import { CRIMEAN_CITIES } from "../../constants/cities.js";
import React from "react";
import {
  getOrderGroupDeliveryHalfDay,
  getOrderGroupDeliveryStatusLabel,
  getOrderGroupDeliveryStatusTone,
  DRIVER_VISIBLE_DELIVERY_STATUSES,
  isOrderGroupVisibleToDriver,
  groupOrderGroupsByDate,
  parseGroupDate,
} from "../../services/orderGroupViews";
import { Badge } from "../UI/Badge";
import { Input } from "../UI/Input";
import { Select } from "../UI/Select";
import { Panel } from "../UI/Panel";

const CHEVRON_DOWN = (
  <svg width="16" height="16" viewBox="0 0 16 16" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
    <path d="M4 6l4 4 4-4" />
  </svg>
);
const CHEVRON_RIGHT = (
  <svg width="16" height="16" viewBox="0 0 16 16" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
    <path d="M6 4l4 4-4 4" />
  </svg>
);

const extractCity = (address) => {
  if (!address || typeof address !== "string") return null;
  const trimmed = address.trim();
  if (!trimmed) return null;

  const cityMatch = trimmed.match(/(?:г\.\s+|гор\.\s+|пос\.\s+|с\.\s+|дер\.\s+|пгт\.\s+|город\s+|село\s+|г\s+)([А-ЯЁA-Z][а-яёa-zA-Z\s\-]+?)(?:\s*[,;.]|\s|$)/i);
  if (cityMatch) {
    return cityMatch[1].trim();
  }


  for (const city of CRIMEAN_CITIES) {
    if (trimmed.toLowerCase().includes(city.toLowerCase())) {
      return city;
    }
  }

  // Бахчисарайский р-н → Бахчисарай
  const district = trimmed.match(/([А-ЯЁа-яё]+)ский\s*(?:р-н|район)/i);
  if (district) {
    const base = district[1];
    for (const city of CRIMEAN_CITIES) {
      if (city.toLowerCase().startsWith(base.toLowerCase())) return city;
    }
  }

  // no match → null (caller falls back to Севастополь)
  return null;
};

const normalizeCity = (address) => {
  const city = extractCity(address);
  return city || "Севастополь";
};

const DRIVER_DELIVERY_STATUS_OPTIONS = [
  { value: "all", label: "Все статусы" },
  ...DRIVER_VISIBLE_DELIVERY_STATUSES.map((status) => ({
    value: status,
    label: status === "driver_assigned" ? "Назначено вам" : getOrderGroupDeliveryStatusLabel(status),
  })),
];

const pluralGroups = (n) => {
  if (n === 1) return "группа";
  if (n >= 2 && n < 5) return "группы";
  return "групп";
};

/** Count items by status, return array of {status, label, tone, count} */
const countByStatus = (items) => {
  const map = new Map();
  for (const item of items) {
    const s = item.deliveryStatus || item.delivery_status || "unknown";
    map.set(s, (map.get(s) || 0) + 1);
  }
  const result = [];
  for (const [status, count] of map) {
    result.push({
      status,
      label: status === "driver_assigned" ? "Назначено" : getOrderGroupDeliveryStatusLabel(status),
      tone: getOrderGroupDeliveryStatusTone(status),
      count,
    });
  }
  // Sort: delivered last (green = done), others by severity
  const order = ["problem", "cancelled", "on_route", "loaded", "driver_assigned", "paid_storage", "delivered"];
  result.sort((a, b) => {
    const ia = order.indexOf(a.status);
    const ib = order.indexOf(b.status);
    if (ia === -1 && ib === -1) return a.status.localeCompare(b.status);
    if (ia === -1) return 1;
    if (ib === -1) return -1;
    return ia - ib;
  });
  return result;
};

export const DriverDeliveryPlanner = ({ orderGroups = [], onOpenOrder, currentUser }) => {
  const [filters, setFilters] = React.useState({
    selectedDate: "",
    deliveryStatus: "all",
    selectedCity: "",
  });
  const [collapsedDates, setCollapsedDates] = React.useState({});

  const toggleDate = (date) => {
    setCollapsedDates((prev) => ({ ...prev, [date]: !prev[date] }));
  };

  const driverOrderGroups = React.useMemo(
    () => orderGroups.filter((group) => {
      const isVisible = isOrderGroupVisibleToDriver(group);
      const isAssignedToMe = currentUser && group.assignedDriverId === currentUser.id;
      return isVisible && isAssignedToMe;
    }),
    [orderGroups, currentUser],
  );

  const dateDeliveryMap = React.useMemo(() => {
    const map = new Map();
    driverOrderGroups.forEach((group) => {
      const date = group.deliveryDate;
      if (date) {
        map.set(date, (map.get(date) || 0) + 1);
      }
    });
    return map;
  }, [driverOrderGroups]);

  const sortedDeliveryDates = React.useMemo(() => {
    return Array.from(dateDeliveryMap.keys()).sort();
  }, [dateDeliveryMap]);

  const cityDeliveryMap = React.useMemo(() => {
    const map = new Map();
    driverOrderGroups.forEach((group) => {
      const city = normalizeCity(group.deliveryAddress || group.delivery_address);
      map.set(city, (map.get(city) || 0) + 1);
    });
    return map;
  }, [driverOrderGroups]);

  const sortedCities = React.useMemo(() => {
    return Array.from(cityDeliveryMap.keys()).sort((a, b) => {
      if (a === "Севастополь") return -1;
      if (b === "Севастополь") return 1;
      return a.localeCompare(b, "ru");
    });
  }, [cityDeliveryMap]);

  const filteredOrderGroups = React.useMemo(() => {
    let result = [...driverOrderGroups];
    if (filters.selectedDate) {
      result = result.filter((group) => group.deliveryDate === filters.selectedDate);
    }
    if (filters.deliveryStatus !== "all") {
      result = result.filter((group) => (group.deliveryStatus || group.delivery_status) === filters.deliveryStatus);
    }
    if (filters.selectedCity) {
      result = result.filter((group) => {
        const city = normalizeCity(group.deliveryAddress || group.delivery_address);
        return city === filters.selectedCity;
      });
    }
    return result;
  }, [driverOrderGroups, filters.selectedDate, filters.deliveryStatus, filters.selectedCity]);

  const groupedOrderGroups = React.useMemo(
    () => groupOrderGroupsByDate(filteredOrderGroups),
    [filteredOrderGroups],
  );

  const deliveryCountLabel = `${filteredOrderGroups.length} ${
    filteredOrderGroups.length === 1 ? "доставка" : filteredOrderGroups.length < 5 ? "доставки" : "доставок"
  }`;

  const isDateSelected = (date) => filters.selectedDate === date;

  // Compute per-date status summary for collapsed badges
  const dateStatusSummary = React.useMemo(() => {
    const summary = {};
    for (const dg of groupedOrderGroups) {
      summary[dg.date] = countByStatus(dg.items);
    }
    return summary;
  }, [groupedOrderGroups]);

  return (
    <div className="space-y-4">
      <Panel className="space-y-3 p-5">
        <div className="space-y-4">
          <div className="flex flex-wrap items-center justify-between gap-3">
            <div>
              <div className="flex flex-wrap items-center gap-3">
                <h3 className="text-lg font-semibold">Мои доставки</h3>
                <Badge tone="neutral">{deliveryCountLabel}</Badge>
              </div>
              <p className="mt-1 text-sm text-[var(--color-text-muted)]">
                Показываем только назначенные вам группы доставки. Выберите дату и город.
              </p>
            </div>
          </div>

          <div className="grid gap-3 md:grid-cols-[minmax(0,1fr)_minmax(0,1fr)]">
            <label className="flex min-w-0 flex-col gap-2">
              <span className="text-xs font-semibold uppercase tracking-[0.14em] text-[var(--color-text-muted)]">
                Дата
              </span>
              <Input
                type="date"
                value={filters.selectedDate}
                onChange={(event) => setFilters((current) => ({ ...current, selectedDate: event.target.value }))}
              />
            </label>
            <label className="flex min-w-0 flex-col gap-2">
              <span className="text-xs font-semibold uppercase tracking-[0.14em] text-[var(--color-text-muted)]">
                Статус
              </span>
              <Select
                value={filters.deliveryStatus}
                onChange={(event) =>
                  setFilters((current) => ({ ...current, deliveryStatus: event.target.value }))
                }
              >
                {DRIVER_DELIVERY_STATUS_OPTIONS.map((option) => (
                  <option key={option.value} value={option.value}>
                    {option.label}
                  </option>
                ))}
              </Select>
            </label>
          </div>

          {/* Date pills */}
          {sortedDeliveryDates.length > 0 && (
            <div className="flex flex-wrap gap-2 pt-2">
              <button
                type="button"
                onClick={() => setFilters((current) => ({ ...current, selectedDate: "" }))}
                className={[
                  "rounded-full border px-3 py-1.5 text-xs font-medium transition",
                  !filters.selectedDate
                    ? "border-[var(--color-accent)] bg-[var(--color-accent-soft)] text-[var(--color-text)]"
                    : "border-[var(--color-border)] bg-[var(--color-surface)] text-[var(--color-text-muted)] hover:border-[var(--color-accent)]",
                ].join(" ")}
              >
                Все даты
              </button>
              {sortedDeliveryDates.map((date) => {
                const count = dateDeliveryMap.get(date) || 0;
                const selected = isDateSelected(date);
                return (
                  <button
                    key={date}
                    type="button"
                    onClick={() => setFilters((current) => ({ ...current, selectedDate: date }))}
                    className={[
                      "flex items-center gap-1.5 rounded-full border px-3 py-1.5 text-xs font-medium transition",
                      selected
                        ? "border-[var(--color-accent)] bg-[var(--color-accent-soft)] text-[var(--color-text)]"
                        : "border-[var(--color-border)] bg-[var(--color-surface)] text-[var(--color-text-muted)] hover:border-[var(--color-accent)]",
                    ].join(" ")}
                  >
                    <span>{parseGroupDate(date)?.toLocaleDateString("ru-RU", { day: "numeric", month: "short" }) || "—"}</span>
                    {count > 0 && (
                      <span className="rounded-full bg-[var(--color-accent)] px-1.5 py-0.5 text-[10px] font-bold text-white">
                        {count}
                      </span>
                    )}
                  </button>
                );
              })}
            </div>
          )}

          {/* City pills */}
          {sortedCities.length > 1 && (
            <div className="flex flex-wrap gap-2">
              <button
                type="button"
                onClick={() => setFilters((current) => ({ ...current, selectedCity: "" }))}
                className={[
                  "rounded-full border px-3 py-1.5 text-xs font-medium transition",
                  !filters.selectedCity
                    ? "border-[var(--color-accent)] bg-[var(--color-accent-soft)] text-[var(--color-text)]"
                    : "border-[var(--color-border)] bg-[var(--color-surface)] text-[var(--color-text-muted)] hover:border-[var(--color-accent)]",
                ].join(" ")}
              >
                Все города
              </button>
              {sortedCities.map((city) => {
                const count = cityDeliveryMap.get(city) || 0;
                const selected = filters.selectedCity === city;
                return (
                  <button
                    key={city}
                    type="button"
                    onClick={() => setFilters((current) => ({ ...current, selectedCity: city }))}
                    className={[
                      "flex items-center gap-1.5 rounded-full border px-3 py-1.5 text-xs font-medium transition",
                      selected
                        ? "border-[var(--color-accent)] bg-[var(--color-accent-soft)] text-[var(--color-text)]"
                        : "border-[var(--color-border)] bg-[var(--color-surface)] text-[var(--color-text-muted)] hover:border-[var(--color-accent)]",
                    ].join(" ")}
                  >
                    <span>{city}</span>
                    {count > 0 && (
                      <span className="rounded-full bg-[var(--color-accent)] px-1.5 py-0.5 text-[10px] font-bold text-white">
                        {count}
                      </span>
                    )}
                  </button>
                );
              })}
            </div>
          )}
        </div>
      </Panel>

      {groupedOrderGroups.length ? (
        groupedOrderGroups.map((group) => {
          const isCollapsed = collapsedDates[group.date];
          const statusCounts = dateStatusSummary[group.date] || [];

          // Group items by delivery status within each date
          const statusBuckets = new Map();
          for (const item of group.items) {
            const s = item.deliveryStatus || item.delivery_status || "unknown";
            const label = s === "driver_assigned" ? "Назначено вам" : getOrderGroupDeliveryStatusLabel(s);
            const tone = getOrderGroupDeliveryStatusTone(s);
            if (!statusBuckets.has(s)) {
              statusBuckets.set(s, { label, tone, items: [] });
            }
            statusBuckets.get(s).items.push(item);
          }

          const statusOrder = ["driver_assigned", "loaded", "on_route", "delivered", "problem"];
          const sortedBuckets = Array.from(statusBuckets.entries()).sort(([a], [b]) => {
            const ia = statusOrder.indexOf(a);
            const ib = statusOrder.indexOf(b);
            if (ia === -1 && ib === -1) return a.localeCompare(b);
            if (ia === -1) return 1;
            if (ib === -1) return -1;
            return ia - ib;
          });

          return (
            <Panel key={group.date} className="space-y-4 p-5">
              <button
                type="button"
                className="flex w-full items-center gap-3 text-left"
                onClick={() => toggleDate(group.date)}
              >
                <span className="shrink-0 text-[var(--color-text-muted)] transition-transform">
                  {isCollapsed ? CHEVRON_RIGHT : CHEVRON_DOWN}
                </span>
                <div className="min-w-0 flex-1">
                  <h4 className="text-lg font-semibold capitalize">
                    {parseGroupDate(group.date)?.toLocaleDateString("ru-RU", {
                      day: "numeric",
                      month: "long",
                      weekday: "long",
                    }) || "Без даты"}
                  </h4>
                </div>
                <div className="flex shrink-0 flex-wrap items-center gap-1.5">
                  {statusCounts.map(({ status, label, tone, count }) => (
                    <Badge key={status} tone={tone}>{count} {label}</Badge>
                  ))}
                </div>
              </button>

              {!isCollapsed && (
                <div className="space-y-4 pt-1">
                  {sortedBuckets.map(([statusValue, { label, tone, items }]) => (
                    <div key={statusValue} className="space-y-2">
                      <div className="flex items-center gap-2">
                        <Badge tone={tone}>{label}</Badge>
                        <span className="text-xs text-[var(--color-text-muted)]">{items.length} {pluralGroups(items.length)}</span>
                      </div>
                      <div className="grid gap-3">
                        {items.map((item) => (
                          <button
                            key={item.id}
                            type="button"
                            className="rounded-[24px] border border-[var(--color-border)] bg-[var(--color-surface-strong)] p-4 text-left transition hover:bg-[var(--color-accent-soft)]"
                            onClick={() => onOpenOrder?.(item.id)}
                          >
                            <div className="flex flex-wrap items-start justify-between gap-3">
                              <div>
                                <div className="font-medium text-[var(--color-text)]">
                                  {item.displayTitle || item.customerName || item.groupKey}
                                </div>
                                <div className="mt-1 text-sm text-[var(--color-text-muted)]">
                                  {item.customerDate} · {item.customerPhone}
                                  {getOrderGroupDeliveryHalfDay(item) ? ` · ${getOrderGroupDeliveryHalfDay(item)}` : ""}
                                </div>
                              </div>
                            </div>

                            <div className="mt-3 text-sm text-[var(--color-text-muted)]">
                              {item.deliveryAddress || item.delivery_address || "Адрес не указан"}
                            </div>
                          </button>
                        ))}
                      </div>
                    </div>
                  ))}
                </div>
              )}
            </Panel>
          );
        })
      ) : (
        <Panel className="p-6">
          <h4 className="text-lg font-semibold">Доставки не найдены</h4>
          <p className="mt-2 text-sm text-[var(--color-text-muted)]">
            Сейчас у вас нет назначенных групп доставки.
          </p>
        </Panel>
      )}
    </div>
  );
};