import uuid
from typing import Literal

from fastapi import APIRouter, Depends, Query, Request
from sqlalchemy.ext.asyncio import AsyncSession

from app.db.engine import get_db
from app.routers.pm import ArrivalScope, arrivals_scope
from app.schemas.project_transfers import (
    ProjectTransferCreate,
    ProjectTransferOut,
    ProjectTransferReceive,
    ProjectTransferUpdate,
)
from app.services import project_transfer_service
from app.utils.errors import ForbiddenError

router = APIRouter(tags=["project-transfers"])


def _to_transfer_out(t) -> dict:
    return {
        "id": t.id,
        "from_project": (
            {"id": t.from_project.id, "name": t.from_project.name}
            if t.from_project
            else {"id": t.from_project_id, "name": ""}
        ),
        "from_warehouse": (
            {"id": t.from_warehouse.id, "name": t.from_warehouse.name}
            if t.from_warehouse
            else {"id": t.from_warehouse_id, "name": ""}
        ),
        "to_project": (
            {"id": t.to_project.id, "name": t.to_project.name}
            if t.to_project
            else {"id": t.to_project_id, "name": ""}
        ),
        "to_warehouse": (
            {"id": t.to_warehouse.id, "name": t.to_warehouse.name}
            if t.to_warehouse
            else None
        ),
        "material": (
            {"id": t.material.id, "name": t.material.name}
            if t.material
            else {"id": t.material_id, "name": ""}
        ),
        "brand": (
            {"id": t.brand.id, "name": t.brand.name}
            if t.brand
            else None
        ),
        "unit": (
            {"id": t.unit.id, "code": t.unit.code, "name_fa": t.unit.name_fa}
            if t.unit
            else {"id": t.unit_id, "code": "", "name_fa": None}
        ),
        "quantity": t.quantity,
        "specs": t.specs or {},
        "specs_hash": t.specs_hash,
        "note": t.note,
        "status": t.status,
        "transfer_date": t.transfer_date,
        "transferred_by": t.transferred_by,
        "received_at": t.received_at,
        "received_by": t.received_by,
        "receipt_allocations": t.receipt_allocations,
        "created_at": t.created_at,
        "updated_at": t.updated_at,
    }


# ---------------------------------------------------------------------------
# POST /inventory/project-transfers — Create inter-project transfer
# ---------------------------------------------------------------------------
@router.post("/inventory/project-transfers", status_code=201)
async def create_transfer(
    payload: ProjectTransferCreate,
    ctx: ArrivalScope = Depends(arrivals_scope),
    db: AsyncSession = Depends(get_db),
):
    transfer = await project_transfer_service.create_project_transfer(
        db=db,
        payload=payload,
        caller_project_id=ctx.project_id,
        caller_role=ctx.role,
        transferred_by=ctx.display_name,
    )
    return {"data": _to_transfer_out(transfer)}


# ---------------------------------------------------------------------------
# GET /inventory/project-transfers — List transfers with direction and filters
# ---------------------------------------------------------------------------
@router.get("/inventory/project-transfers")
async def list_transfers(
    project_id: uuid.UUID | None = Query(default=None),
    direction: Literal["outgoing", "incoming", "all"] = Query(default="all"),
    status: str | None = Query(default=None),
    ctx: ArrivalScope = Depends(arrivals_scope),
    db: AsyncSession = Depends(get_db),
):
    target_pid = project_id or ctx.project_id
    transfers = await project_transfer_service.list_project_transfers(
        db=db,
        project_id=target_pid,
        direction=direction,
        status=status,
    )
    return {"data": [_to_transfer_out(t) for t in transfers]}


# ---------------------------------------------------------------------------
# GET /inventory/project-transfers/{id} — Single transfer details
# ---------------------------------------------------------------------------
@router.get("/inventory/project-transfers/{transfer_id}")
async def get_transfer(
    transfer_id: uuid.UUID,
    ctx: ArrivalScope = Depends(arrivals_scope),
    db: AsyncSession = Depends(get_db),
):
    transfer = await project_transfer_service.get_project_transfer_or_404(db, transfer_id)
    if ctx.role == "pm" and ctx.project_id is not None:
        if transfer.from_project_id != ctx.project_id and transfer.to_project_id != ctx.project_id:
            raise ForbiddenError("شما به این رکورد انتقال دسترسی ندارید")
    return {"data": _to_transfer_out(transfer)}


# ---------------------------------------------------------------------------
# PATCH /inventory/project-transfers/{id} — Edit in-transit transfer (source PM only)
# ---------------------------------------------------------------------------
@router.patch("/inventory/project-transfers/{transfer_id}")
async def update_transfer(
    transfer_id: uuid.UUID,
    payload: ProjectTransferUpdate,
    ctx: ArrivalScope = Depends(arrivals_scope),
    db: AsyncSession = Depends(get_db),
):
    transfer = await project_transfer_service.update_project_transfer(
        db=db,
        transfer_id=transfer_id,
        payload=payload,
        caller_project_id=ctx.project_id,
        caller_role=ctx.role,
    )
    return {"data": _to_transfer_out(transfer)}


# ---------------------------------------------------------------------------
# DELETE /inventory/project-transfers/{id} — Cancel in-transit transfer (source PM only)
# ---------------------------------------------------------------------------
@router.delete("/inventory/project-transfers/{transfer_id}")
async def delete_transfer(
    transfer_id: uuid.UUID,
    ctx: ArrivalScope = Depends(arrivals_scope),
    db: AsyncSession = Depends(get_db),
):
    res = await project_transfer_service.delete_project_transfer(
        db=db,
        transfer_id=transfer_id,
        caller_project_id=ctx.project_id,
        caller_role=ctx.role,
    )
    return {"data": res}


# ---------------------------------------------------------------------------
# GET /pm/transfers/on-the-way — Incoming in-transit transfers for active project
# ---------------------------------------------------------------------------
@router.get("/pm/transfers/on-the-way")
async def pm_incoming_transfers(
    ctx: ArrivalScope = Depends(arrivals_scope),
    db: AsyncSession = Depends(get_db),
):
    if ctx.role == "pm" and ctx.project_id is None:
        raise ForbiddenError("شما به هیچ پروژه‌ای متصل نیستید")

    transfers = await project_transfer_service.list_project_transfers(
        db=db,
        project_id=ctx.project_id,
        direction="incoming",
        status="in_transit",
    )
    return {"data": [_to_transfer_out(t) for t in transfers]}


# ---------------------------------------------------------------------------
# POST /inventory/project-transfers/{id}/receive — Destination PM confirms arrival
# ---------------------------------------------------------------------------
@router.post("/inventory/project-transfers/{transfer_id}/receive")
async def receive_transfer(
    transfer_id: uuid.UUID,
    payload: ProjectTransferReceive,
    ctx: ArrivalScope = Depends(arrivals_scope),
    db: AsyncSession = Depends(get_db),
):
    transfer = await project_transfer_service.receive_project_transfer(
        db=db,
        transfer_id=transfer_id,
        payload=payload,
        caller_project_id=ctx.project_id,
        caller_role=ctx.role,
        received_by=ctx.display_name,
    )
    return {"data": _to_transfer_out(transfer)}