Part 3: Hands-on - Join Game & Pilih Pemenang

"Ini adalah momen yang kamu tunggu - sentuh blockchain secara real!" 🎮

🎯 Tujuan Part Ini

Di part ini, peserta akan:

✅ Connect ke deployed contract via Remix
✅ Join game raffle GRATIS dengan panggil joinGame()
✅ Lihat transaksi di BaseScan
✅ Track semua players yang join
✅ Pilih pemenang dengan pickWinner()
✅ Verifikasi USDC terkirim ke winner
✅ Celebrate pengalaman Web3 pertama! 🎉

Durasi: 25 menit (30-55 menit di workshop)

📋 Prerequisites

Sebelum mulai part ini:

✅ Contract SimpleVibeRaffle sudah deployed (Part 2)
✅ Punya contract address (misal: 0xABC...123)
✅ MetaMask di Base Sepolia network
✅ Punya sedikit ETH Base Sepolia untuk gas (~0.001 ETH)
✅ Remix sudah connect ke MetaMask

🎮 Section 1: Connect ke Deployed Contract

Skenario

Instructor sudah deploy contract sebelum workshop.

Peserta akan connect ke contract yang sama untuk join game.

Step 1: Dapatkan Contract Address

Dari Instructor:

Instructor akan share contract address di slide atau chat:

Contract Address:
0xABC123DEF456...  (contoh)

Copy address ini!

Verifikasi Contract di BaseScan:

Buka: https://sepolia.basescan.org
Paste address di search bar
Check:
- ✅ Contract exists
- ✅ Creator = instructor address
- ✅ Token transfers (USDC jika sudah funded)

Step 2: Load Contract di Remix

Di Remix IDE:

Klik icon "Deploy" 🚀 di sidebar kiri

Pastikan Environment:

Environment: Injected Provider - MetaMask
Network: Base Sepolia (84532)

Pilih Contract:
```
Contract dropdown: SimpleVibeRaffle
```
Load Contract "At Address":
- Paste contract address di field "At Address"
- Klik tombol "At Address" (warna pink/merah muda)
Contract Akan Muncul!

Lihat di section "Deployed Contracts":

📦 SimpleVibeRaffle at 0xABC...123

Functions:
🔵 owner
🔵 gameOpen
🔵 players
🟠 joinGame
🟠 pickWinner
...

Success! Kamu sekarang connected ke contract 🎉

Step 3: Verify Contract Info

Test Read Functions:

Klik button berikut untuk verify:

1. Check Owner:

Klik: owner

Returns: 0x... (instructor address)

2. Check Game Status:

Klik: gameOpen

Returns: true (game masih buka)

3. Check USDC Address:

Klik: usdcToken

Returns: 0x036CbD53842c5426634e7929541eC2318f3dCF7e

4. Check Prize Pool:

Klik: getPrizePool

Returns: 10000000 (10 USDC dalam 6 decimals)

5. Check Players:

Klik: getPlayerCount

Returns: 0 (belum ada yang join)

Kalau semua berfungsi = Ready to play! ✅

🎲 Section 2: Join Game

Cara Peserta Join Game

Important: Siapa saja bisa join, gratis (no entry fee)!

Step 1: Panggil `joinGame()`

Di Remix:

Scroll ke Deployed Contract
Cari button joinGame (warna orange 🟠)
Klik button "joinGame"

MetaMask akan popup:

SimpleVibeRaffle
Function: joinGame()

Gas Fee: ~0.0003 ETH

[Reject] [Confirm]

Klik "Confirm"
Tunggu transaksi di-mine (~15-30 detik)

Check Terminal Remix:

✅ Transaction confirmed
From: 0x1234...5678 (your address)
To: 0xABC...123 (contract)
Function: joinGame()
Status: Success

Selamat! Kamu sudah join game! 🎊

Step 2: Verify Join Berhasil

Method 1: Via Remix

Klik:

getPlayerCount → Returns: 1 (atau lebih kalau ada yang join duluan)

Klik:

getPlayers → Returns: ["0x1234...5678", ...] (array of addresses)

Method 2: Via BaseScan

Buka BaseScan Sepolia: https://sepolia.basescan.org
Paste contract address
Klik tab "Events"

Lihat event:

PlayerJoined
player: 0x1234...5678 (your address)
timestamp: ... (kapan join)

Method 3: Check Transaction Hash

Di Remix terminal, klik transaction hash:

Transaction: 0xdef456...

Akan buka BaseScan dengan details:

Function: joinGame()
From: Your address
To: Contract address
Status: Success ✅
Gas Used: 50000

Step 3: Multiple Entries (Opsional)

Pro tip: Join berkali-kali = peluang lebih besar!

Cara:

Panggil joinGame() lagi
Confirm di MetaMask
Repeat as many times as you want

Contoh:

Player A join 1x → 1 entry
Player B join 3x → 3 entries
Player C join 5x → 5 entries

Total players array: 9 entries
Player C punya peluang 5/9 = 55%!

Catatan:

Butuh gas setiap kali join (~0.0003 ETH)
Untuk workshop, 1-2x cukup (biar semua dapat kesempatan)

👥 Section 3: Monitor All Players

Live Tracking

Instructor bisa tampilkan di screen:

Di Remix:

Klik button getPlayers berkala (setiap 30 detik):

getPlayers

Returns:
[
  "0x1111...aaaa",
  "0x2222...bbbb",
  "0x2222...bbbb",  ← Join 2x
  "0x3333...cccc",
  "0x4444...dddd",
  ...
]

Lihat jumlah total:

getPlayerCount

Returns: 15 (misalnya)

Lihat prize pool:

getPrizePool

Returns: 10000000 (10 USDC dalam 6 decimals)

Visualisasi di Screen

Instructor bisa buat slide/dashboard sederhana:

┌─────────────────────────────────────────┐
│   WEB3 VIBE RAFFLE - LIVE STATS         │
├─────────────────────────────────────────┤
│                                          │
│  🎁 Prize Pool: 10 USDC                 │
│  👥 Total Entries: 15                   │
│  🎮 Game Status: OPEN                   │
│                                          │
│  Recent Players:                         │
│  - 0x1111...aaaa (1 entry)              │
│  - 0x2222...bbbb (2 entries)            │
│  - 0x3333...cccc (1 entry)              │
│  - 0x4444...dddd (3 entries)            │
│  - ...                                   │
│                                          │
│  ⏳ Waiting for more players...         │
│                                          │
└─────────────────────────────────────────┘

Bikin excitement:

"Oke, sudah 10 orang join!"
"Wow, ada yang join 5 kali - all in! 🚀"
"Kita tunggu 5 menit lagi, terus pilih pemenang!"

🎯 Section 4: Pick Winner (The Big Moment!)

Persiapan

Sebelum pick winner:

Pastikan cukup players (minimal 3-5 untuk seru)

Announce:

"Oke guys, game ditutup dalam 1 menit!
Yang mau join, sekarang terakhir kalinya!"

Final check:

getPlayerCount → Returns: 20 (misalnya)
getPrizePool → Returns: 10000000 (10 USDC)

Build hype:

"Alright, 20 entries!
Prize pool: 10 USDC di Base Sepolia!
Mari kita lihat siapa yang beruntung hari ini! 🎲"

Step 1: Call `pickWinner()`

Hanya OWNER (instructor) yang bisa panggil!

Di Remix (Instructor's laptop):

Double-check account:
```
Account: 0x... (owner address)
```
Klik button pickWinner (orange 🟠)

MetaMask popup:

Function: pickWinner()
Gas Fee: ~0.001 ETH

[Reject] [Confirm]

Klik "Confirm"

Tunggu mining...

[pending] Waiting for transaction to be mined...

Screen mungkin freeze sebentar (normal!)

Success! 🎉

✅ Transaction confirmed
Function: pickWinner()
Status: Success
Event: WinnerPicked(winner, prize)

Step 2: Lihat Siapa Pemenangnya!

Method 1: Via Remix Events

Di terminal Remix, expand transaction:

Logs:
- WinnerPicked
  winner: 0x2222...bbbb
  prize: 10000000 (10 USDC dalam 6 decimals)

Method 2: Via BaseScan (Better for presentation!)

Copy transaction hash dari Remix
Buka di BaseScan: https://sepolia.basescan.org
Klik tab "Logs"

Lihat event:

Event: WinnerPicked

Topics:
- winner: 0x2222...bbbb ← PEMENANG!

Data:
- prize: 10000000 (10 USDC dalam 6 decimals)

Announce winner:

"PEMENANGNYA ADALAH...

Address: 0x2222...bbbb

Selamat! Kamu dapat 10 USDC di Base Sepolia! 🎉🎉🎉"

Step 3: Verify Transfer Berhasil

Check Winner Wallet:

Kalau winner ada di ruangan:

Minta dia:

Buka MetaMask
Check balance USDC di Base Sepolia
Harusnya bertambah 10 USDC! (Mungkin perlu add USDC token manual ke MetaMask)

Live Demo di Screen:

Buka BaseScan
Paste winner address
Klik tab "Token Transfers"

Lihat:

Recent Token Transfers:
- IN: 10 USDC from Contract (just now!)

Klik transaction:

ERC-20 Token Transfer:
From: Contract (0xABC...123)
To: Winner (0x2222...bbbb)
Token: USDC (0x036C...)
Value: 10 USDC
Status: Success ✅

Ini adalah momen magic! ✨

Tunjukkan ke peserta:

"Lihat! Tidak ada yang manual.
Tidak ada transfer dari saya.
Smart contract OTOMATIS kirim USDC ke pemenang!

Ini adalah kekuatan Web3! 🚀"

Step 4: Verify Game Closed

Check state contract:

gameOpen → Returns: false (game sudah ditutup)

Coba join lagi:

Kalau ada yang coba joinGame() sekarang:

❌ Transaction will revert
Error: "Game is closed"

Perfect! Contract bekerja sesuai logic 🎯

🎊 Section 5: Celebration & Debrief

Celebrate! 🎉

Momen ini penting untuk learning experience!

Instructor:

"Give applause untuk pemenang! 👏👏👏

Dan give applause untuk KALIAN SEMUA!

Kalian baru saja:
✅ Berinteraksi dengan smart contract
✅ Mengirim transaksi on-chain
✅ Melihat ETH otomatis terkirim by code

Ini adalah pengalaman Web3 REAL! 🚀"

Debrief: Apa Yang Baru Terjadi?

Recap untuk peserta:

1. Join Game:

- Kamu panggil fungsi joinGame()
- Address kamu masuk ke array players[]
- Transaksi tercatat permanent di blockchain

2. Pick Winner:

- Owner panggil pickWinner()
- Contract generate random number
- Pilih 1 address dari players array
- Transfer seluruh prize pool otomatis

3. The Magic:

- Tidak ada yang bisa curang
- Tidak ada manual transfer
- Semua transparan (bisa di-verify di BaseScan)
- Code adalah law!

Key Takeaways

Highlight untuk peserta:

✅ Trustless:

Tidak perlu percaya instructor.
Percaya kode yang sudah di-deploy.
Siapa saja bisa verify kode di BaseScan.

✅ Transparent:

Semua transaksi public.
Semua orang bisa lihat:
- Siapa yang join
- Kapan join
- Siapa pemenang
- Berapa hadiah

✅ Immutable:

Kode tidak bisa diubah.
Rules sudah fixed sejak deploy.
Tidak ada yang bisa manipulate hasil.

✅ Composable:

Contract ini bisa di-combine dengan contract lain.
Misal: Tambah NFT sebagai tiket entry.
Atau: Integrate dengan DAO untuk governance.

🎓 Section 6: Eksperimen Lanjutan (Opsional)

Kalau masih ada waktu (~5-10 menit), bisa coba:

Eksperimen 1: Check Old State

Sekarang game sudah closed, tapi data masih ada!

Coba:

getPlayers → Masih return array lengkap
getPlayerCount → Masih return jumlah total
getPrizePool → Return 0 (karena sudah transfer semua)

Lesson:

State permanent di blockchain
Bisa di-query kapan saja
Useful untuk audit trail!

Eksperimen 2: Try Call After Closed

Coba join lagi:

joinGame() → ❌ Revert: "Game is closed"

Coba pick winner lagi:

pickWinner() → ❌ Revert: "Game already closed"

Lesson:

Validasi berfungsi!
Contract enforce rules automatically
Tidak bisa bypass logic

Eksperimen 3: Lihat di Block Explorer

Di BaseScan, explore:

Contract Page:

Total transactions
Total value transferred
Internal transactions
Events emitted

Winner Transaction:

Gas used
Gas price
Block number
Timestamp
Input data (function call)

Lesson:

Blockchain adalah ledger public
Semua traceable & verifiable
Perfect for transparency!

📊 Workshop Stats Recap

Tampilkan stats akhir:

┌─────────────────────────────────────────┐
│   WEB3 VIBE RAFFLE - FINAL STATS        │
├─────────────────────────────────────────┤
│                                          │
│  🎁 Prize Pool: 10 USDC                 │
│  👥 Total Participants: 20               │
│  📝 Total Entries: 35                   │
│  🎯 Winner: 0x2222...bbbb               │
│  ⛽ Total Gas Used: ~0.005 ETH          │
│  ⏱️  Duration: 45 minutes               │
│  🎉 Success Rate: 100%                  │
│  🌐 Network: Base Sepolia               │
│                                          │
│  Fun Facts:                              │
│  - Fastest join: 3 seconds (Base fast!) │
│  - Most entries: 5x (0x4444...dddd)     │
│  - Lucky winner joined 2x only!         │
│                                          │
└─────────────────────────────────────────┘

💡 Q&A Session

Common Questions & Answers

Q: Kenapa random number tidak aman?

A: Karena block.timestamp, msg.sender, dan data lain bisa diprediksi atau dimanipulasi oleh miner. Untuk uang real, pakai Chainlink VRF yang verifiable & unpredictable.

Q: Bisa tidak 1 orang menang lebih dari 1 kali?

A: Di contract ini, tidak. Setelah pickWinner() dipanggil, gameOpen = false. Untuk multi-winner, perlu ubah logic (pakai loop, pilih N winners).

Q: Kalau owner jahat, bisa curang tidak?

A: Di contract ini, owner punya control besar (bisa pickWinner kapan saja). Untuk production, bisa pakai:

Time-lock (otomatis pick setelah X jam)
Multi-sig (butuh approval multiple owners)
Chainlink Automation (trigger otomatis)

Q: Gas fee bisa lebih murah?

A: Yes! Di Sepolia free (testnet). Di mainnet, bisa pakai:

Layer 2 (Arbitrum, Optimism) → Gas 10-100x lebih murah
Batch transactions
Gas optimization di code

Q: Bisa pakai untuk real money?

A: Bisa, TAPI harus:

Audit security profesional
Pakai Chainlink VRF untuk random
Add access control yang proper
Comply dengan gambling laws (hati-hati legal!)
Insurance & emergency pause mechanism

Q: Berapa biaya deploy contract di mainnet?

A: Tergantung gas price. Estimasi:

Contract deployment: ~0.01 - 0.05 ETH ($20-$100)
Each transaction: ~0.001 - 0.01 ETH ($2-$20)

Makanya kita pakai testnet untuk belajar! 😄

✅ Final Checklist: What You Learned

Check yang sudah kamu pelajari:

Konsep

Praktek

Tools

Remix IDE untuk interact
MetaMask untuk sign transactions
BaseScan untuk verify
Base Sepolia testnet untuk testing

🚀 What's Next?

Immediate Next Steps:

1. Explore More Contracts:

Lihat contracts di block explorers (BaseScan, Etherscan untuk Ethereum, dll)
Coba interact dengan contract popular (misal: USDC di testnet)

2. Learn Solidity:

CryptoZombies - Interactive tutorial
Solidity by Example - Code snippets
Ethereum.org Docs - Official guide

3. Build Your Own:

Modifikasi SimpleVibeRaffle (tambah fitur)
Buat game/raffle sendiri
Deploy & share dengan teman

Intermediate Level:

4. Learn Frameworks:

Hardhat - Testing & deployment
Foundry - Fast Solidity development
Truffle - Suite lengkap

5. Frontend Integration:

Belajar ethers.js atau viem
Build UI untuk interact dengan contract
Next.js + Web3 integration

6. Advanced Concepts:

Security best practices
Gas optimization
Upgradeable contracts
Cross-chain bridges

Resources:

Free Courses:

- Alchemy University (gratis!)
- Buildspace (project-based learning)
- LearnWeb3 DAO (structured curriculum)

Communities:

- Ethereum Stack Exchange (Q&A)
- /r/ethdev (Reddit)
- Discord: Ethereum, Alchemy, Chainlink

Keep Building:

- Hackathons (ETHGlobal, etc)
- Bounties (Gitcoin)
- Open source contributions

🎁 Bonus: Contract Address & Resources

Workshop Materials

Contract Address (Base Sepolia):

[Instructor akan isi address di sini]
0x...

BaseScan Link:

https://sepolia.basescan.org/address/0x...

USDC Address (Base Sepolia):

0x036CbD53842c5426634e7929541eC2318f3dCF7e

Source Code:

GitHub: [link repo]
Gist: [link gist]

Official Resources

Base:

Website: https://base.org
Docs: https://docs.base.org
Base Sepolia Faucet (ETH): https://www.coinbase.com/faucets/base-ethereum-sepolia-faucet
Circle USDC Faucet: https://faucet.circle.com/

Ethereum:

Website: https://ethereum.org
Docs: https://ethereum.org/en/developers/docs/

Tools:

Learning:

Solidity Docs: https://docs.soliditylang.org
CryptoZombies: https://cryptozombies.io
Alchemy University: https://university.alchemy.com

🎉 Terima Kasih!

Selamat! Kamu sudah:

✅ Sentuh blockchain pertama kali
✅ Interact dengan smart contract
✅ Kirim transaksi on-chain
✅ Lihat ETH transfer otomatis by code
✅ Punya foundasi untuk belajar Web3!

Ini baru permulaan! 🚀

Web3 adalah future of internet, dan kamu sudah punya head start.

Keep learning, keep building, and most importantly - have fun! 🎊

Follow Up:

Join komunitas Ethereum Jakarta
Subscribe newsletter Web3
Ikut workshop lanjutan
Build & deploy project sendiri!

Special Thanks:

Web3 Week Asia organizers
Peserta yang enthusiastic
Ethereum Foundation
Open source community

See you in the metaverse! 👋

← Part 2: Smart Contract | Main Index

#Web3WeekAsia | #BuildWeb3 | #LearnInPublic | #GM

🎯 Tujuan Part Ini​

📋 Prerequisites​

🎮 Section 1: Connect ke Deployed Contract​

Skenario​

Step 1: Dapatkan Contract Address​

Step 2: Load Contract di Remix​

Step 3: Verify Contract Info​

🎲 Section 2: Join Game​

Cara Peserta Join Game​

Step 1: Panggil joinGame()​

Step 2: Verify Join Berhasil​

Step 3: Multiple Entries (Opsional)​

👥 Section 3: Monitor All Players​

Live Tracking​

Visualisasi di Screen​

🎯 Section 4: Pick Winner (The Big Moment!)​

Persiapan​

Step 1: Call pickWinner()​

Step 2: Lihat Siapa Pemenangnya!​

Step 3: Verify Transfer Berhasil​

Step 4: Verify Game Closed​

🎊 Section 5: Celebration & Debrief​

Celebrate! 🎉​

Debrief: Apa Yang Baru Terjadi?​

Key Takeaways​

🎓 Section 6: Eksperimen Lanjutan (Opsional)​

Eksperimen 1: Check Old State​

Eksperimen 2: Try Call After Closed​

Eksperimen 3: Lihat di Block Explorer​

📊 Workshop Stats Recap​

💡 Q&A Session​

Common Questions & Answers​

✅ Final Checklist: What You Learned​

Konsep​

Praktek​

Tools​

🚀 What's Next?​

Immediate Next Steps:​

Intermediate Level:​

Resources:​

🎁 Bonus: Contract Address & Resources​

Workshop Materials​

Official Resources​

🎉 Terima Kasih!​

🎯 Tujuan Part Ini

📋 Prerequisites

🎮 Section 1: Connect ke Deployed Contract

Skenario

Step 1: Dapatkan Contract Address

Step 2: Load Contract di Remix

Step 3: Verify Contract Info

🎲 Section 2: Join Game

Cara Peserta Join Game

Step 1: Panggil `joinGame()`

Step 2: Verify Join Berhasil

Step 3: Multiple Entries (Opsional)

👥 Section 3: Monitor All Players

Live Tracking

Visualisasi di Screen

🎯 Section 4: Pick Winner (The Big Moment!)

Persiapan

Step 1: Call `pickWinner()`

Step 2: Lihat Siapa Pemenangnya!

Step 3: Verify Transfer Berhasil

Step 4: Verify Game Closed

🎊 Section 5: Celebration & Debrief

Celebrate! 🎉

Debrief: Apa Yang Baru Terjadi?

Key Takeaways

🎓 Section 6: Eksperimen Lanjutan (Opsional)

Eksperimen 1: Check Old State

Eksperimen 2: Try Call After Closed

Eksperimen 3: Lihat di Block Explorer

📊 Workshop Stats Recap

💡 Q&A Session

Common Questions & Answers

✅ Final Checklist: What You Learned

Konsep

Praktek

Tools

🚀 What's Next?

Immediate Next Steps:

Intermediate Level:

Resources:

🎁 Bonus: Contract Address & Resources

Workshop Materials

Official Resources

🎉 Terima Kasih!