"""Adapters from the archived Jev-style sources to kev Examples.

Each adapter yields one Example per question. `source.dataset` + `family` identify
the leakage unit (a state and all its questions/variants); `source.panel` names
the recipe part so metrics can be reported per panel.
"""

import json
from collections.abc import Iterator
from pathlib import Path
from typing import cast

from kev.types import Example, JSONValue, Label, Target

ADAPTERS = ("kev-suite", "open-jev", "laya", "tasksource-jev")
# Parquet adapters with `source` and `group_id` columns can be pre-sampled without loading states.
GROUPED_PARQUET = ("open-jev", "tasksource-jev")


def _hard(target: list[float]) -> int:
    return max(range(len(target)), key=target.__getitem__)


def _is_one_hot(target: list[float]) -> bool:
    return max(target) > 1 - 1e-9


def kev_suite(path: Path, panel: str) -> Iterator[Example]:
    """kev-suites JSONL: one state with several typed questions and gold labels."""
    with path.open(encoding="utf-8") as stream:
        for line in stream:
            if not line.strip():
                continue
            raw = json.loads(line)
            meta = raw["_meta"]
            for key, question in raw["questions"].items():
                kind = question["type"]
                converted: dict[str, JSONValue] = {"type": kind, "instructions": question.get("instructions")}
                if kind != "noul" or question.get("criteria"):
                    converted["criteria"] = question["criteria"]
                label = cast(Label, question["label"])
                yield cast(Example, {
                    "id": f"{meta['id']}#{key}", "suite": str(meta.get("source") or question.get("src")),
                    "family": str(meta.get("group_id") or meta["id"]), "label": label, "target": label,
                    "state": raw["state"], "question": converted,
                    "source": {"adapter": "kev-suite", "dataset": f"kev:{meta.get('source')}", "panel": panel,
                               "file": str(path), "question_key": key, "row_sha256": meta.get("row_sha256"),
                               "split": meta.get("split"), "variant": meta.get("variant")},
                })


def open_jev(path: Path, panel: str, groups: set[str] | None = None) -> Iterator[Example]:
    """Open-Jev parquet: one question per record with an explicit option list and target distribution."""
    import pyarrow.parquet as pq

    columns = ["id", "group_id", "split", "source", "kind", "question", "options", "target", "state_json"]
    for batch in pq.ParquetFile(path).iter_batches(batch_size=8192, columns=columns):
        for raw in batch.to_pylist():
            if groups is not None and raw["group_id"] not in groups:
                continue
            kind, options, distribution = raw["kind"], list(raw["options"]), [float(p) for p in raw["target"]]
            question: dict[str, JSONValue]
            label: Label
            target: Target
            if kind == "noul":
                if options != ["no", "yes"]:
                    raise ValueError(f"Unexpected noul options {options}: {raw['id']}")
                label, target = distribution[1] >= 0.5, distribution[1]
                question = {"type": "noul", "instructions": raw["question"]}
            elif kind == "score":
                label = _hard(distribution)
                target = label if _is_one_hot(distribution) else distribution
                question = {"type": "score", "instructions": raw["question"], "criteria": cast(JSONValue, options)}
            else:
                label = options[_hard(distribution)]
                target = label if _is_one_hot(distribution) else distribution
                question = {"type": "choice", "instructions": raw["question"],
                            "criteria": {option: None for option in options}}
            yield cast(Example, {
                "id": raw["id"], "suite": raw["source"], "family": raw["group_id"], "label": label, "target": target,
                "state": json.loads(raw["state_json"]), "question": question,
                "source": {"adapter": "open-jev", "dataset": f"open-jev:{raw['source'].split('/')[0]}", "panel": panel,
                           "file": str(path), "split": raw["split"]},
            })


def tasksource_jev(path: Path, panel: str, groups: set[str] | None = None) -> Iterator[Example]:
    """tasksource-jev-typed-decisions parquet: one question per record; noul stores only P(yes)."""
    import pyarrow.parquet as pq

    columns = ["id", "group_id", "source", "kind", "question", "options", "target", "state", "variant"]
    for batch in pq.ParquetFile(path).iter_batches(batch_size=8192, columns=columns):
        for raw in batch.to_pylist():
            if groups is not None and raw["group_id"] not in groups:
                continue
            kind, options, distribution = raw["kind"], list(raw["options"]), [float(p) for p in raw["target"]]
            question: dict[str, JSONValue]
            label: Label
            target: Target
            if kind == "noul":
                if len(distribution) != 1:
                    raise ValueError(f"Expected one noul probability: {raw['id']}")
                label, target = distribution[0] >= 0.5, distribution[0]
                question = {"type": "noul", "instructions": raw["question"]}
            elif kind == "score":
                label = _hard(distribution)
                target = label if _is_one_hot(distribution) else distribution
                question = {"type": "score", "instructions": raw["question"], "criteria": cast(JSONValue, options)}
            else:
                label = options[_hard(distribution)]
                target = label if _is_one_hot(distribution) else distribution
                question = {"type": "choice", "instructions": raw["question"],
                            "criteria": {option: None for option in options}}
            yield cast(Example, {
                "id": raw["id"], "suite": raw["source"], "family": raw["group_id"], "label": label, "target": target,
                "state": raw["state"], "question": question,
                "source": {"adapter": "tasksource-jev", "dataset": f"tasksource:{raw['source']}", "panel": panel,
                           "file": str(path), "variant": raw["variant"]},
            })


def laya(path: Path, panel: str) -> Iterator[Example]:
    """Laya typed-decisions parquet: five questions per case, gold as annotator distributions."""
    import pyarrow.parquet as pq

    for raw in pq.read_table(path).to_pylist():
        questions = json.loads(raw["questions"])
        gold = json.loads(raw["gold"])
        state = json.loads(raw["state"]) if isinstance(raw["state"], str) else raw["state"]
        for key, question in questions.items():
            answer = gold[key]
            # Gold is stored to 6 decimals; renormalize so the distribution sums to 1 exactly.
            total = sum(float(value) for value in answer["probabilities"].values())
            answer["probabilities"] = {name: float(value) / total for name, value in answer["probabilities"].items()}
            kind = question["type"]
            label: Label
            target: Target
            if kind == "noul":
                label, target = answer["label"] == "true", float(answer["probabilities"]["true"])
            elif kind == "score":
                label = int(answer["label"])
                target = [float(answer["probabilities"][str(i)]) for i in range(len(question["criteria"]))]
            else:
                label = answer["label"]
                target = [float(answer["probabilities"][option]) for option in question["criteria"]]
            yield cast(Example, {
                "id": f"laya:{raw['id']}#{key}", "suite": f"laya/{raw['workflow']}", "family": raw["id"],
                "label": label, "target": target, "state": state, "question": question,
                "source": {"adapter": "laya", "dataset": f"laya:{raw['workflow']}", "panel": panel, "file": str(path),
                           "split": raw["split"]},
            })


def group_index(path: Path) -> list[tuple[str, str]]:
    """(source, group_id) per record, read without loading states."""
    import pyarrow.parquet as pq

    table = pq.read_table(path, columns=["source", "group_id"])
    return list(zip(table.column("source").to_pylist(), table.column("group_id").to_pylist(), strict=True))


def load(adapter: str, path: Path, panel: str, groups: set[str] | None = None) -> Iterator[Example]:
    if groups is not None and adapter not in GROUPED_PARQUET:
        raise ValueError(f"Adapter {adapter} cannot pre-select groups")
    if adapter == "kev-suite":
        return kev_suite(path, panel)
    if adapter == "open-jev":
        return open_jev(path, panel, groups)
    if adapter == "tasksource-jev":
        return tasksource_jev(path, panel, groups)
    if adapter == "laya":
        return laya(path, panel)
    raise ValueError(f"Unknown adapter {adapter!r}; choose from {ADAPTERS}")