAMA_LOG_INFO("%s: DFlash with DSpark markov head (rank = %lld)\n", __func__, (long long) dspark_markov_rank);
    }

    fc              = create_tensor(tn(LLM_TENSOR_FC,              "weight"), { n_embd_inp, n_embd }, 0);
    output_norm_enc = create_tensor(tn(LLM_TENSOR_ENC_OUTPUT_NORM, "weight"), { n_embd }, 0); // encoder hidden_norm (after fc)
    output_norm     = create_tensor(tn(LLM_TENSOR_OUTPUT_NORM,    "weight"), { n_embd }, 0); // decoder final norm

    for (int i = 0; i < n_layer; ++i) {
        auto & layer = layers[i];

        layer.attn_norm = create_tensor(tn(LLM_TENSOR_ATTN_NORM, "weight", i), { n_embd }, 0);

        layer.wq = create_tensor(tn(LLM_TENSOR_ATTN_Q,   "weight", i), { n_embd, n_embd_head_k * n_head }, 0);
        layer.wk = create_tensor(tn(LLM_TENSOR_ATTN_K,   "weight", i), { n_embd, n_embd_k_gqa }, 0);
        layer.wv = create_tensor(tn(LLM_TENSOR_ATTN_V,   "weight", i), { n_embd, n_embd_v_gqa }, 0);
        layer.wo = create_tensor(tn(LLM_TENSOR_ATTN_OUT, "weight", i), { n_embd_head_k * n_head, n_embd }, 0);

        layer.attn_q_norm = create_tensor(tn(LLM_TENSOR_ATTN_Q_NORM, "weight", i), { n_embd_head_k }, 0);
        layer.attn_k_norm = create_tensor(tn(LLM_TENSOR_ATTN_K_NORM, "weight", i), { n_embd_head_k }, 0);

        layer.ffn_norm = create_tensor(tn(LLM_TENSOR_FFN_NORM, "weight", i), { n_embd }, 0);
        layer.ffn_gate = create_tensor(tn(LLM_TENSOR_FFN_GATE, "weight", i), { n_embd, n_ff }, 0);
        layer.ffn_down = create_tensor(tn(LLM_TENSOR_FFN_DOWN, "weight", i), { n_ff, n_embd }, 0);
        layer.ffn_up   = create_tensor(tn(LLM_TENSOR_FFN_UP,   "weight", i), { n_embd, n_ff }, 0);
    }
}

std::unique_ptr<llm_graph_context> llama_model_dflash::build_arch_graph(const llm_graph_params & params) const {
    switch (params.gtype) {
        case LLM_GRAPH_TYPE_ENCODER:
            return std::make_unique<graph<true>>(*this, params);
        case LLM_GRAPH_TYPE_DEFAULT:
        case LLM_GRAPH_TYPE_DECODER:
            return std::make_unique<graph<false>>(*this, params);
        default:
            GGML_ABORT("invalid graph type");
    };
}

template <>
ggml_tensor * llama_model_dflash::graph<true>::build_inp_embd_enc() const {
    auto inp_target = std::make_unique<llm_graph_input_embd>(hparams.n_embd_inp_enc());

    inp_target->embd = ggml_new_tensor_2d(ctx0, GGML_TYPE_F32, hparams.n_embd_inp_enc(), n_tokens);
    ggml_set_input(inp_target->embd);

    ggml_tensor * cur = inp_target->embd;
    cb(cur, "inp_embd", -1);

    res->add_input(std::move(inp_target));

    return cur;
}

// DFlash Encoder: processes target model features through feature fusion layer
template <>
llama_model_dflash::graph<true>::graph(const llama_model & model, const llm_graph_params & params) : llm_graph_context(params) {
    ggml_tensor * cur = build_inp_embd_enc();

    cur = build_lora_mm(model.fc, cur);
    cb(cur, "fc_out", -1);

    cur = build_norm(cur, model.output_norm_enc, NULL, LLM_NORM_RMS, -1);
    cb(cur, "enc_norm_out", -1);

    ggml_set_output(cur);
    res->t_h_nextn = cur;

    ggml_build_forward_expand(gf, cur);
}

// DSpark (DFlash + Markov & Confidence head): Markov bias on the draft logits, chained per block position
static void build_dspark_markov_head(llm_graph_context & g, const llama_model & model, ggml_tensor * tokens) {
    ggml_context * ctx0 = g.ctx0;
    auto         & res  = g.res;

    ggml_tensor * w1 = model.dspark_markov_w1;
    ggml_tensor * w2 = model.dspark_markov_w2;
    GGML_ASSERT(w1 && w2 && model.dspark_conf_proj && "DSpark markov/confidence weights not loaded");

    ggml_tensor * base = res->t_logits; // [n_vocab, n_tokens]
    const int64_t n_vocab = base->ne[0];
    const int64_t n_tok   = base->ne[1];

    const auto it = model.gguf_kv.find("dflash.block_size");
    GGML_ASSERT(it != model.gguf_kv.end() && "DSpark draft requires 'dflash.block_size' in GGUF metadata");
    const int64_t block_size = std::stoi(it->second);
    GGML_ASSERT(block_size > 0);

    const int64_t n_blocks = g.ubatch.n_seqs_unq;
    GGML_ASSERT(n_blocks > 0 && n_tok % n_blocks == 0 && "DSpark markov head requires equal-size blocks");
    // runtime tokens per block in this ubatch (anchor + drafted positions), bounded by training block_size
    const int64_t block_drafts = n_tok / n_blocks;
    if (block_drafts > block_size) {
        return;
    }

    // anchor (committed last) token of every block: token 0 of each block, i.e. a strided view
    const size_t token_stride = (size_t) block_drafts * tokens->nb[0];
    const size_t base_stride = (size_t) block_drafts * base->nb[1];

    ggml_tensor * prev = ggml_view_2d(ctx0, tokens, 1, n_blocks, token_stride, 0);
    prev = ggml_cont_1d(ctx0, prev, n_blocks);

    // confidence head input: predicts per-position acceptance
    ggml_tensor * conf_inp = res->t_embd; // [n_embd, n_tok]

    ggml_tensor * cat      = nullptr;
    ggml_tensor * cat_conf = nullptr;

    // TODO: the in-graph chain is greedy (argmax); sampling params affect only the final
    //       token pick, not the Markov conditioning path
    for (int64_t i = 0; i < block_drafts; ++i) {
        ggml_tensor * w1_prev = ggml_get_rows(ctx0, w1, prev);   // [R, n_blocks]
        ggml_tensor * bias    = ggml_mul_mat(ctx0, w2, w1_prev); // [n_vocab, n_blocks]

        // position i of every block: strided view [n_vocab, n_blocks]
        ggml_tensor * base_i = ggml_view_2d(ctx0, base, n_vocab, n_blocks, base_stride, i*base->nb[1]);
        ggml_tensor * col    = ggml_add(ctx0, base_i, bias);

        cat = cat ? ggml_concat(ctx0, cat, col, 1) : col;

        // conf(i) = sigmoid(conf_proj . [conf_inp(i); markov_w1[prev(i)]] + b)  -- [1, n_blocks]
        ggml_tensor * conf_inp_i = ggml_view_2d(ctx0, conf_inp, conf_inp->ne[0], n_blocks,
                                                (size_t) block_drafts * conf_inp->nb[1], i*conf_inp->nb[1]);
        ggml_tensor * feat = ggml_concat(ctx0, ggml_cont(ctx0, conf_inp_i), w1_prev, 0);
        ggml_tensor * conf = ggml_mul_mat(ctx0, model.dspark_conf_proj, feat);
        if (model.dspark_conf_proj_b) {
            conf = ggml_add(ctx0, conf, model.dspark_conf_proj_b);
        }
        conf = ggml_sigmoid(ctx0, conf);

        cat_conf = cat_conf ? ggml_concat(ctx0, cat_conf, conf, 1) : conf;

        if (i + 1 < block_drafts) {
            prev = ggml_argmax(ctx0, col);
        }
    }

    // cat is position-major; restore ubatch block-major order
    ggml_tensor * out = ggml_reshape_3d(ctx0, cat, n_vocab, n_blocks, block_drafts);
    out = ggml_cont(ctx0, ggml_permute(ctx0, out, 0, 2, 1, 3)); // [n_vocab, block_drafts, n_blocks]
    out = ggml_reshape_2d(ctx0, out, n_vocab, n_tok);

    {
        ggml_tensor * conf = ggml_reshape_3d(ctx0, cat_conf, 1, n_blocks, block_drafts);
        conf = ggml_cont(ctx0, ggml_permute(ctx0, conf, 0, 2, 1, 3));
        conf = ggml_reshape_2d(ctx0, conf, 1, n_tok);

        // note: broadcast the [1, n_tok] confidences to n_embd-wide rows to be able to reuse `llama_get_embeddings_nextn`
        conf = ggml_repeat(ctx0, conf, res->t_embd);
        res->t_h_nextn = conf;
        ggml_build_forward_expand(g.gf, conf);
    }

    res->t_logits = out;
    ggml_build_forward_expand(g.gf, out);
}

// DFlash decoder, dual-mode by batch type:
//   * embd batch  -> fused target features: project + inject K/V into the cache.
//   * token batch -> noise-block diffusion: attend over [committed, MASK...] to generate draft tokens
template <>
llama_model_dflash::graph<false>::graph(const llama_model & model, const llm_graph_params & params) : llm_graph_context(params) {
    const int64_t n_embd_head = hparams.n_embd_head_v();

    GGML_ASSERT(n_embd_head == hparams.n_embd_head_k());

    ggml_tensor * inp_pos  = build_inp_pos();

    // optional iSWA: pick the matching attention input
    const bool use_iswa = hparams.swa_type != LLAMA_SWA_TYPE_NONE;

    llm_graph_input_attn_kv      * inp_attn      = nullptr;
    llm_graph_input_attn_kv_iswa * inp_attn_iswa = nullptr;
    if (use_iswa) {
        inp_attn_iswa = build_attn_inp_kv_iswa();
    } else {
        inp_attn = build_attn_inp_kv();
    }

    const float kq_scale = 1.0f/sqrtf(float(n_embd_head));

    // KV cache injection
    if (ubatch.embd) {
        auto inp = std::make_unique<llm_graph_input_embd>(n_embd);

        inp->embd = ggml_new_tensor_2d(ctx0, GGML_TYPE_F32, n_embd, n_tokens);
        ggml_set_input(inp->embd);

        ggml_tensor * inp_g = inp->embd;
        cb(inp_g, "inp_g_embeddings", -1);

        res->add_input(std::move(inp));

        for (int il = 0; il < n_layer; ++il) {
            const auto & layer = model.layers[il];

            ggml_tensor * Kcur = build_lora_mm(layer.wk, inp_g);
            ggml_tensor * Vcur = build_lora_mm(layer.wv, inp_g);

            Kcur = ggml_reshape_3d(ctx0, Kcur, n_embd_head, n_head_kv, n_tokens);
            Vcur = ggml_reshape_3d(ctx0, Vcur, n_embd_head, n_head_kv, n_tokens);

            Kcur = build_norm(Kcur, layer.attn_k_norm, NULL, LLM_NORM_RMS, il);
            Kcur = ggml_rope_ext(
                    ctx0, Kcur, inp_pos, nullptr,
                    n_rot, rope_type, n_ctx_orig, freq_base, freq_scale,
                    ext_factor, attn_factor, beta_fast, beta_slow
                    );
            cb(Kcur, "Kcur_injected", il);
            cb(Vcur, "Vcur_injected", il);

            if (use_iswa) {
                // route each layer's K/V to its sub-cache: SWA layers -> sliding cache, full -> dense
                const bool    is_swa = hparams.is_swa(il);
                const auto  * kv     = is_swa ? inp_attn_iswa->mctx->get_swa() : inp_attn_iswa->mctx->get_base();
                ggml_tensor * k_idxs = is_swa ? inp_attn_iswa->get_k_idxs_swa() : inp_attn_iswa->get_k_idxs();
                ggml_tensor * v_idxs = is_swa ? inp_attn_iswa->get_v_idxs_swa() : inp_attn_iswa->get_v_idxs();
                // rotate K/V into the cache's rotated space
                ggml_tensor * k_rot  = is_swa ? inp_attn_iswa->self_k_rot_swa : inp_attn_iswa->self_k_rot;
                ggml_tensor * v_rot  = is_swa ? inp_attn_iswa->self_v_rot_swa : inp_attn_iswa->self_v_rot;
                if (k_rot) {
                    Kcur = llama_mul_mat_hadamard(ctx0, Kcur, k_rot);
                }
                if (v_rot) {
                    Vcur = llama_mul_mat_hadamard(ctx0, Vcur, v_rot);
                }
                ggml_build_forward_expand(gf, kv->cpy_k(ctx0, Kcur, k_idxs, il));
                ggml_build_forward_expand(gf, kv->cpy_v(ctx0, Vcur, v_idxs, il));
            } else {
                // rotate K/V into the cache's rotated space
                if (inp_attn->self_k_rot) {
                    Kcur = llama_mul_mat_hadamard(ctx0, Kcur, inp_attn->self_k_rot);
                }
                if (inp_attn->self_v_rot) {
                    Vcur = llama_mul_mat_hadamard(ctx0, Vcur, inp_attn->self_v_rot);
                }
                ggml_build_forward_expand(gf, inp_attn->mctx->cpy_k(ctx0, Kcur, inp_attn->get_k_idxs(), il));
                ggml_build_forward_expand(gf, inp_attn->mctx->cpy_v(ctx0, Vcur, inp_attn->get_v_idxs(), il));
            }
        }

        res->t_embd = inp_g;

        ggml_build_forward_expand(gf, inp_g);
        return;
    }

    // tok_embd from the target model (shared via ctx_other)
    auto * tok_embd = model.tok_embd;
    if (tok_embd == nullptr) {
        GGML_ASSERT(cparams.ctx_other != nullptr);
        const auto * model_other = llama_get_model(cparams.ctx_other);

        GGML_ASSERT(model_other->tok_embd != nullptr && "DFlash decoder requires the target model's token embeddings");
        tok_embd = model_other->tok_embd;
    }

    auto inp = std::make_unique<llm_graph_input_embd>(n_embd);

    inp->tokens = ggml_new_tensor_1d(ctx0, GGML_TYPE_I32, n_tokens);
    ggml_set_input(inp->tokens);

    ggml_tensor * inp_tokens = inp->tokens;

    ggml_tensor * inpL = ggml_get_rows(ctx0, tok_embd, inp->tokens);
    cb(inpL, "inp_noise_embd", -1);

    res->add_input(std::move(inp));

    for (int il = 0; il < n_layer; ++il) {
        const auto & layer = model.layers[il];

        ggml_tensor * noise_norm = build_norm(inpL, layer.attn_norm, NULL, LLM_NORM_RMS, il);
        cb(noise_norm, "noise_norm", il);

        ggml_tensor * Qcur = build_lora_mm(layer.wq, noise_norm);
        ggml_tensor * Kcur = build_lora_mm(layer.wk, noise_norm);
        ggml_tensor * Vcur = build_lora_mm(layer.wv, noise_norm);

        Qcur = ggml_reshape_3d(ctx0, Qcur, n_embd_head, n_head,    n_tokens);
        Kcur = ggml_reshape_3d(ctx0, Kcur, n_embd_head, n_head_kv, n_tokens);
        Vcur = ggml_reshape_3d(ctx0, Vcur, n_embd_head, n_head_kv, n_tokens);

        Qcur = build_norm(Qcur, layer.attn_q_norm, NULL, LLM_NORM_RMS, il);
        Kcur = build_norm(Kcur, layer.attn_k_norm, NULL, LLM_NORM_RMS, il);

        Qcur = ggml_rope_ext(
                ctx0, Qcur, inp_pos, nullptr,
                n_rot, rope_type, n_ctx_orig, freq_base, freq_scale,
                ext_factor, attn_factor, beta_fast, beta_slow
                );
        Kcur = ggml_rope_ext(
                ctx0, Kcur, inp_pos, nullptr,
                n_rot, rope_type, n_ctx_orig, freq_base, freq_scale,
                ext_factor, attn_factor, beta_fast, beta_slow
                );
        cb(Qcur, "Qcur", il);
        cb(Kcur, "Kcur", il);
        cb(Vcur, "Vcur", il);

        // cache-aware, non-causal attention
        ggml_tensor * cur = use_iswa
            ? build_attn(inp_attn_iswa, layer.wo, NULL, NULL, Qcur, Kcur, Vcur, nullptr, nullptr, nullptr, kq_scale, il)
            : build_attn(inp_attn,      layer.wo, NULL, NULL, Qcur, Kcur, Vcur, nullptr, nullptr, nullptr, kq_scale, il);

        ggml_tensor * ffn_inp = ggml_add(ctx0, cur, inpL);
        cb(ffn_inp, "ffn_inp", il);

        cur = build_norm(ffn_inp, layer.ffn_norm, NULL, LLM_NORM_RMS, il);
        cb(cur, "ffn_norm", il);

        cur = build_ffn(cur,
                layer.ffn_up,   NULL, NULL,
                layer.ffn_gate, NULL, NULL,
                layer.ffn_down, NULL, NULL,
                NULL,
                LLM_FFN_SILU, LLM_FFN_PAR, il);
        cb(cur, "ffn_out", il);

        cur = ggml_add(ctx0, cur, ffn_inp);
        cb(cur, "l_out", il);

        inpL = cur;
    }

    ggml_tensor * cur = build_norm(inpL, model.output_norm, NULL, LLM_NORM_RMS, -1);
    cb(cur, "result_norm", -1);

    res->t_embd = cur;

    // lm_head from the target model (shared via ctx_other)
    auto * output = model.output;
    if (output == nullptr) {
        GGML_ASSERT(cparams.ctx_other != nullptr);
        const auto * model_other = llama_get_model(cparams.ctx_other);
        GGML_ASSERT(model_other->output != nullptr && "DFlash decoder requires the target model's output projection");
        output = model_other->output;
    }

    cur = build_lora_mm(output, cur);
    cb(cur, "result_output", -1);
    res->t_logits = cur;

    ggml_build_forward_expand(gf, cur);

    // DSpark: bias the draft logits with the Markov head
    if (model.dspark_markov_w1) {
        build_dspark_markov_head(*this, model, inp_tokens);
    }
}
