#!/usr/bin/env python
"""
09_export_bisect.py — Export MIT Qualitaetsmessung nach jeder Stufe.

Unterschied zu 07_export_v3.py:
  * Zwischenstufen werden NICHT geloescht -> Neustart ab beliebiger Stufe moeglich
  * nach JEDER Stufe ein echter Qualitaetstest (Teacher-Forcing-Perplexitaet)
  * am Ende eine Tabelle, die zeigt, WELCHE Stufe das Modell zerstoert
  * Quantisierung asymmetrisch + lm_head ausgenommen (Verdacht aus Code-Review)

Gemessene Stufen:
  S1  fp32                     (roher torch.onnx.export)
  S2  fp16                     (convert_float_to_float16 + fix_edges)
  S3  fp16 + RMSNorm-fp32-Wrap
  S4  q4f16                    (Endprodukt)

Interpretation der Perplexitaet (ppl):
  S1 ist die Referenz. Ein Anstieg um Faktor <1.5 ist unkritisch.
  Die erste Stufe mit ppl > 3x S1 (oder NaN) ist der Schuldige.

Start:
  cd /root/train && nohup python 09_export_bisect.py > bisect.log 2>&1 &
  tail -f bisect.log
"""
import gc, os, json, shutil
from pathlib import Path
import numpy as np
import torch, onnx
from onnx import TensorProto, helper

os.environ.setdefault("HF_HOME", "/root/hf-cache")

MODEL_ID = "/root/gemma4-bund-merged"
STOCK    = "onnx-community/gemma-4-E4B-it-ONNX"
OUT      = Path("/root/train/gemma4-bund-bisect")
ONNX_DIR = OUT / "onnx"
ONNX_DIR.mkdir(parents=True, exist_ok=True)

S1    = ONNX_DIR / "s1_fp32.onnx";        S1_D = "s1_fp32.onnx_data"
S2    = ONNX_DIR / "s2_fp16.onnx";        S2_D = "s2_fp16.onnx_data"
S3    = ONNX_DIR / "s3_fp16_rms.onnx";    S3_D = "s3_fp16_rms.onnx_data"
S4    = ONNX_DIR / "decoder_model_merged_q4f16.onnx"
S4_D  = "decoder_model_merged_q4f16.onnx_data"

PROBE = OUT / "probe.npz"
RESULTS = []

# Testfall: Frage mit eindeutiger, kurzer Antwort. Teacher-Forcing misst,
# wie ueberrascht das Modell von der KORREKTEN Antwort ist.
TEST_Q = "Wie lange dauert die Probezeit bei einer Anstellung beim Bund?"
TEST_A = "Die Probezeit dauert in der Regel drei Monate."


def log(m):
    print(f"\n=== {m}", flush=True)


def fix_edges(m):
    n = 0
    for nd in m.graph.node:
        if nd.op_type == "Cast":
            for a in nd.attribute:
                if a.name == "to" and a.i == TensorProto.FLOAT:
                    a.i = TensorProto.FLOAT16
                    n += 1
    return n


def wrap_rmsnorm_fp32(m):
    g = m.graph; new = []; nw = 0
    for node in list(g.node):
        if node.op_type == "ReduceMean":
            rin = node.input[0]; pre = rin + "_to32"
            new.append(helper.make_node("Cast", [rin], [pre],
                                        to=TensorProto.FLOAT,
                                        name=node.name + "/CastIn32"))
            node.input[0] = pre
            outp = node.output[0]; post = outp + "_f32"
            node.output[0] = post
            new.append(node)
            new.append(helper.make_node("Cast", [post], [outp],
                                        to=TensorProto.FLOAT16,
                                        name=node.name + "/CastOut16"))
            nw += 1
        else:
            new.append(node)
    del g.node[:]; g.node.extend(new)
    return nw


# ---------------------------------------------------------------- Messung
def measure(path, label, fp16_io):
    """Teacher-Forcing-Perplexitaet der Referenzantwort. Kleiner = besser."""
    import onnxruntime as ort
    d = np.load(PROBE)
    emb = d["emb"]; ple = d["ple"]; tgt = d["tgt"]; a_start = int(d["a_start"])
    n_cache = int(d["n_cache"]); kv = d["kv_shapes"]

    dt = np.float16 if fp16_io else np.float32
    seq = emb.shape[1]
    feed = {
        "inputs_embeds":    emb.astype(dt),
        "per_layer_inputs": ple.astype(dt),
        "attention_mask":   np.ones((1, seq), dtype=np.int64),
        "position_ids":     np.arange(seq, dtype=np.int64)[None, :],
    }
    for i in range(n_cache):
        n_kv, hd = int(kv[i][0]), int(kv[i][1])
        z = np.zeros((1, n_kv, 0, hd), dtype=dt)
        feed[f"past_key_values.{i}.key"] = z
        feed[f"past_key_values.{i}.value"] = z

    try:
        so = ort.SessionOptions(); so.intra_op_num_threads = 8
        sess = ort.InferenceSession(str(path), sess_options=so,
                                    providers=["CPUExecutionProvider"])
        logits = sess.run(["logits"], feed)[0].astype(np.float64)
        del sess
    except Exception as e:
        msg = str(e).split(chr(10))[0][:140]
        print(f"    !! LAEDT/LAEUFT NICHT: {msg}", flush=True)
        RESULTS.append((label, "FEHLER", "-", msg[:60]))
        return

    if not np.isfinite(logits).all():
        print("    !! logits enthalten NaN/Inf", flush=True)
        RESULTS.append((label, "NaN/Inf", "-", "numerischer Ueberlauf"))
        return

    # Perplexitaet nur ueber die Antwort-Tokens
    lp = logits[0] - logits[0].max(axis=-1, keepdims=True)
    lp = lp - np.log(np.exp(lp).sum(axis=-1, keepdims=True))
    nll, cnt = 0.0, 0
    for p in range(a_start - 1, len(tgt) - 1):
        nll -= lp[p, int(tgt[p + 1])]; cnt += 1
    ppl = float(np.exp(nll / max(cnt, 1)))

    # Erstes Antwort-Token: was sagt das Modell wirklich?
    top = int(np.argmax(logits[0, a_start - 1]))
    exp = int(tgt[a_start])
    hit = "JA" if top == exp else "nein"

    print(f"    ppl={ppl:.3f}   erstes Antwort-Token korrekt: {hit}", flush=True)
    RESULTS.append((label, f"{ppl:.3f}", hit, ""))
    gc.collect()


def table():
    log("BISEKTIONS-ERGEBNIS")
    print(f"{'Stufe':<22}{'ppl':>12}{'1.Token':>10}  Hinweis")
    print("-" * 72)
    for r in RESULTS:
        print(f"{r[0]:<22}{r[1]:>12}{r[2]:>10}  {r[3]}")
    print("-" * 72)
    print("Die erste Stufe mit ppl > 3x der Stufe S1 (oder FEHLER/NaN)")
    print("ist die Ursache. Bleibt ppl ueberall niedrig, liegt der Fehler")
    print("NICHT im Export, sondern im Embed-Pfad oder im Browser-Prompt.",
          flush=True)


# ================================================================ A) laden
log("A) Modell laden (fp32) + Probe-Tensoren erzeugen")
from transformers import AutoTokenizer, AutoModelForImageTextToText, DynamicCache

tok = AutoTokenizer.from_pretrained(MODEL_ID)
model = AutoModelForImageTextToText.from_pretrained(
    MODEL_ID, dtype=torch.float32, device_map="cpu").eval()
lm = model.model.language_model
lm_head = model.lm_head if hasattr(model, "lm_head") else model.get_output_embeddings()
print("hidden_size:", lm.config.hidden_size, flush=True)

# Chat-Template anwenden — exakt wie im Training
p_txt = tok.apply_chat_template([{"role": "user", "content": TEST_Q}],
                                tokenize=False, add_generation_prompt=True)
p_ids = tok(p_txt, add_special_tokens=False)["input_ids"]
a_ids = tok(TEST_A, add_special_tokens=False)["input_ids"]
full = p_ids + a_ids
a_start = len(p_ids)
print("Prompt-Tokens:", len(p_ids), "| Antwort-Tokens:", len(a_ids), flush=True)
print("Template-Auszug:", repr(p_txt[:120]), flush=True)

log("B) Trockenlauf (Geometrie)")
with torch.no_grad():
    t_ids = torch.tensor([full], dtype=torch.long)
    t_emb = lm.get_input_embeddings()(t_ids)
    t_ple = lm.get_per_layer_inputs(t_ids, t_emb)
    print("per_layer_inputs Shape:", tuple(t_ple.shape), flush=True)
    probe = lm(inputs_embeds=t_emb[:, :4], per_layer_inputs=t_ple[:, :4],
               use_cache=True, return_dict=True)
pkv = probe.past_key_values
N_CACHE = len(pkv.layers)
KV_SHAPES = [(int(pkv.layers[i].keys.shape[1]), int(pkv.layers[i].keys.shape[3]))
             for i in range(N_CACHE)]
print("n_cache_layers:", N_CACHE, "| head_dims:",
      sorted({s[1] for s in KV_SHAPES}), flush=True)

np.savez(PROBE,
         emb=t_emb.numpy().astype(np.float32),
         ple=t_ple.numpy().astype(np.float32),
         tgt=np.array(full, dtype=np.int64),
         a_start=np.array(a_start),
         n_cache=np.array(N_CACHE),
         kv_shapes=np.array(KV_SHAPES, dtype=np.int64))
print("Probe gespeichert:", PROBE, flush=True)
del probe, pkv, t_emb, t_ple, t_ids
gc.collect()


# ================================================================ C) Export
class DecoderWrapper(torch.nn.Module):
    def __init__(s, lm, lm_head, n):
        super().__init__(); s.lm, s.lm_head, s.n = lm, lm_head, n

    def forward(s, inputs_embeds, per_layer_inputs, attention_mask, position_ids, *past):
        cache = None
        if len(past) == 2 * s.n and past[0].shape[2] > 0:
            cache = DynamicCache(config=s.lm.config)
            for i in range(s.n):
                cache.update(past[2 * i], past[2 * i + 1], i)
        out = s.lm(inputs_embeds=inputs_embeds, per_layer_inputs=per_layer_inputs,
                   attention_mask=attention_mask, position_ids=position_ids,
                   past_key_values=cache, use_cache=True, return_dict=True)
        logits = s.lm_head(out.last_hidden_state)
        present = []
        for i in range(s.n):
            present += [out.past_key_values.layers[i].keys,
                        out.past_key_values.layers[i].values]
        return (logits, *present)


if not S1.exists():
    log("C) ONNX-Export fp32 (LANGE STILLE IST NORMAL, 20-40 min)")
    wrapper = DecoderWrapper(lm, lm_head, N_CACHE).eval()
    with torch.no_grad():
        d_ids = torch.tensor([[42]], dtype=torch.long)
        d_emb = lm.get_input_embeddings()(d_ids).detach()
        d_ple = lm.get_per_layer_inputs(d_ids, d_emb).detach()
    d_mask = torch.ones(1, 2, dtype=torch.long)
    d_pos = torch.tensor([[1]], dtype=torch.long)
    d_past = []
    for (n_kv, hd) in KV_SHAPES:
        d_past += [torch.zeros(1, n_kv, 1, hd), torch.zeros(1, n_kv, 1, hd)]

    input_names = ["inputs_embeds", "per_layer_inputs", "attention_mask", "position_ids"]
    output_names = ["logits"]
    dyn = {"inputs_embeds": {0: "batch", 1: "seq"},
           "per_layer_inputs": {0: "batch", 1: "seq"},
           "attention_mask": {0: "batch", 1: "total"},
           "position_ids": {0: "batch", 1: "seq"},
           "logits": {0: "batch", 1: "seq"}}
    for i in range(N_CACHE):
        for kvn in ("key", "value"):
            pn, on = f"past_key_values.{i}.{kvn}", f"present.{i}.{kvn}"
            input_names.append(pn); output_names.append(on)
            dyn[pn] = {0: "batch", 2: "past_seq"}
            dyn[on] = {0: "batch", 2: "total_seq"}

    with torch.no_grad():
        torch.onnx.export(wrapper, (d_emb, d_ple, d_mask, d_pos, *d_past), str(S1),
                          input_names=input_names, output_names=output_names,
                          dynamic_axes=dyn, opset_version=17,
                          do_constant_folding=True, dynamo=False)
    print("Export geschrieben.", flush=True)
    del wrapper, d_past, d_emb, d_ple
    del model, lm, lm_head
    gc.collect()

    log("C.1) Konsolidierung fp32")
    m = onnx.load(str(S1), load_external_data=True)
    onnx.save_model(m, str(S1), save_as_external_data=True,
                    all_tensors_to_one_file=True, location=S1_D, size_threshold=1024)
    del m; gc.collect()
    for f in ONNX_DIR.iterdir():
        if f.name.startswith(("onnx__", "lm.", "_")):
            f.unlink()
else:
    print("S1 existiert bereits — Export uebersprungen.", flush=True)
    del model, lm, lm_head
    gc.collect()

log("MESSUNG S1 (fp32) — das ist die Referenz")
measure(S1, "S1 fp32", fp16_io=False)


# ============================================================ D) fp16
if not S2.exists():
    log("D) fp16-Konvertierung + fix_edges")
    from onnxconverter_common import float16
    m32 = onnx.load(str(S1), load_external_data=True)
    m16 = float16.convert_float_to_float16(m32, keep_io_types=False,
                                           disable_shape_infer=True, op_block_list=[])
    ne = fix_edges(m16)
    print(f"fix_edges Casts: {ne}", flush=True)
    onnx.save_model(m16, str(S2), save_as_external_data=True,
                    all_tensors_to_one_file=True, location=S2_D, size_threshold=1024)
    del m32, m16; gc.collect()
else:
    print("S2 existiert bereits.", flush=True)

log("MESSUNG S2 (fp16, ohne RMSNorm-Wrap)")
measure(S2, "S2 fp16", fp16_io=True)


# ============================================================ E) RMSNorm
if not S3.exists():
    log("E) RMSNorm-fp32-Wrap")
    m = onnx.load(str(S2), load_external_data=True)
    nw = wrap_rmsnorm_fp32(m)
    print(f"ReduceMean gewrappt: {nw}", flush=True)
    onnx.save_model(m, str(S3), save_as_external_data=True,
                    all_tensors_to_one_file=True, location=S3_D, size_threshold=1024)
    del m; gc.collect()
else:
    print("S3 existiert bereits.", flush=True)

log("MESSUNG S3 (fp16 + RMSNorm-fp32)")
measure(S3, "S3 fp16+RMSwrap", fp16_io=True)


# ============================================================ F) q4f16
if not S4.exists():
    log("F) q4f16 — asymmetrisch, lm_head ausgenommen")
    from onnxruntime.quantization.matmul_nbits_quantizer import (
        MatMulNBitsQuantizer as Q, DefaultWeightOnlyQuantConfig)
    mf = onnx.load(str(S3), load_external_data=True)

    # lm_head finden: die MatMul mit der groessten Gewichtsmatrix.
    dims = {i.name: list(i.dims) for i in mf.graph.initializer}
    big, bigsz = None, 0
    for nd in mf.graph.node:
        if nd.op_type in ("MatMul", "Gemm"):
            for inp in nd.input:
                d = dims.get(inp)
                if d and len(d) == 2:
                    sz = d[0] * d[1]
                    if sz > bigsz:
                        bigsz, big = sz, nd.name
    excl = [big] if big else []
    print(f"lm_head-Kandidat ausgenommen: {big} ({bigsz/1e6:.0f}M Params)", flush=True)

    quant = Q(mf, algo_config=DefaultWeightOnlyQuantConfig(
                  block_size=32, is_symmetric=False, accuracy_level=4),
              nodes_to_exclude=excl)
    quant.process()
    qm = quant.model.model if hasattr(quant.model, "model") else quant.model
    onnx.save_model(qm, str(S4), save_as_external_data=True,
                    all_tensors_to_one_file=True, location=S4_D, size_threshold=1024)
    del mf, quant, qm; gc.collect()
else:
    print("S4 existiert bereits.", flush=True)

log("MESSUNG S4 (q4f16 — Endprodukt)")
measure(S4, "S4 q4f16", fp16_io=True)


# ============================================================ G) Beiwerk
log("G) Stock-Embed + Cast auf fp16 + config/tokenizer")
from huggingface_hub import hf_hub_download

for fn in ("onnx/embed_tokens_q4f16.onnx", "onnx/embed_tokens_q4f16.onnx_data"):
    p = hf_hub_download(STOCK, fn, local_dir="/root/stock-embed")
    shutil.copy(p, ONNX_DIR / Path(fn).name)
    print("geholt:", fn, flush=True)

ep = ONNX_DIR / "embed_tokens_q4f16.onnx"
em = onnx.load(str(ep), load_external_data=False)
tg = [o.name for o in em.graph.output if o.type.tensor_type.elem_type == TensorProto.FLOAT]
pr = {o: (nd, i) for nd in em.graph.node for i, o in enumerate(nd.output) if o in tg}
for name in tg:
    nd, idx = pr[name]; pre = name + "_fp32"; nd.output[idx] = pre
    em.graph.node.append(helper.make_node("Cast", [pre], [name],
                                          to=TensorProto.FLOAT16,
                                          name=name + "/CastToFp16"))
    for o in em.graph.output:
        if o.name == name:
            o.type.tensor_type.elem_type = TensorProto.FLOAT16
onnx.save(em, str(ep))
print("Embed-Outputs auf fp16 gecastet:", tg, flush=True)

tok.save_pretrained(str(OUT))
from transformers import AutoConfig
AutoConfig.from_pretrained(MODEL_ID).save_pretrained(str(OUT))
cp = OUT / "config.json"; cfg = json.load(open(cp))
cfg["transformers.js_config"] = {
    "dtype": "q4f16",
    "use_external_data_format": {"decoder_model_merged_q4f16.onnx": 2,
                                 "embed_tokens_q4f16.onnx": True},
    "kv_cache_dtype": "float16"}
json.dump(cfg, open(cp, "w"), indent=2)

tcp = OUT / "tokenizer_config.json"; jinja = OUT / "chat_template.jinja"
if jinja.exists():
    tc = json.load(open(tcp))
    tc["chat_template"] = jinja.read_text(encoding="utf-8")
    json.dump(tc, open(tcp, "w"), ensure_ascii=False, indent=2)
    print("chat_template eingebettet.", flush=True)

gc_cfg = OUT / "generation_config.json"
if not gc_cfg.exists():
    json.dump({"eos_token_id": [1, 106, 50], "bos_token_id": 2,
               "pad_token_id": 0}, open(gc_cfg, "w"), indent=2)
    print("generation_config.json angelegt.", flush=True)

table()
log("FERTIG. Zwischenstufen bleiben liegen. /root ist fluechtig — JETZT sichern!")