#!/usr/bin/env python3
"""Poll Eesti.ee Sitrep API and write events to an RSS feed file."""

import sys
import time
from datetime import datetime, timezone
from xml.sax.saxutils import escape

import requests

API_URL = "https://api.app.eesti.ee/api/sitrep/v1/full-events"
OUTPUT_FILE = "sitrep_feed.xml"
POLL_INTERVAL = 300  # seconds
FEED_TITLE = "Eesti.ee Sitrep Events"
FEED_DESC = "Estonian situational awareness (Sitrep) emergency events"
FEED_LINK = "https://api.app.eesti.ee"


def format_rfc822(dt_str: str) -> str:
    dt = datetime.fromisoformat(dt_str.replace("Z", "+00:00"))
    return dt.strftime("%a, %d %b %Y %H:%M:%S %z")


def text_for_lang(content_list: list, lang: str) -> str:
    for item in content_list:
        if item.get("languageCode") == lang:
            return item.get("text", "")
    for item in content_list:
        return item.get("text", "")
    return ""


def title_for_lang(content_list: list, lang: str) -> str:
    for item in content_list:
        if item.get("languageCode") == lang:
            return item.get("title", "") or ""
    for item in content_list:
        return item.get("title", "") or ""
    return ""


def build_feed_xml(events: list) -> str:
    now_rfc822 = format_rfc822(datetime.now(timezone.utc).isoformat())

    lines = [
        '<?xml version="1.0" encoding="utf-8"?>',
        '<rss version="2.0">',
        '  <channel>',
        f"    <title>{escape(FEED_TITLE)}</title>",
        f"    <link>{escape(FEED_LINK)}</link>",
        f"    <description>{escape(FEED_DESC)}</description>",
        f"    <lastBuildDate>{now_rfc822}</lastBuildDate>",
    ]

    seen = set()

    for event in events:
        data = event.get("data", {})
        ev = data.get("event", {})
        alerts = data.get("alerts", [])

        for alert in alerts:
            if alert.get("type") != "MASS_SMS":
                continue
            content = alert.get("content", [])
            if not any(c.get("text") for c in content):
                continue
            alert_text = text_for_lang(content, "et") or text_for_lang(content, "en")
            key = (ev.get("id"), alert_text)
            if key in seen:
                continue
            seen.add(key)

            alert_title = title_for_lang(content, "et") or title_for_lang(content, "en")
            locs = [l.get("settlementUnit", "") for l in alert.get("ehakLocations", [])]
            state = alert.get("state", "")
            atype = alert.get("type", "")

            item_title = ev.get("title", "Untitled Event")
            if alert_title:
                item_title = f"{item_title} — {alert_title}"
            elif atype:
                item_title = f"{item_title} — {atype}"

            lines.append("    <item>")
            lines.append(f"      <title>{escape(item_title)}</title>")
            lines.append(f"      <link>{escape(FEED_LINK)}</link>")
            lines.append(f'      <guid isPermaLink="false">{alert.get("id", "")}</guid>')

            start = alert.get("startDate", "") or ev.get("startDate", "")
            if start:
                lines.append(f"      <pubDate>{format_rfc822(start)}</pubDate>")

            desc_parts = [alert_text]
            if locs:
                desc_parts.append(f"Affected areas: {', '.join(locs)}")

            lines.append(f"      <description>{escape('<br>'.join(desc_parts))}</description>")
            lines.append(f"      <category>{escape(f'{atype}, {state}')}</category>")
            lines.append("    </item>")

    lines.append("  </channel>")
    lines.append("</rss>")
    return "\n".join(lines) + "\n"


def main():
    last_etag = None

    while True:
        try:
            headers = {"Accept-Language": "et"}
            if last_etag:
                headers["If-None-Match"] = last_etag

            resp = requests.get(API_URL, headers=headers, timeout=30)
            if resp.status_code == 304:
                print(f"[{datetime.now():%H:%M:%S}] No changes (304)")
            elif resp.status_code == 200:
                events = resp.json()
                xml = build_feed_xml(events)
                with open(OUTPUT_FILE, "w", encoding="utf-8") as f:
                    f.write(xml)
                print(f"[{datetime.now():%H:%M:%S}] Wrote {len(events)} events to {OUTPUT_FILE}")
            else:
                print(f"[{datetime.now():%H:%M:%S}] HTTP {resp.status_code}")

            last_etag = resp.headers.get("ETag")
        except Exception as e:
            print(f"[{datetime.now():%H:%M:%S}] Error: {e}", file=sys.stderr)

        time.sleep(POLL_INTERVAL)


if __name__ == "__main__":
    main()