import json
import re

import pandas as pd
import requests
from bs4 import BeautifulSoup

# 市町村区のコード
AREA_CODE = "3820200"


def fetch_soup(url, parser="html.parser"):
    r = requests.get(url)
    r.raise_for_status()

    soup = BeautifulSoup(r.content, parser)

    return soup


def fetch_json(url):
    r = requests.get(url)
    r.raise_for_status()

    result = r.json()
    return result


def fetch_area(url):
    area_json = fetch_json(url)

    df_city = pd.DataFrame(area_json["class20s"]).T.add_prefix("city_")
    df_district = pd.DataFrame(area_json["class15s"]).T.drop("children", axis=1).add_prefix("district_")
    df_region = pd.DataFrame(area_json["class10s"]).T.drop("children", axis=1).add_prefix("region_")
    df_pref = pd.DataFrame(area_json["offices"]).T.drop("children", axis=1).add_prefix("pref_")

    merged_df = pd.merge(df_city, df_district, left_on="city_parent", right_index=True)
    merged_df = pd.merge(merged_df, df_region, left_on="district_parent", right_index=True)
    df_area = pd.merge(merged_df, df_pref, left_on="region_parent", right_index=True)

    return df_area


def extract_js_object(js_content):
    match = re.search(r"f\s*=\s*({[\s\S]*?})\s*,\s*A\s*=", js_content, re.DOTALL)
    if not match:
        print("オブジェクトが見つかりませんでした。")
        return None

    obj_content = re.sub(r"(\w+):", r'"\1":', match.group(1).replace("'", '"'))

    try:
        data = json.loads(obj_content)
        return data
    except json.JSONDecodeError as e:
        print(f"JSONデコードエラー: {e}")
        return None


def fetch_alert(url):
    soup = fetch_soup(url)

    contents = soup.find_all("script")[10]
    js_content = contents.encode("ascii").decode("unicode-escape")

    data = extract_js_object(js_content)

    df_alert = pd.DataFrame(data).T
    df_alert["name"] = df_alert["name1"] + df_alert["name2"]

    df_alert = df_alert.drop(["name1", "name2"], axis=1)

    return df_alert


if __name__ == "__main__":
    # エリア一覧作成
    area_url = "https://www.jma.go.jp/bosai/common/const/area.json"

    df_area = fetch_area(area_url)
    df_area

    # アラート一覧作成
    alert_url = f"https://www.jma.go.jp/bosai/warning/#area_type=class20s&area_code={AREA_CODE}&lang=ja"

    df_alert = fetch_alert(alert_url)
    df_alert

    # 市の情報抽出
    CITY_DATA = df_area.loc[AREA_CODE]

    region_url = f'https://www.jma.go.jp/bosai/warning/data/warning/{CITY_DATA["region_parent"]}.json'

    # アラート情報取得
    warning_json = fetch_json(region_url)

    data = warning_json["areaTypes"][1]["areas"]

    df_warning = pd.json_normalize(
        data,
        record_path="warnings",
        meta=["code"],
        record_prefix="warning_",
        errors="ignore",
    )

    # アラート一覧と結合
    merge_df = pd.merge(df_warning, df_alert, left_on="warning_code", right_index=True)

    # エリア一覧と結合
    df_status = pd.merge(merge_df, df_area, left_on="code", right_index=True)
    df_status

    df = df_status.loc[df_status["code"] == AREA_CODE].copy()
    df

    ts_date = pd.to_datetime(warning_json["reportDatetime"], errors="coerce").tz_localize(None)

    # 警報・注意報を表示
    print(ts_date.strftime("%Y-%m-%d %X"))
    print(f'\n{CITY_DATA["pref_name"]}{CITY_DATA["city_name"]}の気象警報・注意報\n')

    df["warning_attentions"] = df["warning_attentions"].fillna("")

    if df.empty:
        print("現在発表警報・注意報はありません。")
    else:
        for i, row in df.iterrows():
            n = len(row["warning_attentions"])
            attentions = "・".join(row["warning_attentions"]) if n > 0 else ""
            print(f"{row['name']} {attentions}".strip())
参考
