package com.haobang.diagnostics;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.haobang.config.AppProperties;
import com.haobang.wal.SyslogWalStatusProvider;
import io.netty.handler.codec.TooLongFrameException;
import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.io.TempDir;

import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Path;
import java.time.LocalDate;
import java.time.ZoneId;
import java.util.Collections;

import static org.junit.jupiter.api.Assertions.assertFalse;
import static org.junit.jupiter.api.Assertions.assertTrue;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.when;

class SyslogDiagnosticsPersistenceTest {
    @TempDir Path tempDirectory;
    private SyslogDiagnosticsPersistence persistence;

    @AfterEach
    void tearDown() {
        if (persistence != null) persistence.shutdown();
    }

    @Test
    void writesSnapshotAndEventsAndKeepsSevenCalendarDays() throws Exception {
        Path snapshots = Files.createDirectories(tempDirectory.resolve("snapshots"));
        Path events = Files.createDirectories(tempDirectory.resolve("events"));
        LocalDate today = LocalDate.now(ZoneId.of("Asia/Shanghai"));
        Path expired = snapshots.resolve("syslog-status-" + today.minusDays(7) + ".jsonl");
        Path retained = events.resolve("syslog-events-" + today.minusDays(6) + ".jsonl");
        Files.write(expired, "old\n".getBytes(StandardCharsets.UTF_8));
        Files.write(retained, "keep\n".getBytes(StandardCharsets.UTF_8));

        AppProperties properties = properties();
        SyslogIpMetricsRegistry registry = new SyslogIpMetricsRegistry(properties);
        SyslogWalStatusProvider provider = mock(SyslogWalStatusProvider.class);
        when(provider.status()).thenReturn(Collections.singletonMap("wal_pending_approx", 0L));
        persistence = new SyslogDiagnosticsPersistence(properties, registry, provider,
                new ObjectMapper());
        persistence.start();

        registry.recordNetworkReceived("10.56.170.107", 35064, "TCP");
        registry.recordNetworkException("10.56.170.107", 35064, "TCP",
                new TooLongFrameException("too long"));
        persistence.writeSnapshotSafely();
        waitUntil(() -> Files.isRegularFile(persistence.eventFile(today)));

        String snapshot = new String(Files.readAllBytes(persistence.snapshotFile(today)),
                StandardCharsets.UTF_8);
        String ipSnapshot = new String(Files.readAllBytes(persistence.ipSnapshotFile(today)),
                StandardCharsets.UTF_8);
        String event = new String(Files.readAllBytes(persistence.eventFile(today)),
                StandardCharsets.UTF_8);
        assertTrue(snapshot.contains("\"ip_stats_count\":1"));
        assertTrue(ipSnapshot.contains("\"source_ip\":\"10.56.170.107\""));
        assertTrue(ipSnapshot.contains("\"delta\""));
        assertTrue(event.contains("\"event_type\":\"TOO_LONG_FRAME\""));
        assertFalse(Files.exists(expired));
        assertTrue(Files.exists(retained));
    }

    private AppProperties properties() {
        AppProperties value = new AppProperties();
        value.setSyslogDiagnosticsEnabled(true);
        value.setSyslogDiagnosticsDirectory(tempDirectory.toString());
        value.setSyslogDiagnosticsSnapshotIntervalMs(60_000L);
        value.setSyslogDiagnosticsRetentionDays(7);
        value.setSyslogDiagnosticsMaxSourceIps(100);
        value.setSyslogDiagnosticsEventQueueCapacity(100);
        value.setAppServiceDeviceCollectId(7);
        value.setAppServiceDeviceCollectName("probe-7");
        return value;
    }

    private void waitUntil(Check condition) throws Exception {
        long deadline = System.currentTimeMillis() + 3000L;
        while (!condition.done() && System.currentTimeMillis() < deadline) Thread.sleep(10L);
        assertTrue(condition.done(), "condition not reached before timeout");
    }

    private interface Check { boolean done() throws Exception; }
}