"""Archive integration with artifact-store (IB-WP-0014).

The live infospace stays in a local working folder. This module bundles a
finalized snapshot of the infospace (or a curated slice) into a content-
addressed artifact-store package, finalizes it, and records the returned
package id and manifest digest under ``output/archives/index.yaml``.

Storage backend choice (local FS in artifact-store v0.1, S3 in WP-0004) is
delegated to artifact-store - it is not re-implemented here.
"""

from __future__ import annotations

import asyncio
import fnmatch
import json
import mimetypes
import os
from collections.abc import AsyncIterator, Iterable
from dataclasses import dataclass, field
from datetime import datetime, timezone
from pathlib import Path
from typing import Any
from uuid import UUID

import yaml
from sqlalchemy import insert, select
from sqlalchemy.ext.asyncio import create_async_engine

from artifactstore.dataplane import InProcessDataPlane
from artifactstore.db.schema import metadata as artifactstore_metadata
from artifactstore.db.schema import retention_classes as retention_classes_table
from artifactstore.db.seed import RETENTION_CLASS_SEEDS
from artifactstore.events import RegistryViewWriter
from artifactstore.registry import Registry
from artifactstore.storage import LocalBackend

from .errors import InfospaceError
from .lifecycle import load_infospace

ARCHIVE_INDEX_PATH = "output/archives/index.yaml"
ARCHIVE_STORE_DIR = "output/archives/.store"
ARCHIVE_DB_NAME = "registry.sqlite"
ARCHIVE_BACKEND_DIR = "storage"

DEFAULT_INCLUDE: tuple[str, ...] = (
    "infospace.yaml",
    "artifacts",
    "workflows",
    "output",
    "reports",
    "exports",
)
DEFAULT_RETENTION_CLASS = "release-evidence"
PRODUCER = "infospace-bench"
DEFAULT_ACTOR = "infospace-bench"


@dataclass(frozen=True)
class ArchiveRecord:
    """One row of ``output/archives/index.yaml``."""

    package_id: str
    manifest_digest: str
    retention_class: str
    created_at: str
    included_paths: list[str]
    file_count: int
    note: str = ""
    producer: str = PRODUCER
    subject: str = ""
    store_root: str | None = None
    metadata: dict[str, Any] = field(default_factory=dict)

    def to_dict(self) -> dict[str, Any]:
        out: dict[str, Any] = {
            "package_id": self.package_id,
            "manifest_digest": self.manifest_digest,
            "retention_class": self.retention_class,
            "created_at": self.created_at,
            "included_paths": list(self.included_paths),
            "file_count": self.file_count,
            "note": self.note,
            "producer": self.producer,
            "subject": self.subject,
        }
        if self.store_root is not None:
            out["store_root"] = self.store_root
        if self.metadata:
            out["metadata"] = dict(self.metadata)
        return out

    @classmethod
    def from_dict(cls, data: dict[str, Any]) -> "ArchiveRecord":
        return cls(
            package_id=str(data["package_id"]),
            manifest_digest=str(data["manifest_digest"]),
            retention_class=str(data["retention_class"]),
            created_at=str(data["created_at"]),
            included_paths=list(data.get("included_paths", [])),
            file_count=int(data.get("file_count", 0)),
            note=str(data.get("note", "")),
            producer=str(data.get("producer", PRODUCER)),
            subject=str(data.get("subject", "")),
            store_root=(
                str(data["store_root"]) if data.get("store_root") is not None else None
            ),
            metadata=dict(data.get("metadata", {})),
        )


def archive_infospace(
    root: str | Path,
    *,
    retention_class: str = DEFAULT_RETENTION_CLASS,
    include: Iterable[str] | None = None,
    exclude: Iterable[str] | None = None,
    note: str = "",
    registry: Registry | None = None,
    store_root: str | Path | None = None,
    actor: str = DEFAULT_ACTOR,
) -> ArchiveRecord:
    """Bundle the infospace at ``root`` into an artifact-store package.

    Returns the new :class:`ArchiveRecord` and appends it to the infospace's
    ``output/archives/index.yaml``. When ``registry`` is None, a self-contained
    SQLite + local-FS registry is built under ``store_root`` (default:
    ``<root>/output/archives/.store/``).
    """

    include_tuple = tuple(include) if include else DEFAULT_INCLUDE
    exclude_tuple = tuple(exclude or ())
    return asyncio.run(
        _archive_infospace_async(
            Path(root),
            retention_class=retention_class,
            include=include_tuple,
            exclude=exclude_tuple,
            note=note,
            registry=registry,
            store_root=Path(store_root) if store_root else None,
            actor=actor,
        )
    )


@dataclass(frozen=True)
class RestoredArchive:
    """Result of :func:`restore_archive`."""

    package_id: str
    manifest_digest: str
    target: str
    file_count: int
    restored_paths: list[str]

    def to_dict(self) -> dict[str, Any]:
        return {
            "package_id": self.package_id,
            "manifest_digest": self.manifest_digest,
            "target": self.target,
            "file_count": self.file_count,
            "restored_paths": list(self.restored_paths),
        }


def restore_archive(
    package_id: str,
    *,
    target: str | Path,
    store_root: str | Path | None = None,
    source_infospace: str | Path | None = None,
    registry: Registry | None = None,
    force: bool = False,
) -> RestoredArchive:
    """Re-materialize an archived infospace package into ``target``.

    Exactly one of ``store_root``, ``source_infospace``, or ``registry`` must
    locate the artifact-store. ``source_infospace`` is a convenience that
    resolves to ``<source_infospace>/output/archives/.store/``.
    """

    return asyncio.run(
        _restore_archive_async(
            package_id=package_id,
            target=Path(target),
            store_root=Path(store_root) if store_root else None,
            source_infospace=Path(source_infospace) if source_infospace else None,
            registry=registry,
            force=force,
        )
    )


def annotate_retention(
    archives: Iterable[ArchiveRecord],
    *,
    store_root: str | Path | None = None,
    source_infospace: str | Path | None = None,
    registry: Registry | None = None,
) -> list[dict[str, Any]]:
    """Pair each record with its current retention state if reachable.

    Returns a list of ``{"archive": ArchiveRecord.to_dict(), "retention": {...}|None}``
    entries. Records whose registry cannot be opened get ``retention: None``.
    """

    return asyncio.run(
        _annotate_retention_async(
            tuple(archives),
            store_root=Path(store_root) if store_root else None,
            source_infospace=Path(source_infospace) if source_infospace else None,
            registry=registry,
        )
    )


def list_archives(root: str | Path) -> list[ArchiveRecord]:
    """Return the recorded archive entries for an infospace."""
    path = Path(root) / ARCHIVE_INDEX_PATH
    if not path.exists():
        return []
    raw = yaml.safe_load(path.read_text(encoding="utf-8")) or {}
    if not isinstance(raw, dict):
        raise InfospaceError(
            "invalid_archive_index",
            f"Archive index must be a mapping: {path}",
            {"path": str(path)},
        )
    items = raw.get("archives", [])
    if not isinstance(items, list):
        raise InfospaceError(
            "invalid_archive_index",
            f"Archive index 'archives' must be a list: {path}",
            {"path": str(path)},
        )
    return [ArchiveRecord.from_dict(item) for item in items]


async def _archive_infospace_async(
    root: Path,
    *,
    retention_class: str,
    include: tuple[str, ...],
    exclude: tuple[str, ...],
    note: str,
    registry: Registry | None,
    store_root: Path | None,
    actor: str,
) -> ArchiveRecord:
    infospace = load_infospace(root)
    subject = infospace.config.slug
    auto_exclude = (ARCHIVE_STORE_DIR, ARCHIVE_INDEX_PATH)
    effective_exclude = exclude + auto_exclude

    files = _collect_files(root, include=include, exclude=effective_exclude)
    if not files:
        raise InfospaceError(
            "empty_archive",
            "No files matched the include set for archiving",
            {"root": str(root), "include": list(include)},
        )

    owned_registry = registry is None
    effective_store_root: Path | None = None
    if owned_registry:
        effective_store_root = store_root or (root / ARCHIVE_STORE_DIR)
        registry = await _build_local_registry(effective_store_root)

    try:
        assert registry is not None
        package_id = await registry.create_package(
            name=f"infospace {subject}",
            producer=PRODUCER,
            subject=subject,
            retention_class=retention_class,
            actor=actor,
            metadata={
                "infospace_slug": subject,
                "infospace_name": infospace.config.name,
                "topic_domain": infospace.config.topic.domain,
                "included_paths": list(include),
                "note": note,
            },
        )
        for relative_path, abs_path in files:
            media = (
                mimetypes.guess_type(abs_path.name)[0] or "application/octet-stream"
            )
            await registry.ingest_file(
                package_id,
                relative_path=relative_path,
                media_type=media,
                stream=_file_stream(abs_path),
                actor=actor,
            )
        manifest_addr = await registry.finalize_package(package_id, actor=actor)
        pkg = await registry.get_package(package_id)
    finally:
        if owned_registry and registry is not None:
            await registry.dispose()

    finalized_at = pkg.finalized_at or datetime.now(timezone.utc)
    record = ArchiveRecord(
        package_id=str(package_id),
        manifest_digest=str(manifest_addr),
        retention_class=retention_class,
        created_at=finalized_at.isoformat(),
        included_paths=list(include),
        file_count=len(files),
        note=note,
        producer=PRODUCER,
        subject=subject,
        store_root=str(effective_store_root) if effective_store_root else None,
    )
    _append_index(root, record)
    return record


def _collect_files(
    root: Path,
    *,
    include: tuple[str, ...],
    exclude: tuple[str, ...],
) -> list[tuple[str, Path]]:
    seen: dict[str, Path] = {}
    for pattern in include:
        target = root / pattern
        if target.is_file():
            rel = pattern.replace(os.sep, "/")
            if not _is_excluded(rel, exclude):
                seen.setdefault(rel, target)
        elif target.is_dir():
            for path in target.rglob("*"):
                if not path.is_file():
                    continue
                rel = str(path.relative_to(root)).replace(os.sep, "/")
                if _is_excluded(rel, exclude):
                    continue
                seen.setdefault(rel, path)
    return sorted(seen.items())


def _is_excluded(rel_path: str, exclude: tuple[str, ...]) -> bool:
    for pattern in exclude:
        cleaned = pattern.rstrip("/")
        if rel_path == cleaned or rel_path.startswith(cleaned + "/"):
            return True
        if fnmatch.fnmatch(rel_path, pattern):
            return True
    return False


async def _file_stream(
    path: Path,
    chunk_size: int = 1024 * 1024,
) -> AsyncIterator[bytes]:
    with path.open("rb") as fh:
        while True:
            chunk = fh.read(chunk_size)
            if not chunk:
                break
            yield chunk


def _append_index(root: Path, record: ArchiveRecord) -> None:
    path = root / ARCHIVE_INDEX_PATH
    path.parent.mkdir(parents=True, exist_ok=True)
    existing: list[dict[str, Any]] = []
    if path.exists():
        raw = yaml.safe_load(path.read_text(encoding="utf-8")) or {}
        if isinstance(raw, dict):
            items = raw.get("archives", [])
            if isinstance(items, list):
                existing = list(items)
    existing.append(record.to_dict())
    path.write_text(
        yaml.safe_dump({"archives": existing}, sort_keys=False),
        encoding="utf-8",
    )


async def _build_local_registry(store_root: Path) -> Registry:
    store_root.mkdir(parents=True, exist_ok=True)
    db_path = store_root / ARCHIVE_DB_NAME
    backend_root = store_root / ARCHIVE_BACKEND_DIR
    engine = create_async_engine(f"sqlite+aiosqlite:///{db_path}", future=True)
    async with engine.begin() as conn:
        await conn.run_sync(artifactstore_metadata.create_all)
        seeded = (
            await conn.execute(select(retention_classes_table).limit(1))
        ).first()
        if seeded is None:
            for seed in RETENTION_CLASS_SEEDS:
                await conn.execute(insert(retention_classes_table).values(**seed))
    backend = LocalBackend(backend_root, backend_id="local")
    dataplane = InProcessDataPlane(backend)
    return Registry(engine, dataplane, RegistryViewWriter())


def _resolve_store_root(
    *,
    store_root: Path | None,
    source_infospace: Path | None,
) -> Path | None:
    if store_root is not None and source_infospace is not None:
        raise InfospaceError(
            "ambiguous_archive_store",
            "Pass at most one of store_root or source_infospace",
            {},
        )
    if store_root is not None:
        return store_root
    if source_infospace is not None:
        return source_infospace / ARCHIVE_STORE_DIR
    return None


async def _restore_archive_async(
    *,
    package_id: str,
    target: Path,
    store_root: Path | None,
    source_infospace: Path | None,
    registry: Registry | None,
    force: bool,
) -> RestoredArchive:
    owned_registry = registry is None
    if owned_registry:
        resolved_store = _resolve_store_root(
            store_root=store_root,
            source_infospace=source_infospace,
        )
        if resolved_store is None:
            raise InfospaceError(
                "missing_archive_store",
                "restore_archive needs registry, store_root, or source_infospace",
                {},
            )
        if not resolved_store.exists():
            raise InfospaceError(
                "missing_archive_store",
                f"Archive store does not exist: {resolved_store}",
                {"store_root": str(resolved_store)},
            )
        registry = await _build_local_registry(resolved_store)

    try:
        assert registry is not None
        pkg_uuid = UUID(package_id)
        pkg = await registry.get_package(pkg_uuid)
        if pkg.manifest_digest_hex is None:
            raise InfospaceError(
                "unfinalized_package",
                f"Package is not finalized: {package_id}",
                {"package_id": package_id, "status": pkg.status},
            )
        manifest_bytes = await registry.get_manifest_bytes(pkg_uuid, format="json")
        manifest = json.loads(manifest_bytes.decode("utf-8"))

        target.mkdir(parents=True, exist_ok=True)
        if not force and any(target.iterdir()):
            raise InfospaceError(
                "restore_target_not_empty",
                f"Refusing to restore into non-empty directory: {target}",
                {"target": str(target)},
            )

        restored: list[str] = []
        for entry in manifest.get("files", []):
            rel = str(entry["relative_path"])
            file_id = UUID(str(entry["id"]))
            dest = (target / rel).resolve()
            target_resolved = target.resolve()
            if target_resolved not in dest.parents and dest != target_resolved:
                raise InfospaceError(
                    "unsafe_restore_path",
                    f"Manifest path escapes target: {rel}",
                    {"target": str(target), "relative_path": rel},
                )
            dest.parent.mkdir(parents=True, exist_ok=True)
            stream = await registry.get_file(file_id)
            with dest.open("wb") as fh:
                async for chunk in stream:
                    fh.write(chunk)
            restored.append(rel)
    finally:
        if owned_registry and registry is not None:
            await registry.dispose()

    return RestoredArchive(
        package_id=package_id,
        manifest_digest=f"blake3:{pkg.manifest_digest_hex}",
        target=str(target),
        file_count=len(restored),
        restored_paths=restored,
    )


async def _annotate_retention_async(
    archives: tuple[ArchiveRecord, ...],
    *,
    store_root: Path | None,
    source_infospace: Path | None,
    registry: Registry | None,
) -> list[dict[str, Any]]:
    if not archives:
        return []

    owned_registry = registry is None
    used_store_root: Path | None = None
    if owned_registry:
        used_store_root = _resolve_store_root(
            store_root=store_root,
            source_infospace=source_infospace,
        )
        if used_store_root is None or not used_store_root.exists():
            return [{"archive": rec.to_dict(), "retention": None} for rec in archives]
        registry = await _build_local_registry(used_store_root)

    try:
        assert registry is not None
        results: list[dict[str, Any]] = []
        for rec in archives:
            retention: dict[str, Any] | None
            try:
                state = await registry.get_retention_state(UUID(rec.package_id))
                retention = {
                    "current_expires_at": (
                        state.current_expires_at.isoformat()
                        if state.current_expires_at
                        else None
                    ),
                    "effective_class": state.effective_class,
                    "active_hold_id": (
                        str(state.active_hold_id) if state.active_hold_id else None
                    ),
                    "eligible_for_deletion": state.eligible_for_deletion,
                }
            except Exception as exc:
                retention = {"error": f"{type(exc).__name__}: {exc}"}
            results.append({"archive": rec.to_dict(), "retention": retention})
        return results
    finally:
        if owned_registry and registry is not None:
            await registry.dispose()