#!/usr/bin/env bash
# Test zen service command lifecycle on Linux (systemd).
#
# Requires: root/sudo, systemd
#
# Usage:
#   sudo ./scripts/test_linux/service-test.sh [path-to-zen]
#
# If no path is given, defaults to build/linux/x86_64/debug/zen
# relative to the repository root.

set -euo pipefail

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

ZEN_BINARY="${1:-$REPO_ROOT/build/linux/x86_64/debug/zen}"
ZENSERVER_BINARY="$(dirname "$ZEN_BINARY")/zenserver"
SERVICE_NAME="ZenServerTest-$$"
UNIT_NAME="com.epicgames.unreal.${SERVICE_NAME}"
UNIT_FILE="/etc/systemd/system/${UNIT_NAME}.service"

PASSED=0
FAILED=0
TESTS_RUN=0

# Colors
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
NC='\033[0m' # No Color

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

    echo ""
    echo "--- Cleanup ---"

    # Stop service if running
    if systemctl is-active --quiet "$UNIT_NAME" 2>/dev/null; then
        echo "Stopping test service..."
        systemctl stop "$UNIT_NAME" 2>/dev/null
    fi

    # Disable and remove unit file
    if [ -f "$UNIT_FILE" ]; then
        echo "Removing test unit file..."
        systemctl disable "$UNIT_NAME" 2>/dev/null || true
        rm -f "$UNIT_FILE"
        systemctl daemon-reload 2>/dev/null || true
    fi

    echo ""
    echo "=============================="
    printf "  Tests run:    %d\n" "$TESTS_RUN"
    printf "  ${GREEN}Passed:       %d${NC}\n" "$PASSED"
    if [ "$FAILED" -gt 0 ]; then
        printf "  ${RED}Failed:       %d${NC}\n" "$FAILED"
    else
        printf "  Failed:       %d\n" "$FAILED"
    fi
    echo "=============================="

    if [ "$FAILED" -gt 0 ]; then
        exit 1
    fi
    exit "$exit_code"
}

trap cleanup EXIT

pass() {
    TESTS_RUN=$((TESTS_RUN + 1))
    PASSED=$((PASSED + 1))
    printf "  ${GREEN}PASS${NC}: %s\n" "$1"
}

fail() {
    TESTS_RUN=$((TESTS_RUN + 1))
    FAILED=$((FAILED + 1))
    printf "  ${RED}FAIL${NC}: %s\n" "$1"
    if [ -n "${2:-}" ]; then
        printf "        %s\n" "$2"
    fi
}

# ── Preflight checks ──────────────────────────────────────────────

if [ "$(id -u)" -ne 0 ]; then
    echo "Error: this test must be run as root (sudo)."
    exit 1
fi

if ! command -v systemctl &>/dev/null; then
    echo "Error: systemctl not found — this test requires systemd."
    exit 1
fi

if [ ! -x "$ZEN_BINARY" ]; then
    echo "Error: zen binary not found at '$ZEN_BINARY'"
    echo "Build with: xmake config -m debug && xmake build zen"
    exit 1
fi

if [ ! -x "$ZENSERVER_BINARY" ]; then
    echo "Error: zenserver binary not found at '$ZENSERVER_BINARY'"
    echo "Build with: xmake config -m debug && xmake build zenserver"
    exit 1
fi

echo "zen binary:       $ZEN_BINARY"
echo "zenserver binary:  $ZENSERVER_BINARY"
echo "service name:      $SERVICE_NAME"
echo "unit name:         $UNIT_NAME"
echo ""

# Determine which user to run the service as (the user who invoked sudo)
SERVICE_USER="${SUDO_USER:-$(whoami)}"

# ── Test: status before install (should fail) ─────────────────────

echo "--- Test: status before install ---"

OUTPUT=$("$ZEN_BINARY" service status "$SERVICE_NAME" 2>&1 || true)
if echo "$OUTPUT" | grep -qi "not installed"; then
    pass "status reports 'not installed' for non-existent service"
else
    fail "status should report 'not installed'" "got: $OUTPUT"
fi

# ── Test: install ─────────────────────────────────────────────────

echo "--- Test: install ---"

OUTPUT=$("$ZEN_BINARY" service install "$ZENSERVER_BINARY" "$SERVICE_NAME" --user "$SERVICE_USER" 2>&1)
EXIT_CODE=$?

if [ "$EXIT_CODE" -eq 0 ]; then
    pass "install exits with code 0"
else
    fail "install exits with code 0" "got exit code: $EXIT_CODE, output: $OUTPUT"
fi

if [ -f "$UNIT_FILE" ]; then
    pass "unit file created at $UNIT_FILE"
else
    fail "unit file created at $UNIT_FILE"
fi

# Verify unit file contents
if [ -f "$UNIT_FILE" ]; then
    if grep -q "ExecStart=.*zenserver" "$UNIT_FILE"; then
        pass "unit file contains ExecStart with zenserver"
    else
        fail "unit file contains ExecStart with zenserver" "$(cat "$UNIT_FILE")"
    fi

    if grep -q "User=$SERVICE_USER" "$UNIT_FILE"; then
        pass "unit file contains correct User=$SERVICE_USER"
    else
        fail "unit file contains correct User=$SERVICE_USER" "$(grep User "$UNIT_FILE")"
    fi

    if grep -q "Type=notify" "$UNIT_FILE"; then
        pass "unit file uses Type=notify"
    else
        fail "unit file uses Type=notify"
    fi

    if grep -q "WantedBy=multi-user.target" "$UNIT_FILE"; then
        pass "unit file has WantedBy=multi-user.target"
    else
        fail "unit file has WantedBy=multi-user.target"
    fi

    # Verify the service is enabled
    if systemctl is-enabled --quiet "$UNIT_NAME" 2>/dev/null; then
        pass "service is enabled after install"
    else
        fail "service is enabled after install"
    fi
fi

# ── Test: install again (already installed, no --full) ────────────

echo "--- Test: install again (idempotent) ---"

OUTPUT=$("$ZEN_BINARY" service install "$ZENSERVER_BINARY" "$SERVICE_NAME" --user "$SERVICE_USER" 2>&1)
EXIT_CODE=$?

if [ "$EXIT_CODE" -eq 0 ]; then
    pass "re-install exits with code 0"
else
    fail "re-install exits with code 0" "got exit code: $EXIT_CODE"
fi

if echo "$OUTPUT" | grep -qi "already installed"; then
    pass "re-install reports service already installed"
else
    fail "re-install reports service already installed" "got: $OUTPUT"
fi

# ── Test: status after install (not yet started) ──────────────────

echo "--- Test: status after install (stopped) ---"

OUTPUT=$("$ZEN_BINARY" service status "$SERVICE_NAME" 2>&1 || true)
# The status command throws if not running, so we expect an error message
if echo "$OUTPUT" | grep -qi "not running"; then
    pass "status reports 'not running' for stopped service"
else
    fail "status reports 'not running' for stopped service" "got: $OUTPUT"
fi

# ── Test: start ───────────────────────────────────────────────────

echo "--- Test: start ---"

OUTPUT=$("$ZEN_BINARY" service start "$SERVICE_NAME" 2>&1)
EXIT_CODE=$?

if [ "$EXIT_CODE" -eq 0 ]; then
    pass "start exits with code 0"
else
    # The TODO comments in the code indicate start may not work perfectly
    fail "start exits with code 0" "got exit code: $EXIT_CODE, output: $OUTPUT"
fi

# Give the service a moment to start
sleep 1

if systemctl is-active --quiet "$UNIT_NAME" 2>/dev/null; then
    pass "service is active after start"

    # ── Test: status while running ────────────────────────────────

    echo "--- Test: status (running) ---"

    OUTPUT=$("$ZEN_BINARY" service status "$SERVICE_NAME" 2>&1 || true)
    if echo "$OUTPUT" | grep -qi "Running"; then
        pass "status reports 'Running'"
    else
        fail "status reports 'Running'" "got: $OUTPUT"
    fi

    if echo "$OUTPUT" | grep -qi "zenserver"; then
        pass "status shows executable path"
    else
        fail "status shows executable path" "got: $OUTPUT"
    fi

    # ── Test: start again (already running) ───────────────────────

    echo "--- Test: start again (already running) ---"

    OUTPUT=$("$ZEN_BINARY" service start "$SERVICE_NAME" 2>&1)
    if echo "$OUTPUT" | grep -qi "already running"; then
        pass "start reports service already running"
    else
        fail "start reports service already running" "got: $OUTPUT"
    fi

    # ── Test: stop ────────────────────────────────────────────────

    echo "--- Test: stop ---"

    OUTPUT=$("$ZEN_BINARY" service stop "$SERVICE_NAME" 2>&1)
    EXIT_CODE=$?

    if [ "$EXIT_CODE" -eq 0 ]; then
        pass "stop exits with code 0"
    else
        fail "stop exits with code 0" "got exit code: $EXIT_CODE, output: $OUTPUT"
    fi

    sleep 1

    if ! systemctl is-active --quiet "$UNIT_NAME" 2>/dev/null; then
        pass "service is inactive after stop"
    else
        fail "service is inactive after stop"
    fi
else
    fail "service is active after start" "(skipping start-dependent tests)"
fi

# ── Test: stop when already stopped ───────────────────────────────

echo "--- Test: stop when already stopped ---"

# Make sure it's stopped first
systemctl stop "$UNIT_NAME" 2>/dev/null || true
sleep 1

OUTPUT=$("$ZEN_BINARY" service stop "$SERVICE_NAME" 2>&1 || true)
if echo "$OUTPUT" | grep -qi "not running"; then
    pass "stop reports 'not running' when already stopped"
else
    fail "stop reports 'not running' when already stopped" "got: $OUTPUT"
fi

# ── Test: uninstall while running (should fail) ───────────────────

echo "--- Test: uninstall while running (should fail) ---"

# Start the service so we can test uninstall-while-running
"$ZEN_BINARY" service start "$SERVICE_NAME" 2>&1 || true
sleep 1

if systemctl is-active --quiet "$UNIT_NAME" 2>/dev/null; then
    OUTPUT=$("$ZEN_BINARY" service uninstall "$SERVICE_NAME" 2>&1 || true)
    EXIT_CODE=$?

    if [ "$EXIT_CODE" -ne 0 ] || echo "$OUTPUT" | grep -qi "running.*stop"; then
        pass "uninstall refuses while service is running"
    else
        fail "uninstall refuses while service is running" "got: exit=$EXIT_CODE, output: $OUTPUT"
    fi

    # Stop it for the real uninstall test
    "$ZEN_BINARY" service stop "$SERVICE_NAME" 2>&1 || true
    systemctl stop "$UNIT_NAME" 2>/dev/null || true
    sleep 1
else
    echo "  (skipped: could not start service for this test)"
fi

# ── Test: uninstall ───────────────────────────────────────────────

echo "--- Test: uninstall ---"

# Ensure stopped
systemctl stop "$UNIT_NAME" 2>/dev/null || true
sleep 1

OUTPUT=$("$ZEN_BINARY" service uninstall "$SERVICE_NAME" 2>&1)
EXIT_CODE=$?

if [ "$EXIT_CODE" -eq 0 ]; then
    pass "uninstall exits with code 0"
else
    fail "uninstall exits with code 0" "got exit code: $EXIT_CODE, output: $OUTPUT"
fi

if [ ! -f "$UNIT_FILE" ]; then
    pass "unit file removed after uninstall"
else
    fail "unit file removed after uninstall"
fi

# ── Test: status after uninstall ──────────────────────────────────

echo "--- Test: status after uninstall ---"

OUTPUT=$("$ZEN_BINARY" service status "$SERVICE_NAME" 2>&1 || true)
if echo "$OUTPUT" | grep -qi "not installed"; then
    pass "status reports 'not installed' after uninstall"
else
    fail "status reports 'not installed' after uninstall" "got: $OUTPUT"
fi

# ── Test: uninstall when not installed (idempotent) ───────────────

echo "--- Test: uninstall when not installed ---"

OUTPUT=$("$ZEN_BINARY" service uninstall "$SERVICE_NAME" 2>&1)
EXIT_CODE=$?

if [ "$EXIT_CODE" -eq 0 ]; then
    pass "uninstall of non-existent service exits with code 0"
else
    fail "uninstall of non-existent service exits with code 0" "got exit code: $EXIT_CODE"
fi

if echo "$OUTPUT" | grep -qi "not installed"; then
    pass "uninstall reports service not installed"
else
    fail "uninstall reports service not installed" "got: $OUTPUT"
fi