using System.Security.Claims;
using System.Text;
using Campaign_Tracker.Server.Audit;
using Campaign_Tracker.Server.Authentication;
using Campaign_Tracker.Server.Authorization;
using Campaign_Tracker.Server.Configuration;
using Campaign_Tracker.Server.ExtensionData;
using Campaign_Tracker.Server.LegacyData;
using Campaign_Tracker.Server.Municipalities;
using Campaign_Tracker.Server.LegacyData.Schema;
using Campaign_Tracker.Server.Seed;
using Microsoft.AspNetCore.Authentication.JwtBearer;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Authorization.Policy;
using Microsoft.IdentityModel.Protocols.OpenIdConnect;
using Microsoft.IdentityModel.Tokens;

var builder = WebApplication.CreateBuilder(args);
DotEnvConfiguration.Load(builder.Configuration, builder.Environment.ContentRootPath);

// Add services to the container.

builder.Services.AddControllers();
// Learn more about configuring OpenAPI at https://aka.ms/aspnet/openapi
builder.Services.AddOpenApi();
builder.Services.Configure<KeycloakOptions>(builder.Configuration.GetSection(KeycloakOptions.SectionName));

// Shared audit logging infrastructure (Story 1.5).
// AppendOnlyFileAuditService writes JSON Lines to daily rotating files in {logDirectory}.
// The directory is configurable via Audit:LogDirectory; defaults to <ContentRoot>/audit-logs.
var auditLogDirectory = builder.Configuration["Audit:LogDirectory"]
    ?? Path.Combine(builder.Environment.ContentRootPath, "audit-logs");
builder.Services.AddSingleton<IAuditService>(sp =>
    new AppendOnlyFileAuditService(
        auditLogDirectory,
        sp.GetRequiredService<ILogger<AppendOnlyFileAuditService>>()));

// IAuthenticationAuditStore delegates durable writes to IAuditService and
// maintains an in-process queue for fast test / recent-event queries.
builder.Services.AddSingleton<IAuthenticationAuditStore, InMemoryAuthenticationAuditStore>();

// Legacy anti-corruption data access layer (Story 1.6).
// A real OleDb-backed provider is used whenever LegacyDatabase:ConnectionString is configured.
// Development can run with deterministic in-memory records; non-development must not silently
// fall back to sample data.
var legacyConnectionString = builder.Configuration["LegacyDatabase:ConnectionString"];
if (!string.IsNullOrWhiteSpace(legacyConnectionString))
{
    if (!OperatingSystem.IsWindows())
    {
        throw new PlatformNotSupportedException(
            "OleDb legacy Access data access is supported only on Windows.");
    }

    builder.Services.AddSingleton<ILegacyDataAccess>(_ =>
#pragma warning disable CA1416
        new OleDbLegacyDataAccess(legacyConnectionString));
#pragma warning restore CA1416
}
else if (builder.Environment.IsDevelopment())
{
    builder.Services.AddSingleton<ILegacyDataAccess, InMemoryLegacyDataAccess>();
}
else
{
    throw new InvalidOperationException(
        "LegacyDatabase:ConnectionString is required outside Development.");
}

// Legacy schema compatibility validation gate (Story 1.7).
// The baseline is captured at startup from the approved Access schema dump
// shipped in source control. The inspector is in-memory in dev (mirrors the
// baseline → no drift) and is replaced with an OleDb-backed implementation
// when running against a live Access database.
var schemaBaselinePath = builder.Configuration["LegacySchema:BaselineFile"]
    ?? Path.Combine(builder.Environment.ContentRootPath, "..", "Initial Documents", "Access_Schema.txt");
var schemaHistoryPath = builder.Configuration["LegacySchema:HistoryFile"]
    ?? Path.Combine(builder.Environment.ContentRootPath, "legacy-schema-history.jsonl");
builder.Services.AddSingleton<TimeProvider>(TimeProvider.System);
builder.Services.AddSingleton(_ =>
    LegacySchemaBaselineParser.ParseFile(Path.GetFullPath(schemaBaselinePath), DateTimeOffset.UtcNow));
if (!string.IsNullOrWhiteSpace(legacyConnectionString))
{
    if (!OperatingSystem.IsWindows())
    {
        throw new PlatformNotSupportedException(
            "OleDb legacy schema inspection is supported only on Windows.");
    }

    builder.Services.AddSingleton<ILegacySchemaInspector>(_ =>
#pragma warning disable CA1416
        new OleDbLegacySchemaInspector(legacyConnectionString));
#pragma warning restore CA1416
}
else
{
    builder.Services.AddSingleton<ILegacySchemaInspector>(sp =>
        new InMemoryLegacySchemaInspector(sp.GetRequiredService<LegacySchemaBaseline>().Tables));
}
builder.Services.AddSingleton<ILegacySchemaCompatibilityCheck>(sp =>
    new LegacySchemaCompatibilityCheck(
        sp.GetRequiredService<LegacySchemaBaseline>(),
        sp.GetRequiredService<ILegacySchemaInspector>(),
        sp.GetRequiredService<TimeProvider>()));
builder.Services.AddSingleton<ILegacySchemaCheckHistory>(_ =>
    new FileLegacySchemaCheckHistory(Path.GetFullPath(schemaHistoryPath)));

// System reference data and rule defaults (Story 1.9).
// Seed keys are stable idempotency boundaries; reruns insert missing defaults
// without overwriting admin-managed changes to existing values.
var seedDataPath = builder.Configuration["Seed:DataFile"]
    ?? Path.Combine(builder.Environment.ContentRootPath, "seed-data.json");
builder.Services.AddSingleton<ISeedDataStore>(_ =>
    new FileSeedDataStore(Path.GetFullPath(seedDataPath)));
builder.Services.AddSingleton<ISeedService, SeedService>();
builder.Services.AddHostedService<SeedHostedService>();

builder.Services.AddHttpClient<IKeycloakTokenClient, KeycloakTokenClient>();
builder.Services.AddSingleton<IAuthorizationMiddlewareResultHandler, AuthorizationAuditResultHandler>();

// Legacy identifier linking for extension records (Story 1.8).
// ILegacyLinkValidator resolves references through the anti-corruption layer (AC #2, AC #3).
// ILegacyLinkIntegrityCheck scans all registered extension record providers (AC #4, NFR13).
// Additional ILegacyLinkedRecordProvider registrations are added by each extension record story.
builder.Services.Configure<LegacyLinkIntegrityOptions>(
    builder.Configuration.GetSection("LegacyLinkIntegrity"));
builder.Services.AddSingleton<ILegacyLinkValidator, LegacyLinkValidator>();
builder.Services.AddScoped<ILegacyLinkIntegrityCheck, LegacyLinkIntegrityService>();
builder.Services.AddSingleton<InMemoryExtensionRecordStore>();
builder.Services.AddSingleton<IExtensionRecordStore>(sp =>
    sp.GetRequiredService<InMemoryExtensionRecordStore>());
builder.Services.AddSingleton<ILegacyLinkedRecordProvider>(sp =>
    sp.GetRequiredService<InMemoryExtensionRecordStore>());
builder.Services.AddHostedService<LegacyLinkIntegrityHostedService>();

// Municipality account profiles (Story 1.10).
// InMemoryMunicipalityProfileRepository also implements ILegacyLinkedRecordProvider,
// so profiles participate in the nightly link integrity check automatically.
builder.Services.AddSingleton<InMemoryMunicipalityProfileRepository>();
builder.Services.AddSingleton<IMunicipalityProfileRepository>(sp =>
    sp.GetRequiredService<InMemoryMunicipalityProfileRepository>());
builder.Services.AddSingleton<ILegacyLinkedRecordProvider>(sp =>
    sp.GetRequiredService<InMemoryMunicipalityProfileRepository>());

var allowedOrigins = builder.Configuration.GetSection("AllowedOrigins").Get<string[]>() ?? [];
builder.Services.AddCors(options =>
{
    options.AddPolicy("ConfiguredOrigins", policy =>
    {
        if (allowedOrigins.Length > 0)
        {
            policy.WithOrigins(allowedOrigins)
                .AllowAnyHeader()
                .AllowAnyMethod();
        }
    });
});

var keycloakOptions = builder.Configuration
    .GetSection(KeycloakOptions.SectionName)
    .Get<KeycloakOptions>() ?? new KeycloakOptions();

if (!builder.Environment.IsDevelopment())
{
    EnsureHttpsEndpoint(keycloakOptions.Authority, "Keycloak:Authority");
    EnsureHttpsEndpoint(keycloakOptions.TokenIssuer, "Keycloak:ValidIssuer/PublicAuthority");
    EnsureHttpsEndpoint(keycloakOptions.TokenEndpointAuthority, "Keycloak:PublicAuthority/Authority");
    if (!string.IsNullOrWhiteSpace(keycloakOptions.MetadataAddress))
    {
        EnsureHttpsEndpoint(keycloakOptions.MetadataAddress, "Keycloak:MetadataAddress");
    }

    if (keycloakOptions.DisableHttpsMetadata)
    {
        throw new InvalidOperationException("Keycloak HTTPS metadata validation cannot be disabled outside Development.");
    }
}

builder.Services
    .AddAuthentication(JwtBearerDefaults.AuthenticationScheme)
    .AddJwtBearer(options =>
    {
        options.RequireHttpsMetadata = !keycloakOptions.DisableHttpsMetadata;
        if (!string.IsNullOrWhiteSpace(keycloakOptions.MetadataAddress))
        {
            options.MetadataAddress = keycloakOptions.MetadataAddress;
        }
        options.TokenValidationParameters = new TokenValidationParameters
        {
            ValidateIssuer = true,
            ValidIssuer = keycloakOptions.TokenIssuer,
            ValidateAudience = true,
            ValidAudiences = keycloakOptions.TokenAudiences,
            ValidateLifetime = true,
            NameClaimType = ClaimTypes.Name,
            RoleClaimType = ClaimTypes.Role,
        };

        if (!string.IsNullOrWhiteSpace(keycloakOptions.TestSigningKey))
        {
            var issuerSigningKey =
                new SymmetricSecurityKey(Encoding.UTF8.GetBytes(keycloakOptions.TestSigningKey));

            options.TokenValidationParameters.ValidateIssuerSigningKey = true;
            options.TokenValidationParameters.IssuerSigningKey = issuerSigningKey;
            options.TokenValidationParameters.IssuerSigningKeys = [issuerSigningKey];
            options.Configuration = new OpenIdConnectConfiguration
            {
                Issuer = keycloakOptions.TokenIssuer,
            };
            options.Configuration.SigningKeys.Add(issuerSigningKey);
        }
        else
        {
            options.Authority = keycloakOptions.Authority;
        }

        options.Events = new JwtBearerEvents
        {
            OnTokenValidated = context =>
            {
                var auditStore = context.HttpContext.RequestServices
                    .GetRequiredService<IAuthenticationAuditStore>();
                var subject = context.Principal?.Identity?.Name
                    ?? context.Principal?.FindFirstValue(ClaimTypes.NameIdentifier)
                    ?? "unknown";
                if (context.Principal?.Identity is ClaimsIdentity identity)
                {
                    var roles = ApplicationRole.NormalizeMany(
                        ApplicationRole.ExtractKeycloakRoles(identity.Claims, keycloakOptions.ClientId));
                    foreach (var role in roles)
                    {
                        if (!identity.HasClaim(ClaimTypes.Role, role))
                        {
                            identity.AddClaim(new Claim(ClaimTypes.Role, role));
                        }
                    }
                }

                auditStore.RecordSuccess(subject, context.HttpContext.TraceIdentifier);
                return Task.CompletedTask;
            },
            OnAuthenticationFailed = context =>
            {
                var auditStore = context.HttpContext.RequestServices
                    .GetRequiredService<IAuthenticationAuditStore>();

                var reason = context.Exception is null
                    ? "invalid bearer token"
                    : $"invalid bearer token: {context.Exception.GetType().Name}";
                auditStore.RecordFailure(reason, context.HttpContext.TraceIdentifier);
                return Task.CompletedTask;
            },
            OnChallenge = context =>
            {
                if (context.AuthenticateFailure is null &&
                    context.Request.Headers.ContainsKey("Authorization"))
                {
                    var auditStore = context.HttpContext.RequestServices
                        .GetRequiredService<IAuthenticationAuditStore>();

                    auditStore.RecordFailure("invalid authorization header", context.HttpContext.TraceIdentifier);
                }

                return Task.CompletedTask;
            },
        };
    });
builder.Services.AddAuthorization(options =>
{
    var recognizedPolicy = new AuthorizationPolicyBuilder()
        .RequireAuthenticatedUser()
        .RequireAssertion(context => ApplicationRole.NormalizeMany(
            context.User.FindAll(ClaimTypes.Role).Select(claim => claim.Value)).Length > 0)
        .Build();

    options.DefaultPolicy = recognizedPolicy;
    options.AddPolicy(ApplicationPolicy.RecognizedApplicationRole, recognizedPolicy);
    options.AddPolicy(ApplicationPolicy.ClientServicesAccess, policy =>
        policy.RequireAuthenticatedUser()
            .RequireAssertion(context => ApplicationRole.HasAny(
                context.User.FindAll(ClaimTypes.Role).Select(claim => claim.Value),
                ApplicationRole.ClientServices)));
    options.AddPolicy(ApplicationPolicy.ProductionAccess, policy =>
        policy.RequireAuthenticatedUser()
            .RequireAssertion(context => ApplicationRole.HasAny(
                context.User.FindAll(ClaimTypes.Role).Select(claim => claim.Value),
                ApplicationRole.Production)));
    options.AddPolicy(ApplicationPolicy.AdminAccess, policy =>
        policy.RequireAuthenticatedUser()
            .RequireAssertion(context => ApplicationRole.HasAny(
                context.User.FindAll(ClaimTypes.Role).Select(claim => claim.Value),
                ApplicationRole.Admin)));
});

var app = builder.Build();

// Release-gate CLI: when invoked with --check-legacy-schema we run the
// compatibility check and exit instead of starting the web host. CI/CD blocks
// releases on a non-zero exit code (Story 1.7 AC #4).
if (LegacySchemaReleaseGate.ShouldRun(args))
{
    var exitCode = await LegacySchemaReleaseGate.ExecuteAsync(
        app.Services.GetRequiredService<ILegacySchemaCompatibilityCheck>(),
        app.Services.GetRequiredService<ILegacySchemaCheckHistory>(),
        Console.Out);
    return exitCode;
}

// Configure the HTTP request pipeline.
if (app.Environment.IsDevelopment())
{
    app.MapOpenApi();
}

app.UseHttpsRedirection();

app.UseCors("ConfiguredOrigins");
app.UseAuthentication();
app.UseAuthorization();

app.MapControllers();
app.MapGet("/health", () => Results.Ok(new { status = "ok" }));

app.Run();
return 0;

static void EnsureHttpsEndpoint(string endpoint, string settingName)
{
    if (!Uri.TryCreate(endpoint, UriKind.Absolute, out var uri) ||
        !string.Equals(uri.Scheme, Uri.UriSchemeHttps, StringComparison.OrdinalIgnoreCase))
    {
        throw new InvalidOperationException($"{settingName} must be an HTTPS URL outside Development.");
    }
}

public partial class Program;