using Microsoft.Data.Sqlite;
using Microsoft.Extensions.Logging.Abstractions;
using Microsoft.Extensions.Options;

namespace ScadaLink.SiteEventLogging.Tests;

public class SiteEventLoggerTests : IDisposable
{
    private readonly SiteEventLogger _logger;
    private readonly SqliteConnection _verifyConnection;
    private readonly string _dbPath;

    public SiteEventLoggerTests()
    {
        _dbPath = Path.Combine(Path.GetTempPath(), $"test_events_{Guid.NewGuid()}.db");
        var options = Options.Create(new SiteEventLogOptions { DatabasePath = _dbPath });
        _logger = new SiteEventLogger(options, NullLogger<SiteEventLogger>.Instance);

        // Separate connection for verification queries
        _verifyConnection = new SqliteConnection($"Data Source={_dbPath}");
        _verifyConnection.Open();
    }

    public void Dispose()
    {
        _verifyConnection.Dispose();
        _logger.Dispose();
        if (File.Exists(_dbPath)) File.Delete(_dbPath);
    }

    [Fact]
    public async Task LogEventAsync_InsertsRecord()
    {
        await _logger.LogEventAsync("script", "Error", "inst-1", "ScriptActor:Monitor", "Script failed", "{\"stack\":\"...\"}");

        using var cmd = _verifyConnection.CreateCommand();
        cmd.CommandText = "SELECT COUNT(*) FROM site_events";
        var count = (long)cmd.ExecuteScalar()!;
        Assert.Equal(1, count);
    }

    [Fact]
    public async Task LogEventAsync_StoresAllFields()
    {
        await _logger.LogEventAsync("alarm", "Warning", "inst-2", "AlarmActor:TempHigh", "Alarm triggered", "{\"value\":95}");

        using var cmd = _verifyConnection.CreateCommand();
        cmd.CommandText = "SELECT event_type, severity, instance_id, source, message, details FROM site_events LIMIT 1";
        using var reader = cmd.ExecuteReader();
        Assert.True(reader.Read());
        Assert.Equal("alarm", reader.GetString(0));
        Assert.Equal("Warning", reader.GetString(1));
        Assert.Equal("inst-2", reader.GetString(2));
        Assert.Equal("AlarmActor:TempHigh", reader.GetString(3));
        Assert.Equal("Alarm triggered", reader.GetString(4));
        Assert.Equal("{\"value\":95}", reader.GetString(5));
    }

    [Fact]
    public async Task LogEventAsync_NullableFieldsAllowed()
    {
        await _logger.LogEventAsync("deployment", "Info", null, "DeploymentManager", "Deployed instance");

        using var cmd = _verifyConnection.CreateCommand();
        cmd.CommandText = "SELECT instance_id, details FROM site_events LIMIT 1";
        using var reader = cmd.ExecuteReader();
        Assert.True(reader.Read());
        Assert.True(reader.IsDBNull(0));
        Assert.True(reader.IsDBNull(1));
    }

    [Fact]
    public async Task LogEventAsync_StoresIso8601UtcTimestamp()
    {
        await _logger.LogEventAsync("connection", "Info", null, "DCL", "Connected");

        using var cmd = _verifyConnection.CreateCommand();
        cmd.CommandText = "SELECT timestamp FROM site_events LIMIT 1";
        var ts = (string)cmd.ExecuteScalar()!;
        var parsed = DateTimeOffset.Parse(ts);
        Assert.Equal(TimeSpan.Zero, parsed.Offset);
    }

    [Fact]
    public async Task LogEventAsync_ThrowsOnEmptyEventType()
    {
        await Assert.ThrowsAsync<ArgumentException>(() =>
            _logger.LogEventAsync("", "Info", null, "Source", "Message"));
    }

    [Fact]
    public async Task LogEventAsync_ThrowsOnEmptySeverity()
    {
        await Assert.ThrowsAsync<ArgumentException>(() =>
            _logger.LogEventAsync("script", "", null, "Source", "Message"));
    }

    [Fact]
    public async Task LogEventAsync_ThrowsOnEmptySource()
    {
        await Assert.ThrowsAsync<ArgumentException>(() =>
            _logger.LogEventAsync("script", "Info", null, "", "Message"));
    }

    [Fact]
    public async Task LogEventAsync_ThrowsOnEmptyMessage()
    {
        await Assert.ThrowsAsync<ArgumentException>(() =>
            _logger.LogEventAsync("script", "Info", null, "Source", ""));
    }

    [Fact]
    public async Task LogEventAsync_MultipleEvents_AutoIncrementIds()
    {
        await _logger.LogEventAsync("script", "Info", null, "S1", "First");
        await _logger.LogEventAsync("script", "Info", null, "S2", "Second");
        await _logger.LogEventAsync("script", "Info", null, "S3", "Third");

        using var cmd = _verifyConnection.CreateCommand();
        cmd.CommandText = "SELECT id FROM site_events ORDER BY id";
        using var reader = cmd.ExecuteReader();
        var ids = new List<long>();
        while (reader.Read()) ids.Add(reader.GetInt64(0));

        Assert.Equal(3, ids.Count);
        Assert.True(ids[0] < ids[1] && ids[1] < ids[2]);
    }

    [Fact]
    public async Task AllEventTypes_Accepted()
    {
        var types = new[] { "script", "alarm", "deployment", "connection", "store_and_forward", "instance_lifecycle" };
        foreach (var t in types)
        {
            await _logger.LogEventAsync(t, "Info", null, "Test", $"Event type: {t}");
        }

        using var cmd = _verifyConnection.CreateCommand();
        cmd.CommandText = "SELECT COUNT(DISTINCT event_type) FROM site_events";
        var count = (long)cmd.ExecuteScalar()!;
        Assert.Equal(6, count);
    }
}