/**
 * Project Shares Routes – List, create, delete project shares
 */
import type { FastifyInstance } from 'fastify';
import type { DatabaseInterface } from '../database/DatabaseInterface.js';
import type { AuthService } from '../auth/AuthService.js';
import { validateIdParam } from '../utils/validation.js';

function extractToken(request: any): string | null {
  const auth = request.headers?.authorization;
  if (auth && auth.startsWith('Bearer ')) return auth.slice(7);
  return null;
}

const VALID_PERMISSIONS = ['view', 'edit', 'admin'];

export function registerShareRoutes(fastify: FastifyInstance, db: DatabaseInterface, authService: AuthService) {
  // List shares for a project (owner only)
  fastify.get('/api/projects/:projectId/shares', async (request, reply) => {
    const token = extractToken(request);
    if (!token) return reply.code(401).send({ error: 'Authentication required' });
    const user = authService.getUserFromSession(token);
    if (!user) return reply.code(401).send({ error: 'Invalid or expired session' });
    const { projectId } = request.params as { projectId: string };
    const projIdErr = validateIdParam(projectId, 'projectId');
    if (projIdErr) return reply.code(400).send({ error: projIdErr });
    const project = db.getProject(projectId);
    if (!project) return reply.code(404).send({ error: 'Project not found' });
    if (project.owner_id !== user.id) return reply.code(403).send({ error: 'Forbidden' });
    return db.listProjectShares(projectId);
  });

  // Create a project share (owner only)
  fastify.post('/api/projects/:projectId/shares', async (request, reply) => {
    const token = extractToken(request);
    if (!token) return reply.code(401).send({ error: 'Authentication required' });
    const user = authService.getUserFromSession(token);
    if (!user) return reply.code(401).send({ error: 'Invalid or expired session' });
    const { projectId } = request.params as { projectId: string };
    const projIdErr = validateIdParam(projectId, 'projectId');
    if (projIdErr) return reply.code(400).send({ error: projIdErr });
    const project = db.getProject(projectId);
    if (!project) return reply.code(404).send({ error: 'Project not found' });
    if (project.owner_id !== user.id) return reply.code(403).send({ error: 'Forbidden' });
    const body = request.body as { shared_with_email?: string; permission?: string };
    if (!body.shared_with_email) return reply.code(400).send({ error: 'shared_with_email is required' });
    const permission = VALID_PERMISSIONS.includes(body.permission ?? '') ? body.permission! : 'view';

    const share = db.createProjectShare({
      project_id: projectId,
      shared_with_email: body.shared_with_email,
      shared_by: user.id,
      permission,
    });

    // Create a notification for the shared user if they exist
    const sharedUser = db.getUserByEmail(body.shared_with_email);
    if (sharedUser) {
      db.createNotification({
        user_id: sharedUser.id,
        type: 'share',
        title: 'Projekt geteilt',
        message: `${user.name} hat ein Projekt mit Ihnen geteilt: ${project.name}`,
      });
    }

    return reply.code(201).send(share);
  });

  // Delete a project share (owner only)
  fastify.delete('/api/shares/:id', async (request, reply) => {
    const token = extractToken(request);
    if (!token) return reply.code(401).send({ error: 'Authentication required' });
    const user = authService.getUserFromSession(token);
    if (!user) return reply.code(401).send({ error: 'Invalid or expired session' });
    const { id } = request.params as { id: string };
    const idErr = validateIdParam(id, 'id');
    if (idErr) return reply.code(400).send({ error: idErr });
    const share = db.getProjectShare(id);
    if (!share) return reply.code(404).send({ error: 'Share not found' });
    const project = db.getProject(share.project_id);
    if (!project) return reply.code(404).send({ error: 'Project not found' });
    if (project.owner_id !== user.id) return reply.code(403).send({ error: 'Forbidden' });
    const ok = db.deleteProjectShare(id);
    if (!ok) return reply.code(404).send({ error: 'Share not found' });
    return reply.code(204).send();
  });
}