import { plannableTourTypeSchema, type TourLibraryItem, type TourTypeKey } from '@trek/shared';
import { AlertTriangle, ArrowUp, Clock, CopyPlus, Library, Loader2, Ruler, Search, WifiOff } from 'lucide-react';
import { useId, useMemo } from 'react';
import { OFM_POSITRON } from '../../../constants/mapDefaults';
import { useTileUrl } from '../../../hooks/useTileUrl';
import { useTranslation } from '../../../i18n';
import { useSettingsStore } from '../../../store/settingsStore';
import { formatDistance, formatElevation } from '../../../utils/units';
import { MapViewAuto } from '../../Map/MapViewAuto';
import { EditorField, INPUT, PillSelect } from '../../shared/dialogParts';
import {
  DialogButton,
  DialogFooter,
  DialogHeader,
  DialogShell,
  DialogTile,
  FooterSpacer,
  fs,
  NEUTRAL_TINT,
} from '../../shared/DialogShell';
import { TourDayRowPill } from '../TourDayRowFacts';
import { RailFacts, TourNotice, type TourMetricField } from '../tourParts';
import { formatPlannedTourDuration, tourPlannedTimes } from '../tourPresentation';
import { type TourLibrary } from './useTourLibrary';

type Translate = (key: string, params?: Record<string, unknown>) => string;
type Unit = Parameters<typeof formatDistance>[1];

const ALL = 'all';

/** A tour's own measures as badges; one it does not have is left out, never shown as zero. */
function measureBadges(tour: TourLibraryItem, unit: Unit, t: Translate) {
  const minutes = tourPlannedTimes(tour).plannedTotalMinutes;
  return [
    minutes != null && {
      key: 'time',
      icon: Clock,
      value: formatPlannedTourDuration(minutes),
      label: `${t('tours.planner.plannedTotalDuration')}: ${formatPlannedTourDuration(minutes)}`,
    },
    tour.distance != null && {
      key: 'distance',
      icon: Ruler,
      value: formatDistance(tour.distance, unit),
      label: `${t('tours.detail.distance')}: ${formatDistance(tour.distance, unit)}`,
    },
    tour.elevation_gain != null &&
      tour.tour_type !== 'kayak' && {
        key: 'ascent',
        icon: ArrowUp,
        value: formatElevation(tour.elevation_gain, unit),
        label: `${t('tours.detail.ascent')}: ${formatElevation(tour.elevation_gain, unit)}`,
      },
  ].filter((badge) => !!badge);
}

/** One tour of the list: its name, the trip it is in, its measures. */
function LibraryRow({ tour, selected, onChoose }: { tour: TourLibraryItem; selected: boolean; onChoose: () => void }) {
  const { t } = useTranslation();
  const unit = useSettingsStore((state) => state.settings.distance_unit) ?? 'metric';
  return (
    <li>
      <button
        type="button"
        onClick={onChoose}
        aria-pressed={selected}
        data-testid={`tour-library-row-${tour.place_id}`}
        className={`flex w-full min-w-0 flex-col gap-1 rounded-[10px] px-2.5 py-2 text-start transition-colors focus-visible:outline focus-visible:outline-2 focus-visible:outline-accent ${selected ? 'bg-surface-selected' : 'hover:bg-surface-hover'}`}
      >
        <span className="flex min-w-0 items-baseline gap-2">
          <span className="min-w-0 flex-1 truncate font-semibold text-content" style={fs(13, 'body')}>
            {tour.name}
          </span>
          <span className="flex-none text-content-faint" style={fs(11, 'body')}>
            {t(`tourTypes.${tour.tour_type}`)}
          </span>
        </span>
        <span className="min-w-0 truncate text-content-muted" style={fs(11, 'body')}>
          {tour.trip.title}
        </span>
        <span className="flex flex-wrap gap-1.5">
          {measureBadges(tour, unit, t).map((badge) => (
            <TourDayRowPill
              key={badge.key}
              icon={badge.icon}
              value={badge.value}
              label={badge.label}
              testId={`tour-library-${badge.key}`}
            />
          ))}
        </span>
      </button>
    </li>
  );
}

/** A line of the list's state: loading, offline, failed with a retry, empty, or cut short. */
function ListState({ library }: { library: TourLibrary }) {
  const { t } = useTranslation();
  const { listStatus, list } = library;
  if (listStatus === 'offline')
    return <TourNotice icon={<WifiOff size={13} strokeWidth={2} />}>{t('tours.library.offline')}</TourNotice>;
  if (listStatus === 'error')
    return (
      <TourNotice tone="warning" icon={<AlertTriangle size={13} strokeWidth={2} />}>
        <span className="flex flex-wrap items-center gap-2">
          {t('tours.library.loadFailed')}
          <button type="button" onClick={library.retry} className="font-semibold underline underline-offset-2">
            {t('tours.planner.retry')}
          </button>
        </span>
      </TourNotice>
    );
  if (listStatus === 'loading' && !list)
    return (
      <p role="status" className="m-0 flex items-center gap-2 py-4 text-content-faint" style={fs(12, 'body')}>
        <Loader2 size={13} strokeWidth={2.2} className="animate-spin" />
        {t('common.loading')}
      </p>
    );
  if (list && list.tours.length === 0)
    return (
      <p className="m-0 py-4 text-center text-content-muted" style={fs(12.5, 'body')}>
        {list.trips.length === 0 ? t('tours.library.noTrips') : t('tours.library.empty')}
      </p>
    );
  if (list?.truncated) return <TourNotice>{t('tours.library.truncated')}</TourNotice>;
  return null;
}

/** The search box and the two filters over the list. */
function ListFilters({ library }: { library: TourLibrary }) {
  const { t } = useTranslation();
  const searchId = useId();
  const trips = library.list?.trips ?? [];
  const tripOptions = [
    { value: ALL, label: t('tours.library.allTrips') },
    ...trips.map((trip) => ({ value: String(trip.id), label: trip.title, hint: String(trip.tour_count) })),
  ];
  const typeOptions = [
    { value: ALL, label: t('tours.library.allTypes') },
    ...plannableTourTypeSchema.options.map((type) => ({ value: type, label: t(`tourTypes.${type}`) })),
  ];
  return (
    <div className="flex flex-col gap-2">
      <div className="flex items-center gap-2 rounded-[10px] border border-edge bg-surface-input px-2.5 py-2">
        <Search size={13} strokeWidth={2.2} className="flex-none text-content-faint" />
        <label htmlFor={searchId} className="sr-only">
          {t('tours.library.search')}
        </label>
        <input
          id={searchId}
          autoFocus
          value={library.filters.query}
          onChange={(event) => library.filter({ query: event.target.value })}
          placeholder={t('tours.library.search')}
          className="min-w-0 flex-1 border-0 bg-transparent text-content outline-none placeholder:text-content-faint"
          style={fs(12.5, 'body')}
        />
      </div>
      <div className="flex flex-wrap items-center gap-1.5">
        <PillSelect
          quiet
          label={t('tours.library.trip')}
          value={library.filters.tripFilter === null ? ALL : String(library.filters.tripFilter)}
          options={tripOptions}
          onChange={(value) => library.filter({ tripFilter: value === ALL ? null : Number(value) })}
        />
        <PillSelect
          quiet
          label={t('tours.filter.type')}
          value={library.filters.typeFilter ?? ALL}
          options={typeOptions}
          onChange={(value) => library.filter({ typeFilter: value === ALL ? null : (value as TourTypeKey) })}
        />
      </div>
    </div>
  );
}

/** The facts of the chosen tour as the preview shows them, each only where the tour has it. */
function previewFacts(tour: TourLibraryItem, waypoints: number, unit: Unit, t: Translate): TourMetricField[] {
  const minutes = tourPlannedTimes(tour).plannedTotalMinutes;
  const fact = (show: boolean, label: string, value: () => string) => (show ? { label, value: value() } : null);
  return [
    fact(true, t('tours.library.fromTrip'), () => tour.trip.title),
    fact(true, t('tours.filter.type'), () => t(`tourTypes.${tour.tour_type}`)),
    fact(tour.distance != null, t('tours.detail.distance'), () => formatDistance(tour.distance ?? 0, unit)),
    fact(minutes != null, t('tours.planner.plannedTotalDuration'), () => formatPlannedTourDuration(minutes ?? 0)),
    fact(tour.elevation_gain != null && tour.tour_type !== 'kayak', t('tours.detail.ascent'), () =>
      formatElevation(tour.elevation_gain ?? 0, unit)
    ),
    fact(tour.elevation_loss != null && tour.tour_type !== 'kayak', t('tours.detail.descent'), () =>
      formatElevation(tour.elevation_loss ?? 0, unit)
    ),
    fact(waypoints > 0, t('tours.library.controlPoints'), () => String(waypoints)),
  ].filter((field): field is TourMetricField => field !== null);
}

/** The chosen tour: on a map, its facts, and the name the copy gets. */
function Preview({ library }: { library: TourLibrary }) {
  const { t } = useTranslation();
  const unit = useSettingsStore((state) => state.settings.distance_unit) ?? 'metric';
  const tileUrl = useTileUrl(OFM_POSITRON);
  const nameId = useId();
  const line = library.preview?.line;
  const route = useMemo(
    // The client reads the contract's tuples loosely; the points are spelled out as pairs here.
    () =>
      line && line.length > 1 ? [line.map((point): [number, number] => [Number(point[0]), Number(point[1])])] : [],
    [line]
  );
  const { selected } = library;
  if (!selected)
    return (
      <div className="grid h-full min-h-[240px] place-items-center rounded-[14px] border border-dashed border-edge px-6 text-center">
        <p className="m-0 max-w-[260px] text-content-muted" style={fs(12.5, 'body')}>
          {t('tours.library.chooseHint')}
        </p>
      </div>
    );
  return (
    <div className="flex min-w-0 flex-col gap-3" data-testid="tour-library-preview">
      <div className="relative h-[240px] flex-none overflow-hidden rounded-[14px] border border-edge-faint bg-surface-secondary">
        {route.length > 0 && (
          <MapViewAuto
            places={[]}
            route={route}
            tileUrl={tileUrl}
            focusPoints={route[0]}
            focusKey={String(selected.place_id)}
            followSelection={false}
          />
        )}
        {library.previewStatus === 'loading' && (
          <span className="absolute inset-0 grid place-items-center text-content-faint">
            <Loader2 size={18} strokeWidth={2.2} className="animate-spin" />
          </span>
        )}
        {(library.previewStatus === 'error' || library.previewStatus === 'offline') && (
          <span
            className="absolute inset-0 grid place-items-center px-6 text-center text-content-muted"
            style={fs(12, 'body')}
          >
            {t(library.previewStatus === 'offline' ? 'tours.library.offline' : 'tours.library.previewFailed')}
          </span>
        )}
      </div>
      <RailFacts facts={previewFacts(selected, library.preview?.waypoint_count ?? 0, unit, t)} />
      <EditorField label={t('tours.library.nameHere')} htmlFor={nameId} hint={t('tours.library.independent')}>
        <input
          id={nameId}
          className={INPUT}
          value={library.name}
          maxLength={255}
          onChange={(event) => library.setName(event.target.value)}
        />
      </EditorField>
    </div>
  );
}

/**
 * LIB-02: the dialog to take a tour of another trip over into this one. The
 * list on the left, the chosen tour on the right; the copy is made only by the
 * button in its foot.
 */
/** LIB-02: the dialog that takes a tour of another trip into this one, opened from "Add tour". */
export function TourLibraryDialog({ library }: { library: TourLibrary }) {
  const { t } = useTranslation();
  const labelId = useId();
  if (!library.open) return null;
  return (
    <DialogShell
      onClose={library.close}
      labelledBy={labelId}
      width="wide"
      align="top"
      blocked={library.taking}
      header={
        <DialogHeader
          tile={
            <DialogTile>
              <Library size={20} strokeWidth={2} className="text-content" />
            </DialogTile>
          }
          tint={NEUTRAL_TINT}
          labelId={labelId}
          onClose={library.close}
          eyebrow={t('tours.library.eyebrow')}
          title={t('tours.library.title')}
          sub={t('tours.library.sub')}
          subWraps
        />
      }
      footer={
        <DialogFooter>
          <FooterSpacer />
          <DialogButton onClick={library.close} disabled={library.taking}>
            {t('common.cancel')}
          </DialogButton>
          <DialogButton
            variant="primary"
            data-testid="tour-library-confirm"
            icon={
              library.taking ? (
                <Loader2 size={14} strokeWidth={2} className="animate-spin" />
              ) : (
                <CopyPlus size={14} strokeWidth={2} />
              )
            }
            disabled={!library.canConfirm}
            onClick={() => void library.confirm()}
          >
            {t('tours.library.confirm')}
          </DialogButton>
        </DialogFooter>
      }
    >
      <div className="grid min-h-0 grid-cols-1 gap-5 md:grid-cols-[minmax(0,1fr)_minmax(0,1.15fr)]">
        <section aria-label={t('tours.library.title')} className="flex min-w-0 flex-col gap-3">
          <ListFilters library={library} />
          <ListState library={library} />
          {library.list && library.list.tours.length > 0 && (
            <ul
              className={`m-0 flex max-h-[420px] list-none flex-col gap-0.5 overflow-y-auto p-0 transition-opacity ${library.listStatus === 'loading' ? 'opacity-60' : ''}`}
              data-testid="tour-library-list"
            >
              {library.list.tours.map((tour) => (
                <LibraryRow
                  key={tour.place_id}
                  tour={tour}
                  selected={library.selected?.place_id === tour.place_id}
                  onChoose={() => library.choose(tour)}
                />
              ))}
            </ul>
          )}
        </section>
        <Preview library={library} />
      </div>
    </DialogShell>
  );
}