#!/usr/bin/env bash
# Test block-clone functionality on temporary Btrfs and XFS loopback filesystems.
#
# Requires: root/sudo, btrfs-progs (mkfs.btrfs), xfsprogs (mkfs.xfs)
#
# Usage:
#   sudo ./scripts/test_scripts/block-clone-test.sh [path-to-zencore-test]
#
# If no path is given, defaults to build/linux/x86_64/debug/zencore-test
# relative to the repository root.
#
# Options:
#   --btrfs-only   Only test Btrfs
#   --xfs-only     Only test XFS

set -euo pipefail

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
REPO_ROOT="$(cd "$SCRIPT_DIR/../.." && pwd)"

TEST_BINARY=""
RUN_BTRFS=true
RUN_XFS=true

for arg in "$@"; do
    case "$arg" in
        --btrfs-only) RUN_XFS=false ;;
        --xfs-only)   RUN_BTRFS=false ;;
        *)            TEST_BINARY="$arg" ;;
    esac
done

TEST_BINARY="${TEST_BINARY:-$REPO_ROOT/build/linux/x86_64/debug/zencore-test}"
IMAGE_SIZE="512M"
TEST_CASES="TryCloneFile,CopyFile.Clone,SupportsBlockRefCounting,CloneQueryInterface"

# Track all temp files for cleanup
CLEANUP_MOUNTS=()
CLEANUP_DIRS=()
CLEANUP_FILES=()

cleanup() {
    local exit_code=$?
    set +e

    for mnt in "${CLEANUP_MOUNTS[@]}"; do
        if mountpoint -q "$mnt" 2>/dev/null; then
            umount "$mnt"
        fi
    done
    for dir in "${CLEANUP_DIRS[@]}"; do
        [ -d "$dir" ] && rmdir "$dir"
    done
    for f in "${CLEANUP_FILES[@]}"; do
        [ -f "$f" ] && rm -f "$f"
    done

    if [ $exit_code -ne 0 ]; then
        echo "FAILED (exit code $exit_code)"
    fi
    exit $exit_code
}
trap cleanup EXIT

# --- Preflight checks ---

if [ "$(id -u)" -ne 0 ]; then
    echo "error: this script must be run as root (for mount/umount)" >&2
    exit 1
fi

if [ ! -x "$TEST_BINARY" ]; then
    echo "error: test binary not found or not executable: $TEST_BINARY" >&2
    echo "hint:  build with 'xmake config -m debug && xmake build zencore-test'" >&2
    exit 1
fi

if $RUN_BTRFS && ! command -v mkfs.btrfs &>/dev/null; then
    echo "warning: mkfs.btrfs not found — install btrfs-progs to test Btrfs, skipping" >&2
    RUN_BTRFS=false
fi

if $RUN_XFS && ! command -v mkfs.xfs &>/dev/null; then
    echo "warning: mkfs.xfs not found — install xfsprogs to test XFS, skipping" >&2
    RUN_XFS=false
fi

if ! $RUN_BTRFS && ! $RUN_XFS; then
    echo "error: no filesystems to test" >&2
    exit 1
fi

# --- Helper to create, mount, and run tests on a loopback filesystem ---

run_tests_on_fs() {
    local fs_type="$1"
    local mkfs_cmd="$2"

    echo ""
    echo "========================================"
    echo "  Testing block-clone on $fs_type"
    echo "========================================"

    local image_path mount_path
    image_path="$(mktemp "/tmp/${fs_type}-clone-test-XXXXXX.img")"
    mount_path="$(mktemp -d "/tmp/${fs_type}-clone-mount-XXXXXX")"
    CLEANUP_FILES+=("$image_path")
    CLEANUP_DIRS+=("$mount_path")
    CLEANUP_MOUNTS+=("$mount_path")

    echo "Creating ${IMAGE_SIZE} ${fs_type} image at ${image_path} ..."
    truncate -s "$IMAGE_SIZE" "$image_path"
    $mkfs_cmd "$image_path"

    echo "Mounting at ${mount_path} ..."
    mount -o loop "$image_path" "$mount_path"
    chmod 777 "$mount_path"

    echo "Copying test binary ..."
    cp "$TEST_BINARY" "$mount_path/zencore-test"
    chmod +x "$mount_path/zencore-test"

    echo "Running tests ..."
    echo "---"
    "$mount_path/zencore-test" \
        --test-suite="core.filesystem" \
        --test-case="$TEST_CASES"
    echo "---"
    echo "$fs_type: all block-clone tests passed."
}

# --- Run ---

if $RUN_BTRFS; then
    run_tests_on_fs "btrfs" "mkfs.btrfs -q"
fi

if $RUN_XFS; then
    run_tests_on_fs "xfs" "mkfs.xfs -q -m reflink=1"
fi

echo ""
echo "All block-clone tests passed."