from fastapi import APIRouter, HTTPException, Query
from pydantic import BaseModel, Field

from app.services.session_service import SessionService

router = APIRouter()


class SelectedEpisodesAddRequest(BaseModel):
    items: list[dict] = Field(default_factory=list)


class SelectedEpisodesReorderRequest(BaseModel):
    from_index: int = Field(ge=0)
    to_index: int = Field(ge=0)


def _normalize_session_id(session_id: str) -> str:
    normalized = session_id.strip()
    if not normalized:
        raise HTTPException(status_code=400, detail="session_id must not be empty")
    return normalized


@router.get("/selected-episodes")
def get_selected_episodes(session_id: str = Query("default", min_length=1)):
    service = SessionService()
    normalized_session_id = _normalize_session_id(session_id)
    items = service.list_selected_episodes(normalized_session_id)
    return {"session_id": normalized_session_id, "items": items}


@router.post("/selected-episodes")
def add_selected_episodes(
    payload: SelectedEpisodesAddRequest,
    session_id: str = Query("default", min_length=1),
):
    service = SessionService()
    normalized_session_id = _normalize_session_id(session_id)
    items = service.add_selected_episodes(normalized_session_id, payload.items)
    return {"session_id": normalized_session_id, "items": items}


@router.delete("/selected-episodes")
def clear_selected_episodes(session_id: str = Query("default", min_length=1)):
    service = SessionService()
    normalized_session_id = _normalize_session_id(session_id)
    service.clear_selected_episodes(normalized_session_id)
    return {"session_id": normalized_session_id, "items": []}


@router.delete("/selected-episodes/{selection_id}")
def remove_selected_episode(selection_id: int, session_id: str = Query("default", min_length=1)):
    service = SessionService()
    normalized_session_id = _normalize_session_id(session_id)
    items = service.remove_selected_episode(normalized_session_id, selection_id)
    return {"session_id": normalized_session_id, "items": items}


@router.post("/selected-episodes/reorder")
def reorder_selected_episodes(
    payload: SelectedEpisodesReorderRequest,
    session_id: str = Query("default", min_length=1),
):
    service = SessionService()
    normalized_session_id = _normalize_session_id(session_id)
    try:
        items = service.reorder_selected_episodes(
            normalized_session_id,
            payload.from_index,
            payload.to_index,
        )
    except ValueError as exc:
        raise HTTPException(status_code=400, detail=str(exc))

    return {"session_id": normalized_session_id, "items": items}