"use client";

import { useMemo, useState } from "react";
import Link from "next/link";
import type { Destination } from "@/lib/types";
import { useI18n } from "@/lib/i18n";
import { useToast } from "@/lib/toast";
import { mergeDestinationsIntoTrip } from "@/lib/tripActions";
import { meetupCityHref } from "@/lib/meetupLinks";

/** First-month one-time + rent estimates in CNY. */
const LANDING: Record<string, { rent: number; depositMult: number; sim: number; transfer: number; misc: number }> = {
  chiangmai: { rent: 2800, depositMult: 1, sim: 80, transfer: 120, misc: 400 },
  bali: { rent: 3500, depositMult: 1, sim: 100, transfer: 200, misc: 500 },
  lisbon: { rent: 6500, depositMult: 2, sim: 150, transfer: 180, misc: 800 },
  barcelona: { rent: 7000, depositMult: 2, sim: 150, transfer: 200, misc: 900 },
  mexico: { rent: 4500, depositMult: 1, sim: 120, transfer: 250, misc: 600 },
  tokyo: { rent: 9000, depositMult: 2, sim: 200, transfer: 300, misc: 1200 },
};

interface Props {
  destinations: Destination[];
}

export default function FirstMonthCost({ destinations }: Props) {
  const { t } = useI18n();
  const { toast } = useToast();
  const [slug, setSlug] = useState(destinations[0]?.slug || "chiangmai");
  const [housing, setHousing] = useState<"budget" | "mid" | "nice">("mid");
  const [includeDeposit, setIncludeDeposit] = useState(true);

  const base = LANDING[slug] || { rent: 4000, depositMult: 1, sim: 100, transfer: 150, misc: 500 };
  const dest = destinations.find((d) => d.slug === slug);
  const rentFactor = housing === "budget" ? 0.75 : housing === "nice" ? 1.35 : 1;

  const breakdown = useMemo(() => {
    const rent = Math.round(base.rent * rentFactor);
    const deposit = includeDeposit ? Math.round(rent * base.depositMult) : 0;
    const sim = base.sim;
    const transfer = base.transfer;
    const misc = Math.round(base.misc * rentFactor);
    const total = rent + deposit + sim + transfer + misc;
    return [
      { key: "rent", emoji: "🏡", label: "首月房租", amount: rent },
      { key: "deposit", emoji: "🔐", label: `押金 ×${base.depositMult}`, amount: deposit },
      { key: "sim", emoji: "📱", label: "上网卡", amount: sim },
      { key: "transfer", emoji: "🚕", label: "机场接驳", amount: transfer },
      { key: "misc", emoji: "🛒", label: "日用启动", amount: misc },
      { key: "total", emoji: "💳", label: "合计启动金", amount: total },
    ];
  }, [base, rentFactor, includeDeposit]);

  const total = breakdown.find((b) => b.key === "total")!.amount;
  const maxBar = Math.max(...breakdown.filter((b) => b.key !== "total").map((b) => b.amount), 1);

  const addToPlan = () => {
    if (!dest) return;
    const { added } = mergeDestinationsIntoTrip([dest], 1);
    toast(
      added ? `${dest.emoji} ${dest.name} ${t.plan.addedToPlan}` : t.common.alreadyInPlan,
      added ? "success" : "info",
      { href: "/plan", label: t.strip.openPlan }
    );
  };

  return (
    <section className="section firstmonth-section" id="first-month">
      <div className="container">
        <div className="section-header reveal">
          <span className="section-tag">🛬 FIRST MONTH</span>
          <h2>落地首月成本</h2>
          <p>房租、押金、SIM、接机一次算清，避免到了才慌</p>
        </div>

        <div className="firstmonth-card reveal">
          <div className="firstmonth-controls">
            <label>
              <span>城市</span>
              <select value={slug} onChange={(e) => setSlug(e.target.value)}>
                {destinations.map((d) => (
                  <option key={d.slug} value={d.slug}>{d.emoji} {d.name}</option>
                ))}
              </select>
            </label>
            <div className="firstmonth-housing">
              {([
                ["budget", "💰 经济"],
                ["mid", "🏠 舒适"],
                ["nice", "✨ 品质"],
              ] as const).map(([k, label]) => (
                <button
                  key={k}
                  type="button"
                  className={`firstmonth-chip${housing === k ? " active" : ""}`}
                  onClick={() => setHousing(k)}
                >
                  {label}
                </button>
              ))}
            </div>
            <label className="firstmonth-check">
              <input
                type="checkbox"
                checked={includeDeposit}
                onChange={(e) => setIncludeDeposit(e.target.checked)}
              />
              <span>计入押金（当地常见 {base.depositMult} 个月）</span>
            </label>
          </div>

          <div className="firstmonth-result">
            <div className="firstmonth-total">
              <small>{dest?.emoji} 建议准备</small>
              <strong>¥{total.toLocaleString()}</strong>
              <span>含首月硬成本，不含机票与签证费</span>
            </div>
            <div className="firstmonth-bars">
              {breakdown.filter((b) => b.key !== "total" && b.amount > 0).map((b) => (
                <div key={b.key} className="firstmonth-bar-row">
                  <span>{b.emoji} {b.label}</span>
                  <div className="firstmonth-bar-track">
                    <i style={{ width: `${(b.amount / maxBar) * 100}%` }} />
                  </div>
                  <em>¥{b.amount.toLocaleString()}</em>
                </div>
              ))}
            </div>
            {dest && (
              <div className="dating-empty-actions" style={{ marginTop: "1rem" }}>
                <button type="button" className="btn btn-primary btn-sm" onClick={addToPlan}>
                  🗓️ {t.nav.plan}
                </button>
                <Link href={`/destinations/${dest.slug}`} className="btn btn-sm">
                  {t.common.detail}
                </Link>
                <Link href={meetupCityHref(dest.name)} className="btn btn-sm btn-ghost">
                  {t.common.cityMeetups}
                </Link>
              </div>
            )}
          </div>
        </div>
      </div>
    </section>
  );
}