"""Streamlit app for browsing MathVision-like records."""

from __future__ import annotations

import hashlib
import io
import shutil
import tempfile
from importlib import import_module
from pathlib import Path
from typing import Any
from urllib.parse import urlparse
from zipfile import BadZipFile, ZipFile

from mathvision_explorer.dataset import (
    MathVisionRecord,
    filter_records,
    load_jsonl_records,
    load_jsonl_records_from_text,
    record_from_mapping,
    summarize_records,
)
from mathvision_explorer.embeddings import (
    ColorStatsEmbedder,
    IJepaImageEmbedder,
    ImageEmbedder,
    render_patch_interest_overlay,
)
from mathvision_explorer.explorer import build_image_index
from mathvision_explorer.similarity import (
    SimilarityWeights,
    combined_score,
    embedder_description,
    interpret_match,
)

QUERY_IMAGE_WIDTH = 260
NEIGHBOR_IMAGE_WIDTH = 130
RECORD_IMAGE_WIDTH = 320
MATHVISION_DATASET_URL = "https://huggingface.co/datasets/MathLLMs/MathVision"
HF_DATASETS_URL = "https://huggingface.co/datasets"


def main(jsonl_path: Path = Path("data/demo/demo.jsonl")) -> None:
    """Run the Streamlit explorer app."""

    st = _load_streamlit()

    st.set_page_config(page_title="MathVision Explorer", layout="wide")
    _stabilize_layout(st)
    st.title("MathVision Explorer")

    records = _load_active_records(st, jsonl_path)
    subjects = sorted({record.subject for record in records if record.subject is not None})
    levels = sorted({record.level for record in records if record.level is not None})

    with st.sidebar:
        st.header("Dataset")
        st.markdown(
            f"[Example: MathLLMs/MathVision]({MATHVISION_DATASET_URL}) | "
            f"[Browse HF datasets]({HF_DATASETS_URL})"
        )
        dataset_source = st.radio(
            "Dataset source",
            ["Demo", "Hugging Face URL", "Upload file"],
            horizontal=False,
            help=(
                "Choose whether to use the bundled demo, paste a Hub dataset link, "
                "or upload files."
            ),
        )
        if dataset_source == "Hugging Face URL":
            hf_dataset_ref = st.text_input(
                "HF dataset URL or ID",
                value="MathLLMs/MathVision",
                placeholder="https://huggingface.co/datasets/MathLLMs/MathVision",
                help="Paste a Hugging Face dataset URL or repo id.",
            )
            hf_limit = st.number_input(
                "HF max records",
                min_value=1,
                max_value=500,
                value=50,
                step=10,
                help="Cap rows loaded from Hugging Face so exploration stays responsive.",
            )
            if st.button(
                "Load HF dataset",
                help="Download the first available split and convert compatible rows into records.",
            ):
                try:
                    records = _load_hf_dataset_records(
                        st,
                        hf_dataset_ref,
                        limit=int(hf_limit),
                    )
                except (RuntimeError, ValueError, OSError) as error:
                    st.error(str(error))
                    st.stop()
                    raise RuntimeError("Streamlit stopped after HF dataset load error.") from error
                st.session_state["hf_dataset_records"] = records
            elif "hf_dataset_records" in st.session_state:
                records = st.session_state["hf_dataset_records"]
        elif dataset_source == "Upload file":
            uploaded_dataset = st.file_uploader(
                "Upload dataset",
                type=["jsonl", "zip"],
                help=(
                    "Use a JSONL file for text-only records, or a ZIP containing one JSONL "
                    "file plus referenced images."
                ),
            )
            if uploaded_dataset is not None:
                records = _load_uploaded_records(st, uploaded_dataset)
        subjects = sorted({record.subject for record in records if record.subject is not None})
        levels = sorted({record.level for record in records if record.level is not None})
        summary = summarize_records(records)
        st.caption(f"{summary['records']} records | {summary['images']} images")
        st.header("Filters")
        subject = st.selectbox(
            "Subject",
            ["all", *subjects],
            help="Limit the visible record list to one MathVision subject.",
        )
        level_label = st.selectbox(
            "Level",
            ["all", *(str(level) for level in levels)],
            help="Limit the visible record list to one difficulty level.",
        )
        show_solutions = st.toggle(
            "Show solutions",
            value=True,
            help="Show or hide worked solutions in the record browser below the neighbor panel.",
        )
        st.header("Latent Space")
        embedder_label = st.selectbox(
            "Embedder",
            ["color (fast demo)", "ijepa (semantic, requires make sync-ijepa)"],
            help=(
                "Choose the image representation used for nearest-neighbor search. "
                "I-JEPA is slower but more semantic."
            ),
        )
        show_patch_maps = st.toggle(
            "Patch maps",
            value=True,
            help=(
                "When I-JEPA is selected, overlay patch-activation heatmaps on the query "
                "and neighbor images."
            ),
        )
        st.caption("Similarity swatch: red = lower cosine similarity, green = higher.")
        st.subheader("Ranking")
        weights = SimilarityWeights(
            image=st.slider(
                "Image weight",
                min_value=0.0,
                max_value=2.0,
                value=1.0,
                step=0.05,
                help="How much raw image similarity contributes to the final ranking.",
            ),
            subject_bonus=st.slider(
                "Subject bonus",
                min_value=0.0,
                max_value=1.0,
                value=0.15,
                step=0.01,
                help="Extra score for neighbors from the same subject as the query.",
            ),
            problem_type_bonus=st.slider(
                "Problem-type bonus",
                min_value=0.0,
                max_value=1.0,
                value=0.10,
                step=0.01,
                help="Extra score for matching multiple-choice or open-ended format.",
            ),
            level_penalty=st.slider(
                "Level penalty",
                min_value=0.0,
                max_value=1.0,
                value=0.05,
                step=0.01,
                help="Penalty per difficulty-level step between query and neighbor.",
            ),
        )
        query_id = st.selectbox(
            "Query record",
            [record.problem_id for record in records],
            help="The record used as the visual search query.",
        )
        neighbor_count = st.slider(
            "Neighbors",
            min_value=1,
            max_value=8,
            value=3,
            help="Number of nearest records to show in the right-hand panel.",
        )

    selected_subject = None if subject == "all" else subject
    selected_level = None if level_label == "all" else int(level_label)
    filtered = filter_records(records, subject=selected_subject, level=selected_level)

    _render_similarity_panel(
        st,
        records,
        query_id=query_id,
        embedder_name=_embedder_name_from_label(embedder_label),
        neighbor_count=neighbor_count,
        show_patch_maps=show_patch_maps,
        weights=weights,
    )

    st.caption(f"{len(filtered)} of {len(records)} records")
    for record in filtered:
        _render_record(st, record, show_solution=show_solutions)


def _render_similarity_panel(
    st: Any,
    records: list[MathVisionRecord],
    *,
    query_id: str,
    embedder_name: str,
    neighbor_count: int,
    show_patch_maps: bool,
    weights: SimilarityWeights,
) -> None:
    st.header("Nearest Neighbors")
    st.caption(embedder_description(embedder_name))
    record_by_id = {record.problem_id: record for record in records}
    query = record_by_id[query_id]
    if query.image_path is None:
        st.warning("Selected query has no image.")
        return

    try:
        embedder = _load_embedder(embedder_name)
        query_vector = embedder.embed_image(query.image_path)
        index = build_image_index(records, embedder)
        matches = _find_similar_records_combined(
            records,
            index,
            query.problem_id,
            query_vector,
            limit=neighbor_count,
            weights=weights,
        )
    except RuntimeError as error:
        st.error(str(error))
        return

    columns = st.columns([1, 2])
    with columns[0]:
        st.caption("Query")
        st.image(str(query.image_path), width=QUERY_IMAGE_WIDTH)
        if show_patch_maps and embedder_name == "ijepa":
            _render_patch_attention(st, embedder, query.image_path, width=QUERY_IMAGE_WIDTH)
        st.write(query.problem_id)
        st.caption(_record_metadata_line(query))
    with columns[1]:
        for record, neighbor, combined in matches:
            interpretation = interpret_match(query, record, score=neighbor.score)
            with st.container(border=True):
                match_columns = st.columns([0.35, 1])
                with match_columns[0]:
                    if record.image_path is not None:
                        st.image(str(record.image_path), width=NEIGHBOR_IMAGE_WIDTH)
                        if show_patch_maps and embedder_name == "ijepa":
                            _render_patch_attention(
                                st,
                                embedder,
                                record.image_path,
                                width=NEIGHBOR_IMAGE_WIDTH,
                                expanded=False,
                            )
                with match_columns[1]:
                    st.write(f"**{record.problem_id}**")
                    st.caption(
                        f"cosine {neighbor.score:.4f} | combined {combined:.4f} | "
                        f"{interpretation.label} "
                        f"| {_record_metadata_line(record)}"
                    )
                    _render_score_swatch(st, neighbor.score)
                    st.write(record.question)
                    st.write(interpretation.summary)


def _render_record(st: Any, record: MathVisionRecord, *, show_solution: bool) -> None:
    with st.container(border=True):
        columns = st.columns([1, 1.4])
        with columns[0]:
            if record.image_path is not None:
                st.image(str(record.image_path), width=RECORD_IMAGE_WIDTH)
        with columns[1]:
            st.subheader(record.question)
            badges = [record.problem_id]
            if record.subject is not None:
                badges.append(record.subject)
            if record.level is not None:
                badges.append(f"level {record.level}")
            if record.problem_type is not None:
                badges.append(record.problem_type)
            elif record.options:
                badges.append("multiple_choice")
            else:
                badges.append("open_ended")
            st.caption(" | ".join(badges))
            if record.options:
                st.write("Options: " + ", ".join(record.options))
            st.write(f"Answer: **{record.answer}**")
            if show_solution and record.solution:
                st.write(record.solution)


def _load_active_records(st: Any, jsonl_path: Path) -> list[MathVisionRecord]:
    try:
        return load_jsonl_records(jsonl_path)
    except (OSError, ValueError) as error:
        st.error(str(error))
        st.stop()
        raise RuntimeError("Streamlit stopped after dataset load error.") from error


def _load_uploaded_records(st: Any, uploaded_dataset: Any) -> list[MathVisionRecord]:
    dataset_bytes = uploaded_dataset.getvalue()
    dataset_name = uploaded_dataset.name
    dataset_key = _uploaded_dataset_key(dataset_name, dataset_bytes)

    try:
        if dataset_name.lower().endswith(".zip"):
            return _load_uploaded_zip_records(st, dataset_key, dataset_bytes)
        return load_jsonl_records_from_text(dataset_bytes.decode("utf-8"))
    except (BadZipFile, UnicodeDecodeError, ValueError, OSError) as error:
        st.error(str(error))
        st.stop()
        raise RuntimeError("Streamlit stopped after upload load error.") from error


def _load_uploaded_zip_records(
    st: Any,
    dataset_key: str,
    dataset_bytes: bytes,
) -> list[MathVisionRecord]:
    upload_state = st.session_state.setdefault("uploaded_dataset", {})
    if upload_state.get("key") != dataset_key:
        _remove_upload_dir(upload_state.get("extract_dir"))
        extract_dir = Path(tempfile.mkdtemp(prefix="mathvision-upload-"))
        _extract_zip_safely(dataset_bytes, extract_dir)
        upload_state.clear()
        upload_state.update({"key": dataset_key, "extract_dir": str(extract_dir)})

    extract_dir = Path(upload_state["extract_dir"])
    jsonl_files = sorted(extract_dir.rglob("*.jsonl"))
    if not jsonl_files:
        msg = "Uploaded ZIP must contain a .jsonl file."
        raise ValueError(msg)
    return load_jsonl_records(jsonl_files[0])


def _load_hf_dataset_records(
    st: Any,
    dataset_ref: str,
    *,
    limit: int,
) -> list[MathVisionRecord]:
    repo_id = _hf_dataset_id_from_ref(dataset_ref)
    datasets = _load_datasets_library()
    hf_state = st.session_state.setdefault("hf_dataset", {})
    hf_key = f"{repo_id}:{limit}"
    if hf_state.get("key") != hf_key:
        _remove_upload_dir(hf_state.get("image_dir"))
        image_dir = Path(tempfile.mkdtemp(prefix="mathvision-hf-images-"))
        status = st.empty()
        progress = st.progress(0, text="Preparing Hugging Face dataset load")
        status.info(f"Connecting to `{repo_id}`...")
        try:
            progress.progress(20, text="Finding the first usable split")
            split_name = _choose_hf_split(datasets, repo_id)
            status.info(f"Loading `{repo_id}` split `{split_name}`...")
            progress.progress(45, text="Downloading dataset rows")
            dataset = datasets.load_dataset(repo_id, split=split_name)
            progress.progress(65, text=f"Converting up to {limit} rows")
            records = _records_from_hf_dataset(dataset, image_dir=image_dir, limit=limit)
            image_count = sum(1 for record in records if record.image_path is not None)
            progress.progress(100, text="Dataset ready")
            status.success(
                f"Loaded {len(records)} records with {image_count} images from `{split_name}`."
            )
        except Exception:
            progress.empty()
            status.error("Hugging Face dataset load failed.")
            raise
        hf_state.clear()
        hf_state.update({"key": hf_key, "image_dir": str(image_dir), "records": records})
    else:
        cached_records = hf_state.get("records", [])
        if isinstance(cached_records, list):
            st.success(f"Using cached Hugging Face dataset ({len(cached_records)} records).")

    records = hf_state["records"]
    if not isinstance(records, list):
        msg = "Cached HF dataset records are unavailable."
        raise RuntimeError(msg)
    return records


def _choose_hf_split(datasets: Any, repo_id: str) -> str:
    dataset_builder = datasets.load_dataset_builder(repo_id)
    split_names = [str(name) for name in (getattr(dataset_builder.info, "splits", {}) or {})]
    if not split_names:
        return "train"
    for preferred in ("test", "validation", "valid", "train"):
        if preferred in split_names:
            return preferred
    return split_names[0]


def _records_from_hf_dataset(
    dataset: Any,
    *,
    image_dir: Path,
    limit: int,
) -> list[MathVisionRecord]:
    records: list[MathVisionRecord] = []
    skipped = 0
    for row_index, row in enumerate(dataset):
        if len(records) >= limit:
            break
        if not isinstance(row, dict):
            skipped += 1
            continue
        record = _record_from_hf_row(row, row_index=row_index, image_dir=image_dir)
        if record is None:
            skipped += 1
            continue
        records.append(record)

    if not records:
        msg = "No compatible rows found. Expected fields like id, question, answer, and image."
        if skipped:
            msg += f" Skipped {skipped} rows."
        raise ValueError(msg)
    return records


def _record_from_hf_row(
    row: dict[str, Any],
    *,
    row_index: int,
    image_dir: Path,
) -> MathVisionRecord | None:
    question = _text_from_row(row, "question", "problem", "prompt")
    answer = _text_from_row(row, "answer", "label", "target")
    if question is None or answer is None:
        return None

    payload: dict[str, Any] = {
        "id": _text_from_row(row, "id", "problem_id", "question_id") or f"hf-{row_index}",
        "question": question,
        "answer": answer,
        "subject": _text_from_row(row, "subject", "category"),
        "problem_type": _text_from_row(row, "problem_type", "type", "task"),
        "solution": _text_from_row(row, "solution", "rationale", "explanation"),
    }
    if isinstance(row.get("level"), int):
        payload["level"] = row["level"]
    options = row.get("options")
    if isinstance(options, list):
        payload["options"] = [str(option) for option in options]

    image_path = _save_hf_row_image(row, row_index=row_index, image_dir=image_dir)
    if image_path is not None:
        payload["image"] = str(image_path)
    return record_from_mapping(payload)


def _save_hf_row_image(
    row: dict[str, Any],
    *,
    row_index: int,
    image_dir: Path,
) -> Path | None:
    for key in ("decoded_image", "image", "img"):
        image_value = row.get(key)
        save_image = getattr(image_value, "save", None)
        if callable(save_image):
            image_path = image_dir / f"row-{row_index:05d}.png"
            save_image(image_path)
            return image_path
    return None


def _text_from_row(row: dict[str, Any], *keys: str) -> str | None:
    for key in keys:
        value = row.get(key)
        if value is None:
            continue
        if isinstance(value, str):
            stripped = value.strip()
            if stripped:
                return stripped
        elif isinstance(value, int | float):
            return str(value)
    return None


def _hf_dataset_id_from_ref(dataset_ref: str) -> str:
    stripped = dataset_ref.strip()
    if not stripped:
        msg = "Enter a Hugging Face dataset URL or repo id."
        raise ValueError(msg)
    parsed = urlparse(stripped)
    if parsed.netloc:
        parts = [part for part in parsed.path.split("/") if part]
        if parts[:1] == ["datasets"] and len(parts) >= 3:
            return "/".join(parts[1:3])
        msg = "HF dataset URL should look like https://huggingface.co/datasets/org/name."
        raise ValueError(msg)
    return stripped.removeprefix("datasets/")


def _load_datasets_library() -> Any:
    try:
        return import_module("datasets")
    except ImportError as error:
        msg = "Install the `datasets` package to load Hugging Face dataset URLs."
        raise RuntimeError(msg) from error


def _extract_zip_safely(dataset_bytes: bytes, extract_dir: Path) -> None:
    with ZipFile(io.BytesIO(dataset_bytes)) as dataset_zip:
        for member in dataset_zip.infolist():
            target_path = (extract_dir / member.filename).resolve()
            if not target_path.is_relative_to(extract_dir.resolve()):
                msg = f"Unsafe ZIP member path: {member.filename}"
                raise ValueError(msg)
            dataset_zip.extract(member, extract_dir)


def _uploaded_dataset_key(dataset_name: str, dataset_bytes: bytes) -> str:
    digest = hashlib.sha256(dataset_bytes).hexdigest()
    return f"{dataset_name}:{digest}"


def _remove_upload_dir(path: object) -> None:
    if isinstance(path, str):
        shutil.rmtree(path, ignore_errors=True)


def _render_patch_attention(
    st: Any,
    embedder: ImageEmbedder,
    image_path: Path,
    *,
    width: int,
    expanded: bool = True,
) -> None:
    if not isinstance(embedder, IJepaImageEmbedder):
        return

    with st.expander("Patch map", expanded=expanded):
        try:
            interest_map = embedder.patch_interest_map(image_path)
            overlay = render_patch_interest_overlay(image_path, interest_map)
            grid_rows, grid_columns = interest_map.grid_size
        except RuntimeError as error:
            st.warning(str(error))
            return

        st.image(overlay, width=width)
        st.caption(f"{grid_rows} x {grid_columns} patch activation map")


def _stabilize_layout(st: Any) -> None:
    """Keep nested Streamlit columns from resizing while images load."""

    st.markdown(
        """
        <style>
        [data-testid="stHorizontalBlock"] { align-items: flex-start; }
        [data-testid="column"] { min-width: 0; }
        [data-testid="stImage"] img {
            display: block;
            height: auto;
            max-width: 100%;
        }
        [data-testid="stMarkdownContainer"] {
            overflow-wrap: anywhere;
        }
        </style>
        """,
        unsafe_allow_html=True,
    )


def _load_streamlit() -> Any:
    try:
        return import_module("streamlit")
    except ImportError as error:
        msg = "Streamlit is missing. Install it with `uv sync --extra app --dev`."
        raise RuntimeError(msg) from error


def _load_embedder(embedder_name: str) -> ImageEmbedder:
    if embedder_name == "ijepa":
        return IJepaImageEmbedder()
    return ColorStatsEmbedder()


def _embedder_name_from_label(label: str) -> str:
    return "ijepa" if label.startswith("ijepa") else "color"


def _record_metadata_line(record: MathVisionRecord) -> str:
    subject = record.subject or "unknown subject"
    level = f"level {record.level}" if record.level is not None else "unknown level"
    if record.problem_type:
        problem_type = record.problem_type
    elif record.options:
        problem_type = "multiple_choice"
    else:
        problem_type = "open_ended"
    return f"{subject} | {level} | {problem_type}"


def _render_score_swatch(st: Any, score: float) -> None:
    color = _score_to_hex(score)
    st.markdown(
        f"<div style='height: 10px; border-radius: 3px; background: {color}; "
        "border: 1px solid rgba(0,0,0,0.15);'></div>",
        unsafe_allow_html=True,
    )


def _score_to_hex(score: float) -> str:
    """Map cosine similarity (-1..1) to a red->green swatch for quick scanning."""

    clamped = max(-1.0, min(1.0, score))
    t = (clamped + 1.0) / 2.0
    red = int(round(220 * (1.0 - t) + 30 * t))
    green = int(round(30 * (1.0 - t) + 180 * t))
    blue = int(round(60 * (1.0 - t) + 60 * t))
    return f"#{red:02x}{green:02x}{blue:02x}"


def _find_similar_records_combined(
    records: list[MathVisionRecord],
    index: Any,
    query_id: str,
    query_vector: tuple[float, ...],
    *,
    limit: int,
    weights: SimilarityWeights,
) -> list[tuple[MathVisionRecord, Any, float]]:
    """Fetch candidates by cosine similarity, then rerank with metadata weights."""

    record_by_id = {record.problem_id: record for record in records}
    query = record_by_id[query_id]
    candidate_count = max(25, limit * 10)
    neighbors = index.search(query_vector, limit=candidate_count, exclude_id=query_id)
    scored: list[tuple[MathVisionRecord, Any, float]] = []
    for neighbor in neighbors:
        record = record_by_id.get(neighbor.item_id)
        if record is None:
            continue
        combined = combined_score(query, record, image_score=neighbor.score, weights=weights)
        scored.append((record, neighbor, combined))
    scored.sort(key=lambda row: row[2], reverse=True)
    return scored[:limit]


if __name__ == "__main__":
    main()