using System.Linq;
using System.Text.Json;
using Gott.Extensions;
using Gott.Services;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Routing;

namespace Gott.Endpoints;

public static class ProfileEndpoint
{
    public static void MapProfileEndpoints(this WebApplication app)
    {
        app.MapGet("/api/profile", HandleGet);
        app.MapPut("/api/profile", HandleUpdate);
        app.MapPut("/api/profile/password", HandlePasswordChange);
        app.MapGet("/api/users", HandleListDirectory);
    }

    /// <summary>
    /// Minimales User-Verzeichnis für jeden eingeloggten Nutzer (z. B. um eine Session
    /// einem anderen Benutzer zuzuweisen). Gibt bewusst NUR id/username/displayName zurück –
    /// keine sensiblen Felder wie defaultPath/canUseCli/isAdmin (dafür gibt es /api/admin/users).
    /// </summary>
    private static async System.Threading.Tasks.Task HandleListDirectory(HttpContext ctx, DatabaseService db)
    {
        var users = await db.GetUsers();
        var result = users.Select(u => new
        {
            userId = u.UserId,
            username = u.Username,
            displayName = u.DisplayName
        });
        await ctx.Response.WriteAsJsonAsync(result);
    }

    private static async System.Threading.Tasks.Task HandleGet(HttpContext ctx, DatabaseService db)
    {
        var userId = ctx.GetUserId();
        var user = await db.GetUser(userId);
        if (user == null)
        {
            ctx.Response.StatusCode = 404;
            await ctx.Response.WriteAsJsonAsync(new { error = "User not found" });
            return;
        }

        await ctx.Response.WriteAsJsonAsync(new
        {
            userId = user.UserId,
            username = user.Username,
            displayName = user.DisplayName,
            persona = user.Persona,
            defaultPath = user.DefaultPath,
            isAdmin = user.IsAdmin
        });
    }

    private static async System.Threading.Tasks.Task HandleUpdate(HttpContext ctx, DatabaseService db)
    {
        var userId = ctx.GetUserId();
        var body = await JsonSerializer.DeserializeAsync<JsonElement>(ctx.Request.Body);

        var displayName = body.TryGetProperty("displayName", out var dn) ? dn.GetString() : null;
        var persona = body.TryGetProperty("persona", out var p) ? p.GetString() : null;

        await db.UpdateUserProfile(userId, displayName, persona);

        var user = await db.GetUser(userId);
        await ctx.Response.WriteAsJsonAsync(new
        {
            userId = user.UserId,
            username = user.Username,
            displayName = user.DisplayName,
            persona = user.Persona,
            defaultPath = user.DefaultPath,
            isAdmin = user.IsAdmin
        });
    }

    private static async System.Threading.Tasks.Task HandlePasswordChange(HttpContext ctx, DatabaseService db, AuthService auth)
    {
        var userId = ctx.GetUserId();
        var body = await JsonSerializer.DeserializeAsync<JsonElement>(ctx.Request.Body);

        var currentPassword = body.TryGetProperty("currentPassword", out var cp) ? cp.GetString() : null;
        var newPassword = body.TryGetProperty("newPassword", out var np) ? np.GetString() : null;

        if (string.IsNullOrEmpty(currentPassword) || string.IsNullOrEmpty(newPassword))
        {
            ctx.Response.StatusCode = 400;
            await ctx.Response.WriteAsJsonAsync(new { error = "Aktuelles und neues Passwort erforderlich" });
            return;
        }

        if (newPassword.Length < 4)
        {
            ctx.Response.StatusCode = 400;
            await ctx.Response.WriteAsJsonAsync(new { error = "Passwort muss mindestens 4 Zeichen lang sein" });
            return;
        }

        var user = await db.GetUser(userId);
        if (user == null || !auth.VerifyPassword(currentPassword, user.PasswordHash))
        {
            ctx.Response.StatusCode = 403;
            await ctx.Response.WriteAsJsonAsync(new { error = "Aktuelles Passwort ist falsch" });
            return;
        }

        var newHash = auth.HashPassword(newPassword);
        await db.UpdateUserPassword(userId, newHash);

        await ctx.Response.WriteAsJsonAsync(new { ok = true });
    }
}