# =============================================================================
# QWHPI — Quebec Weekly Housing Price Index
# Author  : Simon-Pierre Boucher
# Contact : contact@spboucher.ai
# File    : api/app/main.py
# Purpose : FastAPI application — routers, CORS, rate limiting, OpenAPI.
# =============================================================================
"""QWHPI API service entry point.

Run locally:  uvicorn app.main:app --reload --port 8080  (from api/)
Docs: /docs (OpenAPI). Every response credits the author and exposes
uncertainty (CIs, reliability grades) — the API never hides it.
"""

from __future__ import annotations

import time
from collections import defaultdict, deque

from fastapi import FastAPI, Request
from fastapi.middleware.cors import CORSMiddleware
from fastapi.responses import JSONResponse

from app.routers import geographies, index, liquidity, maps, meta, reports

RATE_LIMIT = 120          # requests
RATE_WINDOW = 60.0        # seconds
_hits: dict[str, deque] = defaultdict(deque)

app = FastAPI(
    title="QWHPI API",
    version="0.1.0",
    description=(
        "Quebec Weekly Housing Price Index — quality-adjusted, hierarchically "
        "pooled weekly indexes for Quebec geographies and property types.\n\n"
        "**Author: Simon-Pierre Boucher — contact@spboucher.ai**"
    ),
    contact={"name": "Simon-Pierre Boucher", "email": "contact@spboucher.ai"},
)

app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_methods=["GET"],
    allow_headers=["*"],
)


@app.middleware("http")
async def rate_limiter(request: Request, call_next):
    ip = request.client.host if request.client else "anon"
    now = time.monotonic()
    q = _hits[ip]
    while q and now - q[0] > RATE_WINDOW:
        q.popleft()
    if len(q) >= RATE_LIMIT:
        return JSONResponse({"detail": "rate limit exceeded"}, status_code=429)
    q.append(now)
    return await call_next(request)


app.include_router(index.router, prefix="/v1", tags=["index"])
app.include_router(reports.router, prefix="/v1", tags=["stats & reports"])
app.include_router(geographies.router, prefix="/v1", tags=["geographies"])
app.include_router(liquidity.router, prefix="/v1", tags=["liquidity"])
app.include_router(maps.router, prefix="/v1", tags=["maps"])
app.include_router(meta.router, tags=["meta"])