# =============================================================================
# QWHPI — Quebec Weekly Housing Price Index
# Author  : Simon-Pierre Boucher
# Contact : contact@spboucher.ai
# File    : api/app/routers/liquidity.py
# Purpose : Weekly transaction-volume (liquidity) endpoint per series.
# =============================================================================
"""Liquidity endpoints."""

from __future__ import annotations

import polars as pl
from fastapi import APIRouter, HTTPException, Request, Response

from app.deps import etag_for, validate_series
from app.schemas import LiquidityPoint, LiquidityResponse
from app.services import data

router = APIRouter()


@router.get("/liquidity", response_model=LiquidityResponse)
def liquidity(request: Request, response: Response,
              geography: str, type: str = "all"):
    """Weekly transaction counts for one series."""
    validate_series(geography, type)
    df = data.liquidity().filter(
        (pl.col("geography_id") == geography)
        & (pl.col("property_type") == type)
    ).sort("period")
    if df.height == 0:
        raise HTTPException(404, "no liquidity data")
    if etag_for(request, response, geography, type):
        return Response(status_code=304)
    return LiquidityResponse(
        geography=geography,
        property_type=type,
        median_monthly_transactions=float(df["transactions"].median()),
        observations=[LiquidityPoint(period=r["period"], transactions=r["transactions"])
                      for r in df.iter_rows(named=True)],
    )