"use client";

import { Plus, X } from "lucide-react";
import { useMemo, useState } from "react";
import { Button } from "@/components/ui/button";
import { Input } from "@/components/ui/input";
import { Label } from "@/components/ui/label";
import {
  Select,
  SelectContent,
  SelectItem,
  SelectTrigger,
  SelectValue,
} from "@/components/ui/select";
import {
  REMINDER_PRESETS,
  customOffsetToMinutes,
  formatReminderOffset,
  normalizeReminderOffsets,
  type ReminderOffsetUnit,
} from "@/lib/reminder-offsets";

type Props = {
  offsets: number[];
  onChange: (offsets: number[]) => void;
  disabled?: boolean;
};

export function ReminderPicker({ offsets, onChange, disabled }: Props) {
  const [customValue, setCustomValue] = useState("1");
  const [customUnit, setCustomUnit] = useState<ReminderOffsetUnit>("hours");
  const normalized = useMemo(() => normalizeReminderOffsets(offsets), [offsets]);

  function addOffset(minutes: number) {
    onChange(normalizeReminderOffsets([...normalized, minutes]));
  }

  function removeOffset(minutes: number) {
    onChange(normalized.filter((o) => o !== minutes));
  }

  function addCustom() {
    const parsed = Number.parseInt(customValue, 10);
    if (!Number.isFinite(parsed) || parsed < 0) return;
    addOffset(customOffsetToMinutes(parsed, customUnit));
  }

  const availablePresets = REMINDER_PRESETS.filter((p) => !normalized.includes(p.offsetMinutes));

  return (
    <div className="space-y-3">
      <Label>Reminders</Label>
      {normalized.length === 0 ? (
        <p className="text-[13px] text-[var(--ink-mute)]">No reminders set.</p>
      ) : (
        <ul className="space-y-1.5">
          {normalized.map((offset) => (
            <li
              key={offset}
              className="flex items-center justify-between gap-2 rounded-md border border-[var(--hair)] px-2.5 py-1.5 text-[13px]"
            >
              <span>{formatReminderOffset(offset)}</span>
              <Button
                type="button"
                size="icon-sm"
                variant="ghost"
                aria-label={`Remove ${formatReminderOffset(offset)}`}
                disabled={disabled}
                onClick={() => removeOffset(offset)}
              >
                <X className="size-3.5" />
              </Button>
            </li>
          ))}
        </ul>
      )}

      {availablePresets.length > 0 && (
        <div className="flex flex-wrap gap-1.5">
          {availablePresets.map((preset) => (
            <Button
              key={preset.offsetMinutes}
              type="button"
              size="sm"
              variant="outline"
              disabled={disabled}
              onClick={() => addOffset(preset.offsetMinutes)}
            >
              <Plus className="size-3" />
              {preset.label}
            </Button>
          ))}
        </div>
      )}

      <div className="grid gap-2 sm:grid-cols-[80px_120px_auto] sm:items-end">
        <div className="space-y-1">
          <Label htmlFor="reminder-custom-value">Custom</Label>
          <Input
            id="reminder-custom-value"
            type="number"
            min={0}
            value={customValue}
            disabled={disabled}
            onChange={(e) => setCustomValue(e.target.value)}
          />
        </div>
        <div className="space-y-1">
          <Label htmlFor="reminder-custom-unit">Unit</Label>
          <Select
            value={customUnit}
            onValueChange={(value) => setCustomUnit(value as ReminderOffsetUnit)}
            disabled={disabled}
          >
            <SelectTrigger id="reminder-custom-unit">
              <SelectValue />
            </SelectTrigger>
            <SelectContent>
              <SelectItem value="minutes">Minutes</SelectItem>
              <SelectItem value="hours">Hours</SelectItem>
              <SelectItem value="days">Days</SelectItem>
              <SelectItem value="weeks">Weeks</SelectItem>
            </SelectContent>
          </Select>
        </div>
        <Button type="button" variant="secondary" disabled={disabled} onClick={addCustom}>
          Add custom
        </Button>
      </div>
    </div>
  );
}