"""Map a pinned Wikidata entity export into a canonical snapshot.

This is the third connector. It does not use the JSON, NDJSON, or Markdown
loaders, and it does not import UI code. Candidates go through
``project_records`` and ``publish_directory``.
"""

from __future__ import annotations

import json
from pathlib import Path
from typing import Any

from content_explorer.ingest import project_records, publish_directory, snapshot_hash

CONNECTOR_ID = "wikidata-export"
CONNECTOR_VERSION = "0.1.0"
SOURCE_NAMESPACE = "https://www.wikidata.org/wiki/"
MAPPING_VERSION = "1"
PROPERTY_PREDICATES = {"P287": "designed-by"}
FORMAT = "wikidata-entity-export"


def _digest(payload: bytes) -> str:
    import hashlib

    return hashlib.sha256(payload).hexdigest()


def _en(block: dict | None) -> str:
    entry = (block or {}).get("en") or {}
    if isinstance(entry, dict):
        return str(entry.get("value") or "").strip()
    return ""


def _target_qid(statement: dict) -> str | None:
    snak = statement.get("mainsnak") or {}
    if snak.get("snaktype") != "value":
        return None
    value = (snak.get("datavalue") or {}).get("value")
    if not isinstance(value, dict):
        return None
    qid = value.get("id")
    if isinstance(qid, str) and len(qid) > 1 and qid[0] == "Q" and qid[1:].isdigit():
        return qid
    return None


def load_export(path: Path) -> tuple[dict[str, Any], str]:
    """Read one pinned Wikidata export. The digest is of the file bytes."""
    raw = path.read_bytes()
    document = json.loads(raw.decode("utf-8"))
    if not isinstance(document, dict) or document.get("format") != FORMAT:
        raise ValueError(f"{path} is not a {FORMAT}")
    if not isinstance(document.get("entities"), dict):
        raise ValueError(f"{path} has no Wikidata entity map")
    return document, _digest(raw)


def map_candidates(document: dict[str, Any]) -> list[dict[str, Any]]:
    """Turn Wikidata items into candidate records. Native Q-ids become aliases."""
    entities = document["entities"]
    bindings = document.get("kindByQid") or {}
    if not isinstance(bindings, dict) or not bindings:
        raise ValueError("kindByQid is required")
    located = {
        qid: f"{binding['kind']}:{binding['key']}"
        for qid, binding in bindings.items()
    }
    records: list[dict[str, Any]] = []
    for qid, binding in bindings.items():
        item = entities.get(qid)
        if not isinstance(item, dict):
            raise ValueError(f"{qid} is not in the export entities")
        title = _en(item.get("labels"))
        description = _en(item.get("descriptions"))
        if not title or not description:
            raise ValueError(f"{qid} needs an English label and description")
        aliases = [qid, f"{SOURCE_NAMESPACE}{qid}"]
        for alias in (item.get("aliases") or {}).get("en") or []:
            value = alias.get("value") if isinstance(alias, dict) else str(alias)
            value = str(value).strip()
            if value and value not in aliases:
                aliases.append(value)
        relations = []
        claims = item.get("claims") or {}
        for prop, predicate in PROPERTY_PREDICATES.items():
            for statement in claims.get(prop) or []:
                target = _target_qid(statement)
                if not target:
                    continue
                relations.append({
                    "predicate": predicate,
                    "to": located.get(target) or f"missing:{target.lower()}",
                })
        records.append({
            "kind": binding["kind"],
            "key": binding["key"],
            "title": title,
            "tldr": description,
            "summary": description,
            "tags": [binding["kind"]],
            "aliases": aliases,
            "relations": relations,
        })
    return records


def _source(document: dict[str, Any]) -> dict[str, str]:
    raw = document.get("source") or {}
    source = {
        "id": str(raw.get("id") or ""),
        "uri": str(raw.get("uri") or ""),
        "title": str(raw.get("title") or ""),
        "license": str(raw.get("license") or ""),
        "attribution": str(raw.get("attribution") or ""),
    }
    retrieved = str(document.get("retrievedAt") or "")
    if retrieved:
        source["retrievedAt"] = retrieved
    return source


def _annotate(report: dict[str, Any], digest: str) -> None:
    report["connectorVersion"] = f"{CONNECTOR_ID}/{CONNECTOR_VERSION}"
    report["sourceDigest"] = digest
    report["inputDigest"] = digest
    report["connector"] = {
        "id": CONNECTOR_ID,
        "version": CONNECTOR_VERSION,
        "sourceNamespace": SOURCE_NAMESPACE,
        "capabilities": ["map", "validate", "commit"],
        "licensePolicy": "CC0-1.0, CC-BY-4.0, MIT",
        "mappingVersion": MAPPING_VERSION,
        "refreshMode": "pinned-export-replay",
        "sourcePriority": 1,
        "lastCheckpoint": digest,
    }
    report["counts"] = {
        "candidates": report.get("candidates", 0),
        "accepted": report.get("accepted", 0),
        "tombstoned": len(report.get("tombstoned") or []),
        "quarantined": len(report.get("quarantined") or []),
        "dangling": len(report.get("dangling") or []),
        "conflicts": len(report.get("conflicts") or []),
    }


def _browsable_columns(manifest: dict[str, Any] | None) -> None:
    if not manifest:
        return
    for view in (manifest.get("kindViews") or {}).values():
        view["columns"] = ["name", "tldr", "tags"]
        view["facets"] = ["tags"]


def run(export_path: Path, destination: Path | None = None) -> dict[str, Any]:
    """Map ``export_path`` and publish only when the existing gate allows it."""
    document, digest = load_export(export_path)
    dataspace = document["dataspace"]
    result = project_records(
        map_candidates(document),
        dataspace_id=dataspace["id"],
        title=dataspace["title"],
        description=dataspace["description"],
        source=_source(document),
        kinds=list(document["kinds"]),
        observed_at=str(document["retrievedAt"]),
        source_digest=digest,
        relation_labels=document.get("relationLabels") or {},
        fact_policy=document.get("factPolicy") or "show-all",
        acyclic_predicates=list(document.get("acyclicPredicates") or []),
    )
    _annotate(result["report"], digest)
    _browsable_columns(result.get("manifest"))
    if result["report"]["published"] and result.get("snapshot") is not None:
        result["report"]["contentHash"] = snapshot_hash(result["snapshot"])
    if destination is not None and result["report"]["published"]:
        publish_directory(destination, result)
    return result