Clean up MetadataLoader.ts

Pigallery2 is using multiple exif, iptc parers (as I could not find one that can do all at once) to get all the metadata for a photo:

1. fs.statSync for silesize, creation date (if i do not find any better from exif) https://github.com/bpatrik/pigallery2/blob/36ecbcbd3d5d3e659ddf20add456982dcb960d3d/src/backend/model/threading/MetadataLoader.ts#L107

2. ts-exif-parser for most of the exif data: https://github.com/bpatrik/pigallery2/blob/36ecbcbd3d5d3e659ddf20add456982dcb960d3d/src/backend/model/threading/MetadataLoader.ts#L114

3. image-size to get the photo dimension if 2) ts-exif-parser fails: https://github.com/bpatrik/pigallery2/blob/36ecbcbd3d5d3e659ddf20add456982dcb960d3d/src/backend/model/threading/MetadataLoader.ts#L169 (The image dimension is a must for this app to work properly )

4. ts-node-iptc for GPS/location, keywords, caption related info: https://github.com/bpatrik/pigallery2/blob/36ecbcbd3d5d3e659ddf20add456982dcb960d3d/src/backend/model/threading/MetadataLoader.ts#L177

5. exifreader for faces and now for orientation as this lib parses that properly https://github.com/bpatrik/pigallery2/blob/36ecbcbd3d5d3e659ddf20add456982dcb960d3d/src/backend/model/threading/MetadataLoader.ts#L206

This class needs a major refactor. Probably. exifreader would be able to handle all cases now. Reducing to only one lib, photo indexing would be probably way faster (instead of 4-5 file open, 1 would do the trick)

[bpatrik]

Thank you, @mattiasw for your library. I think that is the best candidate for pigallry2 to have “one exif reader to rule them all”.

So far I’m not planning to put effort in it on my side. I opened this bug if anyone feels the power to implement it 😃 We already have some unit tests in place for the Metadata loader , so a refactor should be relatively safe.

[bpatrik]

exifr now support sidecars: https://github.com/MikeKovarik/exifr/issues/62