/**
 * Smart Savings Manager
 *
 * Handles upgrading savings accounts to EIP-7702 smart accounts.
 * Enables advanced features like locked savings, spend & save, and periodic savings.
 *
 * Architecture:
 * 1. Take a basic SavingsAccount (BIP-44 derived)
 * 2. Create an EVMSmartWallet instance from its private key
 * 3. Initialize with EIP-7702 delegation
 * 4. Return a SmartSavingsAccount with full AA capabilities
 */

import { Chain } from "viem/chains";
import { EVMSmartWallet } from "../evm/smartWallet";
import { SmartWalletOptions } from "../evm/aa-service";
import { ChainWalletConfig } from "../types";
import { SavingsAccount, SmartSavingsAccount } from "./types";

// ============================================
// SmartSavingsManager Class
// ============================================

/**
 * Manages EIP-7702 smart savings accounts
 *
 * This class provides:
 * 1. Upgrade from basic savings account to smart account
 * 2. Full Account Abstraction capabilities
 * 3. Access to Kernel modules (lock, hooks, session keys)
 * 4. Sponsored transactions via paymaster
 */
export class SmartSavingsManager {
    private chainConfig: ChainWalletConfig;

    constructor(chainConfig: ChainWalletConfig) {
        this.chainConfig = chainConfig;

        // Validate AA support
        if (!chainConfig.aaSupport?.enabled) {
            throw new Error(
                "Smart savings requires Account Abstraction (AA) support.\n" +
                "Your chain config must include aaSupport configuration with:\n" +
                "- bundlerUrl\n" +
                "- entryPoints\n" +
                "- kernelImplementations"
            );
        }
    }

    /**
     * Upgrade a savings account to a smart account with EIP-7702 delegation
     *
     * This enables advanced features:
     * - Lock modules for time-locked savings
     * - Hooks for spend & save
     * - Session keys for periodic savings
     * - Sponsored transactions via paymaster
     *
     * @param savingsAccount - The basic savings account to upgrade
     * @param options - Optional smart wallet configuration
     * @returns SmartSavingsAccount with EVMSmartWallet instance
     *
     * @example
     * const basicSavings = wallet.deriveSavingsAccount(1);
     * const smartSavings = await smartSavingsManager.upgradeSavingsToSmartAccount(basicSavings);
     * await smartSavings.smartWallet.installModule({ ... });
     */
    async upgradeSavingsToSmartAccount(
        savingsAccount: SavingsAccount,
        options?: SmartWalletOptions
    ): Promise<SmartSavingsAccount> {
        // Merge options with chain config
        const mergedOptions: SmartWalletOptions = {
            ...options,
            aaConfig: this.chainConfig.aaSupport,
            bundlerUrl: options?.bundlerUrl || this.chainConfig.aaSupport?.bundlerUrl,
            paymasterUrl: options?.paymasterUrl || this.chainConfig.aaSupport?.paymasterUrl,
            entryPointVersion: options?.entryPointVersion || this.chainConfig.aaSupport?.entryPoints?.[0]?.version
        };

        // Validate bundlerUrl
        if (!mergedOptions.bundlerUrl) {
            throw new Error(
                "bundlerUrl is required for smart savings.\n" +
                "Provide it via upgradeSavingsToSmartAccount options or chain config."
            );
        }

        // Create viem chain object
        const chain: Chain = {
            id: this.chainConfig.chainId,
            name: this.chainConfig.name,
            nativeCurrency: {
                name: this.chainConfig.nativeToken.name,
                symbol: this.chainConfig.nativeToken.symbol,
                decimals: this.chainConfig.nativeToken.decimals
            },
            rpcUrls: {
                default: {
                    http: [this.chainConfig.rpcUrl]
                }
            },
            blockExplorers: {
                default: {
                    name: this.chainConfig.name + " Explorer",
                    url: this.chainConfig.explorerUrl
                }
            },
            testnet: this.chainConfig.testnet || false
        };

        // Create EVMSmartWallet instance from savings account private key
        const smartWallet = new EVMSmartWallet(
            savingsAccount.privateKey,
            chain,
            mergedOptions
        );

        // Note: Initialization (createAuthorization) is optional
        // User can call smartWallet.initialize() separately if needed
        // For now, we return uninitialized smart wallet
        const isInitialized = false;

        return {
            ...savingsAccount,
            smartWallet,
            isInitialized
        };
    }

    /**
     * Upgrade and initialize a savings account in one step
     *
     * This is a convenience method that both upgrades and initializes.
     *
     * @param savingsAccount - The basic savings account to upgrade
     * @param options - Optional smart wallet configuration
     * @returns Initialized SmartSavingsAccount ready for transactions
     *
     * @example
     * const basicSavings = wallet.deriveSavingsAccount(1);
     * const smartSavings = await smartSavingsManager.upgradeSavingsAndInitialize(basicSavings);
     * // smartSavings is now ready for smart transactions
     */
    async upgradeSavingsAndInitialize(
        savingsAccount: SavingsAccount,
        options?: SmartWalletOptions
    ): Promise<SmartSavingsAccount> {
        // First upgrade
        const smartSavings = await this.upgradeSavingsToSmartAccount(savingsAccount, options);

        // Then initialize
        await smartSavings.smartWallet.initialize();

        // Update initialization status
        smartSavings.isInitialized = true;

        return smartSavings;
    }

    /**
     * Check if a savings account can be upgraded to smart account
     *
     * @returns true if chain supports AA and has required configuration
     */
    canUpgradeToSmartAccount(): boolean {
        return !!(
            this.chainConfig.aaSupport?.enabled &&
            this.chainConfig.aaSupport?.bundlerUrl &&
            this.chainConfig.aaSupport?.entryPoints &&
            this.chainConfig.aaSupport?.entryPoints.length > 0
        );
    }

    /**
     * Get the chain configuration
     *
     * @returns ChainWalletConfig
     */
    getChainConfig(): ChainWalletConfig {
        return this.chainConfig;
    }
}