"""Apply manifest/v2-PREREGISTRATION.md to a screen: keep candidates with 0.15 <= r <= 0.85, cap at 40
(at most 8 ev_contracts; a skill with fewer than 4 kept keeps all), order round-robin by skill.

Usage: PYTHONPATH=. .venv/bin/python tools/select_v2.py runs/v2-screen-6x/records.jsonl [--trackio pooled.json]
Prints a JSON report; writes nothing. --trackio: {task_id: [solved, episodes]} of v1 first-visit groups.
"""

import argparse
import json
from collections import defaultdict

SKILLS = ["evidence", "compute", "transform", "repair", "constraints", "contracts"]
PREFIX = {"ev": "evidence", "cmp": "compute", "tx": "transform", "fix": "repair", "plan": "constraints"}


def skill(task_id: str) -> str:
    return "contracts" if task_id.startswith("ev_contracts") else PREFIX[task_id.split("_")[0]]


def main() -> None:
    p = argparse.ArgumentParser()
    p.add_argument("records")
    p.add_argument("--candidates", default="manifest/v2-candidates.txt")
    p.add_argument("--trackio", default="")
    a = p.parse_args()
    cands = [ln.strip() for ln in open(a.candidates) if ln.strip() and not ln.startswith("#")]
    order = {t: i for i, t in enumerate(cands)}
    tally = defaultdict(lambda: [0, 0])
    errors = defaultdict(int)
    for ln in open(a.records):
        r = json.loads(ln)
        if r["task_id"] not in order:
            continue
        if r.get("error"):
            errors[r["task_id"]] += 1
            continue
        tally[r["task_id"]][0] += r["reward"] == 1.0
        tally[r["task_id"]][1] += 1
    if a.trackio:
        for t, (s, n) in json.load(open(a.trackio)).items():
            tally[t][0] += s
            tally[t][1] += n
    rows = []
    for t in cands:
        s, n = tally[t]
        r = s / n if n else None
        rows.append({"task_id": t, "skill": skill(t), "solved": s, "episodes": n, "rate": r,
                     "errors": errors[t], "kept": r is not None and 0.15 <= r <= 0.85})
    kept = sorted((x for x in rows if x["kept"]), key=lambda x: (abs(x["rate"] - 0.5), order[x["task_id"]]))
    by_skill = defaultdict(list)
    for x in kept:
        by_skill[x["skill"]].append(x)
    chosen = []
    if len(kept) > 40:
        protected = [x for s in SKILLS for x in by_skill[s] if len(by_skill[s]) < 4]
        chosen = list(protected)
        n_contracts = sum(x["skill"] == "contracts" for x in chosen)
        for x in kept:
            if len(chosen) >= 40:
                break
            if x in chosen:
                continue
            if x["skill"] == "contracts":
                if n_contracts >= 8:
                    continue
                n_contracts += 1
            chosen.append(x)
    else:
        chosen = kept
    ids = {x["task_id"] for x in chosen}
    queues = {s: [x for x in kept if x["task_id"] in ids and x["skill"] == s] for s in SKILLS}
    final = []
    while any(queues.values()):
        for s in SKILLS:
            if queues[s]:
                final.append(queues[s].pop(0)["task_id"])
    print(json.dumps({"candidates": len(cands), "kept_in_band": len(kept), "selected": len(final),
                      "freeze_allowed": len(final) >= 24,
                      "per_skill": {s: sum(skill(t) == s for t in final) for s in SKILLS},
                      "order": final, "rows": rows}, indent=1))


if __name__ == "__main__":
    main()