// Shared DOM helpers used by all views.

const { DEBUG } = require("../../shared/constants");
const {
    formatUsd,
    getPrice,
    getAddressValueUsd,
} = require("../../shared/prices");
const { state, saveState, currentNetwork } = require("../../shared/state");

// When views are added, removed, or transitions between them change,
// update the view-navigation documentation in README.md to match.
const VIEWS = [
    "welcome",
    "add-wallet",
    "main",
    "address",
    "address-token",
    "send",
    "confirm-tx",
    "wait-tx",
    "success-tx",
    "error-tx",
    "receive",
    "add-token",
    "settings",
    "delete-wallet-confirm",
    "settings-addtoken",
    "transaction",
    "approve-site",
    "approve-tx",
    "approve-sign",
    "export-privkey",
];

function $(id) {
    return document.getElementById(id);
}

function showError(id, msg) {
    const el = $(id);
    el.textContent = msg;
    el.style.visibility = "visible";
}

function hideError(id) {
    const el = $(id);
    el.textContent = "";
    el.style.visibility = "hidden";
}

function showView(name) {
    for (const v of VIEWS) {
        const el = document.getElementById(`view-${v}`);
        if (el) {
            el.classList.toggle("hidden", v !== name);
        }
    }
    clearFlash();
    state.currentView = name;
    saveState();
    const net = currentNetwork();
    if (DEBUG || net.isTestnet) {
        const banner = document.getElementById("debug-banner");
        if (banner) {
            if (DEBUG && net.isTestnet) {
                banner.textContent =
                    "DEBUG / INSECURE [TESTNET] (" + name + ")";
            } else if (net.isTestnet) {
                banner.textContent = "[TESTNET]";
            } else {
                banner.textContent = "DEBUG / INSECURE (" + name + ")";
            }
        }
    }
}

// Callback to re-render the main/home view when navigating back to it.
// Set once by index.js via setRenderMain().
let _renderMain = null;

function setRenderMain(fn) {
    _renderMain = fn;
}

// Push the current view onto the navigation stack so goBack() can
// return to it.  Call this before any forward navigation.
function pushCurrentView() {
    if (state.currentView) {
        state.viewStack.push(state.currentView);
    }
}

// Pop the navigation stack and show the previous view.  If the stack
// is empty, fall back to the main (home) view.
function goBack() {
    let target;
    if (state.viewStack.length > 0) {
        target = state.viewStack.pop();
    } else {
        target = "main";
    }
    if (target === "main" && _renderMain) {
        _renderMain();
    }
    showView(target);
}

// Clear the entire navigation stack (used when resetting to root,
// e.g. after adding or deleting a wallet).
function clearViewStack() {
    state.viewStack = [];
}

let flashTimer = null;

function clearFlash() {
    if (flashTimer) {
        clearTimeout(flashTimer);
        flashTimer = null;
    }
    $("flash-msg").textContent = "";
}

function showFlash(msg, duration = 2000) {
    clearFlash();
    $("flash-msg").textContent = msg;
    flashTimer = setTimeout(() => {
        $("flash-msg").textContent = "";
        flashTimer = null;
    }, duration);
}

function balanceLine(symbol, amount, price, tokenId) {
    const qty = amount.toFixed(4);
    const usd = price ? formatUsd(amount * price) || " " : " ";
    const tokenAttr = tokenId ? ` data-token="${tokenId}"` : "";
    const clickClass = tokenId
        ? " cursor-pointer hover:bg-hover balance-row"
        : "";
    return (
        `<div class="flex text-xs${clickClass}"${tokenAttr}>` +
        `<span class="flex justify-between" style="width:42ch;max-width:100%">` +
        `<span>${symbol}</span>` +
        `<span>${qty}</span>` +
        `</span>` +
        `<span class="text-right text-muted flex-1">${usd}</span>` +
        `</div>`
    );
}

function balanceLinesForAddress(addr, trackedTokens, showZero) {
    let html = balanceLine(
        "ETH",
        parseFloat(addr.balance || "0"),
        getPrice("ETH"),
        "ETH",
    );
    const seen = new Set();
    for (const t of addr.tokenBalances || []) {
        const bal = parseFloat(t.balance || "0");
        if (bal === 0 && !showZero) continue;
        html += balanceLine(
            t.symbol,
            bal,
            getPrice(t.symbol),
            t.address.toLowerCase(),
        );
        seen.add(t.address.toLowerCase());
    }
    if (showZero && trackedTokens) {
        for (const t of trackedTokens) {
            if (seen.has(t.address.toLowerCase())) continue;
            html += balanceLine(
                t.symbol,
                0,
                getPrice(t.symbol),
                t.address.toLowerCase(),
            );
        }
    }
    return html;
}

// Truncate the middle of a string, replacing removed characters with "…".
// Safety: refuses to truncate more than 10 characters, which is the maximum
// that still prevents address spoofing attacks (see Display Consistency in
// README).  Callers that need to display less should use a different UI
// approach rather than silently making addresses insecure.
function truncateMiddle(str, maxLen) {
    if (str.length <= maxLen) return str;
    const removed = str.length - maxLen + 1; // +1 for the ellipsis char
    if (removed > 10) {
        maxLen = str.length - 10 + 1;
    }
    if (maxLen >= str.length) return str;
    const half = Math.floor((maxLen - 1) / 2);
    return str.slice(0, half) + "\u2026" + str.slice(-(maxLen - 1 - half));
}

// 16 colors evenly spaced around the hue wheel (22.5° apart),
// all at HSL saturation 70%, lightness 50% for uniform vibrancy.
const ADDRESS_COLORS = [
    "#d92626",
    "#d96926",
    "#d9ac26",
    "#c2d926",
    "#80d926",
    "#3dd926",
    "#26d953",
    "#26d996",
    "#26d9d9",
    "#2696d9",
    "#2653d9",
    "#3d26d9",
    "#8026d9",
    "#c226d9",
    "#d926ac",
    "#d92669",
];

function addressColor(address) {
    const idx = parseInt(address.slice(2, 6), 16) % 16;
    return ADDRESS_COLORS[idx];
}

function addressDotHtml(address) {
    const color = addressColor(address);
    return `<span style="width:8px;height:8px;border-radius:50%;display:inline-block;background:${color};margin-right:4px;vertical-align:middle;flex-shrink:0;"></span>`;
}

function escapeHtml(s) {
    const div = document.createElement("div");
    div.textContent = s;
    return div.innerHTML;
}

// Look up an address across all wallets and return its title
// (e.g. "Address 1.2") or null if it's not one of ours.
function addressTitle(address, wallets) {
    const lower = address.toLowerCase();
    for (let wi = 0; wi < wallets.length; wi++) {
        const addrs = wallets[wi].addresses;
        for (let ai = 0; ai < addrs.length; ai++) {
            if (addrs[ai].address.toLowerCase() === lower) {
                return wallets[wi].name + " \u2014 Address " + (ai + 1);
            }
        }
    }
    return null;
}

// Render an address with color dot, optional ENS name, optional title,
// and optional truncation. Title and ENS are shown as bold labels above
// the full address.
// Delegates to renderAddressHtml for consistent output.
function formatAddressHtml(address, ensName, maxLen, title) {
    return renderAddressHtml(address, { title, ensName, maxLen });
}

function isoDate(timestamp) {
    const d = new Date(timestamp * 1000);
    const pad = (n) => String(n).padStart(2, "0");
    if (state.utcTimestamps) {
        return (
            d.getUTCFullYear() +
            "-" +
            pad(d.getUTCMonth() + 1) +
            "-" +
            pad(d.getUTCDate()) +
            "T" +
            pad(d.getUTCHours()) +
            ":" +
            pad(d.getUTCMinutes()) +
            ":" +
            pad(d.getUTCSeconds()) +
            "Z"
        );
    }
    const offsetMin = -d.getTimezoneOffset();
    const sign = offsetMin >= 0 ? "+" : "-";
    const absOff = Math.abs(offsetMin);
    const tzStr = sign + pad(Math.floor(absOff / 60)) + ":" + pad(absOff % 60);
    return (
        d.getFullYear() +
        "-" +
        pad(d.getMonth() + 1) +
        "-" +
        pad(d.getDate()) +
        "T" +
        pad(d.getHours()) +
        ":" +
        pad(d.getMinutes()) +
        ":" +
        pad(d.getSeconds()) +
        tzStr
    );
}

function timeAgo(timestamp) {
    const seconds = Math.floor(Date.now() / 1000 - timestamp);
    if (seconds < 60) return seconds + " seconds ago";
    const minutes = Math.floor(seconds / 60);
    if (minutes < 60)
        return minutes + " minute" + (minutes !== 1 ? "s" : "") + " ago";
    const hours = Math.floor(minutes / 60);
    if (hours < 24) return hours + " hour" + (hours !== 1 ? "s" : "") + " ago";
    const days = Math.floor(hours / 24);
    if (days < 30) return days + " day" + (days !== 1 ? "s" : "") + " ago";
    const months = Math.floor(days / 30);
    if (months < 12)
        return months + " month" + (months !== 1 ? "s" : "") + " ago";
    const years = Math.floor(days / 365);
    return years + " year" + (years !== 1 ? "s" : "") + " ago";
}

// Shared external-link icon SVG used across all views.
const EXT_ICON =
    `<span style="display:inline-block;width:10px;height:10px;margin-left:4px;vertical-align:middle">` +
    `<svg viewBox="0 0 12 12" fill="none" stroke="currentColor" stroke-width="1.5">` +
    `<path d="M4.5 1.5H2a.5.5 0 00-.5.5v8a.5.5 0 00.5.5h8a.5.5 0 00.5-.5V7.5"/>` +
    `<path d="M7 1.5h3.5V5M7 5.5L10.5 1.5"/>` +
    `</svg></span>`;

function etherscanAddressUrl(address) {
    return `${currentNetwork().explorerUrl}/address/${address}`;
}

function etherscanLinkHtml(url) {
    return (
        `<a href="${url}" target="_blank" rel="noopener" ` +
        `class="inline-flex items-center">${EXT_ICON}</a>`
    );
}

// Render a copyable text span with dashed underline affordance.
// The caller must attach click handlers via attachCopyHandlers() or
// manually wire up [data-copy] elements after inserting the HTML.
function copyableHtml(text, extraClass) {
    const cls =
        "underline decoration-dashed cursor-pointer" +
        (extraClass ? " " + extraClass : "");
    return `<span class="${cls}" data-copy="${escapeHtml(text)}">${escapeHtml(text)}</span>`;
}

// Attach click-to-copy handlers to all [data-copy] elements within
// a container.  Safe to call multiple times on the same container.
function attachCopyHandlers(container) {
    const root =
        typeof container === "string"
            ? document.getElementById(container)
            : container;
    if (!root) return;
    root.querySelectorAll("[data-copy]").forEach((el) => {
        el.onclick = () => {
            navigator.clipboard.writeText(el.dataset.copy);
            showFlash("Copied!");
            flashCopyFeedback(el);
        };
    });
}

// Unified address rendering.
//
// Produces consistent HTML for any Ethereum address:
//   • Color dot
//   • Optional title (e.g. "Wallet 1 — Address 2") shown bold above address
//   • Optional ENS name shown bold above address
//   • Full address (or truncated via maxLen) with dashed-underline click-to-copy
//   • Etherscan external link icon
//
// Options object:
//   title    — wallet title string (from addressTitle)
//   ensName  — ENS name string
//   maxLen   — if set, truncate address display (min 32 chars enforced)
//   noLink   — if true, omit etherscan link
//
// After inserting the returned HTML into the DOM, call
// attachCopyHandlers() on the parent to wire up click-to-copy.
function renderAddressHtml(address, opts) {
    const { title, ensName, maxLen, noLink } = opts || {};
    const dot = addressDotHtml(address);
    const displayAddr = maxLen ? truncateMiddle(address, maxLen) : address;
    const link = etherscanAddressUrl(address);
    const extLink = noLink ? "" : etherscanLinkHtml(link);

    let html = "";
    if (title) {
        html += `<div class="flex items-center font-bold">${dot}${escapeHtml(title)}</div>`;
    }
    if (ensName) {
        html += `<div class="flex items-center font-bold">${title ? "" : dot}${escapeHtml(ensName)}</div>`;
    }
    if (title || ensName) {
        html += `<div class="flex items-center">${copyableHtml(displayAddr, "break-all")}${extLink}</div>`;
    } else {
        html += `<div class="flex items-center">${dot}${copyableHtml(displayAddr, "break-all")}${extLink}</div>`;
    }
    return html;
}

function flashCopyFeedback(el) {
    if (!el) return;
    el.classList.remove("copy-flash-fade");
    el.classList.add("copy-flash-active");
    setTimeout(() => {
        el.classList.remove("copy-flash-active");
        el.classList.add("copy-flash-fade");
        setTimeout(() => {
            el.classList.remove("copy-flash-fade");
        }, 275);
    }, 75);
}

module.exports = {
    $,
    showError,
    hideError,
    showView,
    setRenderMain,
    pushCurrentView,
    goBack,
    clearViewStack,
    showFlash,
    flashCopyFeedback,
    balanceLine,
    balanceLinesForAddress,
    addressColor,
    addressDotHtml,
    escapeHtml,
    addressTitle,
    formatAddressHtml,
    renderAddressHtml,
    copyableHtml,
    attachCopyHandlers,
    etherscanAddressUrl,
    etherscanLinkHtml,
    EXT_ICON,
    truncateMiddle,
    isoDate,
    timeAgo,
};