import { NextRequest, NextResponse } from 'next/server'
import { getServerSession } from 'next-auth'
import { authOptions } from '@/lib/auth'
import { connectToDatabase } from '@/lib/mongodb'
import { ObjectId } from 'mongodb'
import { coinSchema } from '@/lib/validations'
import { checkRateLimit } from '@/lib/rate-limit'

export async function GET() {
  try {
    const { db } = await connectToDatabase()
    const coins = await db
      .collection('coins')
      .find({})
      .sort({ createdAt: -1 })
      .toArray()

    return NextResponse.json(coins)
  } catch (error) {
    console.error('Error fetching coins:', error)
    return NextResponse.json({ error: 'Failed to fetch coins' }, { status: 500 })
  }
}

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

    const { db } = await connectToDatabase()
    const body = await request.json()
    
    const validationResult = coinSchema.safeParse(body)
    
    if (!validationResult.success) {
      const errorMessage = validationResult.error.errors.map(e => e.message).join(', ')
      return NextResponse.json({ error: errorMessage }, { status: 400 })
    }

    const { name, ticker, description, website, twitter, telegram, initialBuy, useUserImage, verified, boosted } = validationResult.data
    const cleanName = name
    const cleanTicker = ticker
    const cleanDescription = description

    if (!cleanName || !cleanTicker) {
      return NextResponse.json({ error: 'Name and ticker are required' }, { status: 400 })
    }

    const user = await db.collection('users').findOne({ _id: new ObjectId(session.user.id) })
    if (!user) {
        return NextResponse.json({ error: 'User not found' }, { status: 404 })
    }

    //! verify via DB for security cuz client can be manipulated
    let isVerified = false
    if (verified && user.verified) {
        isVerified = true
    }
    
    //? costs
    const creationCost = 0.02;
    const boostCost = boosted ? 1.0 : 0;
    const initialBuyAmount = typeof initialBuy === 'number' && initialBuy > 0 ? initialBuy : 0;
    
    const totalCost = creationCost + boostCost + initialBuyAmount;

    if ((user.balance || 0) < totalCost) {
        return NextResponse.json({ error: `Insufficient balance (${totalCost.toFixed(3)} SOL required)` }, { status: 400 })
    }

    const existingCoin = await db.collection('coins').findOne({ ticker: cleanTicker })
    if (existingCoin) {
      return NextResponse.json({ error: 'Ticker already exists' }, { status: 400 })
    }

    if (checkRateLimit(session.user.id, 'coin_creation', 1, 60000 * 5)) {
        return NextResponse.json({ error: 'Rate limit exceeded. You can only create 1 coin every 5 minutes.' }, { status: 429 })
    }

    let virtualSolReserves = 30;
    const INITIAL_SUPPLY = 1000000000;
    let virtualTokenReserves = 1073000000; 
    let initialLiquidity = 0;
    let initialPrice = virtualSolReserves / virtualTokenReserves;
    let initialVolume = 0;

    let boughtTokens = 0;

    // ! process IB (Snipe)
    if (initialBuyAmount > 0) {
        // chat wahat does calc stand for
        // i hate my life
        const k = virtualSolReserves * virtualTokenReserves;
        const newVirtualSolReserves = virtualSolReserves + initialBuyAmount;
        const newVirtualTokenReserves = k / newVirtualSolReserves;
        
        boughtTokens = virtualTokenReserves - newVirtualTokenReserves;
        
        // ? update states
        virtualSolReserves = newVirtualSolReserves;
        virtualTokenReserves = newVirtualTokenReserves;
        initialPrice = virtualSolReserves / virtualTokenReserves;
        initialLiquidity = initialBuyAmount; // ! real liquidity
        initialVolume = initialBuyAmount;
    }
    
    const now = new Date()
    
    const priceHistory = [{
      timestamp: now,
      price: initialPrice,
      volume: initialVolume,
    }]

    const coinImage = (useUserImage && session.user.image) 
        ? session.user.image 
        : `https://api.dicebear.com/7.x/identicon/svg?seed=${cleanTicker}`;

    const coin = {
      name: cleanName,
      ticker: cleanTicker,
      description: cleanDescription,
      image: coinImage,
      website: website || '',
      twitter: twitter || '',
      telegram: telegram || '',
      creatorId: session.user.id,
      creatorName: user.name || 'Anonymous', // Use DB name, not session name
      createdAt: now,
      verified: isVerified,
      boosted: boosted ? new Date(Date.now() + 24 * 60 * 60 * 1000) : null,
      marketCap: initialPrice * INITIAL_SUPPLY,
      price: initialPrice,
      priceHistory,
      volume24h: initialVolume,
      holders: boughtTokens > 0 ? 1 : 0,
      supply: INITIAL_SUPPLY,
      liquidity: initialLiquidity, 
      virtualSolReserves,
      virtualTokenReserves,
    }

    const result = await db.collection('coins').insertOne(coin)

    // deduct total cost
    await db.collection('users').updateOne(
      { _id: new ObjectId(session.user.id) },
      { $inc: { balance: -totalCost } }
    )

    // give tokens if bought
    if (boughtTokens > 0) {
        await db.collection('users').updateOne(
        { _id: new ObjectId(session.user.id) },
        {
            $push: {
            portfolio: {
                coinId: result.insertedId.toString(),
                amount: boughtTokens, 
                avgBuyPrice: initialBuyAmount / boughtTokens,
            },
            } as any,
        }
        )

        //? record trade
        await db.collection('trades').insertOne({
            userId: session.user.id,
            coinId: result.insertedId.toString(),
            type: 'buy',
            amount: boughtTokens,
            price: initialPrice,
            total: initialBuyAmount,
            timestamp: now,
        })
    }

    return NextResponse.json({ ...coin, _id: result.insertedId })
  } catch (error) {
    console.error('Error creating coin:', error)
    return NextResponse.json({ error: 'Failed to create coin' }, { status: 500 })
  }
}