#!/usr/bin/env node

// Verification script for SHA256 migration from js-sha256 to ecash-lib
// Run with: node verify-sha256-migration.js
//
// This script uses the actual libraries to verify they produce identical results

const { sha256: jsSha256 } = require('js-sha256');
const { sha256: ecashLibSha256, toHex } = require('ecash-lib');

console.log('🔍 SHA256 Migration Verification Script');
console.log('=====================================\n');

console.log('📦 Using actual libraries:');
console.log('- js-sha256 version:', require('js-sha256/package.json').version);
console.log('- ecash-lib version:', require('ecash-lib/package.json').version);
console.log('');

// Test cases that simulate real usage scenarios
const testCases = [
    {
        name: 'Empty file',
        input: '',
        description: 'Empty string (like empty file upload)'
    },
    {
        name: 'Small text file',
        input: 'Hello World',
        description: 'Simple text content'
    },
    {
        name: 'Image file content',
        input: 'This is a test image file content for token creation',
        description: 'Simulates actual file content from CreateTokenForm'
    },
    {
        name: 'Binary data (PNG header)',
        input: Buffer.from([0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A]),
        description: 'PNG file header bytes'
    },
    {
        name: 'Large content',
        input: 'A'.repeat(1000),
        description: 'Large file content (1000 characters)'
    },
    {
        name: 'Special characters',
        input: '🎨📸🖼️ Token Icon with emojis!',
        description: 'Unicode content with emojis'
    }
];

let allTestsPassed = true;
let testCount = 0;

console.log('Running verification tests...\n');

testCases.forEach((testCase, index) => {
    testCount++;
    console.log(`Test ${index + 1}: ${testCase.name}`);
    console.log(`Description: ${testCase.description}`);
    
    const arrayBuffer = Buffer.from(testCase.input);
    
    // Test old js-sha256 approach (exactly as used in CreateTokenForm)
    const jsResult = jsSha256(arrayBuffer);
    
    // Test new ecash-lib approach (exactly as implemented in CreateTokenForm)
    const uint8Array = new Uint8Array(arrayBuffer);
    const hashBytes = ecashLibSha256(uint8Array);
    const hashHex = toHex(hashBytes);
    
    // Compare results
    const resultsMatch = jsResult === hashHex;
    
    if (resultsMatch) {
        console.log(`✅ PASSED: Results match`);
        console.log(`   Hash: ${jsResult}`);
    } else {
        console.log(`❌ FAILED: Results differ`);
        console.log(`   js-sha256: ${jsResult}`);
        console.log(`   ecash-lib:  ${hashHex}`);
        allTestsPassed = false;
    }
    
    console.log('');
});

// Test the exact CreateTokenForm scenario
console.log('🔧 Testing CreateTokenForm exact scenario...\n');

const fileContent = 'This is a test image file content for token creation';
const arrayBuffer = Buffer.from(fileContent);

console.log('File content:', fileContent);
console.log('ArrayBuffer length:', arrayBuffer.length);

// Old approach (js-sha256) - exactly as it was in CreateTokenForm
const jsResult = jsSha256(arrayBuffer);
console.log('\nOLD APPROACH (js-sha256):');
console.log(`  Result: ${jsResult}`);
console.log(`  Type: ${typeof jsResult}`);
console.log(`  Length: ${jsResult.length}`);

// New approach (ecash-lib) - exactly as implemented in CreateTokenForm
const uint8Array = new Uint8Array(arrayBuffer);
const hashBytes = ecashLibSha256(uint8Array);
const hashHex = toHex(hashBytes);

console.log('\nNEW APPROACH (ecash-lib):');
console.log(`  Uint8Array length: ${uint8Array.length}`);
console.log(`  sha256 result (Uint8Array): ${hashBytes}`);
console.log(`  toHex result: ${hashHex}`);
console.log(`  Type: ${typeof hashHex}`);
console.log(`  Length: ${hashHex.length}`);

const exactScenarioMatch = jsResult === hashHex;
console.log(`\nExact scenario match: ${exactScenarioMatch ? '✅ YES' : '❌ NO'}`);

// Additional verification: test with different input types
console.log('\n🔍 Additional verification tests...\n');

// Test with string input directly
const stringInput = 'Direct string input';
const jsStringResult = jsSha256(stringInput);
const ecashStringResult = toHex(ecashLibSha256(Buffer.from(stringInput)));
console.log(`String input test: ${jsStringResult === ecashStringResult ? '✅ PASSED' : '❌ FAILED'}`);

// Test with Uint8Array input
const uint8Input = new Uint8Array([72, 101, 108, 108, 111]); // "Hello"
const jsUint8Result = jsSha256(uint8Input);
const ecashUint8Result = toHex(ecashLibSha256(uint8Input));
console.log(`Uint8Array input test: ${jsUint8Result === ecashUint8Result ? '✅ PASSED' : '❌ FAILED'}`);

console.log('\n=====================================');
console.log('FINAL VERIFICATION RESULTS:');
console.log(`Tests run: ${testCount}`);
console.log(`All tests passed: ${allTestsPassed ? '✅ YES' : '❌ NO'}`);
console.log(`Exact scenario match: ${exactScenarioMatch ? '✅ YES' : '❌ NO'}`);

if (allTestsPassed && exactScenarioMatch) {
    console.log('\n🎉 VERIFICATION SUCCESSFUL!');
    console.log('The ecash-lib implementation produces identical results to js-sha256.');
    console.log('The migration is safe and behavior is preserved.');
} else {
    console.log('\n⚠️  VERIFICATION FAILED!');
    console.log('The implementations produce different results.');
    console.log('Further investigation is needed before proceeding with migration.');
}

console.log('\n📝 Migration Summary:');
console.log('- Removed: js-sha256 dependency');
console.log('- Added: sha256 and toHex imports from ecash-lib');
console.log('- Updated: CreateTokenForm to use ecash-lib sha256');
console.log('- Verified: Identical behavior and results');

console.log('\n🔧 Code Changes Made:');
console.log('1. Removed: import { sha256, Message } from "js-sha256";');
console.log('2. Added: import { toHex, sha256 } from "ecash-lib";');
console.log('3. Updated usage:');
console.log('   const uint8Array = new Uint8Array(hashreader.result as ArrayBuffer);');
console.log('   const hashBytes = sha256(uint8Array);');
console.log('   const hashHex = toHex(hashBytes);');
console.log('4. Removed: js-sha256 from package.json dependencies');

console.log('\n📋 Library Information:');
console.log('- js-sha256: Returns hex string directly');
console.log('- ecash-lib sha256: Returns Uint8Array, requires toHex() conversion');
console.log('- Both produce identical SHA256 hashes for the same input');

🔍 SHA256 Migration Verification Script
=====================================

📦 Using actual libraries:
- js-sha256 version: 0.11.1
- ecash-lib version: 4.3.1

Running verification tests...

Test 1: Empty file
Description: Empty string (like empty file upload)
✅ PASSED: Results match
   Hash: e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855

Test 2: Small text file
Description: Simple text content
✅ PASSED: Results match
   Hash: a591a6d40bf420404a011733cfb7b190d62c65bf0bcda32b57b277d9ad9f146e

Test 3: Image file content
Description: Simulates actual file content from CreateTokenForm
✅ PASSED: Results match
   Hash: feee2fb25fc262c36462b82327cd3fe117f37a1273fa7d72e24fbdf76a70f73d

Test 4: Binary data (PNG header)
Description: PNG file header bytes
✅ PASSED: Results match
   Hash: 4c4b6a3be1314ab86138bef4314dde022e600960d8689a2c8f8631802d20dab6

Test 5: Large content
Description: Large file content (1000 characters)
✅ PASSED: Results match
   Hash: c2e686823489ced2017f6059b8b239318b6364f6dcd835d0a519105a1eadd6e4

Test 6: Special characters
Description: Unicode content with emojis
✅ PASSED: Results match
   Hash: 3d45251179242573b9fdcce4ce8afceb0d8f1677d227f4bf3e7b638e4e03cc77

🔧 Testing CreateTokenForm exact scenario...

File content: This is a test image file content for token creation
ArrayBuffer length: 52

OLD APPROACH (js-sha256):
  Result: feee2fb25fc262c36462b82327cd3fe117f37a1273fa7d72e24fbdf76a70f73d
  Type: string
  Length: 64

NEW APPROACH (ecash-lib):
  Uint8Array length: 52
  sha256 result (Uint8Array): 254,238,47,178,95,194,98,195,100,98,184,35,39,205,63,225,23,243,122,18,115,250,125,114,226,79,189,247,106,112,247,61
  toHex result: feee2fb25fc262c36462b82327cd3fe117f37a1273fa7d72e24fbdf76a70f73d
  Type: string
  Length: 64

Exact scenario match: ✅ YES

🔍 Additional verification tests...

String input test: ✅ PASSED
Uint8Array input test: ✅ PASSED

=====================================
FINAL VERIFICATION RESULTS:
Tests run: 6
All tests passed: ✅ YES
Exact scenario match: ✅ YES

🎉 VERIFICATION SUCCESSFUL!
The ecash-lib implementation produces identical results to js-sha256.
The migration is safe and behavior is preserved.

📝 Migration Summary:
- Removed: js-sha256 dependency
- Added: sha256 and toHex imports from ecash-lib
- Updated: CreateTokenForm to use ecash-lib sha256
- Verified: Identical behavior and results

🔧 Code Changes Made:
1. Removed: import { sha256, Message } from "js-sha256";
2. Added: import { toHex, sha256 } from "ecash-lib";
3. Updated usage:
   const uint8Array = new Uint8Array(hashreader.result as ArrayBuffer);
   const hashBytes = sha256(uint8Array);
   const hashHex = toHex(hashBytes);
4. Removed: js-sha256 from package.json dependencies

📋 Library Information:
- js-sha256: Returns hex string directly
- ecash-lib sha256: Returns Uint8Array, requires toHex() conversion
- Both produce identical SHA256 hashes for the same input