┌─────────┐    ┌─────────┐    ┌─────────┐    ┌─────────┐    ┌──────────┐
│ Deploy  │───▶│ Active  │───▶│ Migrate │───▶│ Sunset  │───▶│ Archived │
└─────────┘    └─────────┘    └─────────┘    └─────────┘    └──────────┘
                   │              │
                   │              ▼
                   │         ┌─────────┐
                   └────────▶│ Monitor │
                             └─────────┘

import { connectContract } from '@midnight-ntwrk/midnight-js-contracts';
import { createIndexerClient } from '@midnight-ntwrk/midnight-js-indexer';

// Connect to contract
const contract = await connectContract({
  address: CONTRACT_ADDRESS,
  artifact: Contract,
  wallet,
  config,
});

// Query state via circuit
const state = await contract.query.get_state();
console.log('Current state:', state);

// Or query via indexer for raw state
const indexer = createIndexerClient({ url: config.indexer });
const rawState = await indexer.getContractState(CONTRACT_ADDRESS);

interface StateBackup {
  contractAddress: string;
  blockHeight: number;
  timestamp: string;
  state: Record<string, unknown>;
}

async function backupState(
  contract: ConnectedContract,
  indexer: IndexerClient
): Promise<StateBackup> {
  const state = await contract.query.get_full_state();
  const info = await indexer.getContractInfo(contract.address);

  return {
    contractAddress: contract.address,
    blockHeight: info.lastUpdateBlock,
    timestamp: new Date().toISOString(),
    state,
  };
}

import { NewContract } from './build-v2/contract.cjs';

const newContract = await deployContract({
  wallet,
  artifact: NewContract,
  initialState: {
    ...backupData.state,
    version: 2,
  },
  config,
});

console.log('New version deployed at:', newContract.address);

interface ContractVersion {
  version: number;
  address: string;
  deployedAt: string;
  status: 'active' | 'deprecated' | 'archived';
}

class VersionRegistry {
  private versions: ContractVersion[] = [];

  addVersion(version: ContractVersion): void {
    this.versions.push(version);
  }

  getActiveVersion(): ContractVersion | undefined {
    return this.versions.find((v) => v.status === 'active');
  }

  deprecateVersion(version: number): void {
    const v = this.versions.find((v) => v.version === version);
    if (v) {
      v.status = 'deprecated';
    }
  }

  getAllVersions(): ContractVersion[] {
    return [...this.versions].sort((a, b) => b.version - a.version);
  }
}

interface ContractHealth {
  address: string;
  isResponding: boolean;
  lastActivity: Date | null;
  stateConsistent: boolean;
  warnings: string[];
}

async function checkContractHealth(
  contract: ConnectedContract,
  indexer: IndexerClient
): Promise<ContractHealth> {
  const warnings: string[] = [];
  let isResponding = false;
  let lastActivity: Date | null = null;
  let stateConsistent = true;

  try {
    // Test responsiveness
    await contract.query.get_version();
    isResponding = true;
  } catch {
    warnings.push('Contract not responding to queries');
  }

  try {
    // Check last activity
    const info = await indexer.getContractInfo(contract.address);
    lastActivity = new Date(info.lastUpdateTimestamp);

    // Warn if inactive for long time
    const daysSinceActivity = (Date.now() - lastActivity.getTime()) / (1000 * 60 * 60 * 24);
    if (daysSinceActivity > 30) {
      warnings.push(`No activity for ${daysSinceActivity.toFixed(0)} days`);
    }
  } catch {
    warnings.push('Could not fetch contract info');
  }

  return {
    address: contract.address,
    isResponding,
    lastActivity,
    stateConsistent,
    warnings,
  };
}

interface MigrationPlan {
  sourceVersion: number;
  targetVersion: number;
  sourceAddress: string;
  steps: MigrationStep[];
}

interface MigrationStep {
  name: string;
  execute: () => Promise<void>;
  rollback?: () => Promise<void>;
}

async function executeMigration(plan: MigrationPlan): Promise<string> {
  console.log(`Migrating from v${plan.sourceVersion} to v${plan.targetVersion}`);

  const completedSteps: MigrationStep[] = [];

  try {
    for (const step of plan.steps) {
      console.log(`Executing: ${step.name}`);
      await step.execute();
      completedSteps.push(step);
    }

    console.log('Migration completed successfully');
    return 'success';
  } catch (error) {
    console.error('Migration failed, rolling back...');

    // Rollback in reverse order
    for (const step of completedSteps.reverse()) {
      if (step.rollback) {
        try {
          await step.rollback();
        } catch (rollbackError) {
          console.error(`Rollback failed for ${step.name}`);
        }
      }
    }

    throw error;
  }
}

async function deprecateContract(
  oldContract: ConnectedContract,
  newContractAddress: string
): Promise<void> {
  // 1. Set deprecation flag in old contract (if supported)
  try {
    await oldContract.call.set_deprecated({
      successor: newContractAddress,
    });
    console.log('Old contract marked as deprecated');
  } catch {
    console.log('Contract does not support deprecation flag');
  }

  // 2. Log deprecation for monitoring
  console.log(`Contract ${oldContract.address} deprecated`);
  console.log(`Successor: ${newContractAddress}`);

  // 3. Update documentation and client configurations
  // (manual step or integrate with your deployment system)
}

// Get all accounts with balances
const accounts = await contract.query.get_all_accounts();

// Get contract metadata
const metadata = await contract.query.get_metadata();

// Get specific state field
const owner = await contract.query.get_owner();

// Get state at specific block (via indexer)
const historicalState = await indexer.getContractStateAtBlock(
  CONTRACT_ADDRESS,
  blockHeight
);