"""Generic vision benchmark: public multiple-choice and yes/no VLM benchmarks that no Sev model was trained on.

    mmstar         Lin-Chen/MMStar (1500, vision-indispensable A-D questions; its ScienceQA items are dropped)
    mmbench        lmms-lab/MMBench en/dev (A-D, 1000 sampled; its ScienceQA items are dropped: Sev trained on ScienceQA)
    mme            lmms-lab/MME (yes/no, 14 perception and cognition subtasks)
    realworldqa    xai-org/RealworldQA (lettered options or yes/no; numeric/free-form answers are dropped)
    hallusion      lmms-lab/HallusionBench image split (yes/no on charts, tables, maps, illusions)

Each item becomes one question: "choice" with the lettered options as criteria, or "noul". Sev models answer in one
forward pass. The baseline is Qwen/Qwen3.5-0.8B (the post-trained VLM Sev's backbone comes from) in zero-shot: its
answer distribution is its next-token probability over the option letters (or Yes/No) after the question, so the same
calibration metrics apply. All models see the image at the same resolution cap (448 x 448 pixels).

    uv run modal run modal_app.py::generic_build            # -> /vol/data/generic.parquet
    KEV_GPU=L4 uv run modal run modal_app.py::generic_eval --runs "Jacqkues/sev-0.8b,Jacqkues/sev-0.8b-docindex,qwen:Qwen/Qwen3.5-0.8B"
"""
import argparse, ast, io, json, random, re
from collections import defaultdict
from pathlib import Path

import numpy as np
import pyarrow as pa
import pyarrow.parquet as pq

LETTERS = "ABCDEFGH"
YESNO = re.compile(r"\s*(please answer (yes or no|directly with a single word or number)\.?)\s*$", re.I)


def _img(v):
    return v["bytes"] if isinstance(v, dict) else v


def _read(repo, prefix, columns=None):
    from kev_vision.sources import _files, _pf
    for f in _files(repo, prefix):
        pfile = _pf(repo, f)
        for b in pfile.iter_batches(batch_size=200, columns=columns):
            yield from b.to_pylist()


def _choice(bench, cat, question, options, answer, image, hint=None):
    keys = [k for k in LETTERS if k in options]
    if answer not in keys or len(keys) < 2: return None
    return {"bench": bench, "category": cat, "type": "choice", "question": question.strip(), "hint": hint,
            "options": json.dumps({k: options[k] for k in keys}), "label": keys.index(answer), "image": image}


def _noul(bench, cat, question, yes, image):
    return {"bench": bench, "category": cat, "type": "noul", "question": YESNO.sub("", question).strip(), "hint": None,
            "options": None, "label": int(yes), "image": image}


def mmstar():
    for r in _read("Lin-Chen/MMStar", ""):
        meta = r.get("meta_info") or {}
        if isinstance(meta, str): meta = ast.literal_eval(meta)
        if "scienceqa" in str(meta.get("source", "")).lower(): continue
        q, _, opts = r["question"].partition("\nOptions:")
        found = dict(re.findall(r"([A-D]):\s*(.*?)(?=,\s*[A-D]:|$)", opts.strip(), re.S))
        found = {k: v.strip().rstrip(".").strip() for k, v in found.items()}
        yield _choice("mmstar", r["category"], q, found, r["answer"].strip(), _img(r["image"]))


def mmbench(n=1000, seed=0):
    rows = [r for r in _read("lmms-lab/MMBench", "en/dev-") if r["source"] != "scienceqa"]
    for r in random.Random(seed).sample(rows, min(n, len(rows))):
        opts = {k: str(r[k]) for k in "ABCD" if r.get(k) is not None and str(r[k]) != "nan"}
        hint = r["hint"] if r.get("hint") and str(r["hint"]) != "nan" else None
        yield _choice("mmbench", r["category"], r["question"], opts, r["answer"], _img(r["image"]), hint)


def mme():
    for r in _read("lmms-lab/MME", "data/test-"):
        if r["answer"] not in ("Yes", "No"): continue
        yield _noul("mme", r["category"], r["question"], r["answer"] == "Yes", _img(r["image"]))


def realworldqa():
    for r in _read("xai-org/RealworldQA", "data/test-"):
        q, a = r["question"], r["answer"].strip().rstrip(".")
        lines = q.split("\n")
        opts = {m.group(1): m.group(2).strip() for l in lines if (m := re.match(r"^([A-F])[.)]\s*(.+)$", l.strip()))}
        if opts and a in opts:
            stem = "\n".join(l for l in lines if not re.match(r"^([A-F])[.)]\s", l.strip()))
            stem = re.sub(r"please answer directly with (only )?the letter.*$", "", stem, flags=re.I | re.S).strip()
            yield _choice("realworldqa", "realworld", stem, opts, a, _img(r["image"]))
        elif a.lower() in ("yes", "no"):
            yield _noul("realworldqa", "realworld", q, a.lower() == "yes", _img(r["image"]))


def hallusion():
    for r in _read("lmms-lab/HallusionBench", "data/image-"):
        if str(r.get("visual_input")) == "0" or r.get("image") is None: continue
        yield _noul("hallusion", f'{r["category"]}/{r["subcategory"]}', r["question"], str(r["gt_answer"]) == "1", _img(r["image"]))


BENCHES = {"mmstar": mmstar, "mmbench": mmbench, "mme": mme, "realworldqa": realworldqa, "hallusion": hallusion}


def build(out):
    from kev_vision.sources import encode
    rows = []
    for name, fn in BENCHES.items():
        got = [r for r in fn() if r is not None]
        for i, r in enumerate(got): r["id"] = f"{name}-{i}"; r["image"] = encode(r["image"], 896)
        print(f"{name}: {len(got)} items, {sum(r['type'] == 'noul' for r in got)} yes/no", flush=True)
        rows += got
    pq.write_table(pa.Table.from_pylist(rows), out, row_group_size=500)
    print(f"{len(rows)} items -> {out}", flush=True)


# --- models -------------------------------------------------------------------------------------------------------------

class SevScorer:
    def __init__(self, run, device):
        from kev_vision.model import VisionDecisionModel
        self.model = VisionDecisionModel(run, device).eval()
        self.T = self.model.head.temperature

    def logits(self, item, image):
        import torch
        from kev.api import SystemOneRequest, to_record
        q = {"type": item["type"], "instructions": item["question"]}
        if item["type"] == "choice": q["criteria"] = json.loads(item["options"])
        state = (item["hint"] + "\n" if item["hint"] else "") + "An image is attached."
        rec, _ = to_record(SystemOneRequest.model_validate({"state": state, "questions": {"q": q}}))
        rec["image"] = image
        with torch.no_grad(), torch.autocast("cuda", dtype=torch.bfloat16, enabled=str(self.model.device).startswith("cuda")):
            return (self.model.forward_records([rec])[0][0].float().cpu().double() / self.T).numpy()


class QwenScorer:
    """Zero-shot generative VLM: next-token probabilities over the option letters (or Yes/No)."""

    def __init__(self, repo, device):
        import torch
        from transformers import AutoModelForImageTextToText, AutoProcessor
        self.proc = AutoProcessor.from_pretrained(repo, min_pixels=128 * 128, max_pixels=448 * 448)
        self.model = AutoModelForImageTextToText.from_pretrained(repo, dtype=torch.bfloat16).to(device).eval()
        self.device, self.T = device, 1.0
        tok = self.proc.tokenizer
        self.ids = {w: tok.encode(w, add_special_tokens=False)[0] for w in list(LETTERS) + ["Yes", "No"]}

    def logits(self, item, image):
        import torch
        if item["type"] == "choice":
            opts = json.loads(item["options"])
            text = (item["hint"] + "\n" if item["hint"] else "") + item["question"] + "\n" + "\n".join(f"{k}. {v}" for k, v in opts.items())
            text += "\nAnswer with the option's letter from the given choices directly."
            cands = list(opts)
        else:
            text, cands = item["question"] + "\nAnswer with Yes or No.", ["No", "Yes"]
        msgs = [{"role": "user", "content": [{"type": "image"}, {"type": "text", "text": text}]}]
        try: prompt = self.proc.apply_chat_template(msgs, add_generation_prompt=True, enable_thinking=False)
        except TypeError: prompt = self.proc.apply_chat_template(msgs, add_generation_prompt=True)
        inputs = self.proc(text=[prompt], images=[image], return_tensors="pt").to(self.device)
        with torch.no_grad():
            z = self.model(**inputs).logits[0, -1].float().cpu()
        return np.array([z[self.ids[c]].item() for c in cands], dtype=np.float64)


def _metrics(rows):
    p = [np.exp(r["z"] - r["z"].max()) / np.exp(r["z"] - r["z"].max()).sum() for r in rows]
    y = np.array([r["label"] for r in rows]); pred = np.array([int(np.argmax(x)) for x in p]); conf = np.array([x.max() for x in p])
    ok = (pred == y).astype(float)
    brier = float(np.mean([((x - np.eye(len(x))[l]) ** 2).sum() for x, l in zip(p, y)]))
    bins = np.minimum((conf * 10).astype(int), 9)
    ece = float(sum(abs(ok[bins == b].mean() - conf[bins == b].mean()) * (bins == b).mean() for b in range(10) if (bins == b).any()))
    order = np.argsort(-conf); err = np.cumsum(1 - ok[order]) / np.arange(1, len(ok) + 1)
    cov = float((np.max(np.nonzero(err <= 0.05)[0]) + 1) / len(ok)) if (err <= 0.05).any() else 0.0
    out = {"n": len(rows), "acc": round(float(ok.mean()), 3), "brier": round(brier, 3), "ece": round(ece, 3),
           "confident_errors": round(float(((conf >= 0.9) & (ok == 0)).mean()), 3), "coverage_at_5pct_error": round(cov, 3),
           "chance": round(float(np.mean([1 / len(x) for x in p])), 3)}
    if all(len(x) == 2 for x in p):
        py = np.array([x[1] for x in p]); pos, neg = py[y == 1], py[y == 0]
        if len(pos) and len(neg): out["auroc"] = round(float((pos[:, None] > neg[None, :]).mean() + 0.5 * (pos[:, None] == neg[None, :]).mean()), 3)
    return out


def evaluate(data, runs, device, out, n=None):
    from PIL import Image
    items = [r for b in pq.ParquetFile(data).iter_batches(batch_size=200) for r in b.to_pylist()][: n or None]
    report = json.loads(Path(out).read_text()) if Path(out).exists() else {}
    for run in runs:
        if run in report: print(f"{run}: already in {out}", flush=True); continue
        scorer = QwenScorer(run.split(":", 1)[1], device) if run.startswith("qwen:") else SevScorer(run, device)
        rows = []
        for i, it in enumerate(items):
            z = scorer.logits(it, Image.open(io.BytesIO(it["image"])).convert("RGB"))
            rows.append({"id": it["id"], "bench": it["bench"], "category": it["category"], "label": it["label"], "z": z})
            if i % 500 == 0: print(f"{run}: {i}/{len(items)}", flush=True)
        rep = {"temperature": scorer.T, "all": _metrics(rows)}
        by = defaultdict(list)
        for r in rows: by[r["bench"]].append(r)
        for b, rs in by.items():
            cats = defaultdict(list)
            for r in rs: cats[r["category"]].append(r)
            rep[b] = {**_metrics(rs), "per_category": {c: _metrics(v)["acc"] for c, v in sorted(cats.items())}}
            print(f"{run} {b:>12}: {({k: v for k, v in rep[b].items() if k != 'per_category'})}", flush=True)
        report[run] = rep
        with open(str(out).replace(".json", ".preds.jsonl"), "a") as f:          # per item: re-slice later (e.g. contamination)
            for r in rows: f.write(json.dumps({"run": run, "id": r["id"], "bench": r["bench"], "category": r["category"],
                                               "label": r["label"], "z": r["z"].tolist()}) + "\n")
        Path(out).parent.mkdir(parents=True, exist_ok=True); Path(out).write_text(json.dumps(report, indent=2))
        del scorer
    print(f"saved {out}", flush=True)


def main():
    ap = argparse.ArgumentParser()
    sub = ap.add_subparsers(dest="cmd", required=True)
    b = sub.add_parser("build"); b.add_argument("--out", required=True)
    e = sub.add_parser("eval"); e.add_argument("--data", required=True); e.add_argument("--runs", nargs="+", required=True)
    e.add_argument("--device", default="cuda"); e.add_argument("--out", required=True); e.add_argument("--n", type=int, default=None)
    a = ap.parse_args()
    if a.cmd == "build": build(a.out)
    else: evaluate(a.data, a.runs, a.device, a.out, a.n)


if __name__ == "__main__":
    main()