#!/usr/bin/env python3
"""Race Radar — static page generator.

Reads a local JSON file of upcoming endurance races and renders a single
self-contained marketing/SEO page that funnels visitors to an AI training
plan coach. Zero dependencies: python3 stdlib only. Atomic writes. Every
JSON-derived string is HTML-escaped before it reaches the page.
"""
import argparse
import datetime as dt
import html
import json
import os
import sys
import tempfile

TARGET_SITE = "https://aitrainingplan.app/"
GUIDE_BASE = "https://aitrainingplan.app/en/learn/guides/"
GUIDE_703 = GUIDE_BASE + "half-ironman-training-plan/"
GUIDE_1406 = GUIDE_BASE + "ironman-training-plan/"
PROMPT_BUILDER = "https://aitrainingplan.app/en/tools/prompt-builder/"


def days_until(race_date: str, today: dt.date) -> int:
    """Calendar-day difference; race_date is treated as a local calendar date."""
    race = dt.date.fromisoformat(race_date)
    return (race - today).days


def window_status(days_left: int, plan_weeks: int) -> tuple[str, str]:
    if days_left < 0:
        return ("past", "")
    if days_left == 0:
        return ("race", "Race day.")
    if 1 <= days_left <= 7:
        return ("race", "Race week — taper, hydrate, trust the block.")
    weeks = days_left // 7
    if weeks >= plan_weeks:
        return ("full", f"A full {plan_weeks}-week plan still fits. Start this week.")
    # integer-exact ceil(0.6*plan_weeks): 0.6*20 floats to 12.000000000000002
    if weeks >= (6 * plan_weeks + 9) // 10:
        return ("tight", f"{weeks} of the ideal {plan_weeks} weeks left — compressed but coachable.")
    return ("short", f"{weeks} weeks left — target a tune-up distance or lock the next edition.")


def fmt_date(d: dt.date) -> str:
    return f"{d.strftime('%a')} {d.day} {d.strftime('%b')} {d.year}"


def guide_url(sport: str) -> str:
    if sport == "703":
        return GUIDE_703
    if sport == "140.6":
        return GUIDE_1406
    return GUIDE_BASE


def safe_url(url: str) -> str:
    url = str(url or "")
    return url if url.startswith("https://") else ""


def build_race_cards(raw_races: list, today: dt.date) -> list:
    """Normalize + escape every field, drop past races, sort by date asc."""
    cards = []
    for r in raw_races:
        if not isinstance(r, dict):
            continue
        date_s = str(r.get("date", ""))
        try:
            days_left = days_until(date_s, today)
            race_date = dt.date.fromisoformat(date_s)
        except (ValueError, TypeError):
            continue  # unparseable entry — skip it, don't blow up the whole page
        if days_left < 0:
            continue  # renderer drops past races
        try:
            plan_weeks = int(r.get("plan_weeks", 12))
        except (ValueError, TypeError):
            plan_weeks = 12
        css_class, message = window_status(days_left, plan_weeks)
        weeks, rem_days = divmod(days_left, 7)
        sport = html.escape(str(r.get("sport", "")))
        cards.append({
            "name": html.escape(str(r.get("name", "Untitled race"))),
            "city": html.escape(str(r.get("city", ""))),
            "flag": html.escape(str(r.get("country_flag", ""))),
            "distance_label": html.escape(str(r.get("distance_label", ""))),
            "sport_raw": str(r.get("sport", "")),
            "sport": sport,
            "url": html.escape(safe_url(r.get("url", ""))),
            "date_iso": date_s,
            "date_text": fmt_date(race_date),
            "days_left": days_left,
            "weeks": weeks,
            "rem_days": rem_days,
            "plan_weeks": plan_weeks,
            "css_class": css_class,
            "message": message,
        })
    cards.sort(key=lambda c: c["date_iso"])
    return cards


CSS = """
:root{color-scheme:dark;}
*{box-sizing:border-box;margin:0;padding:0;}
body{background:#0b0f14;color:#e8ecef;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;line-height:1.5;padding:0 1.25rem 3rem;}
a{color:#c8f55a;}
main{max-width:1100px;margin:0 auto;}
.hero{padding:4rem 0 2.5rem;text-align:center;}
.kicker{letter-spacing:.2em;font-size:.8rem;font-weight:700;color:#c8f55a;margin-bottom:1rem;}
h1{font-size:clamp(2rem,5vw,3.2rem);font-weight:800;max-width:18ch;margin:0 auto 1rem;}
.subline{color:#9aa5ad;font-size:1.05rem;margin-bottom:2rem;}
.btn{display:inline-block;background:#c8f55a;color:#0b0f14;font-weight:700;text-decoration:none;padding:.9rem 1.6rem;border-radius:.6rem;transition:transform .15s ease;}
.btn:hover{transform:translateY(-2px);}
.btn.secondary{background:transparent;color:#e8ecef;border:1px solid #2a333c;}
.grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(340px,1fr));gap:1.25rem;margin:2rem 0;}
.card{background:#121820;border:1px solid #1e2731;border-top:3px solid #2a333c;border-radius:.9rem;padding:1.5rem;display:flex;flex-direction:column;gap:.6rem;}
.card.full{border-top-color:#c8f55a;}
.card.tight{border-top-color:#f5c542;}
.card.race{border-top-color:#ff6b6b;}
.card.short{border-top-color:#7dd3fc;}
.card-head{display:flex;align-items:baseline;gap:.6rem;}
.flag{font-size:1.4rem;}
.card-head h2{font-size:1.15rem;font-weight:700;}
.meta{color:#9aa5ad;font-size:.9rem;}
.days-num{font-size:2.1rem;font-weight:800;color:#e8ecef;}
.days-weeks{color:#9aa5ad;font-size:.85rem;}
.badge{display:inline-block;padding:.35em .8em;border-radius:999px;font-weight:600;font-size:.85rem;border:1px solid currentColor;width:fit-content;}
.badge-full{color:#c8f55a;}
.badge-tight{color:#f5c542;}
.badge-race{color:#ff6b6b;}
.badge-short{color:#7dd3fc;}
.distance{color:#9aa5ad;font-size:.9rem;}
.links{display:flex;gap:1rem;flex-wrap:wrap;font-size:.9rem;margin-top:.3rem;}
.empty{color:#9aa5ad;padding:2rem 0;}
.note{color:#6b747c;font-size:.85rem;border-top:1px solid #1e2731;border-bottom:1px solid #1e2731;padding:1.25rem 0;margin:2rem 0;}
.cta-block{text-align:center;padding:3rem 0;}
.cta-block p{font-size:1.3rem;font-weight:700;margin-bottom:1.5rem;max-width:24ch;margin-left:auto;margin-right:auto;}
.cta-buttons{display:flex;gap:1rem;justify-content:center;flex-wrap:wrap;}
footer{color:#6b747c;font-size:.8rem;text-align:center;padding-top:2rem;}
footer a{color:#6b747c;text-decoration:underline;}
"""


def card_html(c: dict) -> str:
    site_link = ""
    if c["url"]:
        site_link = f'<a href="{c["url"]}" target="_blank" rel="noopener noreferrer">official site →</a>'
    return f"""<article class="card {c['css_class']}" data-date="{c['date_iso']}" data-plan-weeks="{c['plan_weeks']}">
<div class="card-head"><span class="flag">{c['flag']}</span><h2>{c['name']}</h2></div>
<p class="meta">{c['city']} · {c['date_text']}</p>
<p><span class="days-num">{c['days_left']} day{'s' if c['days_left'] != 1 else ''}</span></p>
<p class="days-weeks">= {c['weeks']} week{'s' if c['weeks'] != 1 else ''} {c['rem_days']} day{'s' if c['rem_days'] != 1 else ''}</p>
<p class="badge badge-{c['css_class']}">{c['message']}</p>
<p class="distance">{c['distance_label']}</p>
<div class="links"><a href="{guide_url(c['sport_raw'])}" target="_blank" rel="noopener noreferrer">training guide →</a>{site_link}</div>
</article>"""


JS = """
(function(){
// calendar-day count in the VISITOR's local calendar, DST-proof:
// both endpoints are Y/M/D projected to UTC midnight, so the diff is an
// exact multiple of 86400000. Never new Date("YYYY-MM-DD") — that parses
// as UTC midnight and shifts a day for visitors west of Greenwich.
var now=new Date();
var todayUTC=Date.UTC(now.getFullYear(),now.getMonth(),now.getDate());
var cards=document.querySelectorAll('[data-date]');
for(var i=0;i<cards.length;i++){
  var c=cards[i];
  var p=c.getAttribute('data-date').split('-');
  var raceUTC=Date.UTC(+p[0],+p[1]-1,+p[2]);
  var days=Math.round((raceUTC-todayUTC)/86400000);
  if(days<0)days=0;
  var label=days+' day'+(days===1?'':'s');
  if(days>0&&days<14){
    var hours=Math.round((new Date(+p[0],+p[1]-1,+p[2])-now)/3600000);
    if(hours>0)label+=' \\u00b7 ~'+hours+'h';
  }
  var num=c.querySelector('.days-num');
  if(num)num.textContent=label;
  var wk=c.querySelector('.days-weeks');
  if(wk){
    var w=Math.floor(days/7),d=days%7;
    wk.textContent='= '+w+' week'+(w===1?'':'s')+' '+d+' day'+(d===1?'':'s');
  }
}
})();
"""


def render(cards: list, today: dt.date) -> str:
    count = len(cards)
    generated = dt.datetime.now(dt.timezone.utc).strftime("%Y-%m-%d %H:%M UTC")
    if cards:
        grid = "\n".join(card_html(c) for c in cards)
    else:
        grid = '<p class="empty">No upcoming start lines tracked right now — check back soon.</p>'
    return f"""<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<meta name="description" content="Every major endurance start line, live countdowns, and whether a full training block still fits — updated daily.">
<meta http-equiv="Content-Security-Policy" content="default-src 'none'; style-src 'unsafe-inline'; script-src 'unsafe-inline'">
<title>Race Radar — how many training weeks until your start line?</title>
<style>{CSS}</style>
</head>
<body>
<main>
<section class="hero">
<p class="kicker">RACE RADAR</p>
<h1>Your start line is closer than you think.</h1>
<p class="subline">As of {fmt_date(today)} · {count} start line{'s' if count != 1 else ''} tracked · countdowns update daily</p>
<a class="btn" href="{TARGET_SITE}" target="_blank" rel="noopener noreferrer">Get an AI plan that fits the weeks you have left →</a>
</section>
<section class="grid">
{grid}
</section>
<p class="note">Dates verified against official race sites. Regenerated automatically — this page can't go stale.</p>
<section class="cta-block">
<p>However many weeks you have, there's a right plan for them.</p>
<div class="cta-buttons">
<a class="btn" href="{TARGET_SITE}" target="_blank" rel="noopener noreferrer">Build my plan</a>
<a class="btn secondary" href="{PROMPT_BUILDER}" target="_blank" rel="noopener noreferrer">Try the prompt builder</a>
</div>
</section>
<footer>Generated {generated} · refreshes daily · <a href="source.py.txt">view the generator source</a> · Independent concept page for AiTrainingPlan — not affiliated.</footer>
</main>
<script>{JS}</script>
</body>
</html>"""


def atomic_write(path: str, content: str) -> None:
    d = os.path.dirname(os.path.abspath(path)) or "."
    fd, tmp = tempfile.mkstemp(dir=d, suffix=".tmp")
    try:
        with os.fdopen(fd, "w", encoding="utf-8") as f:
            f.write(content)
        os.replace(tmp, path)  # atomic: a failed run can never blank the live page
    finally:
        if os.path.exists(tmp):
            os.unlink(tmp)


def main() -> int:
    ap = argparse.ArgumentParser()
    ap.add_argument("--out", required=True)
    ap.add_argument("--races", default="races.json", help="path to races JSON array")
    ap.add_argument("--date", help="YYYY-MM-DD override for testing edge days")
    a = ap.parse_args()
    today = dt.date.fromisoformat(a.date) if a.date else dt.datetime.now(dt.timezone.utc).date()

    try:
        with open(a.races, encoding="utf-8") as f:
            raw = json.load(f)
        if not isinstance(raw, list):
            raise ValueError("races file must contain a JSON array")
    except Exception as e:
        print(f"ERROR: could not load races file '{a.races}': {e}", file=sys.stderr)
        return 1  # never write — last good page survives

    cards = build_race_cards(raw, today)
    atomic_write(a.out, render(cards, today))
    print(f"OK wrote {a.out} ({len(cards)} races rendered)")
    return 0


if __name__ == "__main__":
    sys.exit(main())