'use server';

import db from '@/lib/db';
import { User } from '@/lib/types';
import { z } from 'zod';
import { getSession } from '../auth';

const UserUpdateSchema = z.object({
  name: z.string().min(1, 'Name is required'),
  email: z.string().email('Invalid email address'),
  password: z.string().optional(),
});

export async function getUser(): Promise<User | null> {
  const session = await getSession();
  if (!session?.userId) {
    return null;
  }
  try {
    const stmt = db.prepare('SELECT id, name, email FROM users WHERE id = ?');
    const user = stmt.get(session.userId) as User | undefined;
    return user ?? null;
  } catch (error) {
    console.error('Failed to get user:', error);
    return null;
  }
}

export async function updateUser(
  data: z.infer<typeof UserUpdateSchema>
): Promise<{ success: boolean; error?: string }> {
  const session = await getSession();
  if (!session?.userId) {
    return { success: false, error: 'Not authenticated. Please log in again.' };
  }

  const validated = UserUpdateSchema.safeParse(data);
  if (!validated.success) {
    const errors = validated.error.flatten().fieldErrors;
    const firstError = Object.values(errors)[0]?.[0] ?? 'Invalid data provided.';
    return { success: false, error: firstError };
  }

  const { name, email, password } = validated.data;

  try {
    if (password && password.trim().length > 0) {
      // In a real application, hash the password
      const stmt = db.prepare(
        'UPDATE users SET name = ?, email = ?, password = ? WHERE id = ?'
      );
      stmt.run(name, email, password, session.userId);
    } else {
      const stmt = db.prepare('UPDATE users SET name = ?, email = ? WHERE id = ?');
      stmt.run(name, email, session.userId);
    }
    return { success: true };
  } catch (error: any) {
    console.error('Failed to update user:', error);
     if (error.code === 'SQLITE_CONSTRAINT_UNIQUE') {
      return { success: false, error: 'Email already in use.' };
    }
    return { success: false, error: 'Failed to update user profile due to a server error.' };
  }
}