import { Check } from 'lucide-react';
import { Button } from '@/components/ui/button';
import { Label } from '@/components/ui/label';
import type { WeeklySlot } from '@/types';

interface WeeklySlotSelectorProps {
    weeklySlots: WeeklySlot[];
    onChange: (slots: WeeklySlot[]) => void;
    slotAvailability?: Map<string, boolean>;
    weekOffset?: number;
}

const timeSlots = [
    { start: '08:30', end: '09:30' },
    { start: '09:40', end: '10:40' },
    { start: '10:50', end: '11:50' },
    { start: '11:50', end: '12:50' },
    { start: '13:00', end: '14:00' },
    { start: '14:00', end: '15:00' },
    { start: '15:10', end: '16:10' },
    { start: '16:20', end: '17:20' },
    { start: '17:20', end: '18:20' },
];

const weekDays = [
    { value: 1, label: 'Seg' },
    { value: 2, label: 'Ter' },
    { value: 3, label: 'Qua' },
    { value: 4, label: 'Qui' },
    { value: 5, label: 'Sex' },
];

export function WeeklySlotSelector({
    weeklySlots,
    onChange,
    slotAvailability,
    weekOffset = 0,
}: WeeklySlotSelectorProps) {
    // Calculate dates for the week
    const getWeekDates = (offset: number) => {
        const now = new Date();
        const startOfWeek = new Date(now);
        startOfWeek.setDate(now.getDate() - now.getDay() + 1 + offset * 7); // Monday

        const dates: Record<number, Date> = {};

        for (let i = 0; i < 5; i++) {
            const date = new Date(startOfWeek);
            date.setDate(startOfWeek.getDate() + i);
            dates[i + 1] = date;
        }

        return dates;
    };

    const weekDates = getWeekDates(weekOffset);

    const formatDate = (date: Date) => {
        return date.toLocaleDateString('pt-PT', {
            day: '2-digit',
            month: '2-digit',
        });
    };

    const isSlotSelected = (day: number, start: string, end: string) => {
        return weeklySlots.some(
            (slot) =>
                slot.day_of_week === day &&
                slot.start_time === start &&
                slot.end_time === end,
        );
    };

    const isSlotAvailable = (day: number, start: string, end: string) => {
        if (!slotAvailability) {
return true;
}

        const key = `${day}-${start}-${end}`;

        return slotAvailability.get(key) ?? true;
    };

    const toggleSlot = (day: number, start: string, end: string) => {
        if (!isSlotAvailable(day, start, end)) {
            return; // Don't allow selecting unavailable slots
        }

        const existingIndex = weeklySlots.findIndex(
            (slot) =>
                slot.day_of_week === day &&
                slot.start_time === start &&
                slot.end_time === end,
        );

        if (existingIndex >= 0) {
            // Remove slot
            const newSlots = weeklySlots.filter((_, i) => i !== existingIndex);
            onChange(newSlots);
        } else {
            // Add slot
            onChange([
                ...weeklySlots,
                { day_of_week: day, start_time: start, end_time: end },
            ]);
        }
    };

    const clearAll = () => {
        onChange([]);
    };

    return (
        <div className="space-y-4">
            <div className="flex items-center justify-between">
                <Label>Selecione os horários</Label>
                {weeklySlots.length > 0 && (
                    <Button
                        type="button"
                        variant="ghost"
                        size="sm"
                        onClick={clearAll}
                    >
                        Limpar tudo
                    </Button>
                )}
            </div>

            <div className="overflow-x-auto">
                <div className="min-w-[500px]">
                    {/* Header row with day names */}
                    <div className="grid grid-cols-6 gap-2 mb-2">
                        <div className="text-xs font-medium text-muted-foreground" />
                        {weekDays.map((day) => (
                            <div
                                key={day.value}
                                className="text-center text-xs font-medium text-foreground"
                            >
                                {day.label} <span className="text-muted-foreground">{formatDate(weekDates[day.value])}</span>
                            </div>
                        ))}
                    </div>

                    {/* Time slots rows */}
                    {timeSlots.map((time) => (
                        <div key={time.start} className="grid grid-cols-6 gap-2 mb-2">
                            <div className="flex items-center text-xs text-muted-foreground">
                                {time.start}-{time.end}
                            </div>
                            {weekDays.map((day) => {
                                const selected = isSlotSelected(
                                    day.value,
                                    time.start,
                                    time.end,
                                );
                                const available = isSlotAvailable(
                                    day.value,
                                    time.start,
                                    time.end,
                                );

                                return (
                                    <button
                                        key={`${day.value}-${time.start}`}
                                        type="button"
                                        onClick={() =>
                                            toggleSlot(
                                                day.value,
                                                time.start,
                                                time.end,
                                            )
                                        }
                                        disabled={!available}
                                        title={
                                            available
                                                ? `${time.start} - ${time.end}`
                                                : 'Sem equipamentos disponíveis'
                                        }
                                        className={`
                                            relative rounded-lg border-2 p-2 text-center text-xs transition-all
                                            ${
                                                selected
                                                    ? 'border-primary bg-primary text-primary-foreground'
                                                    : available
                                                      ? 'border-slate-200 bg-slate-50 hover:border-slate-300 hover:bg-slate-100 dark:border-slate-700 dark:bg-slate-800/50 dark:hover:border-slate-600 dark:hover:bg-slate-800'
                                                      : 'border-slate-200 bg-slate-100 opacity-50 cursor-not-allowed dark:border-slate-700 dark:bg-slate-800/30'
                                            }
                                        `}
                                    >
                                        <div className="font-medium">
                                            {time.start}-{time.end}
                                        </div>
                                        {selected && (
                                            <div className="absolute right-1 top-1">
                                                <Check className="size-3" />
                                            </div>
                                        )}
                                        {!available && (
                                            <div className="absolute -top-1 -right-1 size-3 rounded-full bg-destructive" />
                                        )}
                                    </button>
                                );
                            })}
                        </div>
                    ))}
                </div>
            </div>

            {weeklySlots.length === 0 && (
                <div className="rounded-lg border border-dashed border-slate-300 p-4 text-center text-sm text-slate-500 dark:border-slate-700 dark:text-slate-400">
                    Selecione pelo menos um horário para continuar
                </div>
            )}
        </div>
    );
}