From 0fd34a6581be6f2b9a729c37f10a4658a9d5e83c Mon Sep 17 00:00:00 2001
From: Jules Dejaeghere <dej.j@live.be>
Date: Sun, 16 Jun 2024 17:10:03 +0200
Subject: [PATCH] Inital support for forecast client

---
 src/open_irceline/__init__.py |  2 +-
 src/open_irceline/api.py      | 54 +++++++++++++++++++++++++++++++++--
 src/open_irceline/data.py     |  9 +++++-
 3 files changed, 61 insertions(+), 4 deletions(-)

diff --git a/src/open_irceline/__init__.py b/src/open_irceline/__init__.py
index 2fc5c75..c255431 100644
--- a/src/open_irceline/__init__.py
+++ b/src/open_irceline/__init__.py
@@ -1,6 +1,6 @@
 from pyproj import Transformer
 
-project_transform = Transformer.from_crs('EPSG:4326', 'EPSG:31370', always_xy=True)
+project_transform = Transformer.from_crs('EPSG:4326', 'EPSG:31370', always_xy=False)
 rio_wfs_base_url = 'https://geo.irceline.be/rio/wfs'
 # noinspection HttpUrlsUsage
 # There is not HTTPS version of this endpoint
diff --git a/src/open_irceline/api.py b/src/open_irceline/api.py
index b536039..26a1863 100644
--- a/src/open_irceline/api.py
+++ b/src/open_irceline/api.py
@@ -1,6 +1,9 @@
 import asyncio
+import csv
 import socket
 from datetime import datetime, timedelta, date
+from io import StringIO
+from itertools import product
 from typing import Tuple, List, Dict, Set
 from xml.etree import ElementTree
 
@@ -8,8 +11,8 @@ import aiohttp
 import async_timeout
 from aiohttp import ClientResponse
 
-from . import project_transform, rio_wfs_base_url, user_agent
-from .data import RioFeature, FeatureValue
+from . import project_transform, rio_wfs_base_url, user_agent, forecast_base_url
+from .data import RioFeature, FeatureValue, ForecastFeature
 from .utils import SizedDict
 
 
@@ -200,3 +203,50 @@ class IrcelineRioClient(IrcelineBaseClient):
 
         return result
 
+
+class IrcelineForecastClient(IrcelineBaseClient):
+    """API client for forecast IRCEL - CELINE open data"""
+
+    @staticmethod
+    def _round_coordinates(x: float, y: float, step=.05):
+        n = 1 / step
+        return round(x * n) / n, round(y * n) / n
+
+    async def get_forecast(self, day: date, features: List[ForecastFeature], position: Tuple[float, float]) -> dict:
+        x, y = self._round_coordinates(position[0], position[1])
+
+        result = dict()
+
+        for feature, d in product(features, range(5)):
+            url = f"{forecast_base_url}/BE_{feature}_{day.strftime('%Y%m%d')}_d{d}.csv"
+            try:
+                r: ClientResponse = await self._api_cached_wrapper(url)
+                ts = day
+            except IrcelineApiError:
+                # retry for the day before
+                yesterday = day - timedelta(days=1)
+                url = f"{forecast_base_url}/BE_{feature}_{yesterday.strftime('%Y%m%d')}_d{d}.csv"
+                try:
+                    r: ClientResponse = await self._api_cached_wrapper(url)
+                    ts = yesterday
+                except IrcelineApiError:
+                    # if it fails twice, just set None and go to the next
+                    result[(feature, day + timedelta(days=d))] = FeatureValue(value=None, timestamp=day)
+                    continue
+
+            result[(feature, ts + timedelta(days=d))] = FeatureValue(
+                value=self.extract_result_from_csv(x, y, await r.text()),
+                timestamp=ts)
+
+        return result
+
+    @staticmethod
+    def extract_result_from_csv(x: float, y: float, csv_text: str) -> float | None:
+        f = StringIO(csv_text)
+        for row in csv.reader(f, delimiter=';'):
+            try:
+                if x == float(row[1]) and y == float(row[2]):
+                    return float(row[3])
+            except ValueError:
+                continue
+        return None
diff --git a/src/open_irceline/data.py b/src/open_irceline/data.py
index 58a7796..9045151 100644
--- a/src/open_irceline/data.py
+++ b/src/open_irceline/data.py
@@ -1,6 +1,6 @@
+from datetime import datetime, date
 from enum import StrEnum
 from typing import TypedDict
-from datetime import datetime, date
 
 
 class RioFeature(StrEnum):
@@ -26,6 +26,13 @@ class RioFeature(StrEnum):
     SO2_HMEAN = 'rio:so2_hmean'
 
 
+class ForecastFeature(StrEnum):
+    NO2_MAXHMEAN = 'chimere_no2_maxhmean'
+    O3_MAXHMEAN = 'chimere_o3_maxhmean'
+    PM10_DMEAN = 'chimere_pm10_dmean'
+    PM25_DMEAN = 'chimere_pm25_dmean'
+
+
 class FeatureValue(TypedDict):
     timestamp: datetime | date
     value: int | float | None