import { PublicKey, Transaction, VersionedTransaction } from './js/lib/vendor/solana-publickey-bundle.js';

const PAGE_REQUEST = 'shine-wallet-page-request';
const PAGE_RESPONSE = 'shine-wallet-page-response';

function bytesToBase64(bytes) {
  let binary = '';
  const chunk = 0x8000;
  for (let i = 0; i < bytes.length; i += chunk) {
    const slice = bytes.subarray(i, i + chunk);
    binary += String.fromCharCode(...slice);
  }
  return btoa(binary);
}

function base64ToBytes(value) {
  const binary = atob(String(value || '').trim());
  const out = new Uint8Array(binary.length);
  for (let i = 0; i < binary.length; i += 1) {
    out[i] = binary.charCodeAt(i);
  }
  return out;
}

function createProviderError(message, code = '') {
  const error = new Error(String(message || 'Wallet provider error'));
  if (code === 'USER_REJECTED' || code === 'NOT_TRUSTED') {
    error.code = 4001;
  } else if (code) {
    error.code = code;
  }
  return error;
}

function createRequest(method, params = {}) {
  const id = `shine-wallet-${Date.now()}-${Math.random().toString(16).slice(2, 8)}`;
  return new Promise((resolve, reject) => {
    const onMessage = (event) => {
      if (event.source !== window) return;
      const data = event.data || {};
      if (data?.target !== PAGE_RESPONSE || String(data?.id || '') !== id) return;
      window.removeEventListener('message', onMessage);
      if (!data?.ok) {
        reject(createProviderError(data?.error || 'Wallet request failed', String(data?.code || '')));
        return;
      }
      resolve(data?.result || {});
    };
    window.addEventListener('message', onMessage);
    window.postMessage({
      target: PAGE_REQUEST,
      id,
      method,
      params,
    }, window.location.origin);
  });
}

function serializeTransactionBase64(transaction) {
  if (!transaction || typeof transaction.serialize !== 'function') {
    throw createProviderError('Unsupported transaction object', 'UNSUPPORTED_TRANSACTION');
  }
  let raw;
  try {
    raw = transaction.serialize({ requireAllSignatures: false, verifySignatures: false });
  } catch {
    raw = transaction.serialize();
  }
  const bytes = raw instanceof Uint8Array ? raw : new Uint8Array(raw);
  return bytesToBase64(bytes);
}

function deserializeSignedTransaction(base64, originalTransaction) {
  const bytes = base64ToBytes(base64);
  const ctor = originalTransaction?.constructor;
  if (ctor && typeof ctor.deserialize === 'function') {
    return ctor.deserialize(bytes);
  }
  if (ctor && typeof ctor.from === 'function') {
    return ctor.from(bytes);
  }
  if (typeof originalTransaction?.version === 'number') {
    return VersionedTransaction.deserialize(bytes);
  }
  return Transaction.from(bytes);
}

class ShineSolanaProvider {
  constructor() {
    this.isSHiNE = true;
    this.isPhantom = true;
    this.publicKey = null;
    this.isConnected = false;
    this._listeners = new Map();
  }

  on(event, handler) {
    const key = String(event || '');
    if (!this._listeners.has(key)) {
      this._listeners.set(key, new Set());
    }
    this._listeners.get(key).add(handler);
    return this;
  }

  off(event, handler) {
    const bucket = this._listeners.get(String(event || ''));
    if (!bucket) return this;
    bucket.delete(handler);
    if (!bucket.size) {
      this._listeners.delete(String(event || ''));
    }
    return this;
  }

  removeListener(event, handler) {
    return this.off(event, handler);
  }

  emit(event, payload) {
    const bucket = this._listeners.get(String(event || ''));
    if (!bucket?.size) return;
    for (const handler of [...bucket]) {
      try {
        handler(payload);
      } catch {}
    }
  }

  async connect(options = {}) {
    const onlyIfTrusted = !!options?.onlyIfTrusted;
    if (!onlyIfTrusted) {
      const confirmed = window.confirm(`Connect SHiNE Wallet to ${window.location.origin}?`);
      if (!confirmed) {
        throw createProviderError('User rejected wallet connection', 'USER_REJECTED');
      }
    }
    const result = await createRequest('connect', { onlyIfTrusted });
    const nextKey = new PublicKey(String(result?.publicKeyBase58 || '').trim());
    this.publicKey = nextKey;
    this.isConnected = true;
    this.emit('connect', nextKey);
    this.emit('accountChanged', nextKey);
    return { publicKey: nextKey };
  }

  async disconnect() {
    await createRequest('disconnect', {});
    this.isConnected = false;
    this.publicKey = null;
    this.emit('disconnect');
    this.emit('accountChanged', null);
  }

  async signTransaction(transaction) {
    if (!this.publicKey) {
      await this.connect();
    }
    const transactionBase64 = serializeTransactionBase64(transaction);
    const comment = `Site ${window.location.origin} requested transaction signature`;
    const result = await createRequest('signTransaction', {
      publicKeyBase58: this.publicKey?.toBase58?.() || '',
      transactionBase64,
      comment,
    });
    return deserializeSignedTransaction(String(result?.signedTransactionBase64 || ''), transaction);
  }

  async request(args = {}) {
    const method = String(args?.method || '');
    const params = args?.params;
    if (method === 'connect') {
      return this.connect(Array.isArray(params) ? params[0] : params || {});
    }
    if (method === 'disconnect') {
      return this.disconnect();
    }
    if (method === 'signTransaction') {
      const tx = Array.isArray(params) ? params[0] : params?.transaction || params;
      return this.signTransaction(tx);
    }
    throw createProviderError(`Unsupported request method: ${method}`, 'UNSUPPORTED_METHOD');
  }
}

if (!window.solana) {
  const provider = new ShineSolanaProvider();
  window.solana = provider;
  window.phantom = window.phantom || {};
  window.phantom.solana = provider;
  window.dispatchEvent(new Event('solana#initialized'));
}