"use client";

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

interface Props { destinations: Destination[] }

export default function Calculator({ destinations }: Props) {
  const { t } = useI18n();
  const { toast } = useToast();
  const [slug, setSlug] = useState(destinations[0]?.slug || "");
  const [housing, setHousing] = useState("mid");
  const [months, setMonths] = useState(3);
  const [result, setResult] = useState<CostResult | null>(null);
  const [loading, setLoading] = useState(false);

  const selected = destinations.find((d) => d.slug === slug);

  const calculate = async () => {
    setLoading(true);
    try {
      const data = await api.calculateCost({ destination_slug: slug, housing, months });
      setResult(data);
    } catch {
      setResult(null);
    } finally {
      setLoading(false);
    }
  };

  const addToPlan = () => {
    if (!selected) return;
    const { added } = mergeDestinationsIntoTrip([selected], months);
    toast(
      added
        ? t.common.addedToPlanMonths
            .replace("{emoji}", selected.emoji)
            .replace("{city}", selected.name)
            .replace("{months}", String(months))
        : t.common.alreadyInPlan,
      added ? "success" : "info",
      { href: "/plan", label: t.strip.openPlan }
    );
  };

  return (
    <section className="section calculator-section" id="calculator">
      <div className="container">
        <div className="section-header reveal">
          <span className="section-tag">🧮 CALCULATOR</span>
          <h2>旅居费用计算器</h2>
          <p>根据目的地和生活方式，精准估算你的旅居预算</p>
        </div>
        <div className="calculator-wrapper reveal">
          <div className="calculator-form">
            <div className="calc-field">
              <label>🏙️ 目的地</label>
              <select value={slug} onChange={(e) => setSlug(e.target.value)}>
                {destinations.map((d) => (
                  <option key={d.slug} value={d.slug}>{d.emoji} {d.name}, {d.country}</option>
                ))}
              </select>
            </div>
            <div className="calc-field">
              <label>🏠 住宿档次</label>
              <div className="calc-options">
                {[{ v: "budget", l: "💰 经济" }, { v: "mid", l: "🏠 舒适" }, { v: "premium", l: "✨ 豪华" }].map((o) => (
                  <button key={o.v} className={`calc-option${housing === o.v ? " active" : ""}`}
                    onClick={() => setHousing(o.v)}>{o.l}</button>
                ))}
              </div>
            </div>
            <div className="calc-field">
              <label>📅 旅居月数: {months} 个月</label>
              <input type="range" min={1} max={12} value={months} onChange={(e) => setMonths(+e.target.value)} />
            </div>
            <button className="btn btn-primary" onClick={calculate} disabled={loading}>
              {loading ? "计算中..." : "🧮 开始计算"}
            </button>
          </div>
          <div className="calculator-result">
            {result ? (
              <div className="result-card">
                <div className="result-header">
                  <span style={{ fontSize: "3rem" }}>{result.emoji}</span>
                  <div>
                    <h3>{result.destination}</h3>
                    <p>{result.months} 个月旅居预算</p>
                  </div>
                </div>
                <div className="result-breakdown">
                  {Object.entries(result.breakdown).map(([k, v]) => (
                    <div key={k} className="breakdown-item">
                      <span>{k}</span>
                      <div className="breakdown-bar">
                        <div className="breakdown-fill" style={{ width: `${(v / result.per_month) * 100}%` }} />
                      </div>
                      <strong>¥{v.toLocaleString()}</strong>
                    </div>
                  ))}
                </div>
                <div className="result-total">
                  <div><span>月均</span><strong>¥{result.per_month.toLocaleString()}</strong></div>
                  <div><span>总计</span><strong className="gradient-text">¥{result.total.toLocaleString()}</strong></div>
                </div>
                {selected && (
                  <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/${selected.slug}`} className="btn btn-sm">
                      {t.common.detail}
                    </Link>
                    <Link href={meetupCityHref(selected.name)} className="btn btn-sm btn-ghost">
                      {t.common.cityMeetups}
                    </Link>
                  </div>
                )}
              </div>
            ) : (
              <div className="result-placeholder">
                <span style={{ fontSize: "4rem" }}>🧮</span>
                <p>选择目的地和参数，点击计算查看预算明细</p>
              </div>
            )}
          </div>
        </div>
      </div>
    </section>
  );
}