import { Request, Response } from 'express';
import prisma from '../lib/prisma.js';
import * as userService from '../services/user.service.js';
import { logChange } from '../services/audit.service.js';
import { ApiResponse } from '../types/index.js';

// Users
export async function getUsers(req: Request, res: Response): Promise<void> {
  try {
    const { search, isActive, roleId, page, limit } = req.query;
    const result = await userService.getAllUsers({
      search: search as string,
      isActive: isActive !== undefined ? isActive === 'true' : undefined,
      roleId: roleId ? parseInt(roleId as string) : undefined,
      page: page ? parseInt(page as string) : undefined,
      limit: limit ? parseInt(limit as string) : undefined,
    });
    res.json({
      success: true,
      data: result.users,
      pagination: result.pagination,
    } as ApiResponse);
  } catch (error) {
    res.status(500).json({
      success: false,
      error: 'Fehler beim Laden der Benutzer',
    } as ApiResponse);
  }
}

export async function getUser(req: Request, res: Response): Promise<void> {
  try {
    const user = await userService.getUserById(parseInt(req.params.id));
    if (!user) {
      res.status(404).json({
        success: false,
        error: 'Benutzer nicht gefunden',
      } as ApiResponse);
      return;
    }
    res.json({ success: true, data: user } as ApiResponse);
  } catch (error) {
    res.status(500).json({
      success: false,
      error: 'Fehler beim Laden des Benutzers',
    } as ApiResponse);
  }
}

export async function createUser(req: Request, res: Response): Promise<void> {
  try {
    const user = await userService.createUser(req.body);
    await logChange({
      req, action: 'CREATE', resourceType: 'User',
      resourceId: user.id.toString(),
      label: `Benutzer ${user.firstName} ${user.lastName} angelegt`,
    });
    res.status(201).json({ success: true, data: user } as ApiResponse);
  } catch (error) {
    res.status(400).json({
      success: false,
      error: error instanceof Error ? error.message : 'Fehler beim Erstellen des Benutzers',
    } as ApiResponse);
  }
}

export async function updateUser(req: Request, res: Response): Promise<void> {
  try {
    const userId = parseInt(req.params.id);
    const data = req.body;

    // Vorherigen Stand laden für Audit
    const before = await prisma.user.findUnique({ where: { id: userId } });

    const user = await userService.updateUser(userId, data);
    if (user) {
      // Audit: Geänderte Felder ermitteln und loggen
      if (before) {
        const changes: Record<string, { von: unknown; nach: unknown }> = {};
        const fieldLabels: Record<string, string> = {
          email: 'E-Mail', firstName: 'Vorname', lastName: 'Nachname', isActive: 'Aktiv',
        };
        for (const [key, newVal] of Object.entries(data)) {
          if (['id', 'createdAt', 'updatedAt'].includes(key)) continue;
          const oldVal = (before as any)[key];
          const norm = (v: unknown) => (v === null || v === undefined || v === '' ? null : v);
          if (JSON.stringify(norm(oldVal)) !== JSON.stringify(norm(newVal))) {
            const label = fieldLabels[key] || key;
            const formatVal = (v: unknown) => {
              if (v === null || v === undefined || v === '') return '-';
              if (typeof v === 'boolean') return v ? 'Ja' : 'Nein';
              return String(v);
            };
            changes[label] = { von: formatVal(oldVal), nach: formatVal(newVal) };
          }
        }
        const changeList = Object.entries(changes).map(([f, c]) => `${f}: ${c.von} → ${c.nach}`).join(', ');
        await logChange({
          req, action: 'UPDATE', resourceType: 'User',
          resourceId: user.id.toString(),
          label: changeList ? `Benutzer ${user.firstName} ${user.lastName} aktualisiert: ${changeList}` : `Benutzer ${user.firstName} ${user.lastName} aktualisiert`,
          details: Object.keys(changes).length > 0 ? changes : undefined,
        });
      } else {
        await logChange({
          req, action: 'UPDATE', resourceType: 'User',
          resourceId: user.id.toString(),
          label: `Benutzer ${user.firstName} ${user.lastName} aktualisiert`,
        });
      }
    }
    res.json({ success: true, data: user } as ApiResponse);
  } catch (error) {
    res.status(400).json({
      success: false,
      error: error instanceof Error ? error.message : 'Fehler beim Aktualisieren des Benutzers',
    } as ApiResponse);
  }
}

export async function deleteUser(req: Request, res: Response): Promise<void> {
  try {
    const userId = parseInt(req.params.id);
    const userBefore = await userService.getUserById(userId);
    await userService.deleteUser(userId);
    await logChange({
      req, action: 'DELETE', resourceType: 'User',
      resourceId: userId.toString(),
      label: `Benutzer ${userBefore?.firstName || ''} ${userBefore?.lastName || ''} gelöscht`,
    });
    res.json({ success: true, message: 'Benutzer gelöscht' } as ApiResponse);
  } catch (error) {
    res.status(400).json({
      success: false,
      error: error instanceof Error ? error.message : 'Fehler beim Löschen des Benutzers',
    } as ApiResponse);
  }
}

// Roles
export async function getRoles(req: Request, res: Response): Promise<void> {
  try {
    const roles = await userService.getAllRoles();
    res.json({ success: true, data: roles } as ApiResponse);
  } catch (error) {
    res.status(500).json({
      success: false,
      error: 'Fehler beim Laden der Rollen',
    } as ApiResponse);
  }
}

export async function getRole(req: Request, res: Response): Promise<void> {
  try {
    const role = await userService.getRoleById(parseInt(req.params.id));
    if (!role) {
      res.status(404).json({
        success: false,
        error: 'Rolle nicht gefunden',
      } as ApiResponse);
      return;
    }
    res.json({ success: true, data: role } as ApiResponse);
  } catch (error) {
    res.status(500).json({
      success: false,
      error: 'Fehler beim Laden der Rolle',
    } as ApiResponse);
  }
}

export async function createRole(req: Request, res: Response): Promise<void> {
  try {
    const role = await userService.createRole(req.body);
    await logChange({
      req, action: 'CREATE', resourceType: 'Role',
      resourceId: role.id.toString(),
      label: `Rolle ${role.name} angelegt`,
    });
    res.status(201).json({ success: true, data: role } as ApiResponse);
  } catch (error) {
    res.status(400).json({
      success: false,
      error: error instanceof Error ? error.message : 'Fehler beim Erstellen der Rolle',
    } as ApiResponse);
  }
}

export async function updateRole(req: Request, res: Response): Promise<void> {
  try {
    const role = await userService.updateRole(parseInt(req.params.id), req.body);
    if (role) {
      await logChange({
        req, action: 'UPDATE', resourceType: 'Role',
        resourceId: role.id.toString(),
        label: `Rolle ${role.name} aktualisiert`,
      });
    }
    res.json({ success: true, data: role } as ApiResponse);
  } catch (error) {
    res.status(400).json({
      success: false,
      error: error instanceof Error ? error.message : 'Fehler beim Aktualisieren der Rolle',
    } as ApiResponse);
  }
}

export async function deleteRole(req: Request, res: Response): Promise<void> {
  try {
    const roleId = parseInt(req.params.id);
    const role = await userService.getRoleById(roleId);
    await userService.deleteRole(roleId);
    await logChange({
      req, action: 'DELETE', resourceType: 'Role',
      resourceId: roleId.toString(),
      label: `Rolle ${role?.name || roleId} gelöscht`,
    });
    res.json({ success: true, message: 'Rolle gelöscht' } as ApiResponse);
  } catch (error) {
    res.status(400).json({
      success: false,
      error: error instanceof Error ? error.message : 'Fehler beim Löschen der Rolle',
    } as ApiResponse);
  }
}

// Permissions
export async function getPermissions(req: Request, res: Response): Promise<void> {
  try {
    const permissions = await userService.getAllPermissions();
    res.json({ success: true, data: permissions } as ApiResponse);
  } catch (error) {
    res.status(500).json({
      success: false,
      error: 'Fehler beim Laden der Berechtigungen',
    } as ApiResponse);
  }
}