import type { Address, Chain } from "viem";
import { mainnet, base, arbitrum, baseSepolia } from "viem/chains";
import type { ChainName } from "./types.js";
import { UnknownTokenError } from "./errors.js";

export interface TokenInfo {
  address: Address;
  decimals: number;
}

export interface ChainConfig {
  name: ChainName;
  id: number;
  viemChain: Chain;
  /** Token symbol -> info. Symbols are case-insensitive at resolution time. */
  tokens: Record<string, TokenInfo>;
  contracts: {
    /** Balancer Vault (flash-loan provider for the Manager). Same address on all three chains. */
    balancerVault: Address;
    /** Aave V3 Pool (for the AaveV3 strategy verb). Verify against resources/chains.md before mainnet. */
    aaveV3Pool?: Address;
    /** Uniswap V3 SwapRouter (the original deadline-bearing router; matches the decoder's exactInput). */
    uniswapV3Router?: Address;
    /** Uniswap V3 NonfungiblePositionManager (decoder constructor arg; used for LP sanitization). */
    uniswapV3PositionManager?: Address;
    /** Odos V2 router (constructor arg for the full syUSD decoder's Odos sanitizer). */
    odosRouter?: Address;
    /** Magpie (fly.trade) router (constructor arg for the full syUSD decoder's Magpie sanitizer). */
    magpieRouter?: Address;
  };
}

const BALANCER_VAULT: Address = "0xBA12222222228d8Ba445958a75a0704d566BF2C8";

export const CHAINS: Record<ChainName, ChainConfig> = {
  ethereum: {
    name: "ethereum",
    id: 1,
    viemChain: mainnet,
    tokens: {
      WETH: { address: "0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2", decimals: 18 },
      USDC: { address: "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48", decimals: 6 },
      USDT: { address: "0xdAC17F958D2ee523a2206206994597C13D831ec7", decimals: 6 },
      WSTETH: { address: "0x7f39C581F595B53c5cb19bD0b3f8dA6c935E2Ca0", decimals: 18 },
    },
    contracts: {
      balancerVault: BALANCER_VAULT,
      aaveV3Pool: "0x87870Bca3F3fD6335C3F4ce8392D69350B4fA4E2",
      uniswapV3Router: "0x68b3465833fb72A70ecDF485E0e4C7bD8665Fc45", // SwapRouter02
      uniswapV3PositionManager: "0xC36442b4a4522E871399CD717aBDD847Ab11FE88",
      odosRouter: "0xCf5540fFFCdC3d510B18bFcA6d2b9987b0772559",
      magpieRouter: "0x20F6ee51340aDEed01A59B0e65cB3703f3dc860c", // fly.trade DexAggregator
    },
  },
  base: {
    name: "base",
    id: 8453,
    viemChain: base,
    tokens: {
      WETH: { address: "0x4200000000000000000000000000000000000006", decimals: 18 },
      USDC: { address: "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913", decimals: 6 },
      WSTETH: { address: "0xc1CBa3fCea344f92D9239c08C0568f6F2F0ee452", decimals: 18 },
    },
    contracts: {
      balancerVault: BALANCER_VAULT,
      aaveV3Pool: "0xA238Dd80C259a72e81d7e4664a9801593F98d1c5",
      uniswapV3Router: "0x2626664c2603336E57B271c5C0b26F421741e481", // SwapRouter02 (Base)
      uniswapV3PositionManager: "0x03a520b32C04BF3bEEf7BEb72E919cf822Ed34f1",
      odosRouter: "0x19cEeAd7105607Cd444F5ad10dd51356436095a1",
      magpieRouter: "0x20F6ee51340aDEed01A59B0e65cB3703f3dc860c", // fly.trade DexAggregator
    },
  },
  arbitrum: {
    name: "arbitrum",
    id: 42161,
    viemChain: arbitrum,
    tokens: {
      WETH: { address: "0x82aF49447D8a07e3bd95BD0d56f35241523fBab1", decimals: 18 },
      USDC: { address: "0xaf88d065e77c8cC2239327C5EDb3A432268e5831", decimals: 6 },
      USDT: { address: "0xFd086bC7CD5C481DCC9C85ebE478A1C0b69FCbb9", decimals: 6 },
      WSTETH: { address: "0x5979D7b546E38E414F7E9822514be443A4800529", decimals: 18 },
    },
    contracts: {
      balancerVault: BALANCER_VAULT,
      aaveV3Pool: "0x794a61358D6845594F94dc1DB02A252b5b4814aD",
      uniswapV3Router: "0x68b3465833fb72A70ecDF485E0e4C7bD8665Fc45", // SwapRouter02
      uniswapV3PositionManager: "0xC36442b4a4522E871399CD717aBDD847Ab11FE88",
      odosRouter: "0xa669e7A0d4b3e4Fa48af2dE86BD4CD7126Be4e13",
      magpieRouter: "0x20F6ee51340aDEed01A59B0e65cB3703f3dc860c", // fly.trade DexAggregator
    },
  },
  // Base Sepolia testnet — for go-live rehearsals with real (free) testnet ETH before mainnet.
  // Only the core vault contracts are needed to deploy; DeFi integration addresses are intentionally
  // omitted (use syUsdSeedMode "none" on testnet). USDC is Circle's official Base Sepolia token.
  baseSepolia: {
    name: "baseSepolia",
    id: 84532,
    viemChain: baseSepolia,
    tokens: {
      WETH: { address: "0x4200000000000000000000000000000000000006", decimals: 18 },
      USDC: { address: "0x036CbD53842c5426634e7929541eC2318f3dCF7e", decimals: 6 },
    },
    contracts: {
      // Balancer V2 vault is stored by the Manager but only called on a flash-loan strategy (not at
      // deploy/finalize); the canonical address is kept for parity and is harmless on testnet.
      balancerVault: BALANCER_VAULT,
    },
  },
};

const ID_TO_NAME: Record<number, ChainName> = {
  1: "ethereum",
  8453: "base",
  42161: "arbitrum",
  84532: "baseSepolia",
};

/** Resolve a chain by name or numeric id. */
export function resolveChain(chain: ChainName | number): ChainConfig {
  if (typeof chain === "number") {
    const name = ID_TO_NAME[chain];
    if (!name) throw new Error(`Unsupported chain id ${chain}. Known: 1, 8453, 42161, 84532.`);
    return CHAINS[name];
  }
  const cfg = CHAINS[chain];
  if (!cfg) throw new Error(`Unknown chain "${chain}". Known: ethereum, base, arbitrum, baseSepolia.`);
  return cfg;
}

const ADDRESS_RE = /^0x[0-9a-fA-F]{40}$/;

/** Resolve a token symbol (case-insensitive) or raw 0x address to an Address on the given chain. */
export function resolveToken(chain: ChainConfig, symbolOrAddress: Address | string): Address {
  if (ADDRESS_RE.test(symbolOrAddress)) return symbolOrAddress as Address;
  const info = chain.tokens[symbolOrAddress.toUpperCase()];
  if (!info) throw new UnknownTokenError(symbolOrAddress, chain.name);
  return info.address;
}

/** Look up known decimals for a token symbol or address on the given chain (undefined if unknown). */
export function tokenDecimals(chain: ChainConfig, symbolOrAddress: Address | string): number | undefined {
  if (ADDRESS_RE.test(symbolOrAddress)) {
    const hit = Object.values(chain.tokens).find(
      (t) => t.address.toLowerCase() === symbolOrAddress.toLowerCase(),
    );
    return hit?.decimals;
  }
  return chain.tokens[symbolOrAddress.toUpperCase()]?.decimals;
}