using System.Text.Json;
using Journal.Core;
using Journal.Core.Services.Config;
using Journal.Core.Services.Database;
using Journal.WebGateway.Infrastructure;
using Journal.WebGateway.Security;
using Microsoft.AspNetCore.Authentication;
using Microsoft.AspNetCore.Authentication.Cookies;
using Microsoft.AspNetCore.Authorization;
using Microsoft.Extensions.FileProviders;

namespace Journal.WebGateway.Extensions;

public static class EndpointExtensions
{
    public static void MapGatewayEndpoints(this IEndpointRouteBuilder app, string webDistPath)
    {
        MapAuthEndpoints(app);
        MapApiEndpoints(app);
        MapStaticFiles(app, webDistPath);
    }

    private static void MapAuthEndpoints(IEndpointRouteBuilder app)
    {
        app.MapGet("/gateway/login", [AllowAnonymous] async (HttpContext context) =>
        {
            context.Response.ContentType = "text/html; charset=utf-8";
            await context.Response.WriteAsync(LoginPage.GetHtml());
        });

        app.MapPost("/gateway/login", [AllowAnonymous] async (HttpContext context, IConfiguration config, ILogger<Program> logger) =>
        {
            var form = await context.Request.ReadFormAsync();
            var password = form["password"].ToString();
            var configuredHash = config.GetValue<string>("Security:AccessPasswordHash");
            var ip = context.Connection.RemoteIpAddress?.ToString() ?? "unknown";

            var timestamp = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss");

            if (string.IsNullOrWhiteSpace(configuredHash))
            {
                logger.LogError("[{Timestamp}] Gateway login rejected because Security:AccessPasswordHash is not configured.", timestamp);
                return Results.Redirect("/gateway/login?error=config");
            }

            if (GatewayPasswordHasher.VerifyPassword(password, configuredHash))
            {
                logger.LogInformation("[{Timestamp}] Audit: Successful login from {IP}", timestamp, ip);
                var claims = new[] { new System.Security.Claims.Claim(System.Security.Claims.ClaimTypes.Name, "WebUser") };
                var identity = new System.Security.Claims.ClaimsIdentity(claims, CookieAuthenticationDefaults.AuthenticationScheme);
                var principal = new System.Security.Claims.ClaimsPrincipal(identity);

                await context.SignInAsync(CookieAuthenticationDefaults.AuthenticationScheme, principal);
                return Results.Redirect("/");
            }

            logger.LogWarning("[{Timestamp}] Audit: FAILED login attempt from {IP}", timestamp, ip);
            return Results.Redirect("/gateway/login?error=invalid");
        });

        app.MapGet("/gateway/logout", async (HttpContext context) =>
        {
            await context.SignOutAsync(CookieAuthenticationDefaults.AuthenticationScheme);
            return Results.Redirect("/gateway/login");
        });
    }

    private static void MapApiEndpoints(IEndpointRouteBuilder app)
    {
        var group = app.MapGroup("/api");

        group.MapGet("/health", [AllowAnonymous] () => Results.Ok(new
        {
            ok = true,
            service = "Journal.WebGateway"
        }));

        group.MapGet("/web/status", (WebUiState webUiState) => Results.Ok(new
        {
            distPath = webUiState.DistPath,
            exists = webUiState.Exists
        }));

        group.MapPost("/command", async (CommandEnvelope? command, Entry entry, ILogger<Program> logger) =>
        {
            if (command is null || string.IsNullOrWhiteSpace(command.Action))
            {
                return Results.Json(new { ok = false, error = "Missing action" }, statusCode: 400);
            }

            var options = new JsonSerializerOptions { PropertyNamingPolicy = JsonNamingPolicy.CamelCase };
            var inputJson = JsonSerializer.Serialize(command, options);

            logger.LogInformation("Executing command: {Action}", command.Action);
            var responseJson = await entry.HandleCommandAsync(inputJson);

            return Results.Content(responseJson, "application/json");
        });

        group.MapGet("/sidecar/root", (SidecarRootState rootState) =>
        {
            var (root, isCustom) = rootState.Get();
            return Results.Ok(new { root, isCustom });
        });

        group.MapPost("/sidecar/root", () =>
        {
            return Results.BadRequest(new
            {
                ok = false,
                error = "WebGateway root is startup-only. Configure GatewaySettings:RepoRoot or JOURNAL_PROJECT_ROOT before launch."
            });
        });

        group.MapGet("/runtime/diagnostics", (
            SidecarRootState rootState,
            IJournalConfigService configService,
            IJournalDatabaseService databaseService,
            HttpContext context) =>
        {
            var (root, isCustom) = rootState.Get();
            var config = configService.Current;
            var gatewayUrl = $"{context.Request.Scheme}://{context.Request.Host}";

            return Results.Ok(new
            {
                backendMode = "webgateway",
                root,
                isCustomRoot = isCustom,
                vaultDirectory = config.VaultDirectory,
                databasePath = databaseService.GetDatabasePath(),
                sidecarPath = "Not used by WebGateway",
                gatewayPath = Environment.ProcessPath ?? AppContext.BaseDirectory,
                gatewayUrl
            });
        });
    }

    private static void MapStaticFiles(IEndpointRouteBuilder app, string webDistPath)
    {
        if (!Directory.Exists(webDistPath) || !File.Exists(Path.Combine(webDistPath, "index.html")))
        {
            app.MapGet("/", () => Results.Ok(new
            {
                name = "Journal.WebGateway",
                status = "ok",
                uiAvailable = false,
                message = "No built web UI found. Build Journal.App with ./scripts/publish-app.ps1 -Target web.",
                expectedDist = webDistPath
            }));
            return;
        }

        var fileProvider = new PhysicalFileProvider(webDistPath);
        var indexPath = Path.Combine(webDistPath, "index.html");

        // Note: Generic static file middleware should be in Program.cs
        // but the specific root/fallback routes can be here.

        app.MapGet("/", async (HttpContext context) =>
        {
            context.Response.ContentType = "text/html; charset=utf-8";
            await context.Response.SendFileAsync(indexPath);
        });

        app.MapFallback(async (HttpContext context) =>
        {
            if (context.Request.Path.StartsWithSegments("/api"))
            {
                context.Response.StatusCode = StatusCodes.Status404NotFound;
                return;
            }

            context.Response.ContentType = "text/html; charset=utf-8";
            await context.Response.SendFileAsync(indexPath);
        });
    }
}