"use client";

import { useState } from "react";

import type { NeighborsSummary } from "@/types/site-finder";

interface Props {
  data: NeighborsSummary;
}

function fmtPrice(n: number | null | undefined): string {
  if (n == null) return "—";
  if (n >= 1000) {
    return `${(n / 1000).toFixed(0)} тыс ₽/м²`;
  }
  return `${n.toLocaleString("ru-RU")} ₽/м²`;
}

function fmtYearBuilt(y: number | null | undefined): string {
  if (y == null || y === 0) return "—";
  return String(y);
}

// Русский plural: 1 → "здание", 2-4 → "здания", 5+ → "зданий".
// Также корректно для 11-14 (zданий), 21 (здание), 22 (здания) etc.
function pluralBuildings(n: number): string {
  const mod10 = n % 10;
  const mod100 = n % 100;
  if (mod100 >= 11 && mod100 <= 14) return "зданий";
  if (mod10 === 1) return "здание";
  if (mod10 >= 2 && mod10 <= 4) return "здания";
  return "зданий";
}

export function NeighborsBlock({ data }: Props) {
  const [expanded, setExpanded] = useState(false);

  if (!data.data_available) {
    return (
      <div
        style={{
          border: "1px solid #e5e7eb",
          borderRadius: 10,
          padding: "12px 16px",
          background: "#f9fafb",
        }}
      >
        <div
          style={{
            fontSize: 12,
            fontWeight: 600,
            color: "#6b7280",
            textTransform: "uppercase",
            letterSpacing: "0.05em",
            marginBottom: 6,
          }}
        >
          Соседи (100 м)
        </div>
        <div style={{ fontSize: 12, color: "#9ca3af" }}>
          {data.note ?? "Данные о соседних зданиях недоступны"}
        </div>
      </div>
    );
  }

  const count = data.count_buildings_100m ?? 0;
  const hasOverlap = !!data.has_existing_buildings;

  return (
    <div
      style={{
        border: hasOverlap ? "1px solid #fca5a5" : "1px solid #e5e7eb",
        background: "#fff",
        borderRadius: 10,
        padding: "14px 18px",
        display: "flex",
        flexDirection: "column",
        gap: 12,
      }}
    >
      <div
        style={{
          display: "flex",
          alignItems: "center",
          justifyContent: "space-between",
          gap: 12,
        }}
      >
        <span
          style={{
            fontSize: 11,
            fontWeight: 700,
            color: "#6b7280",
            textTransform: "uppercase",
            letterSpacing: "0.06em",
          }}
        >
          Соседи (100 м)
        </span>
        <span
          style={{
            fontSize: 12,
            color: "#374151",
            fontVariantNumeric: "tabular-nums",
          }}
        >
          {count} {pluralBuildings(count)}
        </span>
      </div>

      {/* Overlap warning — hard warn */}
      {hasOverlap &&
        data.overlap_buildings &&
        data.overlap_buildings.length > 0 && (
          <div
            style={{
              padding: "10px 14px",
              background: "#fee2e2",
              border: "1px solid #fca5a5",
              borderRadius: 8,
              color: "#b91c1c",
              fontSize: 13,
            }}
          >
            <div style={{ fontWeight: 700, marginBottom: 4 }}>
              На участке уже есть здания (overlap &gt;50 м²)
            </div>
            <ul
              style={{
                margin: 0,
                paddingLeft: 18,
                fontSize: 12,
                lineHeight: 1.5,
              }}
            >
              {data.overlap_buildings.map((b) => (
                <li key={b.cad_num}>
                  {b.building_name ?? b.readable_address ?? b.cad_num}
                  {b.floors ? `, ${b.floors} эт.` : ""}
                  {b.overlap_m2 ? ` — пересечение ~${b.overlap_m2} м²` : ""}
                </li>
              ))}
            </ul>
            <div style={{ marginTop: 6, fontSize: 11, fontStyle: "italic" }}>
              Инвестиции невозможны без сноса.
            </div>
          </div>
        )}

      {/* Summary metrics */}
      {count > 0 && (
        <div
          style={{
            display: "grid",
            gridTemplateColumns: "repeat(auto-fit, minmax(130px, 1fr))",
            gap: 10,
            fontSize: 12,
            color: "#374151",
          }}
        >
          <div>
            <div style={{ color: "#9ca3af", fontSize: 11 }}>
              Средн. этажность
            </div>
            <div
              style={{
                fontWeight: 600,
                fontSize: 14,
                fontVariantNumeric: "tabular-nums",
              }}
            >
              {data.avg_floors_100m ?? "—"}
            </div>
          </div>
          <div>
            <div style={{ color: "#9ca3af", fontSize: 11 }}>Макс. этажей</div>
            <div
              style={{
                fontWeight: 600,
                fontSize: 14,
                fontVariantNumeric: "tabular-nums",
              }}
            >
              {data.max_floors_100m ?? "—"}
            </div>
          </div>
          <div>
            <div
              style={{ color: "#9ca3af", fontSize: 11 }}
              title="Медиана кадастровой стоимости / м² — proxy для «premium quarter»"
            >
              Медиана цены
            </div>
            <div
              style={{
                fontWeight: 600,
                fontSize: 14,
                fontVariantNumeric: "tabular-nums",
              }}
            >
              {fmtPrice(data.median_cost_per_m2_100m)}
            </div>
          </div>
        </div>
      )}

      {/* Toggle neighbor list */}
      {data.neighbors && data.neighbors.length > 0 && (
        <div>
          <button
            type="button"
            onClick={() => setExpanded((e) => !e)}
            aria-expanded={expanded}
            style={{
              background: "none",
              border: "none",
              padding: 0,
              color: "#1d4ed8",
              fontSize: 13,
              cursor: "pointer",
              fontWeight: 500,
            }}
          >
            {expanded
              ? "Скрыть список"
              : `Показать ${data.neighbors.length} ближайших`}
          </button>
          {expanded && (
            <div
              style={{
                marginTop: 10,
                maxHeight: 280,
                overflowY: "auto",
                border: "1px solid #f3f4f6",
                borderRadius: 6,
              }}
            >
              <table
                style={{
                  width: "100%",
                  borderCollapse: "collapse",
                  fontSize: 12,
                }}
              >
                <thead
                  style={{
                    background: "#f9fafb",
                    position: "sticky",
                    top: 0,
                  }}
                >
                  <tr>
                    <th
                      style={{
                        padding: "6px 10px",
                        textAlign: "left",
                        color: "#6b7280",
                        fontWeight: 500,
                      }}
                    >
                      Здание
                    </th>
                    <th
                      style={{
                        padding: "6px 10px",
                        textAlign: "right",
                        color: "#6b7280",
                        fontWeight: 500,
                      }}
                    >
                      Эт.
                    </th>
                    <th
                      style={{
                        padding: "6px 10px",
                        textAlign: "right",
                        color: "#6b7280",
                        fontWeight: 500,
                      }}
                    >
                      Год
                    </th>
                    <th
                      style={{
                        padding: "6px 10px",
                        textAlign: "right",
                        color: "#6b7280",
                        fontWeight: 500,
                      }}
                    >
                      ₽/м²
                    </th>
                    <th
                      style={{
                        padding: "6px 10px",
                        textAlign: "right",
                        color: "#6b7280",
                        fontWeight: 500,
                      }}
                    >
                      Дист.
                    </th>
                  </tr>
                </thead>
                <tbody>
                  {data.neighbors.map((n) => (
                    <tr
                      key={n.cad_num}
                      style={{ borderTop: "1px solid #f3f4f6" }}
                    >
                      <td style={{ padding: "6px 10px", color: "#374151" }}>
                        {n.building_name ?? n.readable_address ?? n.cad_num}
                      </td>
                      <td
                        style={{
                          padding: "6px 10px",
                          textAlign: "right",
                          color: "#374151",
                          fontVariantNumeric: "tabular-nums",
                        }}
                      >
                        {n.floors ?? "—"}
                      </td>
                      <td
                        style={{
                          padding: "6px 10px",
                          textAlign: "right",
                          color: "#6b7280",
                          fontVariantNumeric: "tabular-nums",
                        }}
                      >
                        {fmtYearBuilt(n.year_built)}
                      </td>
                      <td
                        style={{
                          padding: "6px 10px",
                          textAlign: "right",
                          color: "#374151",
                          fontVariantNumeric: "tabular-nums",
                        }}
                      >
                        {fmtPrice(n.cost_per_m2)}
                      </td>
                      <td
                        style={{
                          padding: "6px 10px",
                          textAlign: "right",
                          color: "#6b7280",
                          fontVariantNumeric: "tabular-nums",
                        }}
                      >
                        {n.distance_m} м
                      </td>
                    </tr>
                  ))}
                </tbody>
              </table>
            </div>
          )}
        </div>
      )}

      {data.note && (
        <div style={{ fontSize: 11, color: "#9ca3af", fontStyle: "italic" }}>
          {data.note}
        </div>
      )}
    </div>
  );
}