#!/bin/sh
# Fetches the ANISE kernels listed in data/kernels.tsv and verifies their
# checksums. Idempotent: a file that is already present and correct is left alone.
#
# Usage: scripts/fetch-kernels.sh [directory]
#        ASTROKIT_KERNELS=/somewhere scripts/fetch-kernels.sh

set -e

root=$(CDPATH= cd -- "$(dirname -- "$0")/.." && pwd)
manifest="$root/data/kernels.tsv"
target=${1:-${ASTROKIT_KERNELS:-$root/data/kernels}}

if [ ! -f "$manifest" ]; then
    echo "no manifest at $manifest" >&2
    exit 1
fi

mkdir -p "$target"
echo "kernels -> $target"

status=0
while IFS="$(printf '\t')" read -r name sha downloaded url purpose; do
    case "$name" in '' | \#*) continue ;; esac

    path="$target/$name"
    if [ -f "$path" ] && [ "$(sha256sum "$path" | cut -d' ' -f1)" = "$sha" ]; then
        echo "  ok       $name"
        continue
    fi

    echo "  fetching $name  (pinned $downloaded)"
    if ! curl -sfL --retry 3 -o "$path.partial" "$url"; then
        echo "  FAILED   $name: could not download $url" >&2
        rm -f "$path.partial"
        status=1
        continue
    fi

    got=$(sha256sum "$path.partial" | cut -d' ' -f1)
    if [ "$got" != "$sha" ]; then
        echo "  FAILED   $name: checksum mismatch" >&2
        echo "             expected $sha" >&2
        echo "             got      $got" >&2
        rm -f "$path.partial"
        status=1
        continue
    fi

    mv "$path.partial" "$path"
    echo "  verified $name"
done < "$manifest"

exit $status