"""GQA-v1.2 source adapter backed only by native questions and scene graphs.

The released question files are mappings keyed by question id.  Each question
contains a native dependency-indexed ``semantic`` program and points to an image
whose released scene graph supplies object names, attributes, relations, and
bounding boxes.  This adapter joins those records deterministically and never
uses a VLM or the source answer to infer a program operand.
"""

from __future__ import annotations

import json
from collections.abc import Iterator, Mapping
from pathlib import Path
from typing import TYPE_CHECKING, Any

from ..hashing import canonical_json_hash
from ..ingest.base import (
    AnswerType,
    ImageStore,
    IngestError,
    NormalizedItem,
    Policy,
    infer_open_answer_type,
    make_item,
)
from .base import AdapterError, CertificateTier, RawItem, World, store_images

if TYPE_CHECKING:
    from ..executors.gqa import GQASemanticProgram

SOURCE = "gqa"
WORLD_SCHEMA = "gqa_scene_graph_v1"
_HIDDEN_OBJECTS_KEY = "_gqa_hidden_object_ids"

_VALID_SPLITS = frozenset({"train", "val", "validation", "test", "testdev", "challenge"})


class GQAAdapter:
    """Deterministic adapter for GQA-v1.2 native JSON files."""

    def __init__(
        self,
        raw_dir: Path,
        store: ImageStore,
        *,
        revision: str,
        images_dir: Path | None = None,
        questions_path: Path | None = None,
        scene_graphs_path: Path | None = None,
    ) -> None:
        self.raw_dir = Path(raw_dir)
        self.store = store
        self.revision = revision
        self.images_dir = Path(images_dir) if images_dir is not None else self.raw_dir / "images"
        self.questions_path = Path(questions_path) if questions_path is not None else None
        self.scene_graphs_path = Path(scene_graphs_path) if scene_graphs_path is not None else None

    @classmethod
    def is_materialized(cls, raw_dir: Path, split: str) -> bool:
        if split not in _VALID_SPLITS:
            return False
        root = Path(raw_dir)
        return (
            _first_existing(root, _question_names(split)) is not None
            and _first_existing(root, _scene_graph_names(split)) is not None
            and (root / "images").is_dir()
        )

    @classmethod
    def materialize(
        cls,
        raw_dir: Path,
        split: str,
        *,
        source_config: Mapping[str, Any],
        expected_sha256: Mapping[str, str] | None = None,
    ) -> Path:
        """Validate an already materialized native GQA tree.

        GQA's multi-gigabyte image/question archives are intentionally not
        downloaded implicitly.  Callers materialize the pinned source snapshot
        out of band, then this method performs the same fail-closed check used by
        the ingest CLI.  ``source_config`` and ``expected_sha256`` are accepted
        for protocol parity; hashes belong in the surrounding resource manifest.
        """

        del source_config, expected_sha256
        root = Path(raw_dir)
        if not cls.is_materialized(root, split):
            raise AdapterError(
                f"{SOURCE}: native {split!r} questions, scene graphs, and images "
                f"are not materialized under {root}"
            )
        return root

    def iter_base_items(self, split: str) -> Iterator[RawItem]:
        from ..executors.gqa import compile_gqa_program

        if split not in _VALID_SPLITS:
            raise AdapterError(f"{SOURCE}: unsupported split {split!r}")
        questions = _load_mapping(self._questions_file(split), label="questions")
        scene_graphs = _load_mapping(self._scene_graphs_file(split), label="scene graphs")
        for question_id in sorted(str(key) for key in questions):
            row = questions.get(question_id)
            if not isinstance(row, Mapping):
                raise AdapterError(f"{SOURCE}/{question_id}: question row must be an object")
            image_id = str(row.get("imageId", "")).strip()
            if not image_id:
                raise AdapterError(f"{SOURCE}/{question_id}: imageId missing/empty")
            scene_graph = scene_graphs.get(image_id)
            if not isinstance(scene_graph, Mapping):
                raise AdapterError(f"{SOURCE}/{question_id}: scene graph {image_id!r} missing")
            # Compile during iteration so an unsupported native operation is a
            # typed hard rejection, never a silently dropped candidate.
            compile_gqa_program(question_id, row)
            image = self._image_bytes(image_id)
            payload = {
                "question_id": question_id,
                **dict(row),
                "scene_graph": dict(scene_graph),
            }
            yield RawItem(
                source=SOURCE,
                split=split,
                source_revision=self.revision,
                native_id=question_id,
                payload=payload,
                images={image_id: image},
            )

    def normalize(self, raw: RawItem) -> NormalizedItem:
        from ..executors.gqa import compile_gqa_program

        if raw.source != SOURCE:
            raise IngestError(f"{SOURCE}: cannot normalize raw source {raw.source!r}")
        row = raw.payload
        question = row.get("question")
        if not isinstance(question, str) or not question.strip():
            raise IngestError(f"{SOURCE}/{raw.native_id}: question missing/empty")
        answer = row.get("answer")
        if answer is None or not str(answer).strip():
            raise IngestError(f"{SOURCE}/{raw.native_id}: answer missing/empty")
        image_id = str(row.get("imageId", "")).strip()
        scene_graph = row.get("scene_graph")
        if not image_id or not isinstance(scene_graph, Mapping):
            raise IngestError(f"{SOURCE}/{raw.native_id}: joined scene graph missing")
        if not raw.images:
            raise IngestError(f"{SOURCE}/{raw.native_id}: image missing")

        program = compile_gqa_program(raw.native_id, row)
        paths, image_hashes = store_images(self.store, raw.images)
        answer_text = str(answer).strip()
        answer_type: AnswerType
        if answer_text.casefold() in {"yes", "no"}:
            answer_type = "boolean"
            answer_canonical = answer_text.casefold()
        else:
            answer_type = infer_open_answer_type(answer_text)
            answer_canonical = answer_text
        policy: Policy = (
            "c1_train_candidate"
            if raw.split in {"train", "val", "validation"}
            else "c1_certified_eval_candidate"
        )
        types = row.get("types")
        subject = None
        if isinstance(types, Mapping) and types.get("semantic"):
            subject = f"gqa_{str(types['semantic']).strip()}"
        extra = {
            "image_id": image_id,
            "semantic": [step.to_dict() for step in program.steps],
            "semanticStr": program.semantic_str,
            "semantic_program_sha256": program.canonical_program_sha256,
            "annotations": row.get("annotations")
            if isinstance(row.get("annotations"), Mapping)
            else {},
            "types": dict(types) if isinstance(types, Mapping) else {},
            "scene_graph": dict(scene_graph),
            "source_record_sha256": canonical_json_hash(
                {
                    "question_id": raw.native_id,
                    "question": {key: value for key, value in row.items() if key != "scene_graph"},
                    "scene_graph": scene_graph,
                }
            ),
        }
        return make_item(
            source=SOURCE,
            source_revision=raw.source_revision,
            source_config="default",
            source_split=raw.split,
            source_native_id=raw.native_id,
            question=question,
            choices=[],
            answer_raw=answer_text,
            answer_canonical=answer_canonical,
            answer_type=answer_type,
            image_paths=paths,
            image_sha256=image_hashes,
            policy=policy,
            native_row={key: value for key, value in row.items() if key != "scene_graph"},
            subject=subject,
            extra_provenance=extra,
        )

    def build_world(self, item: NormalizedItem) -> World:
        scene_graph = item.provenance.get("scene_graph")
        image_id = str(item.provenance.get("image_id", "")).strip()
        if not isinstance(scene_graph, Mapping) or not image_id:
            raise IngestError(f"{SOURCE}/{item.source_native_id}: scene graph provenance missing")
        return build_gqa_world(scene_graph, image_id=image_id, question_id=item.source_native_id)

    def get_or_compile_program(self, item: NormalizedItem) -> GQASemanticProgram:
        from ..executors.gqa import compile_gqa_program

        semantic = item.provenance.get("semantic")
        if not isinstance(semantic, list):
            raise IngestError(f"{SOURCE}/{item.source_native_id}: semantic provenance missing")
        return compile_gqa_program(
            item.source_native_id,
            {
                "imageId": item.provenance.get("image_id"),
                "semantic": semantic,
                "semanticStr": item.provenance.get("semanticStr", ""),
            },
        )

    def official_answer(self, item: NormalizedItem) -> str | int | bool:
        return item.answer_canonical

    def source_certificate_tier(self, item: NormalizedItem) -> CertificateTier:
        return "C1_SOURCE_NATIVE"

    def _questions_file(self, split: str) -> Path:
        if self.questions_path is not None:
            if not self.questions_path.is_file():
                raise AdapterError(f"{SOURCE}: questions file not found: {self.questions_path}")
            return self.questions_path
        path = _first_existing(self.raw_dir, _question_names(split))
        if path is None:
            raise AdapterError(f"{SOURCE}: no native questions file for split {split!r}")
        return path

    def _scene_graphs_file(self, split: str) -> Path:
        if self.scene_graphs_path is not None:
            if not self.scene_graphs_path.is_file():
                raise AdapterError(
                    f"{SOURCE}: scene-graphs file not found: {self.scene_graphs_path}"
                )
            return self.scene_graphs_path
        path = _first_existing(self.raw_dir, _scene_graph_names(split))
        if path is None:
            raise AdapterError(f"{SOURCE}: no native scene-graphs file for split {split!r}")
        return path

    def _image_bytes(self, image_id: str) -> bytes:
        roots = (self.images_dir, self.raw_dir / "images", self.raw_dir)
        for root in roots:
            for suffix in (".jpg", ".jpeg", ".png"):
                candidate = root / f"{image_id}{suffix}"
                if candidate.is_file():
                    return candidate.read_bytes()
        raise AdapterError(f"{SOURCE}: image {image_id!r} not found")


def build_gqa_world(
    scene_graph: Mapping[str, Any],
    *,
    image_id: str,
    question_id: str | None = None,
) -> World:
    """Validate and canonicalize one native GQA scene graph.

    Object ids remain the released ids.  Relations are sorted only after their
    source order has been validated, making hashes stable even when the native
    relation container is a mapping.  Dangling relation targets are rejected.
    """

    width = _positive_int(scene_graph.get("width"), "width")
    height = _positive_int(scene_graph.get("height"), "height")
    raw_objects = scene_graph.get("objects")
    if not isinstance(raw_objects, Mapping) or not raw_objects:
        raise IngestError(f"{SOURCE}/{image_id}: objects must be a non-empty mapping")

    objects: dict[str, dict[str, Any]] = {}
    for raw_id in sorted(raw_objects, key=str):
        object_id = str(raw_id)
        raw = raw_objects[raw_id]
        if not isinstance(raw, Mapping):
            raise IngestError(f"{SOURCE}/{image_id}: object {object_id!r} must be an object")
        name = str(raw.get("name", "")).strip()
        if not name:
            raise IngestError(f"{SOURCE}/{image_id}: object {object_id!r} name missing")
        x = _nonnegative_int(raw.get("x"), f"object {object_id} x")
        y = _nonnegative_int(raw.get("y"), f"object {object_id} y")
        w = _positive_int(raw.get("w"), f"object {object_id} w")
        h = _positive_int(raw.get("h"), f"object {object_id} h")
        if x + w > width or y + h > height:
            raise IngestError(
                f"{SOURCE}/{image_id}: object {object_id!r} bbox exceeds image bounds"
            )
        raw_attributes = raw.get("attributes", [])
        if not isinstance(raw_attributes, list) or any(
            not isinstance(attribute, str) for attribute in raw_attributes
        ):
            raise IngestError(
                f"{SOURCE}/{image_id}: object {object_id!r} attributes must be strings"
            )
        relations = _normalize_relations(raw.get("relations", []), image_id, object_id)
        objects[object_id] = {
            "id": object_id,
            "name": name,
            "x": x,
            "y": y,
            "w": w,
            "h": h,
            "attributes": list(raw_attributes),
            "relations": relations,
        }

    known = frozenset(objects)
    for source_id, obj in objects.items():
        for relation in obj["relations"]:
            target = str(relation["object"])
            if target not in known:
                raise IngestError(
                    f"{SOURCE}/{image_id}: relation {source_id!r}->{target!r} is dangling"
                )

    world: World = {
        "world_schema": WORLD_SCHEMA,
        "image_id": str(image_id),
        "width": width,
        "height": height,
        "objects": objects,
        _HIDDEN_OBJECTS_KEY: [],
        "provenance": {
            "source": SOURCE,
            "image_id": str(image_id),
            "question_id": question_id,
        },
    }
    for field in ("location", "weather"):
        value = scene_graph.get(field)
        if isinstance(value, str) and value.strip():
            world[field] = value.strip()
    return world


def _normalize_relations(
    raw: Any,
    image_id: str,
    object_id: str,
) -> list[dict[str, str]]:
    values = list(raw.values()) if isinstance(raw, Mapping) else raw
    if not isinstance(values, list):
        raise IngestError(
            f"{SOURCE}/{image_id}: object {object_id!r} relations must be a list or mapping"
        )
    out: list[dict[str, str]] = []
    for index, relation in enumerate(values):
        if not isinstance(relation, Mapping):
            raise IngestError(
                f"{SOURCE}/{image_id}: object {object_id!r} relation {index} must be an object"
            )
        name = str(relation.get("name", "")).strip()
        target = str(relation.get("object", "")).strip()
        if not name or not target:
            raise IngestError(
                f"{SOURCE}/{image_id}: object {object_id!r} relation {index} is incomplete"
            )
        out.append({"name": name, "object": target})
    return sorted(out, key=lambda relation: (relation["name"], relation["object"]))


def _question_names(split: str) -> tuple[str, ...]:
    aliases = _split_aliases(split)
    names: list[str] = []
    for alias in aliases:
        names.extend(
            (
                f"{alias}_balanced_questions.json",
                f"{alias}_all_questions.json",
                f"{alias}_questions.json",
            )
        )
    names.extend(("questions.json", "Questions.json"))
    return tuple(names)


def _scene_graph_names(split: str) -> tuple[str, ...]:
    aliases = _split_aliases(split)
    names: list[str] = []
    for alias in aliases:
        names.extend(
            (
                f"{alias}_sceneGraphs.json",
                f"{alias}_scene_graphs.json",
            )
        )
    names.extend(("sceneGraphs.json", "scene_graphs.json", "Scene_graphs.json"))
    return tuple(names)


def _split_aliases(split: str) -> tuple[str, ...]:
    if split == "validation":
        return ("validation", "val")
    if split == "val":
        return ("val", "validation")
    return (split,)


def _first_existing(root: Path, names: tuple[str, ...]) -> Path | None:
    for name in names:
        path = root / name
        if path.is_file():
            return path
    return None


def _load_mapping(path: Path, *, label: str) -> dict[str, Any]:
    try:
        value = json.loads(path.read_text(encoding="utf-8"))
    except (OSError, UnicodeDecodeError, json.JSONDecodeError) as exc:
        raise AdapterError(f"{SOURCE}: cannot read {label} at {path}: {exc}") from exc
    if not isinstance(value, Mapping):
        raise AdapterError(f"{SOURCE}: {label} at {path} must be a JSON object")
    return {str(key): row for key, row in value.items()}


def _positive_int(value: Any, label: str) -> int:
    number = _integer(value, label)
    if number <= 0:
        raise IngestError(f"{SOURCE}: {label} must be positive")
    return number


def _nonnegative_int(value: Any, label: str) -> int:
    number = _integer(value, label)
    if number < 0:
        raise IngestError(f"{SOURCE}: {label} must be non-negative")
    return number


def _integer(value: Any, label: str) -> int:
    if isinstance(value, bool) or not isinstance(value, int):
        raise IngestError(f"{SOURCE}: {label} must be an integer")
    return int(value)


__all__ = [
    "GQAAdapter",
    "SOURCE",
    "WORLD_SCHEMA",
    "build_gqa_world",
]