import { importPkcs8Ed25519, sha256Bytes, signBytes } from './crypto-utils.js';
import { extractSeed32FromPkcs8B64 } from './device-key-utils.js';
import { SHINE_PAYMENTS_PROGRAM_ID, SHINE_USERS_ECONOMY_CONFIG_SEED, SHINE_USERS_PROGRAM_ID } from '../solana-programs.js';

const MAGIC = 'SHiNE';
const LAST_BLOCK_STATE_PREFIX = 'SHiNE_LAST_BLOCK';
const SHINE_PAYMENTS_INFLOW_VAULT_SEED = 'shine_payments_inflow_vault';
const LIMIT_STEP = 10_000n;
const UPDATE_USER_PDA_DISCRIMINATOR = new Uint8Array([42, 133, 114, 232, 38, 245, 167, 234]);
const ED25519_PROGRAM_ID = 'Ed25519SigVerify111111111111111111111111111';
const SYSVAR_INSTRUCTIONS_ID = 'Sysvar1nstructions1111111111111111111111111';

const BLOCK_TYPE_ROOT_KEY = 1;
const BLOCK_TYPE_DEVICE_KEY = 2;
const BLOCK_TYPE_BLOCKCHAIN_REGISTRY = 3;
const BLOCK_TYPE_SERVER_PROFILE = 30;
const BLOCK_TYPE_ACCESS_SERVERS = 40;
const BLOCK_TYPE_TRUSTED_STATE = 50;

let solanaLibPromise = null;
function loadSolanaLib() {
  if (!solanaLibPromise) solanaLibPromise = import('https://esm.sh/@solana/web3.js@1.98.4?bundle');
  return solanaLibPromise;
}

function pushU32LE(buf, v) {
  const n = Number(v) >>> 0;
  buf.push(n & 0xff, (n >>> 8) & 0xff, (n >>> 16) & 0xff, (n >>> 24) & 0xff);
}
function pushU64LE(buf, v) {
  const b = BigInt(v);
  const lo = Number(b & 0xffffffffn) >>> 0;
  const hi = Number((b >> 32n) & 0xffffffffn) >>> 0;
  pushU32LE(buf, lo);
  pushU32LE(buf, hi);
}
function pushStrU8(buf, value) {
  const bytes = new TextEncoder().encode(String(value || ''));
  if (bytes.length > 255) throw new Error('Слишком длинная строка для формата U8');
  buf.push(bytes.length);
  for (const x of bytes) buf.push(x);
}
function pushStrU32(buf, value) {
  const bytes = new TextEncoder().encode(String(value || ''));
  pushU32LE(buf, bytes.length);
  for (const x of bytes) buf.push(x);
}
function pushVecU8(buf, bytes) {
  const data = bytes || new Uint8Array();
  pushU32LE(buf, data.length);
  for (const x of data) buf.push(x);
}
function pushVecStrU32(buf, values) {
  const arr = Array.isArray(values) ? values : [];
  pushU32LE(buf, arr.length);
  for (const s of arr) pushStrU32(buf, s);
}

function makeReader(bytes) {
  let o = 0;
  const dv = new DataView(bytes.buffer, bytes.byteOffset, bytes.byteLength);
  const ensure = (n) => { if (o + n > bytes.length) throw new Error('Повреждённый формат PDA'); };
  const readU8 = () => { ensure(1); const v = dv.getUint8(o); o += 1; return v; };
  const readU16 = () => { ensure(2); const v = dv.getUint16(o, true); o += 2; return v; };
  const readU32 = () => { ensure(4); const v = dv.getUint32(o, true); o += 4; return v; };
  const readU64 = () => { ensure(8); const v = dv.getBigUint64(o, true); o += 8; return v; };
  const readBytes = (n) => { ensure(n); const out = bytes.slice(o, o + n); o += n; return out; };
  const readStrU8 = () => {
    const len = readU8();
    return new TextDecoder().decode(readBytes(len));
  };
  return { readU8, readU16, readU32, readU64, readBytes, readStrU8 };
}

function parseShineUserPda(dataBytes) {
  const r = makeReader(dataBytes);
  const magic = new TextDecoder().decode(r.readBytes(5));
  if (magic !== MAGIC) throw new Error('Некорректный формат PDA');
  r.readU8();
  r.readU8();
  r.readU16();
  const createdAtMs = r.readU64();
  const updatedAtMs = r.readU64();
  const recordNumber = r.readU32();
  const prevRecordHash = r.readBytes(32);
  const login = r.readStrU8();
  const blocksCount = r.readU8();

  const out = {
    createdAtMs,
    updatedAtMs,
    recordNumber,
    prevRecordHash,
    login,
    rootKey: null,
    deviceKey: null,
    blockchain: null,
    isServer: false,
    serverKey: new Uint8Array(32),
    serverAddress: '',
    syncServers: [],
    accessServers: [],
    trustedCount: 0,
  };

  for (let i = 0; i < blocksCount; i += 1) {
    const type = r.readU8();
    r.readU8();
    if (type === BLOCK_TYPE_ROOT_KEY) { out.rootKey = r.readBytes(32); continue; }
    if (type === BLOCK_TYPE_DEVICE_KEY) { out.deviceKey = r.readBytes(32); continue; }
    if (type === BLOCK_TYPE_BLOCKCHAIN_REGISTRY) {
      const count = r.readU8();
      for (let j = 0; j < count; j += 1) {
        const blockchainType = r.readU8();
        const blockchainName = r.readStrU8();
        const blockchainPublicKey = r.readBytes(32);
        const paidLimitBytes = r.readU64();
        const usedBytes = r.readU64();
        const lastBlockNumber = r.readU32();
        const lastBlockHash = r.readBytes(32);
        const lastBlockSignature = r.readBytes(64);
        const arPresent = r.readU8();
        const arweaveTxId = arPresent ? r.readStrU8() : '';
        if (!out.blockchain) {
          out.blockchain = {
            blockchainType,
            blockchainName,
            blockchainPublicKey,
            paidLimitBytes,
            usedBytes,
            lastBlockNumber,
            lastBlockHash,
            lastBlockSignature,
            arweaveTxId,
          };
        }
      }
      continue;
    }
    if (type === BLOCK_TYPE_SERVER_PROFILE) {
      out.isServer = r.readU8() === 1;
      out.serverKey = r.readBytes(32);
      out.serverAddress = r.readStrU8();
      const syncCount = r.readU8();
      out.syncServers = [];
      for (let k = 0; k < syncCount; k += 1) out.syncServers.push(r.readStrU8());
      continue;
    }
    if (type === BLOCK_TYPE_ACCESS_SERVERS) {
      const accessCount = r.readU8();
      out.accessServers = [];
      for (let k = 0; k < accessCount; k += 1) out.accessServers.push(r.readStrU8());
      continue;
    }
    if (type === BLOCK_TYPE_TRUSTED_STATE) {
      out.trustedCount = r.readU8();
      continue;
    }
    throw new Error(`Неизвестный блок PDA: ${type}`);
  }

  if (!out.rootKey || !out.deviceKey || !out.blockchain) {
    throw new Error('В PDA отсутствуют обязательные блоки');
  }
  return out;
}

function serializeUnsignedRecordFromState(stateLike) {
  const buf = [];
  const login = String(stateLike.login || '');
  const bch = stateLike.blockchain;
  buf.push(0x53, 0x48, 0x69, 0x4e, 0x45, 1, 0, 0, 0);
  pushU64LE(buf, stateLike.createdAtMs);
  pushU64LE(buf, stateLike.updatedAtMs);
  pushU32LE(buf, stateLike.recordNumber);
  for (const x of stateLike.prevRecordHash) buf.push(x);
  pushStrU8(buf, login);
  const blocksCount = stateLike.isServer ? 6 : 5;
  buf.push(blocksCount);

  buf.push(BLOCK_TYPE_ROOT_KEY, 0);
  for (const x of stateLike.rootKey) buf.push(x);
  buf.push(BLOCK_TYPE_DEVICE_KEY, 0);
  for (const x of stateLike.deviceKey) buf.push(x);

  buf.push(BLOCK_TYPE_BLOCKCHAIN_REGISTRY, 0, 1);
  buf.push(bch.blockchainType);
  pushStrU8(buf, bch.blockchainName);
  for (const x of bch.blockchainPublicKey) buf.push(x);
  pushU64LE(buf, bch.paidLimitBytes);
  pushU64LE(buf, bch.usedBytes);
  pushU32LE(buf, bch.lastBlockNumber);
  for (const x of bch.lastBlockHash) buf.push(x);
  for (const x of bch.lastBlockSignature) buf.push(x);
  if (String(bch.arweaveTxId || '').trim()) {
    buf.push(1);
    pushStrU8(buf, bch.arweaveTxId);
  } else {
    buf.push(0);
  }

  if (stateLike.isServer) {
    buf.push(BLOCK_TYPE_SERVER_PROFILE, 0, 1);
    for (const x of stateLike.serverKey) buf.push(x);
    pushStrU8(buf, stateLike.serverAddress);
    const sync = Array.isArray(stateLike.syncServers) ? stateLike.syncServers : [];
    buf.push(sync.length & 0xff);
    for (const s of sync) pushStrU8(buf, s);
  }

  buf.push(BLOCK_TYPE_ACCESS_SERVERS, 0);
  const access = Array.isArray(stateLike.accessServers) ? stateLike.accessServers : [];
  buf.push(access.length & 0xff);
  for (const s of access) pushStrU8(buf, s);

  buf.push(BLOCK_TYPE_TRUSTED_STATE, 0, Number(stateLike.trustedCount || 0) & 0xff);
  const recLen = buf.length + 64;
  buf[7] = recLen & 0xff;
  buf[8] = (recLen >>> 8) & 0xff;
  return new Uint8Array(buf);
}

function buildLastBlockStateBytes(login, blockchainName, lastBlockNumber, lastBlockHash32, usedBytes) {
  const buf = [];
  for (const x of new TextEncoder().encode(LAST_BLOCK_STATE_PREFIX)) buf.push(x);
  pushStrU8(buf, login);
  pushStrU8(buf, blockchainName);
  pushU32LE(buf, lastBlockNumber);
  for (const x of lastBlockHash32) buf.push(x);
  pushU64LE(buf, usedBytes);
  return new Uint8Array(buf);
}

function buildEd25519IxData(sig64, pubkey32, msgHash32) {
  const sigOff = 16;
  const pkOff = sigOff + 64;
  const msgOff = pkOff + 32;
  const data = new Uint8Array(msgOff + 32);
  const v = new DataView(data.buffer);
  data[0] = 1;
  data[1] = 0;
  v.setUint16(2, sigOff, true);
  v.setUint16(4, 0xffff, true);
  v.setUint16(6, pkOff, true);
  v.setUint16(8, 0xffff, true);
  v.setUint16(10, msgOff, true);
  v.setUint16(12, 32, true);
  v.setUint16(14, 0xffff, true);
  data.set(sig64, sigOff);
  data.set(pubkey32, pkOff);
  data.set(msgHash32, msgOff);
  return data;
}

function serializeUpdateUserPdaArgs(args) {
  const b = [];
  for (const x of UPDATE_USER_PDA_DISCRIMINATOR) b.push(x);
  pushStrU32(b, args.login);
  for (const x of args.rootKey32) b.push(x);
  pushU64LE(b, args.createdAtMs);
  pushU64LE(b, args.updatedAtMs);
  pushU32LE(b, args.version);
  pushVecU8(b, args.prevHash32);
  pushU64LE(b, args.additionalLimitBytes);
  for (const x of args.deviceKey32) b.push(x);
  for (const x of args.blockchainPublicKey32) b.push(x);
  pushStrU32(b, args.blockchainName);
  pushU64LE(b, args.usedBytes);
  pushU32LE(b, args.lastBlockNumber);
  pushVecU8(b, args.lastBlockHash32);
  pushVecU8(b, args.lastBlockSignature64);
  pushStrU32(b, args.arweaveTxId);
  b.push(args.isServer ? 1 : 0);
  for (const x of args.serverKey32) b.push(x);
  pushStrU32(b, args.serverAddress);
  pushVecStrU32(b, args.syncServers);
  pushVecStrU32(b, args.accessServers);
  b.push(Number(args.trustedCount || 0) & 0xff);
  pushVecU8(b, args.rootSignature64);
  return new Uint8Array(b);
}

function parseUsersEconomyConfig(dataBytes) {
  const v = new DataView(dataBytes.buffer, dataBytes.byteOffset, dataBytes.byteLength);
  if (dataBytes.byteLength < 25) throw new Error('Некорректный economy config');
  return {
    version: v.getUint8(0),
    registrationFeeLamports: v.getBigUint64(1, true),
    lamportsPerLimitStep: v.getBigUint64(9, true),
    startBonusLimit: v.getBigUint64(17, true),
  };
}

export async function getShineUsersEconomyConfig({ solanaEndpoint }) {
  const endpoint = String(solanaEndpoint || '').trim();
  if (!endpoint) throw new Error('Не указан Solana RPC endpoint');
  const solana = await loadSolanaLib();
  const connection = new solana.Connection(endpoint, 'confirmed');
  const usersProgram = new solana.PublicKey(SHINE_USERS_PROGRAM_ID);
  const [economyPda] = solana.PublicKey.findProgramAddressSync(
    [new TextEncoder().encode(SHINE_USERS_ECONOMY_CONFIG_SEED)],
    usersProgram,
  );
  const ai = await connection.getAccountInfo(economyPda, 'confirmed');
  if (!ai?.data) throw new Error('Economy config PDA не найден');
  const economy = parseUsersEconomyConfig(ai.data);
  return { endpoint, economyPda: economyPda.toBase58(), ...economy };
}

export async function getShineBlockchainUsage({ login, solanaEndpoint }) {
  const cleanLogin = String(login || '').trim().toLowerCase();
  const endpoint = String(solanaEndpoint || '').trim();
  if (!cleanLogin) throw new Error('Не указан логин');
  if (!endpoint) throw new Error('Не указан Solana RPC endpoint');
  const solana = await loadSolanaLib();
  const connection = new solana.Connection(endpoint, 'confirmed');
  const usersProgram = new solana.PublicKey(SHINE_USERS_PROGRAM_ID);
  const enc = new TextEncoder();
  const [userPda] = solana.PublicKey.findProgramAddressSync([enc.encode('login='), enc.encode(cleanLogin)], usersProgram);
  const ai = await connection.getAccountInfo(userPda, 'confirmed');
  if (!ai?.data) throw new Error('Пользовательский PDA не найден в Solana');
  const parsed = parseShineUserPda(ai.data);
  const bch = parsed.blockchain;
  const leftBytes = bch.paidLimitBytes > bch.usedBytes ? (bch.paidLimitBytes - bch.usedBytes) : 0n;
  return {
    endpoint,
    userPda: userPda.toBase58(),
    login: parsed.login,
    recordNumber: parsed.recordNumber,
    paidLimitBytes: bch.paidLimitBytes,
    usedBytes: bch.usedBytes,
    leftBytes,
    lastBlockNumber: bch.lastBlockNumber,
    lastBlockHashHex: Array.from(bch.lastBlockHash).map((x) => x.toString(16).padStart(2, '0')).join(''),
  };
}

export async function updateShineUserPdaOnSolana({
  login,
  solanaEndpoint,
  rootPrivatePkcs8B64,
  devicePrivatePkcs8B64,
  blockchainPrivatePkcs8B64,
  additionalLimitBytes = 0n,
  nextUsedBytes,
  nextLastBlockNumber,
  nextLastBlockHashHex,
}) {
  const cleanLogin = String(login || '').trim().toLowerCase();
  if (!cleanLogin) throw new Error('Не указан логин');
  const endpoint = String(solanaEndpoint || '').trim();
  if (!endpoint) throw new Error('Не указан Solana RPC endpoint');

  const solana = await loadSolanaLib();
  const connection = new solana.Connection(endpoint, 'confirmed');
  const usersProgram = new solana.PublicKey(SHINE_USERS_PROGRAM_ID);
  const paymentsProgram = new solana.PublicKey(SHINE_PAYMENTS_PROGRAM_ID);
  const ed25519Program = new solana.PublicKey(ED25519_PROGRAM_ID);
  const sysvarInstructions = new solana.PublicKey(SYSVAR_INSTRUCTIONS_ID);
  const enc = new TextEncoder();
  const [userPda] = solana.PublicKey.findProgramAddressSync([enc.encode('login='), enc.encode(cleanLogin)], usersProgram);
  const [economyPda] = solana.PublicKey.findProgramAddressSync([enc.encode(SHINE_USERS_ECONOMY_CONFIG_SEED)], usersProgram);
  const [inflowVault] = solana.PublicKey.findProgramAddressSync([enc.encode(SHINE_PAYMENTS_INFLOW_VAULT_SEED)], paymentsProgram);

  const userAi = await connection.getAccountInfo(userPda, 'confirmed');
  if (!userAi?.data) throw new Error('PDA пользователя не найден');
  const current = parseShineUserPda(userAi.data);
  const currentBch = current.blockchain;

  const effectiveUsed = nextUsedBytes == null ? currentBch.usedBytes : BigInt(nextUsedBytes);
  const effectiveLastNum = nextLastBlockNumber == null ? currentBch.lastBlockNumber : Number(nextLastBlockNumber);
  const effectiveLastHash = nextLastBlockHashHex
    ? Uint8Array.from(String(nextLastBlockHashHex).match(/.{1,2}/g).map((h) => parseInt(h, 16)))
    : currentBch.lastBlockHash;

  if (effectiveLastHash.length !== 32) throw new Error('last block hash должен быть 32 байта');
  const addLimit = BigInt(additionalLimitBytes || 0);
  if (addLimit < 0n) throw new Error('Нельзя уменьшать лимит');
  if (addLimit % LIMIT_STEP !== 0n) throw new Error(`Лимит можно увеличивать только шагом ${LIMIT_STEP}`);

  const rootPriv = await importPkcs8Ed25519(rootPrivatePkcs8B64);
  const bchPriv = await importPkcs8Ed25519(blockchainPrivatePkcs8B64);
  const deviceSeed32 = extractSeed32FromPkcs8B64(devicePrivatePkcs8B64);
  const deviceKeypair = solana.Keypair.fromSeed(deviceSeed32);

  const updatedAtMs = BigInt(Date.now());
  const newPaid = currentBch.paidLimitBytes + addLimit;
  const newRecordNumber = current.recordNumber + 1;
  const prevHash = await sha256Bytes(serializeUnsignedRecordFromState(current));

  const lastBlockStateBytes = buildLastBlockStateBytes(cleanLogin, currentBch.blockchainName, effectiveLastNum, effectiveLastHash, effectiveUsed);
  const lastBlockStateHash = await sha256Bytes(lastBlockStateBytes);
  const lastBlockSig64 = await signBytes(bchPriv, lastBlockStateHash);

  const nextState = {
    ...current,
    updatedAtMs,
    recordNumber: newRecordNumber,
    prevRecordHash: prevHash,
    blockchain: {
      ...currentBch,
      paidLimitBytes: newPaid,
      usedBytes: effectiveUsed,
      lastBlockNumber: effectiveLastNum,
      lastBlockHash: effectiveLastHash,
      lastBlockSignature: lastBlockSig64,
    },
  };
  const unsignedNext = serializeUnsignedRecordFromState(nextState);
  const unsignedNextHash = await sha256Bytes(unsignedNext);
  const rootSig64 = await signBytes(rootPriv, unsignedNextHash);

  const ixData = serializeUpdateUserPdaArgs({
    login: cleanLogin,
    rootKey32: current.rootKey,
    createdAtMs: current.createdAtMs,
    updatedAtMs,
    version: newRecordNumber,
    prevHash32: prevHash,
    additionalLimitBytes: addLimit,
    deviceKey32: current.deviceKey,
    blockchainPublicKey32: currentBch.blockchainPublicKey,
    blockchainName: currentBch.blockchainName,
    usedBytes: effectiveUsed,
    lastBlockNumber: effectiveLastNum,
    lastBlockHash32: effectiveLastHash,
    lastBlockSignature64: lastBlockSig64,
    arweaveTxId: currentBch.arweaveTxId,
    isServer: current.isServer,
    serverKey32: current.serverKey,
    serverAddress: current.serverAddress,
    syncServers: current.syncServers,
    accessServers: current.accessServers,
    trustedCount: current.trustedCount,
    rootSignature64: rootSig64,
  });

  const edIxRoot = new solana.TransactionInstruction({
    programId: ed25519Program,
    keys: [],
    data: buildEd25519IxData(rootSig64, current.rootKey, unsignedNextHash),
  });
  const edIxBch = new solana.TransactionInstruction({
    programId: ed25519Program,
    keys: [],
    data: buildEd25519IxData(lastBlockSig64, currentBch.blockchainPublicKey, lastBlockStateHash),
  });
  const updIx = new solana.TransactionInstruction({
    programId: usersProgram,
    keys: [
      { pubkey: deviceKeypair.publicKey, isSigner: true, isWritable: true },
      { pubkey: userPda, isSigner: false, isWritable: true },
      { pubkey: solana.SystemProgram.programId, isSigner: false, isWritable: false },
      { pubkey: inflowVault, isSigner: false, isWritable: true },
      { pubkey: sysvarInstructions, isSigner: false, isWritable: false },
      { pubkey: economyPda, isSigner: false, isWritable: false },
    ],
    data: ixData,
  });

  const signature = await solana.sendAndConfirmTransaction(
    connection,
    new solana.Transaction().add(edIxRoot, edIxBch, updIx),
    [deviceKeypair],
    { commitment: 'confirmed' },
  );

  return {
    signature,
    userPda: userPda.toBase58(),
    paidLimitBytes: newPaid,
    usedBytes: effectiveUsed,
    leftBytes: newPaid > effectiveUsed ? (newPaid - effectiveUsed) : 0n,
    lastBlockNumber: effectiveLastNum,
    lastBlockHashHex: Array.from(effectiveLastHash).map((x) => x.toString(16).padStart(2, '0')).join(''),
  };
}

export function calcLimitTopupPriceLamports(additionalLimitBytes, lamportsPerLimitStep) {
  const add = BigInt(additionalLimitBytes || 0);
  const pricePerStep = BigInt(lamportsPerLimitStep || 0);
  if (add < 0n) throw new Error('Некорректный размер увеличения лимита');
  if (add % LIMIT_STEP !== 0n) throw new Error(`Увеличение лимита должно быть кратно ${LIMIT_STEP} байт`);
  return (add / LIMIT_STEP) * pricePerStep;
}

export function getLimitStepBytes() {
  return LIMIT_STEP;
}