import json
from collections import defaultdict

from sqlalchemy.orm import Session

from app.models import NetObjectModel, RelationModel
from app.schemas import InventoryTreeNode, NetObject, NodeContext, NodeContextRelations, Relation


def _to_net_object(m: NetObjectModel) -> NetObject:
    return NetObject(
        id=m.id, name=m.name, slug=m.slug, type=m.type,
        parent_id=m.parent_id, status=m.status, vendor=m.vendor,
        model=m.model, serial=m.serial, notes=m.notes,
        created_at=m.created_at, updated_at=m.updated_at,
    )


def _to_relation(m: RelationModel) -> Relation:
    return Relation(
        id=m.id, type=m.type, layer=m.layer,
        source_id=m.source_id, target_id=m.target_id,
        direction=m.direction, source=m.source,
        confidence=m.confidence, status=m.status,
        attributes=json.loads(m.attributes_json or "{}"),
        created_at=m.created_at, updated_at=m.updated_at,
    )


def get_object_map(db: Session) -> dict[str, NetObject]:
    return {r.id: _to_net_object(r) for r in db.query(NetObjectModel).all()}


def get_children_map(db: Session) -> dict[str, list[NetObject]]:
    object_map = get_object_map(db)
    rels = db.query(RelationModel).filter(
        RelationModel.type == "contains",
        RelationModel.status == "active",
    ).all()
    children: dict[str, list[NetObject]] = defaultdict(list)
    for rel in rels:
        if rel.target_id in object_map:
            children[rel.source_id].append(object_map[rel.target_id])
    return children


def get_badges(db: Session, object_id: str) -> list[str]:
    obj = get_object_map(db).get(object_id)
    if not obj:
        return []
    badges: list[str] = []
    if obj.type == "physical_host":
        badges.append("virtualization-host")
    if obj.type in {"vm", "router", "firewall"}:
        badges.append("network-node")
    outgoing = db.query(RelationModel).filter(
        RelationModel.source_id == object_id,
        RelationModel.status == "active",
    ).all()
    if any(r.type == "routes_via" for r in outgoing):
        badges.append("gateway-dependent")
    if any(r.type in {"routes_via", "bridges_to"} for r in outgoing) \
            or obj.name.lower().startswith("openwrt"):
        badges.append("gateway")
    return badges


def build_tree_node(db: Session, object_id: str, depth: int | None = None) -> InventoryTreeNode:
    om = get_object_map(db)
    cm = get_children_map(db)
    obj = om[object_id]
    ch = cm.get(object_id, [])
    child_nodes = []
    if depth is None or depth > 0:
        nd = None if depth is None else depth - 1
        child_nodes = [build_tree_node(db, c.id, nd) for c in ch]
    return InventoryTreeNode(
        id=obj.id, name=obj.name, type=obj.type, status=obj.status,
        badges=get_badges(db, obj.id),
        children_count=len(ch),
        children=child_nodes,
    )


def build_inventory_tree(
    db: Session, root_id: str | None = None, depth: int | None = None
) -> list[InventoryTreeNode]:
    om = get_object_map(db)
    if root_id:
        return [build_tree_node(db, root_id, depth)] if root_id in om else []
    roots = db.query(NetObjectModel).filter(NetObjectModel.parent_id == None).all()  # noqa: E711
    return [build_tree_node(db, r.id, depth) for r in roots]


def build_node_context(db: Session, item_id: str) -> NodeContext | None:
    row = db.query(NetObjectModel).filter(NetObjectModel.id == item_id).first()
    if not row:
        return None
    item = _to_net_object(row)
    parent = None
    if item.parent_id:
        p = db.query(NetObjectModel).filter(NetObjectModel.id == item.parent_id).first()
        parent = _to_net_object(p) if p else None
    children = get_children_map(db).get(item_id, [])
    inc = [_to_relation(r) for r in db.query(RelationModel).filter(
        RelationModel.target_id == item_id, RelationModel.status == "active").all()]
    out = [_to_relation(r) for r in db.query(RelationModel).filter(
        RelationModel.source_id == item_id, RelationModel.status == "active").all()]
    return NodeContext(
        item=item, parent=parent, children=children,
        relations=NodeContextRelations(incoming=inc, outgoing=out),
    )


def get_node_relations(
    db: Session, item_id: str,
    layer: str | None = None,
    rel_type: str | None = None,
    direction: str = "both",
) -> list[Relation]:
    result: list[Relation] = []
    base = db.query(RelationModel).filter(RelationModel.status == "active")
    if direction in {"incoming", "both"}:
        result += [_to_relation(r) for r in base.filter(RelationModel.target_id == item_id).all()]
    if direction in {"outgoing", "both"}:
        result += [_to_relation(r) for r in base.filter(RelationModel.source_id == item_id).all()]
    if layer:
        result = [r for r in result if r.layer == layer]
    if rel_type:
        result = [r for r in result if r.type == rel_type]
    return result