code/scripts/build_validator_v4_orpo.py

"""
Validator v4 ORPO data builder.

SFT trains on single completions. ORPO adds a contrastive signal:
  - wrong SQL:   chosen = "INCORRECT: [critique]",  rejected = "None"
    → model learns: "don't stay silent on wrong SQL"
  - correct SQL: chosen = "None",                   rejected = "INCORRECT: [critique]"
    → model learns: "don't falsely flag correct SQL"

Each example becomes ONE ORPO pair (prompt, chosen, rejected).
One dataset handles both sel (SELECT critique) and cond (CONDITION critique)
by creating two rows per trajectory — one per validator role.

Output: data/hf_validator_v4_orpo/{train_dpo, test_dpo}
columns: prompt, chosen, rejected, question, db_id
"""
import json, os, re, random, sqlite3
from datasets import Dataset, DatasetDict

ROOT = "/weka/s225250685/mats-tist"
os.chdir(ROOT)

SRC_PATHS = [
    "data/rollouts/scaleup_bird_train_2stage_K4.jsonl",
    "data/rollouts/bird_train_3stage_K4.jsonl",
    "data/rollouts/iter2_bird_train_3stage_K8.jsonl",
]
OUT_DIR = "data/hf_validator_v4_orpo"

SEL_INSTR  = ("You are a SQL SELECT-clause critique agent. Output ONE critique section "
              "<select>...</select> analysing the SELECT clause of the SQL query below; "
              "do NOT output any SQL. Use 'None' if the SELECT clause looks correct.")
COND_INSTR = ("You are a SQL CONDITION critique agent. Output ONE critique section "
              "<condition>...</condition> analysing the WHERE/HAVING/CASE-WHEN conditions "
              "of the SQL query below; do NOT output any SQL. Use 'None' if the conditions look correct.")

NONE_SEL  = "<select>\nSELECT.\nNone\n</select>"
NONE_COND = "<condition>\nCONDITION.\nNone\n</condition>"


def resolve_db(d):
    p = d.get("db_path", "")
    if p and os.path.exists(p): return p
    db_id = d.get("db_id", "")
    for tmpl in [f"data/train_databases/{db_id}/{db_id}.sqlite",
                 f"data/dev_databases/{db_id}/{db_id}.sqlite"]:
        if os.path.exists(tmpl): return tmpl
    return None


def exec_str(db_path, sql, n=5):
    try:
        conn = sqlite3.connect(db_path)
        conn.text_factory = lambda b: b.decode(errors="ignore")
        rows = conn.execute(sql).fetchmany(n)
        conn.close()
        return str(rows)[:300]
    except Exception as e:
        return f"Error: {str(e)[:150]}"


def safe_trunc(s, n=2800):
    s = str(s or ""); return s if len(s) <= n else s[:n] + "..."


def gen_sel_critique(wrong, gold):
    wl, gl = wrong.lower(), gold.lower()
    issues = []
    for agg in ["count(", "sum(", "avg(", "max(", "min("]:
        if agg in gl and agg not in wl: issues.append(f"Missing {agg[:-1].upper()}")
        elif agg in wl and agg not in gl: issues.append(f"Unexpected {agg[:-1].upper()}")
    if "distinct" in gl and "distinct" not in wl: issues.append("Missing DISTINCT")
    elif "distinct" in wl and "distinct" not in gl: issues.append("Unexpected DISTINCT")
    gs, ws = gl.count("select")-1, wl.count("select")-1
    if gs > ws: issues.append("Missing subquery")
    d = ("INCORRECT: " + "; ".join(issues) + ".") if issues else \
        "INCORRECT: SELECT clause returns wrong results."
    return f"<select>\nSELECT.\n{d}\n</select>"


def gen_cond_critique(wrong, gold):
    wl, gl = wrong.lower(), gold.lower()
    issues = []
    gj, wj = gl.count("join"), wl.count("join")
    if gj > wj: issues.append(f"Missing JOIN")
    elif wj > gj: issues.append(f"Extra JOIN")
    if ("group by" in gl) != ("group by" in wl): issues.append("GROUP BY mismatch")
    if "having" in gl and "having" not in wl: issues.append("Missing HAVING")
    if ("limit" in gl) != ("limit" in wl): issues.append("LIMIT mismatch")
    d = ("INCORRECT: " + "; ".join(issues) + ".") if issues else \
        "INCORRECT: WHERE/HAVING conditions return wrong results."
    return f"<condition>\nCONDITION.\n{d}\n</condition>"


def build_prompt(instr, schema, question, evidence, sql, exec_result):
    # Field labels must match VALIDATOR_SEL_HEADER/COND_HEADER + VALIDATOR_PROMPT_BODY
    # in run_pipeline_rollouts.py exactly, so the trained model generalises to inference.
    return (instr + "\n\ndatabase schema:\n" + schema +
            "\n\nQuestion: " + question +
            "\nExternal knowledge: " + (evidence or "None") +
            "\n\nGenerated SQL query: " + sql +
            "\n\nExecution response:\n" + exec_result + "\n\n")


def main():
    rng = random.Random(42)
    pairs = []  # each: {prompt, chosen, rejected, question, db_id}
    seen = set()

    for src in SRC_PATHS:
        if not os.path.exists(src):
            print(f"skip {src}"); continue
        n_wrong = n_correct = 0
        with open(src) as f:
            for line in f:
                line = line.strip()
                if not line: continue
                d = json.loads(line)
                db_path = resolve_db(d)
                if not db_path: continue
                schema   = safe_trunc(str(d.get("schema", "")), 2500)
                question = d.get("question", "")
                evidence = d.get("evidence", "") or "None"
                gold_sql = (d.get("sql") or "").strip()

                for t in d.get("trajectories", []):
                    sql = (t.get("planner_sql") or "").strip()
                    if not sql: continue
                    exec_ok = bool(t.get("planner_exec_ok", True))
                    if not exec_ok: continue  # only exec_ok=True cases
                    correct = bool(t.get("is_planner_correct") or t.get("is_fixed_correct"))
                    key = (hash(question), sql[:60])
                    if key in seen: continue
                    seen.add(key)

                    es = exec_str(db_path, sql)

                    if not correct and gold_sql:
                        # WRONG SQL — teach validator to flag it
                        sel_crit  = gen_sel_critique(sql, gold_sql)
                        cond_crit = gen_cond_critique(sql, gold_sql)
                        for instr, tag, chosen_crit, none_crit in [
                            (SEL_INSTR,  "select",    sel_crit,  NONE_SEL),
                            (COND_INSTR, "condition", cond_crit, NONE_COND),
                        ]:
                            prompt = build_prompt(instr, schema, question, evidence, sql, es)
                            pairs.append({"prompt": prompt, "chosen": chosen_crit,
                                          "rejected": none_crit,  # rejected = staying silent
                                          "question": question, "db_id": d.get("db_id", ""),
                                          "role": tag, "label": "wrong"})
                        n_wrong += 1

                    elif correct:
                        # CORRECT SQL — teach validator NOT to flag it
                        # Rejected = a plausible-looking but wrong critique
                        for instr, tag, none_crit, fake_critique in [
                            (SEL_INSTR,  "select",    NONE_SEL,
                             "<select>\nSELECT.\nINCORRECT: SELECT clause returns wrong results.\n</select>"),
                            (COND_INSTR, "condition", NONE_COND,
                             "<condition>\nCONDITION.\nINCORRECT: WHERE conditions are wrong.\n</condition>"),
                        ]:
                            prompt = build_prompt(instr, schema, question, evidence, sql, es)
                            pairs.append({"prompt": prompt, "chosen": none_crit,
                                          "rejected": fake_critique,  # rejected = false alarm
                                          "question": question, "db_id": d.get("db_id", ""),
                                          "role": tag, "label": "correct"})
                        n_correct += 1

        print(f"  {src}: {n_wrong} wrong + {n_correct} correct examples")

    rng.shuffle(pairs)
    n_wrong_total = sum(1 for p in pairs if p["label"] == "wrong")
    n_correct_total = sum(1 for p in pairs if p["label"] == "correct")
    print(f"\nTotal ORPO pairs: {len(pairs)} ({n_wrong_total} wrong, {n_correct_total} correct)")

    n_test = max(300, len(pairs) // 20)
    test, train = pairs[:n_test], pairs[n_test:]
    DatasetDict({
        "train_dpo": Dataset.from_list(train),
        "test_dpo":  Dataset.from_list(test),
    }).save_to_disk(OUT_DIR)
    print(f"Saved {len(train)} train + {len(test)} test → {OUT_DIR}")


if __name__ == "__main__":
    main()