import { Fragment, useMemo, useState } from "react";
import {
  ChevronDown,
  ChevronRight,
  ChevronsDownUp,
  ListFilter,
  Search,
  X,
  ArrowUpRight,
} from "lucide-react";
import { Button } from "@/components/ui/button";
import { Input } from "@/components/ui/input";
import type { RegionalInventoryStats } from "../types";
import { Picker, unique, useMobile } from "./shared";
import { ExportButton } from "./export";
import { InventoryExplorer } from "./InventoryExplorer";
import {
  groupInventory,
  INVENTORY_TYPES,
  inventoryColumn,
  inventoryTotals,
  type InventoryScope,
} from "./inventory-view";

type Inspect = (scope: InventoryScope) => void;
export function InventoryNumber({
  rows,
  label,
  inspect,
}: {
  rows: RegionalInventoryStats[];
  label: string;
  inspect: Inspect;
}) {
  const total = inventoryTotals(rows);
  if (!total.quantity) return <span className="matrix-zero">0</span>;
  return (
    <div className="matrix-number">
      <button
        className="matrix-value"
        onClick={() => inspect({ rows, label })}
        aria-label={`${label}，库存 ${total.quantity} 台，查看构成`}
      >
        {total.quantity.toLocaleString()}
        <ArrowUpRight aria-hidden="true" />
      </button>
      {(total.pending > 0 || total.abnormal > 0) && (
        <div className="matrix-secondary">
          {total.pending > 0 && (
            <button
              onClick={() =>
                inspect({ rows, label, initialCategory: "Pending" })
              }
            >
              待交车 {total.pending}
            </button>
          )}
          {total.abnormal > 0 && (
            <button
              className="matrix-warning"
              onClick={() =>
                inspect({ rows, label, initialCategory: "Abnormal" })
              }
            >
              异动 {total.abnormal}
            </button>
          )}
        </div>
      )}
    </div>
  );
}
export function InventorySection({
  inventory,
  inspect,
  subject,
}: {
  subject: string | null;
  inventory: RegionalInventoryStats[];
  inspect: Inspect;
}) {
  const mobile = useMobile();
  const [query, setQuery] = useState("");
  const [filters, setFilters] = useState({ region: "", city: "", brand: "" });
  const [filterOpen, setFilterOpen] = useState(false);
  const [expanded, setExpanded] = useState<Set<string>>(new Set());
  const [expandedType, setExpandedType] = useState("");
  const filtered = useMemo(
    () =>
      inventory.filter(
        (row) =>
          Object.entries(filters).every(
            ([key, value]) =>
              !value || row[key as keyof typeof filters] === value,
          ) &&
          (!query.trim() ||
            [
              row.region,
              row.city,
              row.brand,
              row.type,
              row.model,
              inventoryColumn(row.type),
            ]
              .join(" ")
              .toLowerCase()
              .includes(query.trim().toLowerCase())),
      ),
    [inventory, filters, query],
  );
  const rows = filtered;
  const groups = groupInventory(rows, "region");
  const brands = unique(
    filtered
      .filter((row) => inventoryColumn(row.type) === expandedType)
      .map((row) => row.brand),
  );
  const hasBrandColumns = Boolean(expandedType) && brands.length > 0;
  const columns = INVENTORY_TYPES.flatMap((type) => [
    {
      key: type,
      title: expandedType === type && brands.length ? "小计" : type,
      type,
      brand: "",
    },
    ...(expandedType === type
      ? brands.map((brand) => ({
          key: `${type}-${brand}`,
          title: brand,
          type,
          brand,
        }))
      : []),
  ]);
  const activeCount = Object.values(filters).filter(Boolean).length;
  const total = inventoryTotals(rows);
  const toggleRegion = (region: string) =>
    setExpanded((old) => {
      const next = new Set(old);
      if (next.has(region)) next.delete(region);
      else next.add(region);
      return next;
    });
  const cellRows = (
    records: RegionalInventoryStats[],
    type: string,
    brand: string,
  ) =>
    records.filter(
      (row) =>
        inventoryColumn(row.type) === type && (!brand || row.brand === brand),
    );
  const renderCells = (records: RegionalInventoryStats[], label: string) => (
    <>
      <td className="matrix-total">
        <InventoryNumber rows={records} label={label} inspect={inspect} />
      </td>
      {columns.map((col) => (
        <td
          key={col.key}
          className={[
            col.brand ? "matrix-brand-cell" : "",
            expandedType === col.type ? "matrix-selected-column" : "",
          ]
            .filter(Boolean)
            .join(" ")}
        >
          <InventoryNumber
            rows={cellRows(records, col.type, col.brand)}
            label={[label, col.type, col.brand].filter(Boolean).join(" / ")}
            inspect={inspect}
          />
        </td>
      ))}
    </>
  );
  if (mobile)
    return <InventoryExplorer inventory={inventory} subject={subject} />;
  return (
    <section className="inventory-matrix" aria-label="库存统计">
      <header className="matrix-heading">
        <div>
          <h2>库存统计</h2>
          <p>地区 × 车型总览，展开城市核对库存</p>
        </div>
        <div className="matrix-heading-actions">
          <div className="matrix-header-total">
            <span>{query || activeCount ? "筛选库存" : "总库存"}</span>
            <InventoryNumber rows={rows} label="当前库存" inspect={inspect} />
          </div>
          <Button
            variant="outline"
            aria-expanded={filterOpen}
            onClick={() => setFilterOpen(!filterOpen)}
          >
            <ListFilter aria-hidden="true" />
            筛选{activeCount ? ` ${activeCount}` : ""}
          </Button>
        </div>
      </header>
      <div className="matrix-toolbar">
        <label className="matrix-search">
          <Search aria-hidden="true" />
          <Input
            value={query}
            onChange={(event) => setQuery(event.target.value)}
            placeholder="搜索区域、城市、品牌或型号"
            aria-label="搜索库存"
          />
          {query && (
            <button onClick={() => setQuery("")} aria-label="清空库存搜索">
              <X />
            </button>
          )}
        </label>
        <div className="matrix-tools">
          <Button
            variant="ghost"
            onClick={() =>
              setExpanded(
                expanded.size
                  ? new Set()
                  : new Set(groups.map((group) => group.name)),
              )
            }
          >
            <ChevronsDownUp aria-hidden="true" />
            {expanded.size ? "收起区域" : "展开区域"}
          </Button>
          <ExportButton
            rows={rows}
            columns={[
              { key: "region", label: "区域" },
              { key: "city", label: "城市" },
              { key: "brand", label: "品牌" },
              {
                key: "type",
                label: "车型",
                format: (value) => inventoryColumn(String(value)),
              },
              { key: "model", label: "原始型号" },
              { key: "quantity", label: "库存" },
              { key: "available", label: "可运营" },
              { key: "awaiting", label: "待运营" },
              { key: "abnormal", label: "异动" },
              { key: "pending", label: "待交车" },
            ]}
            filename="库存统计"
            sheetName="库存"
          />
        </div>
      </div>
      {filterOpen && (
        <div className="matrix-filters">
          <Picker
            label="区域"
            value={filters.region}
            values={unique(inventory.map((row) => row.region))}
            change={(region) =>
              setFilters((old) => ({ ...old, region, city: "" }))
            }
          />
          <Picker
            label="城市"
            value={filters.city}
            values={unique(
              inventory
                .filter(
                  (row) => !filters.region || row.region === filters.region,
                )
                .map((row) => row.city),
            )}
            change={(city) => setFilters((old) => ({ ...old, city }))}
          />
          <Picker
            label="品牌"
            value={filters.brand}
            values={unique(inventory.map((row) => row.brand))}
            change={(brand) => setFilters((old) => ({ ...old, brand }))}
          />
          <Button
            variant="ghost"
            onClick={() => {
              setFilters({ region: "", city: "", brand: "" });
              setQuery("");
            }}
          >
            重置筛选
          </Button>
        </div>
      )}
      {activeCount > 0 && (
        <div className="matrix-filter-summary">
          {Object.values(filters).filter(Boolean).join(" / ")}
          <button
            onClick={() => setFilters({ region: "", city: "", brand: "" })}
          >
            清除条件
          </button>
        </div>
      )}
      <div className="matrix-type-overview" aria-label="各车型库存总览">
        {INVENTORY_TYPES.map((type) => {
          const counts = inventoryTotals(cellRows(rows, type, ""));
          return (
            <button
              key={type}
              aria-pressed={expandedType === type}
              onClick={() => setExpandedType(expandedType === type ? "" : type)}
            >
              <span>
                {type}
                <ChevronDown aria-hidden="true" />
              </span>
              <strong>
                {counts.quantity.toLocaleString()}
                <small>台</small>
              </strong>
              <span>可运营 {counts.available.toLocaleString()}</span>
            </button>
          );
        })}
      </div>
      <div className="matrix-reading-guide">
        <span>地区合计与车型合计均为当前筛选范围</span>
        <span>点击车型展开品牌 · 点击数字查看明细</span>
      </div>
      {!rows.length ? (
        <div className="matrix-empty">
          <strong>暂无匹配库存</strong>
          <p>尝试切换车型或调整筛选条件</p>
          <Button
            variant="outline"
            onClick={() => {
              setQuery("");
              setFilters({ region: "", city: "", brand: "" });
            }}
          >
            查看全部库存
          </Button>
        </div>
      ) : (
        <div
          className="matrix-scroll"
          tabIndex={0}
          aria-label="库存矩阵，可横向滚动"
        >
          <table className="matrix-table">
            <caption className="sr-only">
              区域展开城市，车型展开品牌，点击库存数量查看构成与车辆明细
            </caption>
            <thead>
              <tr>
                <th
                  rowSpan={hasBrandColumns ? 2 : 1}
                  scope="col"
                  className="matrix-geography"
                >
                  区域 / 城市
                </th>
                <th
                  rowSpan={hasBrandColumns ? 2 : 1}
                  scope="col"
                  className="matrix-total"
                >
                  总库存
                </th>
                {INVENTORY_TYPES.map((type) => (
                  <th
                    key={type}
                    colSpan={expandedType === type ? 1 + brands.length : 1}
                    rowSpan={expandedType === type || !hasBrandColumns ? 1 : 2}
                    scope="colgroup"
                  >
                    <button
                      className="matrix-column-toggle"
                      aria-expanded={expandedType === type}
                      onClick={() =>
                        setExpandedType(expandedType === type ? "" : type)
                      }
                    >
                      {type}
                      {expandedType === type ? (
                        <ChevronDown />
                      ) : (
                        <ChevronRight />
                      )}
                    </button>
                  </th>
                ))}
              </tr>
              {hasBrandColumns && (
                <tr>
                  <th scope="col">小计</th>
                  {brands.map((brand) => (
                    <th key={brand} scope="col">
                      {brand}
                    </th>
                  ))}
                </tr>
              )}
            </thead>
            <tbody>
              {groups.map((group) => (
                <Fragment key={group.name}>
                  <tr className="matrix-region-row">
                    <th scope="row" className="matrix-geography">
                      <button
                        className="matrix-expand"
                        aria-expanded={expanded.has(group.name)}
                        onClick={() => toggleRegion(group.name)}
                      >
                        {expanded.has(group.name) ? (
                          <ChevronDown />
                        ) : (
                          <ChevronRight />
                        )}
                        {group.name}
                        <small>{group.cities.length} 城市</small>
                      </button>
                    </th>
                    {renderCells(
                      group.cities.flatMap((city) => city.rows),
                      group.name,
                    )}
                  </tr>
                  {expanded.has(group.name) &&
                    group.cities.map((city) => (
                      <tr key={city.key} className="matrix-city-row">
                        <th scope="row" className="matrix-geography">
                          <span>{city.name}</span>
                        </th>
                        {renderCells(city.rows, `${group.name} / ${city.name}`)}
                      </tr>
                    ))}
                </Fragment>
              ))}
            </tbody>
            <tfoot>
              <tr>
                <th scope="row" className="matrix-geography">
                  当前范围合计
                </th>
                {renderCells(rows, "当前库存合计")}
              </tr>
            </tfoot>
          </table>
        </div>
      )}
      <footer className="matrix-footer">
        <span>
          {groups.length} 个区域 ·{" "}
          {groups.reduce((sum, group) => sum + group.cities.length, 0)} 个城市 ·{" "}
          {total.quantity} 台
        </span>
        <span>异动、待交车已包含在库存中 ·「其他」包含挂车及未单列车型</span>
      </footer>
    </section>
  );
}