import { useState, useCallback } from 'react';
import { Slider } from '../ui/Slider';
import { PillToggle } from '../ui/PillToggle';
import { PillGroup } from '../ui/PillGroup';
import { IconButton } from '../ui/IconButton';
import { CloseIcon } from '../ui/icons/CloseIcon';
import { MapPinIcon } from '../ui/icons/MapPinIcon';
import { RouteIcon } from '../ui/icons/RouteIcon';
import { formatFilterValue } from '../../lib/format';
import { authHeaders } from '../../lib/api';
import type { TransportMode } from '../../hooks/useTravelTime';

const MODES: { value: TransportMode; label: string }[] = [
  { value: 'transit', label: 'Transit' },
  { value: 'car', label: 'Car' },
  { value: 'bicycle', label: 'Bicycle' },
];

interface TravelTimeCardProps {
  destination: [number, number] | null;
  destinationLabel: string;
  mode: TransportMode;
  timeRange: [number, number] | null;
  dataRange: [number, number] | null;
  onSetDestination: (lat: number, lon: number, label: string) => void;
  onModeChange: (mode: TransportMode) => void;
  onTimeRangeChange: (range: [number, number]) => void;
  onRemove: () => void;
}

export function TravelTimeCard({
  destination,
  destinationLabel,
  mode,
  timeRange,
  dataRange,
  onSetDestination,
  onModeChange,
  onTimeRangeChange,
  onRemove,
}: TravelTimeCardProps) {
  const [query, setQuery] = useState('');
  const [loading, setLoading] = useState(false);
  const [error, setError] = useState<string | null>(null);

  const handleSearch = useCallback(
    async (e: React.FormEvent) => {
      e.preventDefault();
      const trimmed = query.trim();
      if (!trimmed) return;

      setError(null);
      setLoading(true);
      try {
        const res = await fetch(
          `/api/postcode/${encodeURIComponent(trimmed)}`,
          authHeaders()
        );
        if (!res.ok) {
          setError('Postcode not found');
          return;
        }
        const json: { postcode: string; latitude: number; longitude: number } =
          await res.json();
        onSetDestination(json.latitude, json.longitude, json.postcode);
        setQuery('');
      } catch {
        setError('Lookup failed');
      } finally {
        setLoading(false);
      }
    },
    [query, onSetDestination]
  );

  const sliderMin = dataRange ? Math.floor(dataRange[0]) : 0;
  const sliderMax = dataRange ? Math.ceil(dataRange[1]) : 120;
  const displayRange = timeRange ?? [sliderMin, sliderMax];

  return (
    <div className="space-y-2 px-2 py-2 rounded ring-2 ring-teal-400 bg-teal-50/50 dark:bg-teal-900/20">
      {/* Header */}
      <div className="flex items-center justify-between">
        <div className="flex items-center gap-1.5">
          <RouteIcon className="w-4 h-4 text-teal-600 dark:text-teal-400" />
          <span className="text-sm font-medium text-navy-950 dark:text-warm-100">
            Travel Time
          </span>
        </div>
        <IconButton onClick={() => onRemove()} title="Remove travel time">
          <CloseIcon className="w-3.5 h-3.5" />
        </IconButton>
      </div>

      {/* Destination search */}
      <div>
        <form onSubmit={handleSearch} className="flex gap-1">
          <input
            type="text"
            value={query}
            onChange={(e) => {
              setQuery(e.target.value);
              setError(null);
            }}
            placeholder={destination ? 'Change destination...' : 'Enter postcode...'}
            className="flex-1 min-w-0 px-2 py-1 text-xs rounded border border-warm-200 dark:border-warm-600 bg-white dark:bg-warm-800 text-navy-950 dark:text-warm-200 placeholder-warm-400 dark:placeholder-warm-500 outline-none focus:ring-1 focus:ring-teal-400"
          />
          <button
            type="submit"
            disabled={loading || !query.trim()}
            className="px-2 py-1 text-xs rounded bg-teal-600 text-white hover:bg-teal-700 disabled:opacity-50"
          >
            {loading ? '...' : 'Go'}
          </button>
        </form>
        {error && (
          <p className="text-xs text-red-600 dark:text-red-400 mt-0.5">{error}</p>
        )}
        {destination && destinationLabel && (
          <div className="flex items-center gap-1 mt-1">
            <MapPinIcon className="w-3 h-3 text-red-500 shrink-0" />
            <span className="text-xs text-warm-600 dark:text-warm-300">
              {destinationLabel}
            </span>
          </div>
        )}
      </div>

      {/* Mode selector */}
      <div>
        <span className="text-[10px] font-medium text-warm-500 dark:text-warm-400 uppercase tracking-wide">
          Mode
        </span>
        <PillGroup className="mt-0.5">
          {MODES.map((m) => (
            <PillToggle
              key={m.value}
              label={m.label}
              active={mode === m.value}
              onClick={() => onModeChange(m.value)}
              size="xs"
            />
          ))}
        </PillGroup>
      </div>

      {/* Time range slider — only show when we have data */}
      {destination && dataRange && (
        <div>
          <span className="text-[10px] font-medium text-warm-500 dark:text-warm-400 uppercase tracking-wide">
            Max time
          </span>
          <Slider
            min={sliderMin}
            max={sliderMax}
            step={1}
            value={[displayRange[0], displayRange[1]]}
            onValueChange={([min, max]) => onTimeRangeChange([min, max])}
          />
          <div className="relative h-4 mt-1 mx-2.5 text-[10px] text-warm-500 dark:text-warm-400 leading-tight">
            <span className="absolute left-0">
              {formatFilterValue(displayRange[0])} min
            </span>
            <span className="absolute right-0">
              {formatFilterValue(displayRange[1])} min
            </span>
          </div>
        </div>
      )}
    </div>
  );
}