// app.js — frontend logic for IPFS Web Uploader (EGAZ / ETI)

const $  = (id) => document.getElementById(id);
const log = (msg) => {
  const el = $("log");
  const now = new Date().toISOString().replace("T"," ").replace("Z","");
  el.textContent += `[${now}] ${msg}\n`;
  el.scrollTop = el.scrollHeight;
};

let CFG = null;
let RATES = null;
let CURRENT_QUOTE = null;
let CURRENT_TX = null;
let POLL_TIMER = null;
let SELECTED_ACCOUNT = null;
let UPLOADED_CID = null;

async function api(path, opts) {
  const res = await fetch(path, opts);
  if (!res.ok) throw new Error(`${path} HTTP ${res.status}`);
  return res.json();
}

// ===== helpers =====
function updateWalletUI() {
  const btn = $("btnConnectTop");
  const acctEl = $("tbAcct");
  if (!SELECTED_ACCOUNT) {
    btn.disabled = !window.ethereum;
    btn.textContent = window.ethereum ? "MetaMask Login" : "No MetaMask";
    acctEl.textContent = "wallet: not connected";
  } else {
    btn.disabled = false;
    btn.textContent = "MetaMask Logout";
    acctEl.textContent = `wallet: ${SELECTED_ACCOUNT}`;
  }
}
function middleEllipsis(addr, head=14, tail=12){
  if (!addr) return "–";
  if (addr.length <= head+tail) return addr;
  return addr.slice(0, head) + "…" + addr.slice(-tail);
}
function fmtDec(decStr, digits=6){
  const [i,f=""] = String(decStr).split(".");
  const cut = f.slice(0, digits).replace(/0+$/,"");
  return cut ? `${i}.${cut}` : i;
}
function bytesHuman(n){
  const b=Number(n); if(b<1024) return `${b} B`;
  const u=['KB','MB','GB','TB']; let i=-1,x=b;
  do{x/=1024;i++;}while(x>=1024&&i<u.length-1);
  return `${x.toFixed(2)} ${u[i]}`;
}
function parseUnits(decStr, decimals=18){
  if (typeof decStr !== "string") decStr = String(decStr);
  const neg=decStr.startsWith("-"); if(neg) decStr=decStr.slice(1);
  if(!/^\d+(\.\d+)?$/.test(decStr)) throw new Error("bad decimal");
  const [ip,frRaw=""]=decStr.split(".");
  const fr=(frRaw+"0".repeat(decimals)).slice(0,decimals);
  const bi=BigInt(ip+fr.replace(/^0+$/,""));
  return neg?-bi:bi;
}
function to0xHex(big){ return "0x" + big.toString(16); }
function encodeErc20Transfer(to, amountWei){
  const method="a9059cbb";
  const addr=to.toLowerCase().replace(/^0x/,"").padStart(64,"0");
  const amt=amountWei.toString(16).padStart(64,"0");
  return "0x"+method+addr+amt;
}

// ===== theme toggle =====
$("btnTheme").onclick = () => {
  const cur = document.documentElement.dataset.theme === "dark" ? "dark" : "light";
  const next = cur === "dark" ? "light" : "dark";
  document.documentElement.dataset.theme = next;
  try { localStorage.setItem("theme", next); } catch {}
};

// ===== config/health/rates =====
async function loadConfigAndHealth(){
  CFG = await api("/api/config/public");
  $("cfgChain").textContent = CFG.chain;
  $("cfgRpc").textContent   = CFG.rpc;
  $("cfgPayTo").textContent = CFG.payTo;
  $("cfgTier").textContent  = `${CFG.tierMB} MB`;
  $("cfgPpt").textContent   = `${CFG.pricePerTierEgaz} ${CFG.currencyBase || "EGAZ"}`;
  $("cfgCurrencies").textContent = (CFG.supportedCurrencies||["EGAZ"]).join(", ");
  $("cfgConf").textContent = CFG.requiredConfirmations ?? "3";
  $("confReq").textContent = CFG.requiredConfirmations ?? "3";

  const h = await api("/api/health");
  $("healthBlock").textContent = h.latestBlock;
  $("healthReq").textContent   = h.requiredConfirmations;
  $("healthNow").textContent   = h.now;
  log(`RPC ok, latest=${h.latestBlock}`);

  try{
    RATES = await api("/api/rates");
    $("rateSrc").textContent = RATES.source || "fallback";
    $("rateEgazUsd").textContent = RATES.egazUsd ? `$${RATES.egazUsd}` : "–";
    $("rateEtiUsd").textContent  = RATES.etiUsd  ? `$${RATES.etiUsd}`  : "–";
    $("rateEtiPerEgaz").textContent = RATES.etiPerEgaz ? `${RATES.etiPerEgaz.toFixed(6)} ETI` : "–";
    log(`Rates source=${RATES.source} egazUsd=${RATES.egazUsd||0} etiUsd=${RATES.etiUsd||0} etiPerEgaz=${RATES.etiPerEgaz||1}`);
  }catch(e){
    $("rateSrc").textContent = "unavailable";
    $("rateEgazUsd").textContent = "–";
    $("rateEtiUsd").textContent  = "–";
    $("rateEtiPerEgaz").textContent = "–";
    log(`rates error: ${e.message}`);
  }
}

// ===== wallet =====
async function ensureWallet(){
  if (!window.ethereum) {
    $("tbAcct").textContent = "wallet: no metamask";
    $("btnConnectTop").disabled = true;
    $("btnConnectTop").textContent = "No MetaMask";
    return;
  }
  const accts = await ethereum.request({ method:"eth_accounts" });
  if (accts && accts.length){ setAccount(accts[0]); }
  ethereum.on?.("accountsChanged", (acc) => setAccount(acc[0] || null));
}
function setAccount(a){
  SELECTED_ACCOUNT = a || null;
  $("tbAcct").textContent = a ? `wallet: ${middleEllipsis(a)}` : "wallet: disconnected";
  if (a){
    $("btnConnectTop").textContent = "Connected";
    $("btnConnectTop").disabled = true;
    loadFiles();
  } else {
    $("btnConnectTop").textContent = "Connect MetaMask";
    $("btnConnectTop").disabled = false;
    renderFiles([]);
  }
}
$("btnConnectTop").onclick = async ()=>{
  if (!window.ethereum){ alert("MetaMask not found"); return; }
  const acc = await ethereum.request({ method:"eth_requestAccounts" });
  setAccount(acc[0] || null);
};

// ===== files panel =====
async function loadFiles(){
  try{
    $("filesStatus").textContent = "loading…";
    const addr = SELECTED_ACCOUNT || "0x0000000000000000000000000000000000000000";
    const res = await api(`/api/files?address=${addr}`);
    renderFiles(res.files || []);
    $("filesStatus").textContent = `showing ${(res.files||[]).length} file(s) for ${middleEllipsis(addr)}`;
  }catch(e){
    $("filesStatus").textContent = `error: ${e.message}`;
    renderFiles([]);
  }
}
function renderFiles(files){
  const wrap = $("filesTableWrap");
  const empty = $("filesEmpty");
  const tbody = $("filesTbody");
  tbody.innerHTML = "";
  if (!files || files.length === 0){
    empty.classList.remove("hidden");
    wrap.classList.add("hidden");
    return;
  }
  empty.classList.add("hidden");
  wrap.classList.remove("hidden");
  for (const f of files){
    const tr = document.createElement("tr");
    const size = f.size_bytes ?? f.sizeBytes ?? 0;
    const cid  = f.cid || "";
    const path = f.path || "";
    const label = f.label || "";
    const when = f.created_at || f.createdAt || "";
    const status = f.status || "stored";
    tr.innerHTML = `
      <td>${f.filename || "—"}</td>
      <td>${bytesHuman(size)}</td>
      <td class="mono">${cid || "—"}</td>
      <td class="mono">${path || "—"}</td>
      <td>${label || "—"}</td>
      <td><span class="tag">${status}</span></td>
      <td class="small">${when ? new Date(when).toLocaleString() : "—"}</td>
    `;
    tbody.appendChild(tr);
  }
}
$("btnRefreshFiles").onclick = loadFiles;

// ===== quote & pay & upload =====
function resetQuoteUI(){
  $("quoteBox").classList.add("hidden");
  $("confirmBox").classList.add("hidden");
  $("quoteStatus").textContent = "";
  $("payStatus").textContent = "";
  $("btnUploadNow").classList.add("hidden");
  CURRENT_QUOTE = null; CURRENT_TX = null; UPLOADED_CID = null;
  if (POLL_TIMER) { clearInterval(POLL_TIMER); POLL_TIMER = null; }
}

$("btnQuote").onclick = async ()=>{
  try{
    resetQuoteUI();
    const f = $("file").files[0];
    if (!f){ alert("Choose a file"); return; }
    $("quoteStatus").textContent = "requesting quote…";
    const body = {
      filename: f.name,
      sizeBytes: f.size,
      address: SELECTED_ACCOUNT || "0x0000000000000000000000000000000000000000",
      path: $("path").value || null
    };
    const q = await api("/api/quote", {
      method: "POST",
      headers: { "content-type":"application/json" },
      body: JSON.stringify(body)
    });
    CURRENT_QUOTE = q;
    $("qId").textContent = q.quoteId;
    $("qFile").textContent = q.filename;
    $("qSize").textContent = bytesHuman(q.sizeBytes);
    $("qTiers").textContent = q.tiers;
    $("qTierMb").textContent = `${q.tierMB} MB`;
    $("qEgaz").textContent  = `${fmtDec(q.priceEgaz)} EGAZ`;
    $("qEti").textContent   = `${fmtDec(q.priceEti)} ETI`;
    $("qPayTo").textContent = q.payTo;
    $("qExp").textContent   = new Date(q.expiresAt).toLocaleString();
    $("quoteBox").classList.remove("hidden");
    $("quoteStatus").textContent = "quote ready";
    log(`quote ${q.quoteId} priceEgaz=${q.priceEgaz} priceEti=${q.priceEti}`);
  }catch(e){
    $("quoteStatus").textContent = `error: ${e.message}`;
    log(`quote error: ${e.stack||e}`);
  }
};

$("btnPay").onclick = async ()=>{
  try{
    if (!CURRENT_QUOTE) { alert("Get a quote first"); return; }
    if (!window.ethereum) { alert("MetaMask not found"); return; }
    if (!SELECTED_ACCOUNT){
      const acc = await ethereum.request({ method:"eth_requestAccounts" });
      setAccount(acc[0] || null);
      if (!SELECTED_ACCOUNT) throw new Error("no account");
    }
    const sel = $("currencySel").value; // "EGAZ" or "ETI"
    const payTo = CURRENT_QUOTE.payTo;
    let txParams = { from: SELECTED_ACCOUNT };

    if (sel === "EGAZ"){
      const wei = parseUnits(CURRENT_QUOTE.priceEgaz, 18);
      txParams.to = payTo;
      txParams.value = to0xHex(wei);
      txParams.data = "0x";
      log(`sending EGAZ value=${CURRENT_QUOTE.priceEgaz} -> ${payTo}`);
    } else {
      const token = CFG.etiContract || "0x34c61EA91bAcdA647269d4e310A86b875c09946f";
      const wei = parseUnits(CURRENT_QUOTE.priceEti, 18);
      txParams.to = token; txParams.value = "0x0"; txParams.data = encodeErc20Transfer(payTo, wei);
      log(`sending ETI token=${token} amount=${CURRENT_QUOTE.priceEti} -> ${payTo}`);
    }

    $("payStatus").textContent = "opening MetaMask…";
    const txHash = await ethereum.request({ method: "eth_sendTransaction", params: [txParams] });
    CURRENT_TX = txHash;
    $("payStatus").textContent = `tx sent: ${middleEllipsis(txHash)}`;
    log(`tx sent ${txHash}`);

    const rec = await api("/api/payments/record", {
      method: "POST",
      headers: { "content-type": "application/json" },
      body: JSON.stringify({ quoteId: String(CURRENT_QUOTE.quoteId), txHash })
    });
    log(`payments/record ok currency=${rec.currency||"?"}`);

    $("confirmBox").classList.remove("hidden");
    $("confTx").textContent = txHash;
    $("confReq").textContent = CFG.requiredConfirmations ?? 3;
    pollStatusStart(Number(CURRENT_QUOTE.quoteId));
  }catch(e){
    $("payStatus").textContent = `error: ${e.message}`;
    log(`pay error: ${e.stack||e}`);
  }
};

async function uploadNow(){
  try{
    const f = $("file").files[0];
    if (!f){ alert("Choose a file"); return; }
    if (!CURRENT_QUOTE){ alert("Get quote & pay first"); return; }

    const form = new FormData();
    form.append("file", f);
    form.append("quoteId", String(CURRENT_QUOTE.quoteId));
    form.append("address", SELECTED_ACCOUNT || "");
    if ($("path").value)  form.append("path", $("path").value);
    if ($("label").value) form.append("label", $("label").value);

    $("payStatus").textContent = "uploading to IPFS…";
    const res = await fetch("/api/upload", { method:"POST", body: form });
    if (!res.ok) throw new Error(`/api/upload HTTP ${res.status}`);
    const j = await res.json();
    if (!j.ok) throw new Error(j.error || "upload failed");
    UPLOADED_CID = j.cid;
    $("payStatus").textContent = `uploaded: ${j.cid}`;
    log(`upload ok cid=${j.cid}`);
    await loadFiles();
  }catch(e){
    $("payStatus").textContent = `upload error: ${e.message}`;
    log(`upload error: ${e.stack||e}`);
  }
}
$("btnUploadNow").onclick = uploadNow;

async function pollOnce(quoteId){
  try{
    const st = await api(`/api/payments/status?quoteId=${quoteId}`);
    $("confStatus").textContent = st.status;
    $("confCount").textContent = st.confs;
    if (st.txHash) $("confTx").textContent = st.txHash;
    if (st.status === "paid"){
      log(`quote ${quoteId} paid (confs ${st.confs}/${st.required})`);
      clearInterval(POLL_TIMER); POLL_TIMER = null;
      $("btnUploadNow").classList.remove("hidden");
      // Auto-upload if a file is selected and not uploaded yet
      if ($("file").files[0] && !UPLOADED_CID){
        uploadNow();
      }
    }
  }catch(e){
    log(`status poll error: ${e.message}`);
  }
}
function pollStatusStart(quoteId){
  if (POLL_TIMER) clearInterval(POLL_TIMER);
  pollOnce(quoteId);
  POLL_TIMER = setInterval(()=>pollOnce(quoteId), 5000);
}

// ===== init =====
(async function init(){
  try{
    await loadConfigAndHealth();
    await ensureWallet();
    await loadFiles();
  }catch(e){
    log(`init error: ${e.message}`);
  }
})();