"use client";
import type { ValuationResponse } from "@/types/api";
import { deltaClass, fmtCurrency, fmtLarge, fmtPct } from "@/lib/format";

type Props = { data: ValuationResponse };

function pctVsCurrent(implied?: number | null, current?: number | null): number | null {
  if (implied == null || current == null || current === 0) return null;
  return (implied - current) / current;
}

function SummaryChip({
  label,
  price,
  current,
  accent = false,
}: {
  label: string;
  price?: number | null;
  current?: number | null;
  accent?: boolean;
}) {
  const pct = pctVsCurrent(price, current);
  return (
    <div className={`psm-val-chip${accent ? " accent" : ""}`}>
      <span className="psm-val-chip-label">{label}</span>
      <span className="psm-val-chip-price">{price != null ? fmtCurrency(price) : "—"}</span>
      {pct != null && (
        <span className={`psm-val-chip-pct ${deltaClass(pct)}`}>{fmtPct(pct, 1, true)}</span>
      )}
    </div>
  );
}

function MultipleRow({
  label,
  multiple,
  price,
  current,
}: {
  label: string;
  multiple?: number | null;
  price?: number | null;
  current?: number | null;
}) {
  const pct = pctVsCurrent(price, current);
  return (
    <div className="psm-val-mult-row">
      <span className="psm-val-mult-label">{label}</span>
      <span className="psm-val-mult-x">{multiple != null ? `${multiple.toFixed(1)}×` : "—"}</span>
      <span className="psm-val-mult-price">{price != null ? fmtCurrency(price) : "—"}</span>
      <span className={`psm-val-mult-pct ${pct != null ? deltaClass(pct) : "neutral"}`}>
        {pct != null ? fmtPct(pct, 1, true) : "—"}
      </span>
    </div>
  );
}

export function ValuationCard({ data }: Props) {
  const { dcf, ev_ebitda, ev_revenue, price_to_book, current_price } = data;
  const dcfPrice = dcf.available && !dcf.error ? dcf.intrinsic_value_per_share : null;
  const hasMultiples = ev_ebitda.available || ev_revenue.available || price_to_book.available;

  return (
    <section className="psm-card psm-val-card">
      {/* Summary strip */}
      <div className="psm-val-strip">
        <div className="psm-val-chip accent">
          <span className="psm-val-chip-label">Market Price</span>
          <span className="psm-val-chip-price">
            {current_price != null ? fmtCurrency(current_price) : "—"}
          </span>
        </div>
        <SummaryChip label="DCF" price={dcfPrice} current={current_price} />
        <SummaryChip
          label="EV / EBITDA"
          price={ev_ebitda.available ? ev_ebitda.implied_price_per_share : null}
          current={current_price}
        />
        <SummaryChip
          label="EV / Revenue"
          price={ev_revenue.available ? ev_revenue.implied_price_per_share : null}
          current={current_price}
        />
        <SummaryChip
          label="P / Book"
          price={price_to_book.available ? price_to_book.implied_price_per_share : null}
          current={current_price}
        />
      </div>

      {/* DCF detail */}
      <div className="psm-val-section">
        <div className="psm-val-section-head">
          <span className="psm-eyebrow">Discounted Cash Flow</span>
          <span className="psm-val-wacc-note">
            WACC {(dcf.wacc * 100).toFixed(1)}% · Terminal {(dcf.terminal_growth * 100).toFixed(1)}%
          </span>
        </div>

        {!dcf.available && (
          <p className="psm-muted-copy">Insufficient free cash flow history for DCF.</p>
        )}
        {dcf.available && dcf.error && (
          <p className="psm-val-dcf-error">{dcf.error}</p>
        )}
        {dcf.available && !dcf.error && (
          <div className="psm-val-dcf-body">
            <div className="psm-val-kv-list">
              <div className="psm-val-kv-row">
                <span className="psm-val-kv-label">Base FCF (TTM)</span>
                <span className="psm-val-kv-val">{dcf.base_fcf != null ? fmtLarge(dcf.base_fcf) : "—"}</span>
              </div>
              <div className="psm-val-kv-row">
                <span className="psm-val-kv-label">Historical growth</span>
                <span className="psm-val-kv-val">
                  {dcf.growth_rate_used != null ? fmtPct(dcf.growth_rate_used) : "—"}
                </span>
              </div>
              <div className="psm-val-kv-row is-divider">
                <span className="psm-val-kv-label">Enterprise Value</span>
                <span className="psm-val-kv-val">
                  {dcf.enterprise_value != null ? fmtLarge(dcf.enterprise_value) : "—"}
                </span>
              </div>
              <div className="psm-val-kv-row">
                <span className="psm-val-kv-label">Net Debt</span>
                <span className="psm-val-kv-val">
                  {dcf.net_debt != null ? fmtLarge(dcf.net_debt) : "—"}
                </span>
              </div>
              <div className="psm-val-kv-row is-total">
                <span className="psm-val-kv-label">Equity Value</span>
                <span className="psm-val-kv-val">
                  {dcf.equity_value != null ? fmtLarge(dcf.equity_value) : "—"}
                </span>
              </div>
            </div>
            <div className="psm-val-intrinsic">
              <span className="psm-val-intrinsic-label">Intrinsic Value</span>
              <span className="psm-val-intrinsic-price">
                {dcf.intrinsic_value_per_share != null ? fmtCurrency(dcf.intrinsic_value_per_share) : "—"}
              </span>
              {data.shares_outstanding != null && (
                <span className="psm-val-intrinsic-shares">
                  {fmtLarge(data.shares_outstanding)} shares
                </span>
              )}
            </div>
          </div>
        )}
      </div>

      {/* Multiples */}
      {hasMultiples && (
        <div className="psm-val-section">
          <div className="psm-val-section-head">
            <span className="psm-eyebrow">Multiples — at current market multiple</span>
          </div>
          <div className="psm-val-mult-list">
            {ev_ebitda.available && (
              <MultipleRow
                label="EV / EBITDA"
                multiple={ev_ebitda.multiple_used}
                price={ev_ebitda.implied_price_per_share}
                current={current_price}
              />
            )}
            {ev_revenue.available && (
              <MultipleRow
                label="EV / Revenue"
                multiple={ev_revenue.multiple_used}
                price={ev_revenue.implied_price_per_share}
                current={current_price}
              />
            )}
            {price_to_book.available && (
              <MultipleRow
                label="P / Book"
                multiple={price_to_book.multiple_used}
                price={price_to_book.implied_price_per_share}
                current={current_price}
              />
            )}
          </div>
        </div>
      )}
    </section>
  );
}