// Licensed to StellaOps under the BUSL-1.1 license.

using StellaOps.Auth.ServerIntegration;
using Microsoft.AspNetCore.RateLimiting;
using Npgsql;
using StackExchange.Redis;
using StellaOps.ReachGraph.Cache;
using StellaOps.ReachGraph.Hashing;
using StellaOps.ReachGraph.Persistence;
using StellaOps.ReachGraph.Serialization;
using StellaOps.ReachGraph.WebService.Services;
using System.Threading.RateLimiting;

var builder = WebApplication.CreateBuilder(args);

// Add services
builder.Services.AddControllers();
builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen(options =>
{
    options.SwaggerDoc("v1", new()
    {
        Title = "ReachGraph Store API",
        Version = "v1",
        Description = "Content-addressed storage for reachability subgraphs"
    });
});

// PostgreSQL (lazy so integration tests can replace before first resolve)
builder.Services.AddSingleton<NpgsqlDataSource>(sp =>
{
    var config = sp.GetRequiredService<IConfiguration>();
    var connStr = config.GetConnectionString("PostgreSQL")
        ?? throw new InvalidOperationException("PostgreSQL connection string not configured");
    return new NpgsqlDataSourceBuilder(connStr).Build();
});

// Redis/Valkey (lazy so integration tests can replace before first resolve)
builder.Services.AddSingleton<IConnectionMultiplexer>(sp =>
{
    var config = sp.GetRequiredService<IConfiguration>();
    var redisConnStr = config.GetConnectionString("Redis") ?? "localhost:6379";
    return ConnectionMultiplexer.Connect(redisConnStr);
});

// Core services
builder.Services.AddSingleton<CanonicalReachGraphSerializer>();
builder.Services.AddSingleton<ReachGraphDigestComputer>();

// Persistence
builder.Services.AddScoped<IReachGraphRepository, PostgresReachGraphRepository>();

// Cache
builder.Services.Configure<ReachGraphCacheOptions>(
    builder.Configuration.GetSection("ReachGraphCache"));
builder.Services.AddScoped<IReachGraphCache>(sp =>
{
    var redisMultiplexer = sp.GetRequiredService<IConnectionMultiplexer>();
    var serializer = sp.GetRequiredService<CanonicalReachGraphSerializer>();
    var options = Microsoft.Extensions.Options.Options.Create(
        builder.Configuration.GetSection("ReachGraphCache").Get<ReachGraphCacheOptions>()
        ?? new ReachGraphCacheOptions());
    var logger = sp.GetRequiredService<ILogger<ReachGraphValkeyCache>>();

    // TODO: Get tenant from request context
    return new ReachGraphValkeyCache(redisMultiplexer, serializer, options, logger, "default");
});

// Application services
builder.Services.AddScoped<IReachGraphStoreService, ReachGraphStoreService>();
builder.Services.AddScoped<IReachGraphSliceService, ReachGraphSliceService>();
builder.Services.AddScoped<IReachGraphReplayService, ReachGraphReplayService>();

// Rate limiting
builder.Services.AddRateLimiter(options =>
{
    options.RejectionStatusCode = StatusCodes.Status429TooManyRequests;

    options.AddPolicy("reachgraph-read", ctx =>
        RateLimitPartition.GetFixedWindowLimiter(
            ctx.User.FindFirst("tenant")?.Value ?? ctx.Request.Headers["X-Tenant-ID"].FirstOrDefault() ?? "anonymous",
            _ => new FixedWindowRateLimiterOptions
            {
                Window = TimeSpan.FromMinutes(1),
                PermitLimit = 100
            }));

    options.AddPolicy("reachgraph-write", ctx =>
        RateLimitPartition.GetFixedWindowLimiter(
            ctx.User.FindFirst("tenant")?.Value ?? ctx.Request.Headers["X-Tenant-ID"].FirstOrDefault() ?? "anonymous",
            _ => new FixedWindowRateLimiterOptions
            {
                Window = TimeSpan.FromMinutes(1),
                PermitLimit = 20
            }));
});

// Response compression
builder.Services.AddResponseCompression(options =>
{
    options.EnableForHttps = true;
});

builder.Services.AddStellaOpsCors(builder.Environment, builder.Configuration);

builder.TryAddStellaOpsLocalBinding("reachgraph");
var app = builder.Build();
app.LogStellaOpsLocalHostname("reachgraph");

// Configure pipeline
if (app.Environment.IsDevelopment())
{
    app.UseSwagger();
    app.UseSwaggerUI();
}

app.UseHttpsRedirection();
app.UseResponseCompression();
app.UseStellaOpsCors();
app.UseRateLimiter();
app.UseAuthorization();
app.MapControllers();

app.Run();

// Make Program class accessible for integration testing
namespace StellaOps.ReachGraph.WebService
{
    public partial class Program { }
}