from __future__ import annotations

from fastapi import APIRouter, HTTPException, Request, Response, status

from app.automations.models import (
    AutomationProposal,
    ProposalDecision,
    ProposalStatus,
)
from app.automations.store import AutomationStore

router = APIRouter(prefix="/v1/automations", tags=["automations"])


@router.post("/proposals", response_model=AutomationProposal, status_code=201)
def create_proposal(payload: AutomationProposal, request: Request) -> AutomationProposal:
    if payload.trigger.above is None and payload.trigger.below is None:
        raise HTTPException(status_code=422, detail="Trigger benötigt above oder below.")
    return _store(request).create(payload.model_copy(update={"status": ProposalStatus.DRAFT}))


@router.get("/proposals", response_model=list[AutomationProposal])
def list_proposals(request: Request) -> list[AutomationProposal]:
    return _store(request).list()


@router.post("/proposals/{proposal_id}/approve", response_model=AutomationProposal)
def approve(
    proposal_id: str,
    payload: ProposalDecision,
    request: Request,
) -> AutomationProposal:
    return _decide(request, proposal_id, ProposalStatus.APPROVED, payload.expected_revision)


@router.post("/proposals/{proposal_id}/reject", response_model=AutomationProposal)
def reject(
    proposal_id: str,
    payload: ProposalDecision,
    request: Request,
) -> AutomationProposal:
    return _decide(request, proposal_id, ProposalStatus.REJECTED, payload.expected_revision)


@router.get("/proposals/{proposal_id}/yaml")
def export_yaml(proposal_id: str, request: Request) -> Response:
    try:
        content = _store(request).export_yaml(proposal_id)
    except KeyError as exc:
        raise HTTPException(status_code=404, detail=str(exc)) from exc
    except ValueError as exc:
        raise HTTPException(status_code=409, detail=str(exc)) from exc
    return Response(content=content, media_type="application/yaml")


def _decide(
    request: Request,
    proposal_id: str,
    decision: ProposalStatus,
    expected_revision: int,
) -> AutomationProposal:
    try:
        return _store(request).decide(proposal_id, decision, expected_revision)
    except KeyError as exc:
        raise HTTPException(status_code=404, detail=str(exc)) from exc
    except ValueError as exc:
        raise HTTPException(status_code=409, detail=str(exc)) from exc


def _store(request: Request) -> AutomationStore:
    store = getattr(request.app.state, "automation_store", None)
    if not isinstance(store, AutomationStore):
        raise HTTPException(
            status_code=status.HTTP_503_SERVICE_UNAVAILABLE,
            detail="Automation Store nicht initialisiert.",
        )
    return store