afilmory/apps/web/src/lib/map-utils.ts

import type { PhotoManifestItem, PickedExif } from '@afilmory/builder'

import type {
  GPSCoordinates,
  MapBounds,
  MapViewState,
  PhotoMarker,
} from '~/types/map'
import { GPSDirection } from '~/types/map'

/**
 * Convert EXIF GPS data to decimal coordinates with proper directional handling
 */
export function convertExifGPSToDecimal(exif: PickedExif | null): {
  latitude: number
  longitude: number
  latitudeRef: GPSDirection.North | GPSDirection.South
  longitudeRef: GPSDirection.East | GPSDirection.West
  altitude?: number
  altitudeRef?: 'Above Sea Level' | 'Below Sea Level'
} | null {
  if (!exif?.GPSLatitude || !exif?.GPSLongitude) {
    return null
  }

  // Convert GPS coordinates from EXIF format to decimal degrees
  let latitude: number
  let longitude: number

  try {
    // Handle different EXIF coordinate formats
    if (typeof exif.GPSLatitude === 'number') {
      latitude = exif.GPSLatitude
    } else {
      latitude = Number(exif.GPSLatitude)
    }

    if (typeof exif.GPSLongitude === 'number') {
      longitude = exif.GPSLongitude
    } else {
      longitude = Number(exif.GPSLongitude)
    }

    // Get GPS direction references
    const latitudeRef =
      exif.GPSLatitudeRef === 'S' || exif.GPSLatitudeRef === 'South'
        ? GPSDirection.South
        : GPSDirection.North

    const longitudeRef =
      exif.GPSLongitudeRef === 'W' || exif.GPSLongitudeRef === 'West'
        ? GPSDirection.West
        : GPSDirection.East

    // Apply reference direction to coordinates
    if (latitudeRef === GPSDirection.South) {
      latitude = -latitude
    }

    if (longitudeRef === GPSDirection.West) {
      longitude = -longitude
    }

    // Process altitude information
    let altitude: number | undefined
    let altitudeRef: 'Above Sea Level' | 'Below Sea Level' | undefined

    if (exif.GPSAltitude && typeof exif.GPSAltitude === 'number') {
      altitude = exif.GPSAltitude
      altitudeRef =
        exif.GPSAltitudeRef === 'Below Sea Level'
          ? 'Below Sea Level'
          : 'Above Sea Level'

      // Apply altitude reference
      if (altitudeRef === 'Below Sea Level') {
        altitude = -altitude
      }
    }

    // Validate coordinates using the validation function
    const coordinatesToValidate = { latitude, longitude }
    if (!isValidGPSCoordinates(coordinatesToValidate)) {
      return null
    }

    return { latitude, longitude, latitudeRef, longitudeRef, altitude, altitudeRef }
  } catch (error) {
    console.warn('Failed to parse GPS coordinates from EXIF:', error)
    return null
  }
}

/**
 * GPS coordinate validation function
 */
export function isValidGPSCoordinates(
  coords: GPSCoordinates | null,
): coords is GPSCoordinates {
  if (!coords) return false

  const { latitude, longitude } = coords

  return (
    typeof latitude === 'number' &&
    typeof longitude === 'number' &&
    !Number.isNaN(latitude) &&
    !Number.isNaN(longitude) &&
    latitude >= -90 &&
    latitude <= 90 &&
    longitude >= -180 &&
    longitude <= 180
  )
}

/**
 * Convert PhotoManifestItem to PhotoMarker if it has GPS coordinates in EXIF
 */
export function convertPhotoToMarkerFromEXIF(
  photo: PhotoManifestItem,
): PhotoMarker | null {
  const { exif } = photo

  if (!exif) {
    return null
  }

  // Use the common GPS conversion function
  const gpsData = convertExifGPSToDecimal(exif)
  if (!gpsData) {
    return null
  }

  const { latitude, longitude, latitudeRef, longitudeRef, altitude, altitudeRef } = gpsData

  return {
    id: photo.id,
    longitude,
    latitude,
    altitude,
    latitudeRef,
    longitudeRef,
    altitudeRef,
    photo,
  }
}

/**
 * Convert array of PhotoManifestItem to PhotoMarker array using EXIF data
 */
export function convertPhotosToMarkersFromEXIF(
  photos: PhotoManifestItem[],
): PhotoMarker[] {
  return photos
    .map((photo) => convertPhotoToMarkerFromEXIF(photo))
    .filter((marker): marker is PhotoMarker => marker !== null)
}

/**
 * Calculate the bounds and center point for a set of markers
 */
export function calculateMapBounds(markers: PhotoMarker[]): MapBounds | null {
  if (markers.length === 0) {
    return null
  }

  const latitudes = markers.map((m) => m.latitude)
  const longitudes = markers.map((m) => m.longitude)

  const minLat = Math.min(...latitudes)
  const maxLat = Math.max(...latitudes)
  const minLng = Math.min(...longitudes)
  const maxLng = Math.max(...longitudes)

  return {
    minLat,
    maxLat,
    minLng,
    maxLng,
    centerLat: (minLat + maxLat) / 2,
    centerLng: (minLng + maxLng) / 2,
    bounds: [
      [minLng, minLat], // Southwest coordinates
      [maxLng, maxLat], // Northeast coordinates
    ] as [[number, number], [number, number]],
  }
}

/**
 * Get initial view state that fits all markers
 */
export function getInitialViewStateForMarkers(
  markers: PhotoMarker[],
): MapViewState {
  const bounds = calculateMapBounds(markers)

  if (!bounds) {
    // Default view if no markers
    return {
      longitude: -122.4,
      latitude: 37.8,
      zoom: 10,
    }
  }

  // Calculate zoom level based on bounds
  const latDiff = bounds.maxLat - bounds.minLat
  const lngDiff = bounds.maxLng - bounds.minLng
  const maxDiff = Math.max(latDiff, lngDiff)

  let zoom = 10
  if (maxDiff < 0.01) zoom = 15
  else if (maxDiff < 0.1) zoom = 12
  else if (maxDiff < 1) zoom = 8
  else if (maxDiff < 10) zoom = 5
  else zoom = 2

  return {
    longitude: bounds.centerLng,
    latitude: bounds.centerLat,
    zoom,
  }
}