'use server';

import { redirect } from "next/navigation";
import { prisma } from "@/lib/prisma";
import { hashPassword, verifyPassword, generateToken } from "@/lib/crypto";
import {
  createSession,
  deleteSession,
  requireCurrentUser,
} from "@/lib/auth";
import { Resend } from "resend";
import type { FormState } from "@/lib/types";

export async function login(
  prevState: FormState | undefined,
  formData: FormData,
): Promise<FormState> {
  const email = formData.get("email") as string;
  const password = formData.get("password") as string;

  if (!email || !password) {
    return { message: "Email and password are required" };
  }

  const user = await prisma.user.findUnique({ where: { email } });

  if (!user) {
    return { message: "Invalid email or password" };
  }

  const valid = await verifyPassword(password, user.passwordHash);

  if (!valid) {
    return { message: "Invalid email or password" };
  }

  await createSession(user.id);

  redirect("/");
}

export async function logout(): Promise<never> {
  await deleteSession();

  redirect("/login");
}

export async function changePassword(
  prevState: FormState | undefined,
  formData: FormData,
): Promise<FormState> {
  const currentUser = await requireCurrentUser();

  const currentPassword = formData.get("currentPassword") as string;
  const newPassword = formData.get("newPassword") as string;
  const confirmPassword = formData.get("confirmPassword") as string;

  if (!currentPassword || !newPassword || !confirmPassword) {
    return { message: "All fields are required" };
  }

  if (newPassword.length < 8) {
    return {
      errors: { newPassword: ["Password must be at least 8 characters"] },
      message: "Password must be at least 8 characters",
    };
  }

  if (newPassword !== confirmPassword) {
    return {
      errors: { confirmPassword: ["Passwords do not match"] },
      message: "Passwords do not match",
    };
  }

  const user = await prisma.user.findUnique({
    where: { id: currentUser.id },
  });

  if (!user) {
    return { message: "User not found" };
  }

  const valid = await verifyPassword(currentPassword, user.passwordHash);

  if (!valid) {
    return {
      errors: { currentPassword: ["Current password is incorrect"] },
      message: "Current password is incorrect",
    };
  }

  const newHash = await hashPassword(newPassword);

  await prisma.user.update({
    where: { id: user.id },
    data: { passwordHash: newHash },
  });

  return { message: "Password changed successfully", success: true };
}

export async function forgotPassword(
  prevState: FormState | undefined,
  formData: FormData,
): Promise<FormState> {
  const email = formData.get("email") as string;

  if (!email) {
    return { message: "Email is required" };
  }

  const user = await prisma.user.findUnique({ where: { email } });

  if (user) {
    const token = generateToken();

    await prisma.passwordResetToken.create({
      data: {
        token,
        userId: user.id,
        expiresAt: new Date(Date.now() + 60 * 60 * 1000),
      },
    });

    const resetLink = `${process.env.NEXT_PUBLIC_APP_URL}/reset-password?token=${token}`;

    if (process.env.RESEND_API_KEY) {
      try {
        const resend = new Resend(process.env.RESEND_API_KEY);
        await resend.emails.send({
          from: "Order Loop <onboarding@resend.dev>",
          to: email,
          subject: "Reset your password",
          html: `<p>Click <a href="${resetLink}">here</a> to reset your password. This link expires in 1 hour.</p>`,
        });
      } catch (error) {
        console.error("Failed to send reset email:", error);
        console.log("Password reset link:", resetLink);
      }
    } else {
      console.log("Password reset link:", resetLink);
    }
  }

  return {
    message: "If an account exists, a reset link has been sent",
    success: true,
  };
}

export async function resetPassword(
  prevState: FormState | undefined,
  formData: FormData,
): Promise<FormState> {
  const token = formData.get("token") as string;
  const password = formData.get("password") as string;
  const confirmPassword = formData.get("confirmPassword") as string;

  if (!token || !password || !confirmPassword) {
    return { message: "All fields are required" };
  }

  if (password.length < 8) {
    return {
      errors: { password: ["Password must be at least 8 characters"] },
      message: "Password must be at least 8 characters",
    };
  }

  if (password !== confirmPassword) {
    return {
      errors: { confirmPassword: ["Passwords do not match"] },
      message: "Passwords do not match",
    };
  }

  const resetToken = await prisma.passwordResetToken.findUnique({
    where: { token },
  });

  if (!resetToken || resetToken.used || resetToken.expiresAt < new Date()) {
    return { message: "Invalid or expired reset token" };
  }

  const newHash = await hashPassword(password);

  await prisma.user.update({
    where: { id: resetToken.userId },
    data: { passwordHash: newHash },
  });

  await prisma.passwordResetToken.update({
    where: { id: resetToken.id },
    data: { used: true },
  });

  return {
    message: "Password reset successfully. You can now log in.",
    success: true,
  };
}