import DLMM from '@meteora-ag/dlmm'
import {
	Connection,
	Keypair,
	PublicKey,
	sendAndConfirmTransaction,
} from '@solana/web3.js'
import BN from 'bn.js'

import {
	DEFAULT_COPY_RATIO,
	DEFAULT_MAX_POSITION_SIZE_SOL,
	DEFAULT_SLIPPAGE_BPS,
} from '../constants'
import type { ParsedDlmmOperation, WorkerSettings } from './types'
import { getEnvNumber } from '../utils'

export function getSettings(): WorkerSettings {
	return {
		autoCopyEnabled: process.env.AUTO_COPY_ENABLED !== 'false',
		copyRatio: getEnvNumber('COPY_RATIO', DEFAULT_COPY_RATIO),
		maxPositionSizeSol: getEnvNumber(
			'MAX_POSITION_SIZE_SOL',
			DEFAULT_MAX_POSITION_SIZE_SOL
		),
		slippageBps: getEnvNumber('SLIPPAGE_BPS', DEFAULT_SLIPPAGE_BPS),
	}
}

function scaleAmount(amount: BN, ratio: number): BN {
	const scaledBps = Math.round(ratio * 10000)
	return amount.mul(new BN(scaledBps)).div(new BN(10000))
}

/**
 * Map on-chain strategy type (0-8) to SDK StrategyType (0-2).
 *
 * On-chain enum order (from DLMM IDL):
 *   0=SpotOneSide, 1=CurveOneSide, 2=BidAskOneSide,
 *   3=SpotBalanced, 4=CurveBalanced, 5=BidAskBalanced,
 *   6=SpotImBalanced, 7=CurveImBalanced, 8=BidAskImBalanced
 *
 * SDK StrategyType: Spot=0, Curve=1, BidAsk=2
 */
function toSdkStrategyType(onChainType: number | undefined): number {
	if (onChainType === undefined || onChainType < 0) return 0 // Default: Spot
	return onChainType % 3
}

export async function copyOpenPosition(
	connection: Connection,
	follower: Keypair,
	leaderOp: ParsedDlmmOperation,
	settings: WorkerSettings
): Promise<{ positionAddress: PublicKey; txSignature: string }> {
	const dlmmPool = await DLMM.create(connection, leaderOp.lbPairAddress)

	const followerAmountX = scaleAmount(
		leaderOp.totalXAmount ?? new BN(0),
		settings.copyRatio
	)
	const followerAmountY = scaleAmount(
		leaderOp.totalYAmount ?? new BN(0),
		settings.copyRatio
	)

	const activeBin = await dlmmPool.getActiveBin()
	const minBinId = leaderOp.minBinId ?? activeBin.binId
	const maxBinId = leaderOp.maxBinId ?? activeBin.binId
	const sdkStrategyType = toSdkStrategyType(leaderOp.strategyType)

	console.log(
		`[DLMM] Opening position: bins [${minBinId}, ${maxBinId}], activeBin ${activeBin.binId}, strategy ${sdkStrategyType}, amountX ${followerAmountX.toString()}, amountY ${followerAmountY.toString()}`
	)

	// Generate position keypair — must be included as signer
	const positionKeypair = Keypair.generate()

	const createPositionTx =
		await dlmmPool.initializePositionAndAddLiquidityByStrategy({
			positionPubKey: positionKeypair.publicKey,
			user: follower.publicKey,
			totalXAmount: followerAmountX,
			totalYAmount: followerAmountY,
			strategy: {
				minBinId,
				maxBinId,
				strategyType: sdkStrategyType,
			},
			slippage: settings.slippageBps / 100, // Convert BPS to percentage
		})

	const txSignature = await sendAndConfirmTransaction(
		connection,
		createPositionTx,
		[follower, positionKeypair],
		{ commitment: 'confirmed' }
	)

	return { positionAddress: positionKeypair.publicKey, txSignature }
}

export async function copyRemoveLiquidity(
	connection: Connection,
	follower: Keypair,
	followerPositionAddress: PublicKey,
	lbPairAddress: PublicKey,
	bpsToRemove: number = 10000, // 100% default
	settings: WorkerSettings
): Promise<string> {
	const dlmmPool = await DLMM.create(connection, lbPairAddress)

	const { userPositions } = await dlmmPool.getPositionsByUserAndLbPair(
		follower.publicKey
	)

	const position = userPositions.find((p) =>
		p.publicKey.equals(followerPositionAddress)
	)

	if (!position) {
		throw new Error(
			`Follower position ${followerPositionAddress.toBase58()} not found`
		)
	}

	const binIds = position.positionData.positionBinData.map((b) => b.binId)
	if (binIds.length === 0) {
		throw new Error('Position has no bins')
	}

	const removeLiqTxs = await dlmmPool.removeLiquidity({
		user: follower.publicKey,
		position: followerPositionAddress,
		fromBinId: Math.min(...binIds),
		toBinId: Math.max(...binIds),
		bps: new BN(bpsToRemove),
		shouldClaimAndClose: bpsToRemove >= 10000,
	})

	let lastSignature = ''
	for (const tx of removeLiqTxs) {
		lastSignature = await sendAndConfirmTransaction(
			connection,
			tx,
			[follower],
			{ commitment: 'confirmed' }
		)
	}

	return lastSignature
}

export async function copyRebalanceLiquidity(
	connection: Connection,
	follower: Keypair,
	followerPositionAddress: PublicKey,
	lbPairAddress: PublicKey,
	leaderOp: ParsedDlmmOperation,
	settings: WorkerSettings
): Promise<string> {
	const dlmmPool = await DLMM.create(connection, lbPairAddress)

	const { userPositions } = await dlmmPool.getPositionsByUserAndLbPair(
		follower.publicKey
	)

	const position = userPositions.find((p) =>
		p.publicKey.equals(followerPositionAddress)
	)

	if (!position) {
		throw new Error(
			`Follower position ${followerPositionAddress.toBase58()} not found for rebalance`
		)
	}

	// Step 1: Remove all liquidity from the current position
	const binIds = position.positionData.positionBinData.map((b) => b.binId)
	if (binIds.length > 0) {
		const removeLiqTxs = await dlmmPool.removeLiquidity({
			user: follower.publicKey,
			position: followerPositionAddress,
			fromBinId: Math.min(...binIds),
			toBinId: Math.max(...binIds),
			bps: new BN(10000), // Remove 100%
			shouldClaimAndClose: false, // Keep position open for re-adding
		})

		for (const tx of removeLiqTxs) {
			await sendAndConfirmTransaction(connection, tx, [follower], {
				commitment: 'confirmed',
			})
		}
	}

	// Step 2: Add liquidity to the new bin range using delta-based strategy
	// The leader's rebalance uses delta IDs relative to active bin
	// We use the same deltas relative to the current active bin
	const activeBin = await dlmmPool.getActiveBin()
	const activeId = activeBin.binId

	let minBinId = leaderOp.minBinId ?? 0
	let maxBinId = leaderOp.maxBinId ?? 0

	// If we have delta-based adds, compute absolute bin IDs from the current active bin
	// (not the leader's active bin, since it may have moved)
	if (leaderOp.rebalanceAdds && leaderOp.rebalanceAdds.length > 0) {
		const allMinBins = leaderOp.rebalanceAdds.map(
			(a) => activeId + a.minDeltaId
		)
		const allMaxBins = leaderOp.rebalanceAdds.map(
			(a) => activeId + a.maxDeltaId
		)
		minBinId = Math.min(...allMinBins)
		maxBinId = Math.max(...allMaxBins)
	}

	// Validate bin range — if both are 0, the parameter extraction failed
	if (minBinId === 0 && maxBinId === 0 && activeId !== 0) {
		throw new Error(
			`Rebalance failed: could not determine target bin range (activeBin=${activeId}). ` +
				`Leader rebalanceAdds: ${JSON.stringify(leaderOp.rebalanceAdds)}`
		)
	}

	console.log(
		`[DLMM] Rebalancing: new bins [${minBinId}, ${maxBinId}], activeBin ${activeId}`
	)

	// For rebalance, use the follower's actual available token balances
	// (not the leader's amounts — those are just safety caps from the IDL).
	// After step 1 removed all liquidity, the tokens are in the follower's accounts.
	const WSOL_MINT = new PublicKey(
		'So11111111111111111111111111111111111111112'
	)
	const tokenXMint = dlmmPool.tokenX.publicKey
	const tokenYMint = dlmmPool.tokenY.publicKey

	const SOL_RESERVE = 10_000_000 // Keep 0.01 SOL for tx fees

	let followerAmountX = new BN(0)
	let followerAmountY = new BN(0)

	// Token X balance
	if (tokenXMint.equals(WSOL_MINT)) {
		const balance = await connection.getBalance(follower.publicKey)
		followerAmountX = new BN(Math.max(0, balance - SOL_RESERVE))
	} else {
		const xAccounts = await connection.getParsedTokenAccountsByOwner(
			follower.publicKey,
			{ mint: tokenXMint }
		)
		for (const { account } of xAccounts.value) {
			followerAmountX = followerAmountX.add(
				new BN(
					(
						account.data.parsed as {
							info: { tokenAmount: { amount: string } }
						}
					).info.tokenAmount.amount
				)
			)
		}
	}

	// Token Y balance
	if (tokenYMint.equals(WSOL_MINT)) {
		const balance = await connection.getBalance(follower.publicKey)
		followerAmountY = new BN(Math.max(0, balance - SOL_RESERVE))
	} else {
		const yAccounts = await connection.getParsedTokenAccountsByOwner(
			follower.publicKey,
			{ mint: tokenYMint }
		)
		for (const { account } of yAccounts.value) {
			followerAmountY = followerAmountY.add(
				new BN(
					(
						account.data.parsed as {
							info: { tokenAmount: { amount: string } }
						}
					).info.tokenAmount.amount
				)
			)
		}
	}

	if (followerAmountX.isZero() && followerAmountY.isZero()) {
		throw new Error(
			'Rebalance failed: follower has no token balance to re-deposit after removing liquidity.'
		)
	}

	const sdkStrategyType = toSdkStrategyType(leaderOp.strategyType)

	console.log(
		`[DLMM] Rebalance addLiquidity: strategy ${sdkStrategyType}, amountX ${followerAmountX.toString()}, amountY ${followerAmountY.toString()}`
	)

	const addLiqTx = await dlmmPool.addLiquidityByStrategy({
		positionPubKey: followerPositionAddress,
		user: follower.publicKey,
		totalXAmount: followerAmountX,
		totalYAmount: followerAmountY,
		strategy: {
			minBinId,
			maxBinId,
			strategyType: sdkStrategyType,
		},
		slippage: settings.slippageBps / 100, // Convert BPS to percentage
	})

	const txSignature = await sendAndConfirmTransaction(
		connection,
		addLiqTx,
		[follower],
		{ commitment: 'confirmed' }
	)

	return txSignature
}

export async function copyClosePosition(
	connection: Connection,
	follower: Keypair,
	followerPositionAddress: PublicKey,
	lbPairAddress: PublicKey
): Promise<string> {
	// First check if the position account still exists on-chain.
	// It may have been already closed by removeLiquidity(shouldClaimAndClose=true).
	const positionAccountInfo = await connection.getAccountInfo(
		followerPositionAddress
	)
	if (!positionAccountInfo) {
		console.log(
			`[DLMM] Position ${followerPositionAddress.toBase58()} already closed on-chain, skipping close`
		)
		return 'already-closed'
	}

	const dlmmPool = await DLMM.create(connection, lbPairAddress)

	// Need full LbPosition object for closePosition
	const { userPositions } = await dlmmPool.getPositionsByUserAndLbPair(
		follower.publicKey
	)

	const position = userPositions.find((p) =>
		p.publicKey.equals(followerPositionAddress)
	)

	if (!position) {
		// Position account exists but not found by SDK (edge case).
		// This shouldn't happen if the account exists on-chain, but
		// handle it gracefully.
		console.warn(
			`[DLMM] Position ${followerPositionAddress.toBase58()} exists on-chain but not returned by SDK`
		)
		throw new Error(
			`Position ${followerPositionAddress.toBase58()} not found for close`
		)
	}

	const closePositionTx = await dlmmPool.closePosition({
		owner: follower.publicKey,
		position,
	})

	const txSignature = await sendAndConfirmTransaction(
		connection,
		closePositionTx,
		[follower],
		{ commitment: 'confirmed' }
	)

	return txSignature
}