"use client";

import { useMemo } from "react";
import { cn } from "@/shared/lib/utils";
import type { DeskReservation } from "../types";
import { DESKS } from "../types";
import {
  getMonday,
  toDateKey,
  formatDateShort,
  getReservationsForDate,
  isDateBookable,
} from "../services/reservation-service";

interface DeskCalendarProps {
  /** The week anchor date */
  weekStart: Date;
  selectedDate: string;
  reservations: DeskReservation[];
  onSelectDate: (dateKey: string) => void;
  onPrevWeek: () => void;
  onNextWeek: () => void;
  canGoPrev: boolean;
  canGoNext: boolean;
}

export function DeskCalendar({
  weekStart,
  selectedDate,
  reservations,
  onSelectDate,
  onPrevWeek,
  onNextWeek,
  canGoPrev,
  canGoNext,
}: DeskCalendarProps) {
  const monday = useMemo(() => getMonday(weekStart), [weekStart]);

  const weekDays = useMemo(() => {
    const days: string[] = [];
    for (let i = 0; i < 5; i++) {
      const d = new Date(monday);
      d.setDate(monday.getDate() + i);
      days.push(toDateKey(d));
    }
    return days;
  }, [monday]);

  const todayKey = toDateKey(new Date());

  return (
    <div className="flex flex-col gap-2">
      {/* Week navigation */}
      <div className="flex items-center justify-between">
        <button
          type="button"
          onClick={onPrevWeek}
          disabled={!canGoPrev}
          className={cn(
            "rounded-md px-2 py-1 text-xs font-medium transition-colors",
            canGoPrev
              ? "text-muted-foreground hover:text-foreground hover:bg-muted/60"
              : "text-muted-foreground/30 cursor-not-allowed",
          )}
        >
          ← Săpt. anterioară
        </button>
        <button
          type="button"
          onClick={onNextWeek}
          disabled={!canGoNext}
          className={cn(
            "rounded-md px-2 py-1 text-xs font-medium transition-colors",
            canGoNext
              ? "text-muted-foreground hover:text-foreground hover:bg-muted/60"
              : "text-muted-foreground/30 cursor-not-allowed",
          )}
        >
          Săpt. următoare →
        </button>
      </div>

      {/* Day cells */}
      <div className="grid grid-cols-5 gap-1.5">
        {weekDays.map((dateKey) => {
          const dayReservations = getReservationsForDate(dateKey, reservations);
          const bookedCount = dayReservations.length;
          const totalDesks = DESKS.length;
          const isSelected = dateKey === selectedDate;
          const isToday = dateKey === todayKey;
          const bookable = isDateBookable(dateKey);
          const isPast = dateKey < todayKey;
          const hasNoBookings = bookedCount === 0 && !isPast;

          return (
            <button
              key={dateKey}
              type="button"
              onClick={() => onSelectDate(dateKey)}
              disabled={!bookable && !isPast}
              className={cn(
                "relative flex flex-col items-center gap-0.5 rounded-lg border px-2 py-2 text-center transition-all",
                isSelected
                  ? "border-primary/50 bg-primary/8 ring-1 ring-primary/20"
                  : "border-border/40 hover:border-border/70 hover:bg-muted/30",
                isPast && !isSelected && "opacity-50",
                !bookable && !isPast && "opacity-40 cursor-not-allowed",
              )}
            >
              {/* Today dot */}
              {isToday && (
                <div className="absolute top-1 right-1 h-1.5 w-1.5 rounded-full bg-primary" />
              )}

              {/* Day name + date */}
              <span
                className={cn(
                  "text-[11px] font-medium leading-tight",
                  isSelected ? "text-primary" : "text-muted-foreground",
                )}
              >
                {formatDateShort(dateKey)}
              </span>

              {/* Occupancy indicator */}
              <div className="flex gap-0.5 mt-0.5">
                {Array.from({ length: totalDesks }).map((_, i) => (
                  <div
                    key={i}
                    className={cn(
                      "h-1 w-3 rounded-full transition-colors",
                      i < bookedCount
                        ? "bg-primary/60"
                        : hasNoBookings
                          ? "bg-amber-400/40"
                          : "bg-muted-foreground/15",
                    )}
                  />
                ))}
              </div>

              {/* Count label */}
              <span
                className={cn(
                  "text-[10px] leading-tight",
                  bookedCount === totalDesks
                    ? "text-primary/70"
                    : hasNoBookings
                      ? "text-amber-500/70"
                      : "text-muted-foreground/60",
                )}
              >
                {bookedCount}/{totalDesks}
              </span>
            </button>
          );
        })}
      </div>
    </div>
  );
}