#!/usr/bin/env bash

# The production change that breaks these cases is accepting an unverified
# download, a wrong signer, or executable/malformed provenance data.
set -euo pipefail

repo_dir="$(cd "$(dirname "${BASH_SOURCE[0]}")/../.." && pwd)"
fixtures="$repo_dir/tests/setup/fixtures/provenance"
config="$repo_dir/setup/provenance/installers.conf"
test_tmp="$(mktemp -d)"
host_gnupg="${GNUPGHOME:-$HOME/.gnupg}"
host_rpmdb="/usr/lib/sysimage/rpm/rpmdb.sqlite"

cleanup() {
    rm -rf -- "$test_tmp"
}
trap cleanup EXIT
trap 'exit 130' INT
trap 'exit 143' TERM

fail() {
    printf 'package provenance contract: %s\n' "$*" >&2
    exit 1
}

expect_success() {
    "$@" || fail "expected success: $*"
}

expect_failure() {
    if "$@"; then
        fail "expected failure: $*"
    fi
}

assert_file_bytes() {
    local path="$1" expected="$2"
    [[ "$(<"$path")" == "$expected" ]] || fail "unexpected bytes in $path"
}

snapshot() {
    local path="$1"
    if [[ -e "$path" ]]; then
        stat -c '%i:%s:%Y:%Z' "$path"
    else
        printf 'absent'
    fi
}

snapshot_gpg_state() {
    local path="$1" file
    [[ -d "$path" ]] || return 0
    while IFS= read -r file; do
        sha256sum "$file"
    done < <(find "$path" -maxdepth 1 -type f \( -name pubring.kbx -o -name trustdb.gpg \) | sort)
}

# This must be the only production file sourced by the contract.
# shellcheck source=../../setup/lib/artifact-provenance
source "$repo_dir/setup/lib/artifact-provenance"

fixture_fingerprint='6016FF18CAE298CE3648EE2325E01F765E1EF9FA'
tiny_sha256='291bd319ae85488101e908e37fc0fa1b0da1429ba27e10d2b391cb3f60dd44ea'
base64 --decode "$fixtures/signed-fixture.rpm.base64" > "$test_tmp/signed-fixture.rpm"
base64 --decode "$fixtures/unsigned-fixture.rpm.base64" > "$test_tmp/unsigned-fixture.rpm"
base64 --decode "$fixtures/wrong-signer-fixture.rpm.base64" > "$test_tmp/wrong-signer-fixture.rpm"

[[ "$(wc -l < "$fixtures/SHASUMS256.txt")" -eq 4 ]] || fail 'signed checksum fixture is not four lines'
[[ "$(cmp -l "$fixtures/tiny-artifact" "$fixtures/tiny-artifact-tampered" | wc -l)" -eq 1 ]] \
    || fail 'tampered artifact does not differ by exactly one byte'

expect_success key_fingerprint_matches "$fixtures/fixture-key.asc" "$fixture_fingerprint"
expect_failure key_fingerprint_matches "$fixtures/fixture-key.asc" '0000000000000000000000000000000000000000'
cat "$fixtures/fixture-key.asc" "$fixtures/wrong-signer-key.asc" > "$test_tmp/combined-key.asc"
expect_failure key_fingerprint_matches "$test_tmp/combined-key.asc" "$fixture_fingerprint"

expect_success verify_detached_signature \
    "$fixtures/fixture-key.asc" "$fixtures/SHASUMS256.txt.asc" "$fixtures/SHASUMS256.txt"
expect_failure verify_detached_signature \
    "$fixtures/fixture-key.asc" "$fixtures/SHASUMS256.txt.asc" "$fixtures/tiny-artifact"
cp "$fixtures/SHASUMS256.txt.asc" "$test_tmp/bad-signature.asc"
sed -i 's/^=MJqv$/=MJqa/' "$test_tmp/bad-signature.asc"
expect_failure verify_detached_signature \
    "$fixtures/fixture-key.asc" "$test_tmp/bad-signature.asc" "$fixtures/SHASUMS256.txt"
expect_failure verify_detached_signature \
    "$test_tmp/combined-key.asc" "$fixtures/wrong-signer-SHASUMS256.txt.asc" "$fixtures/SHASUMS256.txt"

mkdir "$test_tmp/bin"
cat > "$test_tmp/bin/curl" <<'STUB'
#!/usr/bin/env bash
set -euo pipefail
output=''
connect_timeout=''
max_time=''
max_filesize=''
while (($#)); do
    case "$1" in
        --output) output="$2"; shift 2 ;;
        --connect-timeout) connect_timeout="$2"; shift 2 ;;
        --max-time) max_time="$2"; shift 2 ;;
        --max-filesize) max_filesize="$2"; shift 2 ;;
        *) shift ;;
    esac
done
[[ "$connect_timeout" == 10 && "$max_time" == 600 && "$max_filesize" == "${CURL_EXPECTED_MAX_BYTES:?}" ]] || exit 65
case "${CURL_FIXTURE:?}" in
    good) cp "$CURL_FIXTURE_ROOT/tiny-artifact" "$output" ;;
    oversized) head -c 1025 /dev/zero > "$output" ;;
    interrupted) printf 'partial' > "$output"; exit 42 ;;
    *) exit 64 ;;
esac
STUB
chmod +x "$test_tmp/bin/curl"
PATH="$test_tmp/bin:$PATH"
export PATH CURL_FIXTURE_ROOT="$fixtures" CURL_EXPECTED_MAX_BYTES=1024

destination="$test_tmp/destination"
export CURL_FIXTURE=good
expect_success download_sha256 'https://fixture.invalid/good' "$tiny_sha256" 1024 "$destination"
cmp -s "$fixtures/tiny-artifact" "$destination" || fail 'verified download changed artifact bytes'
[[ ! -e "$destination.part" ]] || fail 'successful download left a part file'

export CURL_FIXTURE=good
expect_failure download_sha256 'https://fixture.invalid/uppercase-digest' \
    '291BD319AE85488101E908E37FC0FA1B0DA1429BA27E10D2B391CB3F60DD44EA' 1024 \
    "$test_tmp/uppercase-destination"

printf 'known-good\n' > "$destination"
export CURL_FIXTURE=good
expect_failure download_sha256 'https://fixture.invalid/bad-digest' \
    '0000000000000000000000000000000000000000000000000000000000000000' 1024 "$destination"
assert_file_bytes "$destination" 'known-good'
[[ ! -e "$destination.part" ]] || fail 'bad digest left a part file'

protected="$test_tmp/protected-known-good"
printf 'known-good\n' > "$protected"
ln -s "$protected" "$destination.part"
expect_failure download_sha256 'https://fixture.invalid/symlink-part' \
    '0000000000000000000000000000000000000000000000000000000000000000' 1024 "$destination"
assert_file_bytes "$protected" 'known-good'
[[ -L "$destination.part" ]] || fail 'symlinked destination part was not preserved'
rm -f -- "$destination.part"

ln "$protected" "$destination.part"
expect_failure download_sha256 'https://fixture.invalid/hard-link-part' \
    '0000000000000000000000000000000000000000000000000000000000000000' 1024 "$destination"
assert_file_bytes "$protected" 'known-good'
[[ "$(stat -c %i "$protected")" == "$(stat -c %i "$destination.part")" ]] \
    || fail 'hard-linked destination part was not preserved'
rm -f -- "$destination.part"

export CURL_FIXTURE=oversized
expect_failure download_sha256 'https://fixture.invalid/oversized' "$tiny_sha256" 1024 "$destination"
assert_file_bytes "$destination" 'known-good'
[[ ! -e "$destination.part" ]] || fail 'oversized download left a part file'

export CURL_FIXTURE=interrupted
expect_failure download_sha256 'https://fixture.invalid/interrupted' "$tiny_sha256" 1024 "$destination"
assert_file_bytes "$destination" 'known-good'
[[ ! -e "$destination.part" ]] || fail 'interrupted download left a part file'

before_gnupg="$(snapshot "$host_gnupg")"
before_gpg_files="$(snapshot_gpg_state "$host_gnupg")"
before_rpmdb="$(snapshot "$host_rpmdb")"
expect_success rpm_signature_matches \
    "$test_tmp/signed-fixture.rpm" "$fixtures/fixture-key.asc" "$fixture_fingerprint"
expect_failure rpm_signature_matches \
    "$test_tmp/unsigned-fixture.rpm" "$fixtures/fixture-key.asc" "$fixture_fingerprint"
expect_failure rpm_signature_matches \
    "$test_tmp/signed-fixture.rpm" "$fixtures/fixture-key.asc" '0000000000000000000000000000000000000000'
expect_failure rpm_signature_matches \
    "$test_tmp/wrong-signer-fixture.rpm" "$fixtures/fixture-key.asc" "$fixture_fingerprint"
expect_failure rpm_signature_matches \
    "$test_tmp/wrong-signer-fixture.rpm" "$test_tmp/combined-key.asc" "$fixture_fingerprint"
[[ "$before_gnupg" == "$(snapshot "$host_gnupg")" ]] || fail 'host GPG state changed'
[[ "$before_gpg_files" == "$(snapshot_gpg_state "$host_gnupg")" ]] || fail 'host GPG keybox or trust database changed'
[[ "$before_rpmdb" == "$(snapshot "$host_rpmdb")" ]] || fail 'host RPM database changed'

expect_success load_installer_provenance "$config"
[[ "${INSTALLER_PROVENANCE[BUN_VERSION]:-}" == '1.4.0' ]] || fail 'valid provenance was not loaded'
for key_spec in \
    'terra44 TERRA_FINGERPRINT' \
    'claude-code CLAUDE_CODE_FINGERPRINT' \
    'bun BUN_FINGERPRINT' \
    'rpmfusion-free RPMFUSION_FREE_FINGERPRINT' \
    'rpmfusion-nonfree RPMFUSION_NONFREE_FINGERPRINT' \
    'hyprland-copr HYPRLAND_COPR_FINGERPRINT' \
    'flathub FLATHUB_FINGERPRINT' \
    'claude-desktop CLAUDE_DESKTOP_FINGERPRINT'; do
    read -r key_file fingerprint_name <<<"$key_spec"
    expect_success key_fingerprint_matches "$repo_dir/setup/provenance/keys/$key_file.asc" \
        "${INSTALLER_PROVENANCE[$fingerprint_name]}"
done

parser_fixture="$test_tmp/installers.conf"
cp "$config" "$parser_fixture"
printf 'UNKNOWN_KEY=value\n' >> "$parser_fixture"
expect_failure load_installer_provenance "$parser_fixture"

cp "$config" "$parser_fixture"
printf 'BUN_VERSION=1.4.0\n' >> "$parser_fixture"
expect_failure load_installer_provenance "$parser_fixture"

grep -v '^NODE_VERSION=' "$config" > "$parser_fixture"
expect_failure load_installer_provenance "$parser_fixture"

cp "$config" "$parser_fixture"
sed -i 's/^BUN_VERSION=/ BUN_VERSION=/' "$parser_fixture"
expect_failure load_installer_provenance "$parser_fixture"

cp "$config" "$parser_fixture"
sed -i 's/^BUN_VERSION=.*/BUN_VERSION=$(id -u)/' "$parser_fixture"
expect_failure load_installer_provenance "$parser_fixture"

cp "$config" "$parser_fixture"
printf 'BUN_ARMV7_URL=https://fixture.invalid/bun\n' >> "$parser_fixture"
expect_failure load_installer_provenance "$parser_fixture"

printf 'package provenance contract: PASS\n'