#!/bin/sh
set -eu

for f in *.JPG; do
    mv "$f" "${f%JPG}jpg"
done

for f in *.jpg; do
    echo "$f"
    chmod 644 "$f"
    info="$(exiv2 -Pnv "$f")"
    # copy tags to IPTC description (sigal)
    tags=$(echo "$info" | sed -n 's/^subject *//p' | tr '[:upper:]' '[:lower:]')
    if [ -n "$tags" ]; then
        exiv2 -M"add Iptc.Application2.Caption String $tags" mo "$f"
    fi

    # rename to EXIF date, if available
    if echo "$info" | grep -q '^DateTime'; then
        exiv2 mv "$f"
    fi
done