"""
Phase 4 — Analyse selector v5 failures.

Reads:  eval_results/v5_<label>_results.jsonl  (from compute_bestofn_pairwise_v5.py)
Writes: stdout report + eval_results/v5_<label>_failures.jsonl

A "failure" = oracle@K is True AND selector pick is wrong (i.e. correct SQL was
in the candidate pool but the tournament dropped it). Each failure is tagged
with buckets:
  B1 near-duplicate SQLs           — chosen and correct differ by 1-2 tokens
  B2 misleading exec rows           — wrong SQL returns many rows but is incorrect
  B3 schema ambiguity               — multiple candidates use semantically similar columns
  B4 aggregation/grouping mismatch  — agg differs between chosen and correct
  B5 date/time semantics            — date/strftime present in correct but not chosen
  B6 format-parse fail              — no <answer> tag parsed in any tournament round
  B8 other
"""
import argparse
import json
import os
import re
import sys
from collections import Counter


def tokens(sql):
    return set(re.findall(r"[a-zA-Z_][a-zA-Z0-9_]+|[<>=!]+", (sql or "").lower()))


def jaccard(a, b):
    if not a or not b:
        return 0.0
    return len(a & b) / max(len(a | b), 1)


def bucket(rec):
    # Skip non-failures
    if not rec.get("oracle_correct"):
        return None
    if rec.get("pick_correct"):
        return None
    chosen_sql = rec["pick_sql"]
    correct_sqls = [s for s, ok in zip(rec["cand_sqls"], rec["cand_is_correct"]) if ok]
    if not correct_sqls:
        return None
    buckets = []
    # B1 near-duplicate
    chosen_tok = tokens(chosen_sql)
    sims = [jaccard(chosen_tok, tokens(c)) for c in correct_sqls]
    if max(sims, default=0) >= 0.85:
        buckets.append("B1_near_duplicate")
    # B2 misleading rows: chosen has many rows ≠ correct exec
    if "Rows preview" in (chosen_sql or "") or "rows" in chosen_sql.lower():
        pass  # rough check; need exec result for full check
    # B4 aggregation mismatch
    aggs = ("count", "sum", "avg", "min", "max", "group by")
    chosen_has_agg = any(a in chosen_sql.lower() for a in aggs)
    correct_has_agg = any(any(a in c.lower() for a in aggs) for c in correct_sqls)
    if chosen_has_agg != correct_has_agg:
        buckets.append("B4_aggregation")
    # B5 date/time
    date_kw = ("strftime", "date(", "datetime(", "julianday", " between '")
    chosen_has_date = any(k in chosen_sql.lower() for k in date_kw)
    correct_has_date = any(any(k in c.lower() for k in date_kw) for c in correct_sqls)
    if chosen_has_date != correct_has_date:
        buckets.append("B5_date_time")
    # B6 format parse fail — check rounds_log for None decisions
    rounds_log = rec.get("rounds_log", [])
    if rounds_log:
        all_decisions = []
        for rnd in rounds_log:
            for pair in rnd:
                if isinstance(pair, list) and len(pair) >= 4 and pair[0] == "pair":
                    all_decisions.append(pair[3])
        if all_decisions and all(d == -1 for d in all_decisions):
            buckets.append("B6_parse_or_neither")
    if not buckets:
        buckets.append("B8_other")
    return buckets


def main():
    ap = argparse.ArgumentParser()
    ap.add_argument("results_jsonl")
    ap.add_argument("--top_n_per_bucket", type=int, default=5)
    args = ap.parse_args()

    rows = []
    with open(args.results_jsonl) as f:
        for line in f:
            line = line.strip()
            if line:
                rows.append(json.loads(line))

    n_total = len(rows)
    n_oracle = sum(1 for r in rows if r.get("oracle_correct"))
    n_pick = sum(1 for r in rows if r.get("pick_correct"))
    print(f"== {args.results_jsonl} ==")
    print(f"  rows: {n_total}  oracle@K: {n_oracle}  pick: {n_pick}")
    print(f"  EX: {100*n_pick/max(n_total,1):.2f}%  pick-rate (vs oracle): {100*n_pick/max(n_oracle,1):.2f}%")

    failures = []
    bucket_counts = Counter()
    bucket_examples = {}
    for r in rows:
        b = bucket(r)
        if b is None:
            continue
        failures.append({**r, "buckets": b})
        for bb in b:
            bucket_counts[bb] += 1
            bucket_examples.setdefault(bb, []).append(r)

    print(f"\nFailures (oracle ok, pick wrong): {len(failures)}")
    for b, n in bucket_counts.most_common():
        print(f"  {b}: {n}")

    print("\nExamples:")
    for b, n in bucket_counts.most_common():
        print(f"\n--- bucket {b} ({n}) ---")
        for r in bucket_examples[b][: args.top_n_per_bucket]:
            print(f"Q[{r.get('db_id','?')}]: {r.get('question','')[:140]}")
            print(f"  PICK : {r['pick_sql'][:200]}")
            for c, ok in zip(r['cand_sqls'], r['cand_is_correct']):
                if ok:
                    print(f"  CORR : {c[:200]}")
                    break
            print("")

    # Save augmented file
    out = args.results_jsonl.replace("_results.jsonl", "_failures.jsonl")
    with open(out, "w") as f:
        for r in failures:
            f.write(json.dumps(r) + "\n")
    print(f"Saved failure-tagged: {out}")


if __name__ == "__main__":
    main()