import {
  ChevronDown,
  Clock3,
  FileEdit,
  Inbox,
  ListChecks,
  LogOut,
  Mail,
  Menu,
  Plug,
  Send,
  Settings,
  ShieldAlert,
  Sparkles,
  Star,
  Trash2,
  X,
} from "lucide-react";
import { useCallback, useEffect, useState } from "react";
import { getCurrentAccount, getMyCompanyDomain } from "../api";
import Brand from "./Brand";
import CompanyDnsSetup from "./CompanyDnsSetup";
import ComposeModal from "./ComposeModal";
import MailboxView from "./MailboxView";

const mailItems = [
  [Inbox, "Inbox", "unread"],
  [Star, "Starred", "starred"],
  [Clock3, "Snoozed"],
  [Send, "Sent"],
  [FileEdit, "Drafts", "drafts"],
  [ShieldAlert, "Spam"],
  [Trash2, "Trash"],
  [Clock3, "Scheduled"],
];

const labels = [
  ["Important", "rose", "Important"],
  ["Projects", "violet", "Projects"],
  ["Clients", "blue", "Clients"],
  ["Finance", "amber", "Finance"],
  ["Personal", "green", "Personal"],
];

const agentItems = [
  [Sparkles, "Ask Agent", "ask"],
  [ListChecks, "Action Items", "actions"],
  [Sparkles, "Summaries", "summaries"],
  [Plug, "Integrations", "integrations"],
];

function clearSession() {
  sessionStorage.removeItem("agmail_access_token");
  sessionStorage.removeItem("agmail_account");
}

function SidebarSection({ title, children, className = "" }) {
  return (
    <section className={`dashboard-sidebar-section ${className}`}>
      <h2>{title}</h2>
      {children}
    </section>
  );
}

function NavBadge({ value, variant = "coral" }) {
  if (!value || value <= 0) return null;
  return <em className={variant === "neutral" ? "nav-badge-neutral" : "nav-badge-coral"}>{value}</em>;
}

export default function DashboardPage() {
  const [account, setAccount] = useState(null);
  const [companyDomain, setCompanyDomain] = useState(null);
  const [needsDnsSetup, setNeedsDnsSetup] = useState(false);
  const [domainError, setDomainError] = useState("");
  const [active, setActive] = useState("Inbox");
  const [menuOpen, setMenuOpen] = useState(false);
  const [composeOpen, setComposeOpen] = useState(false);
  const [notice, setNotice] = useState("");
  const [loading, setLoading] = useState(true);
  const [mailRefreshKey, setMailRefreshKey] = useState(0);
  const [lens, setLens] = useState("all");
  const [agentNav, setAgentNav] = useState(null);
  const [labelsExpanded, setLabelsExpanded] = useState(false);
  const [mailStats, setMailStats] = useState({
    unread: 0,
    starred: 0,
    important: 0,
    drafts: 0,
    actionItems: 0,
    labels: {},
  });
  const handleStats = useCallback((stats) => setMailStats(stats), []);

  useEffect(() => {
    const token = sessionStorage.getItem("agmail_access_token");
    if (!token) {
      window.location.replace("/login");
      return;
    }

    getCurrentAccount(token)
      .then(async (currentAccount) => {
        sessionStorage.setItem("agmail_account", JSON.stringify(currentAccount));
        setAccount(currentAccount);
        if (currentAccount.account_type === "company") {
          try {
            const domain = await getMyCompanyDomain(token);
            setCompanyDomain(domain);
            setNeedsDnsSetup(domain.status === "pending_dns");
          } catch (error) {
            setDomainError(error.message || "Could not load your company domain.");
          }
        }
        setLoading(false);
      })
      .catch(() => {
        clearSession();
        window.location.replace("/login");
      });
  }, []);

  function logout() {
    clearSession();
    window.location.assign("/login");
  }

  function selectMailItem(item) {
    setAgentNav(null);
    if (item === "Starred") {
      setActive("Inbox");
      setLens("starred");
    } else if (item === "Sent") {
      setActive("Outbox");
      setLens("all");
    } else {
      setActive(item);
      setLens("all");
    }
    setMenuOpen(false);
  }

  function selectLabel(name) {
    setAgentNav(null);
    setActive("Inbox");
    setLens(name);
    setMenuOpen(false);
  }

  function selectAgentItem(item, actionKey) {
    setActive("Inbox");
    setLens("all");
    setAgentNav(actionKey);
    setMenuOpen(false);
  }

  function emailSent() {
    setComposeOpen(false);
    setActive("Outbox");
    setMailRefreshKey((key) => key + 1);
    setNotice("Message accepted by the mail server. Delivery can take a few minutes — check spam if it does not arrive.");
    window.setTimeout(() => setNotice(""), 4000);
  }

  if (loading || !account) {
    return <main className="dashboard-loading"><Brand /><span>Opening your workspace…</span></main>;
  }

  if (account.account_type === "company" && domainError) {
    return (
      <main className="company-dns-setup">
        <header className="company-dns-header">
          <Brand />
          <button type="button" onClick={logout}>Log out</button>
        </header>
        <section className="company-dns-card">
          <p className="eyebrow">Company setup</p>
          <h1>Domain not ready</h1>
          <p className="form-error" role="alert">{domainError}</p>
        </section>
      </main>
    );
  }

  if (needsDnsSetup && companyDomain) {
    return (
      <CompanyDnsSetup
        account={account}
        domain={companyDomain}
        onComplete={() => {
          setCompanyDomain({ ...companyDomain, status: "active" });
          setNeedsDnsSetup(false);
        }}
        onLogout={logout}
      />
    );
  }

  const workspaceLabel = account.account_type === "company" ? "Company" : "Individual";
  const workspaceTitle = account.account_type === "company" && companyDomain
    ? companyDomain.domain_name
    : "Personal workspace";
  const mailActive = lens === "starred"
    ? "Starred"
    : active === "Outbox"
      ? "Sent"
      : labels.some(([name]) => lens === name)
        ? "Inbox"
        : active;

  return (
    <div className="dashboard">
      <header className="dashboard-mobile-header">
        <Brand />
        <button aria-label="Open navigation" type="button" onClick={() => setMenuOpen(true)}>
          <Menu size={21} />
        </button>
      </header>

      {menuOpen && <button className="dashboard-scrim" aria-label="Close navigation" onClick={() => setMenuOpen(false)} />}
      <aside className={menuOpen ? "dashboard-sidebar open" : "dashboard-sidebar"}>
        <div className="dashboard-brand-row">
          <Brand />
          <button aria-label="Close navigation" type="button" onClick={() => setMenuOpen(false)}><X size={19} /></button>
        </div>

        <div className="dashboard-compose-wrap">
          <button className="dashboard-compose" type="button" onClick={() => setComposeOpen(true)}>
            <span className="dashboard-compose-main">
              <Mail size={16} strokeWidth={1.75} />
              <span>Compose</span>
            </span>
          </button>
          <button className="dashboard-compose-menu" type="button" aria-label="Compose options">
            <ChevronDown size={14} strokeWidth={1.75} />
          </button>
        </div>

        <SidebarSection title="Mail" className="dashboard-sidebar-mail">
          <nav aria-label="Mail">
            {mailItems.map(([ItemIcon, label, countKey]) => (
              <button
                className={`dashboard-nav-item${mailActive === label ? " active" : ""}`}
                key={label}
                type="button"
                onClick={() => selectMailItem(label)}
              >
                <ItemIcon size={16} strokeWidth={1.75} />
                <span>{label}</span>
                <NavBadge value={countKey ? mailStats[countKey] : 0} />
              </button>
            ))}
          </nav>
        </SidebarSection>

        <SidebarSection title="Labels" className="dashboard-sidebar-labels">
          <nav aria-label="Labels">
            {labels.map(([name, tone, countKey]) => (
              <button
                className={`dashboard-nav-item dashboard-label-item${lens === name ? " active" : ""}`}
                key={name}
                type="button"
                onClick={() => selectLabel(name)}
              >
                <i className={`label-dot label-dot-${tone}`} />
                <span>{name}</span>
                <NavBadge variant="neutral" value={mailStats.labels?.[countKey]} />
              </button>
            ))}
            <button
              type="button"
              className="dashboard-nav-item dashboard-label-more"
              onClick={() => setLabelsExpanded((open) => !open)}
            >
              <ChevronDown size={14} strokeWidth={1.75} className={labelsExpanded ? "open" : ""} />
              <span>{labelsExpanded ? "Less" : "More"}</span>
            </button>
          </nav>
        </SidebarSection>

        <SidebarSection title="Agent" className="dashboard-sidebar-agent">
          <nav aria-label="Agent">
            {agentItems.map(([ItemIcon, label, actionKey]) => (
              <button
                className={`dashboard-nav-item dashboard-agent-item${agentNav === actionKey ? " active" : ""}`}
                key={label}
                type="button"
                onClick={() => selectAgentItem(label, actionKey)}
              >
                <ItemIcon size={16} strokeWidth={1.75} />
                <span>{label}</span>
                <NavBadge value={actionKey === "actions" ? mailStats.actionItems : 0} />
              </button>
            ))}
          </nav>
        </SidebarSection>

        <div className="dashboard-profile">
          <span>{account.first_name[0]}{account.last_name[0]}</span>
          <div><strong>{account.first_name} {account.last_name}</strong><small>{account.email}</small></div>
          <button aria-label="Log out" title="Log out" type="button" onClick={logout}><LogOut size={17} /></button>
        </div>
      </aside>

      <main className="dashboard-content">
        {!["Inbox", "Outbox", "Trash"].includes(active) && (
          <div className="dashboard-content-heading">
            <div><p>{workspaceTitle}</p><h1>{active}</h1></div>
            <span className="dashboard-account-pill">{workspaceLabel}</span>
          </div>
        )}
        {active === "Inbox" && (
          <MailboxView
            mailbox="inbox"
            title="Inbox"
            refreshKey={mailRefreshKey}
            account={account}
            lens={lens}
            agentNav={agentNav}
            onLogout={logout}
            onOpenSettings={() => selectMailItem("Settings")}
            onStats={handleStats}
          />
        )}
        {active === "Outbox" && (
          <MailboxView
            mailbox="sent"
            title="Sent"
            refreshKey={mailRefreshKey}
            account={account}
            onLogout={logout}
            onOpenSettings={() => selectMailItem("Settings")}
          />
        )}
        {active === "Trash" && (
          <MailboxView
            mailbox="trash"
            title="Trash"
            refreshKey={mailRefreshKey}
            account={account}
            onLogout={logout}
            onOpenSettings={() => selectMailItem("Settings")}
          />
        )}
        {!["Inbox", "Outbox", "Trash"].includes(active) && (
          <section className="dashboard-empty">
            <span><Sparkles size={24} /></span>
            <h2>{active} is ready for you</h2>
            <p>Your personal mail and agent tools will appear here.</p>
          </section>
        )}
      </main>
      {notice && <div className="dashboard-notice" role="status">{notice}</div>}
      {composeOpen && <ComposeModal account={account} onClose={() => setComposeOpen(false)} onSent={emailSent} />}
    </div>
  );
}