'use server'

import { revalidatePath } from 'next/cache'
import prisma from '@/lib/prisma'
import { auth } from '@/auth'
import bcrypt from 'bcryptjs'
import { z } from 'zod'

const ProfileSchema = z.object({
  name: z.string().min(2, "Name must be at least 2 characters"),
  email: z.string().email().optional(), // Email change might require verification logic, keeping it simple for now or read-only
})

const PasswordSchema = z.object({
  currentPassword: z.string().min(1, "Current password is required"),
  newPassword: z.string().min(6, "New password must be at least 6 characters"),
  confirmPassword: z.string().min(6, "Confirm password must be at least 6 characters"),
}).refine((data) => data.newPassword === data.confirmPassword, {
  message: "Passwords don't match",
  path: ["confirmPassword"],
})

export async function updateProfile(data: { name: string }) {
  const session = await auth()
  if (!session?.user?.id) throw new Error('Unauthorized')

  const validated = ProfileSchema.safeParse(data)
  if (!validated.success) {
    return { error: validated.error.flatten().fieldErrors }
  }

  try {
    await prisma.user.update({
      where: { id: session.user.id },
      data: { name: validated.data.name },
    })
    revalidatePath('/settings/profile')
    return { success: true }
  } catch (error) {
    return { error: { _form: ['Failed to update profile'] } }
  }
}

export async function changePassword(formData: FormData) {
  const session = await auth()
  if (!session?.user?.id) throw new Error('Unauthorized')

  const rawData = {
    currentPassword: formData.get('currentPassword'),
    newPassword: formData.get('newPassword'),
    confirmPassword: formData.get('confirmPassword'),
  }

  const validated = PasswordSchema.safeParse(rawData)
  if (!validated.success) {
    return { error: validated.error.flatten().fieldErrors }
  }

  const { currentPassword, newPassword } = validated.data

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

  if (!user || !user.password) {
    return { error: { _form: ['User not found'] } }
  }

  const passwordsMatch = await bcrypt.compare(currentPassword, user.password)
  if (!passwordsMatch) {
    return { error: { currentPassword: ['Incorrect current password'] } }
  }

  const hashedPassword = await bcrypt.hash(newPassword, 10)

  try {
    await prisma.user.update({
      where: { id: session.user.id },
      data: { password: hashedPassword },
    })
    return { success: true }
  } catch (error) {
    return { error: { _form: ['Failed to change password'] } }
  }
}

export async function updateTheme(theme: string) {
  const session = await auth()
  if (!session?.user?.id) return { error: 'Unauthorized' }

  try {
    await prisma.user.update({
      where: { id: session.user.id },
      data: { theme },
    })
    return { success: true }
  } catch (error) {
    return { error: 'Failed to update theme' }
  }
}

export async function updateLanguage(language: string) {
  const session = await auth()
  if (!session?.user?.id) return { error: 'Unauthorized' }

  try {
    // Update or create UserAISettings with the preferred language
    await prisma.userAISettings.upsert({
      where: { userId: session.user.id },
      create: {
        userId: session.user.id,
        preferredLanguage: language,
      },
      update: {
        preferredLanguage: language,
      },
    })

    // Note: The language will be applied on next page load
    // The client component should handle updating localStorage and reloading
    revalidatePath('/settings/profile')
    return { success: true, language }
  } catch (error) {
    console.error('Failed to update language:', error)
    return { error: 'Failed to update language' }
  }
}

export async function updateFontSize(fontSize: string) {
  const session = await auth()
  if (!session?.user?.id) return { error: 'Unauthorized' }

  try {
    // Check if UserAISettings exists
    const existing = await prisma.userAISettings.findUnique({
      where: { userId: session.user.id }
    })

    let result
    if (existing) {
      // Update existing - only update fontSize field
      result = await prisma.userAISettings.update({
        where: { userId: session.user.id },
        data: { fontSize: fontSize }
      })
      } else {
      // Create new with all required fields
      result = await prisma.userAISettings.create({
        data: {
          userId: session.user.id,
          fontSize: fontSize,
          // Set default values for required fields
          titleSuggestions: true,
          semanticSearch: true,
          paragraphRefactor: true,
          memoryEcho: true,
          memoryEchoFrequency: 'daily',
          aiProvider: 'auto',
          preferredLanguage: 'auto'
        }
      })
      }

    revalidatePath('/settings/profile')
    return { success: true, fontSize }
  } catch (error) {
    console.error('[updateFontSize] Failed to update font size:', error)
    return { error: 'Failed to update font size' }
  }
}