#!/usr/bin/env bash
set -euo pipefail

root="$(cd "$(dirname "$0")/.." && pwd)"
version=0.17.0
crate_checksum=80a5eca878900c2e39e9e52fd797954b7fc39eeefc8558257114bfea6a698fcf
patch_file="$root/patches/fuser-$version-lock-flags.patch"
destination="$root/.lazaret/vendor/fuser-$version"
cargo_home="${CARGO_HOME:-$HOME/.cargo}"
fetch_tests=false

if [ "${1:-}" = "--test-dependencies" ] && [ "$#" -eq 1 ]; then
    fetch_tests=true
elif [ "$#" -ne 0 ]; then
    printf '%s\n' "usage: tools/materialize-fuser [--test-dependencies]" >&2
    exit 2
fi

fail() {
    printf '%s\n' "materialize-fuser: $*" >&2
    exit 1
}

for command in cargo patch sha256sum tar; do
    command -v "$command" >/dev/null 2>&1 || fail "$command is required"
done

[ -f "$patch_file" ] || fail "missing patch: $patch_file"
patch_checksum="$(sha256sum "$patch_file" | cut -d ' ' -f 1)"
stamp="$crate_checksum $patch_checksum"

fetch_test_dependencies() {
    local manifest="$destination/Cargo.toml"
    if ! cargo fetch --manifest-path "$manifest" --locked --offline >/dev/null 2>&1; then
        cargo fetch --manifest-path "$manifest" --locked
    fi
}

if [ -f "$destination/.lazaret-materialization" ] &&
    [ "$(tr -d '\n' < "$destination/.lazaret-materialization")" = "$stamp" ]; then
    if $fetch_tests; then
        fetch_test_dependencies
    fi
    exit 0
fi

find_archive() {
    local candidate actual
    for candidate in "$cargo_home"/registry/cache/*/"fuser-$version.crate"; do
        [ -f "$candidate" ] || continue
        actual="$(sha256sum "$candidate" | cut -d ' ' -f 1)"
        if [ "$actual" = "$crate_checksum" ]; then
            printf '%s\n' "$candidate"
            return 0
        fi
    done
    return 1
}

archive="$(find_archive || true)"
if [ -z "$archive" ]; then
    cargo --manifest-path "$root/Cargo.toml" --config 'paths=[]' fetch --locked
    archive="$(find_archive || true)"
fi
[ -n "$archive" ] || fail "Cargo did not fetch the checksum-matching fuser archive"

mkdir -p "$root/.lazaret/vendor"
temporary="$(mktemp -d "$root/.lazaret/vendor/.fuser-$version.XXXXXX")"
trap 'rm -rf "$temporary"' EXIT

tar -xzf "$archive" -C "$temporary"
source="$temporary/fuser-$version"
[ -d "$source" ] || fail "archive did not contain fuser-$version"
patch --directory="$source" --strip=1 --batch --forward < "$patch_file"
printf '%s\n' "$stamp" > "$source/.lazaret-materialization"

rm -rf "$destination"
mv "$source" "$destination"
if $fetch_tests; then
    fetch_test_dependencies
fi