import type { AssetResponseDto } from '@immich/sdk';
import {
  mdiBrightness6,
  mdiCalendar,
  mdiCamera,
  mdiCameraIris,
  mdiCameraOutline,
  mdiClockEditOutline,
  mdiCrosshairsGps,
  mdiEarth,
  mdiFileClockOutline,
  mdiFileEditOutline,
  mdiFileImageOutline,
  mdiFitToScreen,
  mdiFolderOutline,
  mdiMapMarkerOutline,
  mdiPanorama,
  mdiPhoneRotateLandscape,
  mdiRayStartArrow,
  mdiStarOutline,
  mdiTextBox,
  mdiTimerOutline,
  mdiWeightKilogram,
} from '@mdi/js';
import { DateTime } from 'luxon';
import type { MessageFormatter } from 'svelte-i18n';
import { getAssetResolution, getFileSize } from '$lib/utils/asset-utils';
import { fromISODateTime, fromISODateTimeUTC } from '$lib/utils/timeline-util';

const truncateMiddle = (path: string, maxLength = 50): string => {
  if (path.length <= maxLength) {
    return path;
  }

  const lastSlash = path.lastIndexOf('/');
  const tail = lastSlash === -1 ? path : path.slice(lastSlash);

  if (tail.length >= maxLength - 3) {
    const half = Math.floor((maxLength - 3) / 2);
    return path.slice(0, half) + '...' + path.slice(-half);
  }

  const headLength = maxLength - 3 - tail.length;
  return path.slice(0, headLength) + '...' + tail;
};

const formatISODateToLocale = (iso: string, locale: string | undefined): string =>
  fromISODateTimeUTC(iso).toLocaleString({ month: 'short', day: 'numeric', year: 'numeric' }, { locale });

const getDateTime = (asset: AssetResponseDto) => {
  const timeZone = asset.exifInfo?.timeZone;
  return timeZone && asset.exifInfo?.dateTimeOriginal
    ? fromISODateTime(asset.exifInfo.dateTimeOriginal, timeZone)
    : fromISODateTimeUTC(asset.localDateTime);
};

type MetadataFieldDefinition = {
  icon: string;
  titleKey: string;
  keys: readonly string[];
  render: (asset: AssetResponseDto, $t: MessageFormatter, locale: string | undefined) => string;
};

const metadataFields = [
  {
    icon: mdiFileImageOutline,
    titleKey: 'file_name_text',
    keys: ['originalFileName'],
    render: (asset, $t) => asset.originalFileName || $t('unknown'),
  },
  {
    icon: mdiFolderOutline,
    titleKey: 'path',
    keys: ['originalPath'],
    render: (asset, $t) => truncateMiddle(asset.originalPath) || $t('unknown'),
  },
  {
    icon: mdiWeightKilogram,
    titleKey: 'file_size',
    keys: ['fileSize'],
    render: (asset) => getFileSize(asset),
  },
  {
    icon: mdiFitToScreen,
    titleKey: 'resolution',
    keys: ['resolution'],
    render: (asset, $t) => getAssetResolution(asset) || $t('unknown'),
  },
  {
    icon: mdiFileClockOutline,
    titleKey: 'created_at',
    keys: ['fileCreatedAt'],
    render: (asset, _t, locale) => formatISODateToLocale(asset.fileCreatedAt, locale),
  },
  {
    icon: mdiFileEditOutline,
    titleKey: 'updated_at',
    keys: ['fileModifiedAt'],
    render: (asset, _t, locale) => formatISODateToLocale(asset.fileModifiedAt, locale),
  },
  {
    icon: mdiCalendar,
    titleKey: 'date_time_original',
    keys: ['dateTimeOriginal'],
    render: (asset, $t, locale) => {
      const dateTime = getDateTime(asset);
      return dateTime
        ? dateTime.toLocaleString(
            {
              month: 'short',
              day: 'numeric',
              year: 'numeric',
              hour: 'numeric',
              minute: '2-digit',
              second: '2-digit',
              timeZoneName: 'shortOffset',
            },
            { locale },
          )
        : $t('unknown');
    },
  },
  {
    icon: mdiEarth,
    titleKey: 'timezone',
    keys: ['timeZone'],
    render: (asset, $t) => getDateTime(asset)?.offsetNameShort ?? $t('unknown'),
  },
  {
    icon: mdiClockEditOutline,
    titleKey: 'modify_date',
    keys: ['modifyDate'],
    render: (asset, $t, locale) =>
      asset.exifInfo?.modifyDate ? formatISODateToLocale(asset.exifInfo.modifyDate, locale) : $t('unknown'),
  },
  {
    icon: mdiMapMarkerOutline,
    titleKey: 'location',
    keys: ['city', 'state', 'country'],
    render: (asset, $t) => {
      const parts = [asset.exifInfo?.city, asset.exifInfo?.state, asset.exifInfo?.country].filter(Boolean);
      return parts.length > 0 ? parts.join(', ') : $t('unknown');
    },
  },
  {
    icon: mdiCrosshairsGps,
    titleKey: 'gps',
    keys: ['latitude', 'longitude'],
    render: (asset, $t) =>
      asset.exifInfo?.latitude != null && asset.exifInfo?.longitude != null
        ? `${asset.exifInfo.latitude.toFixed(4)}, ${asset.exifInfo.longitude.toFixed(4)}`
        : $t('unknown'),
  },
  {
    icon: mdiCameraOutline,
    titleKey: 'make',
    keys: ['make'],
    render: (asset, $t) => asset.exifInfo?.make || $t('unknown'),
  },
  {
    icon: mdiCamera,
    titleKey: 'model',
    keys: ['model'],
    render: (asset, $t) => asset.exifInfo?.model || $t('unknown'),
  },
  {
    icon: mdiCameraIris,
    titleKey: 'lens_model',
    keys: ['lensModel'],
    render: (asset, $t) => asset.exifInfo?.lensModel || $t('unknown'),
  },
  {
    icon: mdiCameraIris,
    titleKey: 'f_number',
    keys: ['fNumber'],
    render: (asset, $t) => (asset.exifInfo?.fNumber == null ? $t('unknown') : `f/${asset.exifInfo.fNumber.toFixed(1)}`),
  },
  {
    icon: mdiRayStartArrow,
    titleKey: 'focal_length',
    keys: ['focalLength'],
    render: (asset, $t) => (asset.exifInfo?.focalLength == null ? $t('unknown') : `${asset.exifInfo.focalLength} mm`),
  },
  {
    icon: mdiBrightness6,
    titleKey: 'iso',
    keys: ['iso'],
    render: (asset, $t) => (asset.exifInfo?.iso == null ? $t('unknown') : `ISO ${asset.exifInfo.iso}`),
  },
  {
    icon: mdiTimerOutline,
    titleKey: 'exposure_time',
    keys: ['exposureTime'],
    render: (asset, $t) => asset.exifInfo?.exposureTime || $t('unknown'),
  },
  {
    icon: mdiTextBox,
    titleKey: 'description',
    keys: ['description'],
    render: (asset, $t) => asset.exifInfo?.description || $t('unknown'),
  },
  {
    icon: mdiStarOutline,
    titleKey: 'rating',
    keys: ['rating'],
    render: (asset, $t) => (asset.exifInfo?.rating == null ? $t('unknown') : `${asset.exifInfo.rating} stars`),
  },
  {
    icon: mdiPhoneRotateLandscape,
    titleKey: 'orientation',
    keys: ['orientation'],
    render: (asset, $t) => String(asset.exifInfo?.orientation || $t('unknown')),
  },
  {
    icon: mdiPanorama,
    titleKey: 'projection_type',
    keys: ['projectionType'],
    render: (asset, $t) => asset.exifInfo?.projectionType || $t('unknown'),
  },
] as const satisfies readonly MetadataFieldDefinition[];

export type MetadataFieldKey = (typeof metadataFields)[number]['keys'][number];
export type DifferingMetadataFields = Partial<Record<MetadataFieldKey, boolean>>;

export const metadataKeys: readonly MetadataFieldKey[] = metadataFields.flatMap(({ keys }) => keys);

export const countDifferingMetadataItems = (differing: DifferingMetadataFields): number =>
  metadataFields.filter(({ keys }) => keys.some((k) => differing[k as MetadataFieldKey])).length;

export const getAllMetadataItems = (asset: AssetResponseDto, $t: MessageFormatter, locale: string | undefined) =>
  metadataFields.map(({ icon, titleKey, keys, render }) => ({
    icon,
    title: $t(titleKey),
    render: render(asset, $t, locale),
    keys,
  }));

const normalizeForComparison = (key: MetadataFieldKey, value: unknown): unknown => {
  if (value === null || value === undefined) {
    return value;
  }

  if (key === 'fileCreatedAt' || key === 'fileModifiedAt' || key === 'dateTimeOriginal' || key === 'modifyDate') {
    const dateTime = DateTime.fromISO(String(value));
    return dateTime.isValid ? dateTime.toISO() : String(value);
  }

  if (key === 'fNumber' && typeof value === 'number') {
    return Number(value.toFixed(1));
  }
  if ((key === 'latitude' || key === 'longitude') && typeof value === 'number') {
    return Number(value.toFixed(4));
  }
  if (key === 'focalLength' && typeof value === 'number') {
    return Number(value.toFixed(2));
  }

  return value;
};

const getValueForAsset = (asset: AssetResponseDto, key: MetadataFieldKey): unknown => {
  switch (key) {
    case 'fileCreatedAt':
    case 'fileModifiedAt':
    case 'originalFileName':
    case 'originalPath': {
      return asset[key];
    }
    case 'fileSize': {
      return getFileSize(asset);
    }
    case 'resolution': {
      return getAssetResolution(asset);
    }
    default: {
      if (asset.exifInfo && key in asset.exifInfo) {
        return asset.exifInfo[key as keyof typeof asset.exifInfo];
      }
      return undefined;
    }
  }
};

export const computeDifferingMetadataFields = (assets: AssetResponseDto[]): DifferingMetadataFields => {
  const diffs: DifferingMetadataFields = {};

  for (const key of metadataKeys) {
    const uniqueValues = new Set<unknown>();

    for (const asset of assets) {
      const value = getValueForAsset(asset, key);
      if (value !== undefined && value !== null) {
        uniqueValues.add(normalizeForComparison(key, value));
      }
    }

    diffs[key] = uniqueValues.size > 1;
  }

  return diffs;
};