using System.Text;
using System.Text.Json.Serialization;
using Microsoft.AspNetCore.Authentication.JwtBearer;
using Microsoft.AspNetCore.HttpOverrides;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Options;
using Microsoft.IdentityModel.Tokens;
using QMax.Api.Configuration;
using QMax.Api.Data;
using QMax.Api.Infrastructure.Auth;
using QMax.Api.Infrastructure.Hubs;
using QMax.Api.Infrastructure.Max;
using QMax.Api.Infrastructure.Storage;
using QMax.Api.Services;

var builder = WebApplication.CreateBuilder(args);

builder.Services.Configure<QMaxOptions>(builder.Configuration.GetSection("QMax"));
var configuredOptions = builder.Configuration.GetSection("QMax").Get<QMaxOptions>() ?? new QMaxOptions();
var databaseDirectory = Path.GetDirectoryName(Path.GetFullPath(configuredOptions.DatabasePath));
if (!string.IsNullOrWhiteSpace(databaseDirectory))
{
    Directory.CreateDirectory(databaseDirectory);
}

builder.Services.AddDbContext<QMaxDbContext>(options =>
{
    options.UseSqlite($"Data Source={configuredOptions.DatabasePath}");
});

builder.Services.AddCors(options =>
{
    options.AddDefaultPolicy(policy =>
    {
        var origins = configuredOptions.CorsAllowedOrigins
            .Split(',', StringSplitOptions.TrimEntries | StringSplitOptions.RemoveEmptyEntries);

        if (origins.Length > 0)
        {
            policy.WithOrigins(origins).AllowAnyHeader().AllowAnyMethod().AllowCredentials();
        }
        else
        {
            policy.AllowAnyHeader().AllowAnyMethod().SetIsOriginAllowed(_ => true).AllowCredentials();
        }
    });
});

var jwtSecret = !string.IsNullOrWhiteSpace(configuredOptions.JwtSecret) && configuredOptions.JwtSecret.Length >= 32
    ? configuredOptions.JwtSecret
    : builder.Environment.IsDevelopment()
        ? "development-only-qmax-secret-change-before-production"
        : throw new InvalidOperationException("QMax:JwtSecret must be set to at least 32 characters in production.");

builder.Services
    .AddAuthentication(JwtBearerDefaults.AuthenticationScheme)
    .AddJwtBearer(options =>
    {
        options.TokenValidationParameters = new TokenValidationParameters
        {
            ValidateIssuer = true,
            ValidateAudience = true,
            ValidateLifetime = true,
            ValidateIssuerSigningKey = true,
            ValidIssuer = configuredOptions.JwtIssuer,
            ValidAudience = configuredOptions.JwtAudience,
            IssuerSigningKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(jwtSecret)),
            ClockSkew = TimeSpan.FromMinutes(1)
        };
        options.Events = new JwtBearerEvents
        {
            OnMessageReceived = context =>
            {
                var accessToken = context.Request.Query["access_token"];
                var path = context.HttpContext.Request.Path;
                if (!string.IsNullOrEmpty(accessToken) && path.StartsWithSegments("/hubs/qmax"))
                {
                    context.Token = accessToken;
                }

                return Task.CompletedTask;
            }
        };
    });

builder.Services.AddAuthorization();
builder.Services.AddControllers().AddJsonOptions(options =>
{
    options.JsonSerializerOptions.Converters.Add(new JsonStringEnumConverter());
});
builder.Services.AddSignalR();
builder.Services.AddHttpClient();
builder.Services.AddSingleton<ITokenService, TokenService>();
builder.Services.AddScoped<ChatProjectionService>();
builder.Services.AddScoped<IPushNotificationService, FirebasePushNotificationService>();
builder.Services.AddSingleton<IAttachmentStorageService, AttachmentStorageService>();
builder.Services.AddSingleton<MaxBridgeSyncService>();
builder.Services.AddHostedService<MaxSyncWorker>();

if (string.Equals(configuredOptions.MaxMode, "Mock", StringComparison.OrdinalIgnoreCase))
{
    builder.Services.AddSingleton<IMaxBridgeClient, MockMaxBridgeClient>();
}
else
{
    builder.Services.AddHttpClient<IMaxBridgeClient, WorkerMaxBridgeClient>();
}

var app = builder.Build();

app.UseForwardedHeaders(new ForwardedHeadersOptions
{
    ForwardedHeaders = ForwardedHeaders.XForwardedFor | ForwardedHeaders.XForwardedProto
});

app.UseCors();
app.UseAuthentication();
app.UseAuthorization();
app.MapControllers();
app.MapHub<QMaxHub>("/hubs/qmax");

using (var scope = app.Services.CreateScope())
{
    var options = scope.ServiceProvider.GetRequiredService<IOptions<QMaxOptions>>().Value;
    Directory.CreateDirectory(options.StoragePath);
    Directory.CreateDirectory(options.ReleasesPath);
    var db = scope.ServiceProvider.GetRequiredService<QMaxDbContext>();
    await db.Database.EnsureCreatedAsync();
    await EnsureCompatibilitySchemaAsync(db);
}

app.Run();

static async Task EnsureCompatibilitySchemaAsync(QMaxDbContext db)
{
    var connection = db.Database.GetDbConnection();
    if (connection.State != System.Data.ConnectionState.Open)
    {
        await connection.OpenAsync();
    }

    var attachmentColumns = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
    await using (var command = connection.CreateCommand())
    {
        command.CommandText = "PRAGMA table_info(MessageAttachments);";
        await using var reader = await command.ExecuteReaderAsync();
        while (await reader.ReadAsync())
        {
            attachmentColumns.Add(reader.GetString(1));
        }
    }

    if (!attachmentColumns.Contains("RemoteUrl"))
    {
        await db.Database.ExecuteSqlRawAsync("ALTER TABLE MessageAttachments ADD COLUMN RemoteUrl TEXT;");
    }

    if (!attachmentColumns.Contains("ExternalId"))
    {
        await db.Database.ExecuteSqlRawAsync("ALTER TABLE MessageAttachments ADD COLUMN ExternalId TEXT;");
    }

    await db.Database.ExecuteSqlRawAsync("""
        CREATE INDEX IF NOT EXISTS IX_MessageAttachments_MessageId_ExternalId
        ON MessageAttachments (MessageId, ExternalId);
        """);

    await db.Database.ExecuteSqlRawAsync("""
        CREATE TABLE IF NOT EXISTS MessageReactions (
            Id TEXT NOT NULL CONSTRAINT PK_MessageReactions PRIMARY KEY,
            MessageId TEXT NOT NULL,
            Emoji TEXT NOT NULL,
            ActorKey TEXT NOT NULL,
            ActorName TEXT NULL,
            CreatedAt TEXT NOT NULL,
            CONSTRAINT FK_MessageReactions_Messages_MessageId FOREIGN KEY (MessageId) REFERENCES Messages (Id) ON DELETE CASCADE
        );
        """);
    await db.Database.ExecuteSqlRawAsync("""
        CREATE UNIQUE INDEX IF NOT EXISTS IX_MessageReactions_MessageId_ActorKey
        ON MessageReactions (MessageId, ActorKey);
        """);

    await RemoveGenericMediaLabelsAsync(db);
}

static async Task RemoveGenericMediaLabelsAsync(QMaxDbContext db)
{
    var placeholderMessages = await db.Messages
        .Where(message => !db.MessageAttachments.Any(attachment => attachment.MessageId == message.Id))
        .ToListAsync();

    foreach (var message in placeholderMessages.Where(message => MessageTextSanitizer.IsGenericMediaLabel(message.Text)))
    {
        db.Messages.Remove(message);
    }

    var messages = await db.Messages.ToListAsync();
    foreach (var message in messages)
    {
        var cleanText = MessageTextSanitizer.CleanMessageText(
            message.Text,
            await db.MessageAttachments.AnyAsync(attachment => attachment.MessageId == message.Id));

        if (!string.Equals(message.Text, cleanText, StringComparison.Ordinal))
        {
            message.Text = cleanText;
        }
    }

    var chats = await db.Chats.ToListAsync();
    foreach (var chat in chats)
    {
        var cleanPreview = MessageTextSanitizer.CleanChatPreview(chat.LastMessagePreview);
        if (!string.Equals(chat.LastMessagePreview, cleanPreview, StringComparison.Ordinal))
        {
            chat.LastMessagePreview = cleanPreview;
        }
    }

    var attachments = await db.MessageAttachments.ToListAsync();
    foreach (var attachment in attachments)
    {
        var normalizedFileName = AttachmentStorageService.NormalizeRemoteFileName(
            attachment.OriginalFileName,
            attachment.ContentType,
            attachment.Kind);

        if (!string.Equals(attachment.OriginalFileName, normalizedFileName, StringComparison.Ordinal))
        {
            attachment.OriginalFileName = normalizedFileName;
        }
    }

    await db.SaveChangesAsync();
}

public partial class Program;