import { NextRequest, NextResponse } from "next/server"
import { getServerSession } from "next-auth/next"
import dbConnect from "@/lib/mongodb"
import User from "@/model/User"
import { authOptions } from "@/lib/auth"
import { updateProfileSchema } from "@/lib/validation"

export async function PATCH(request: NextRequest) {
  try {
    const session = await getServerSession(authOptions)
    
    if (!session?.user?.id) {
      return NextResponse.json(
        { error: "Unauthorized" },
        { status: 401 }
      )
    }

    const body = await request.json()
    
    const result = updateProfileSchema.safeParse(body)
    
    if (!result.success) {
      return NextResponse.json(
        { error: "Validation failed", details: result.error.errors },
        { status: 400 }
      )
    }

    const { name, email } = result.data

    await dbConnect()

    // Check if email is already taken by another user
    const existingUser = await User.findOne({ 
      email, 
      _id: { $ne: session.user.id } 
    })
    
    if (existingUser) {
      return NextResponse.json(
        { error: "Email is already in use" },
        { status: 409 }
      )
    }

    // Update user
    const updatedUser = await User.findByIdAndUpdate(
      session.user.id,
      { name, email },
      { new: true }
    )

    if (!updatedUser) {
      return NextResponse.json(
        { error: "User not found" },
        { status: 404 }
      )
    }

    return NextResponse.json({
      message: "Profile updated successfully",
      user: {
        id: updatedUser._id,
        name: updatedUser.name,
        email: updatedUser.email,
      }
    })

  } catch (error) {
    console.error("Profile update error:", error)
    
    return NextResponse.json(
      { error: "Internal server error" },
      { status: 500 }
    )
  }
}