"""Location related endpoints."""

from typing import Annotated, Optional

from fastapi import APIRouter, Depends
from pydantic import BaseModel, Field
from sqlalchemy.ext.asyncio import AsyncSession

from spoolman.api.v1.models import Message
from spoolman.database import location
from spoolman.database.database import get_db_session
from spoolman.database import models

router = APIRouter(
    prefix="/location",
    tags=["location"],
)


class LocationResponse(BaseModel):
    """Location response model."""

    id: int
    name: str
    parent_id: Optional[int] = None
    location_type: Optional[str] = None
    description: Optional[str] = None
    full_path: Optional[str] = None  # Only populated for single-item requests
    spool_count: Optional[int] = None  # Only populated when requested

    @staticmethod
    def from_db(item: models.Location, full_path: Optional[str] = None) -> "LocationResponse":
        return LocationResponse(
            id=item.id,
            name=item.name,
            parent_id=item.parent_id,
            location_type=item.location_type,
            description=item.description,
            full_path=full_path,
        )


class LocationTreeNode(BaseModel):
    """Location tree node for nested structure."""

    id: int
    name: str
    location_type: Optional[str] = None
    description: Optional[str] = None
    children: list["LocationTreeNode"] = []


class LocationParameters(BaseModel):
    """Parameters for creating a location."""

    name: str = Field(max_length=64, description="Location name.")
    parent_id: Optional[int] = Field(None, description="Parent location ID.")
    location_type: Optional[str] = Field(None, max_length=32, description="Type: room, shelf, bin, etc.")
    description: Optional[str] = Field(None, max_length=256, description="Optional description.")


class LocationUpdateParameters(BaseModel):
    """Parameters for updating a location."""

    name: Optional[str] = Field(None, max_length=64, description="Location name.")
    parent_id: Optional[int] = Field(None, description="Parent location ID.")
    location_type: Optional[str] = Field(None, max_length=32, description="Type: room, shelf, bin, etc.")
    description: Optional[str] = Field(None, max_length=256, description="Optional description.")


@router.get(
    "",
    name="Find locations",
    description="Get all locations as a flat list.",
    response_model=list[LocationResponse],
)
async def find_locations(
    db: Annotated[AsyncSession, Depends(get_db_session)],
) -> list[LocationResponse]:
    db_items = await location.find_all(db=db)
    return [LocationResponse.from_db(item) for item in db_items]


@router.get(
    "/tree",
    name="Get location tree",
    description="Get all locations as a nested tree structure.",
    response_model=list[LocationTreeNode],
)
async def get_location_tree(
    db: Annotated[AsyncSession, Depends(get_db_session)],
) -> list[dict]:
    return await location.get_tree(db=db)


@router.get(
    "/{location_id}",
    name="Get location",
    description="Get a specific location by ID.",
    response_model=LocationResponse,
    responses={404: {"model": Message}},
)
async def get_location(
    db: Annotated[AsyncSession, Depends(get_db_session)],
    location_id: int,
) -> LocationResponse:
    db_item = await location.get_by_id(db=db, location_id=location_id)
    full_path = await location.get_full_path(db=db, location_id=location_id)
    spool_count = await location.get_spool_count(db=db, location_id=location_id)
    response = LocationResponse.from_db(db_item, full_path=full_path)
    response.spool_count = spool_count
    return response


@router.post(
    "",
    name="Create location",
    description="Create a new location.",
    response_model=LocationResponse,
    responses={400: {"model": Message}, 404: {"model": Message}},
)
async def create_location(
    db: Annotated[AsyncSession, Depends(get_db_session)],
    body: LocationParameters,
) -> LocationResponse:
    db_item = await location.create(
        db=db,
        name=body.name,
        parent_id=body.parent_id,
        location_type=body.location_type,
        description=body.description,
    )
    return LocationResponse.from_db(db_item)


@router.patch(
    "/{location_id}",
    name="Update location",
    description="Update a location.",
    response_model=LocationResponse,
    responses={400: {"model": Message}, 404: {"model": Message}},
)
async def update_location(
    db: Annotated[AsyncSession, Depends(get_db_session)],
    location_id: int,
    body: LocationUpdateParameters,
) -> LocationResponse:
    data = body.model_dump(exclude_unset=True)
    db_item = await location.update(db=db, location_id=location_id, data=data)
    return LocationResponse.from_db(db_item)


@router.delete(
    "/{location_id}",
    name="Delete location",
    description="Delete a location. Spools using this location will have their location_id set to null.",
    responses={404: {"model": Message}},
)
async def delete_location(
    db: Annotated[AsyncSession, Depends(get_db_session)],
    location_id: int,
) -> Message:
    await location.delete(db=db, location_id=location_id)
    return Message(message="Success!")