import Link from "next/link";
import {
  Bell,
  Bookmark,
  Calendar,
  Clock,
  FileText,
  Heart,
  HelpCircle,
  Rss,
  Shield,
  Share2,
  Zap,
} from "lucide-react";

function Section({ id, title, icon: Icon, children }: {
  id: string;
  title: string;
  icon: React.ElementType;
  children: React.ReactNode;
}) {
  return (
    <section id={id} className="bg-card border border-border rounded-lg p-6 space-y-4 scroll-mt-6">
      <h2 className="text-lg font-semibold flex items-center gap-2">
        <Icon className="w-5 h-5 text-primary" />
        {title}
      </h2>
      {children}
    </section>
  );
}

function Item({ icon: Icon, color, title, children }: {
  icon: React.ElementType;
  color: string;
  title: string;
  children: React.ReactNode;
}) {
  return (
    <div className="flex gap-3">
      <div className={`mt-0.5 shrink-0 w-7 h-7 rounded-full flex items-center justify-center ${color}`}>
        <Icon className="w-3.5 h-3.5" />
      </div>
      <div>
        <p className="text-sm font-medium">{title}</p>
        <p className="text-xs text-muted-foreground mt-0.5 leading-relaxed">{children}</p>
      </div>
    </div>
  );
}

export default function HowItWorksPage() {
  return (
    <div className="max-w-2xl mx-auto space-y-6">
      <div>
        <h1 className="text-2xl font-bold flex items-center gap-2">
          <HelpCircle className="w-5 h-5" /> How it works
        </h1>
        <p className="text-muted-foreground text-sm mt-1">
          A quick guide to PocketVeto&apos;s features.
        </p>
        {/* Jump links */}
        <div className="flex flex-wrap gap-2 mt-3">
          {[
            { href: "#follow", label: "Following" },
            { href: "#collections", label: "Collections" },
            { href: "#notifications", label: "Notifications" },
            { href: "#briefs", label: "AI Briefs" },
            { href: "#bills", label: "Bills" },
          ].map(({ href, label }) => (
            <a
              key={href}
              href={href}
              className="text-xs px-2.5 py-1 bg-muted rounded-full hover:bg-accent transition-colors"
            >
              {label}
            </a>
          ))}
        </div>
      </div>

      {/* Following */}
      <Section id="follow" title="Following bills" icon={Heart}>
        <p className="text-sm text-muted-foreground">
          Follow any bill to track it. PocketVeto checks for changes — new text, amendments, status
          updates — and notifies you through your configured channels. Three modes let you tune the
          signal to your interest level.
        </p>
        <div className="space-y-3">
          <Item icon={Heart} color="bg-red-100 text-red-600 dark:bg-red-900/30 dark:text-red-400" title="Following (neutral)">
            Alerts on all material changes: new text published, amendments filed, and status updates
            like floor votes or committee referrals.
          </Item>
          <Item icon={Shield} color="bg-amber-100 text-amber-700 dark:bg-amber-900/30 dark:text-amber-400" title="Pocket Veto">
            Alerts only when the bill advances toward becoming law — new official text, floor
            scheduling, or committee passage. Useful when you oppose a bill and only need to act
            if it gains traction.
          </Item>
          <Item icon={Zap} color="bg-green-100 text-green-700 dark:bg-green-900/30 dark:text-green-400" title="Pocket Boost">
            All the alerts of neutral mode, plus periodic reminders to contact your representative.
            Use this when you actively support a bill and want to stay engaged.
          </Item>
        </div>
        <p className="text-xs text-muted-foreground">
          You can also follow <strong>members</strong> (get alerts when they sponsor new bills) and{" "}
          <strong>topics</strong> (get alerts when new bills matching that topic are briefed).
          Member and topic follows use the neutral mode only.
        </p>
      </Section>

      {/* Collections */}
      <Section id="collections" title="Collections" icon={Bookmark}>
        <p className="text-sm text-muted-foreground">
          A collection is a named, curated group of bills — like a playlist for legislation. Use
          collections to track a policy area, build a watchlist for an advocacy campaign, or share
          research with colleagues.
        </p>
        <div className="space-y-3">
          <Item icon={Bookmark} color="bg-blue-100 text-blue-600 dark:bg-blue-900/30 dark:text-blue-400" title="Creating a collection">
            Give it a name (e.g. &ldquo;Healthcare Watch&rdquo;) and add bills from any bill detail
            page using the bookmark icon next to the Follow button.
          </Item>
          <Item icon={Share2} color="bg-purple-100 text-purple-600 dark:bg-purple-900/30 dark:text-purple-400" title="Sharing">
            Every collection has a unique share link. Anyone with the link can view the collection —
            no account required. The link works whether the collection is public or private.
          </Item>
        </div>
        <p className="text-xs text-muted-foreground">
          <strong>Public vs. private:</strong> Both have share links. Marking a collection public
          signals it may appear in a future public directory; private collections are invisible to
          anyone without your link.
        </p>
      </Section>

      {/* Notifications */}
      <Section id="notifications" title="Notifications" icon={Bell}>
        <p className="text-sm text-muted-foreground">
          PocketVeto delivers alerts through two independent channels — use either or both.
        </p>
        <div className="space-y-3">
          <Item icon={Bell} color="bg-blue-100 text-blue-600 dark:bg-blue-900/30 dark:text-blue-400" title="Push via ntfy">
            <a href="https://ntfy.sh" target="_blank" rel="noopener noreferrer" className="text-primary hover:underline">
              ntfy
            </a>
            {" "}is a free, open-source push notification service. Configure a topic URL in{" "}
            <Link href="/notifications" className="text-primary hover:underline">Notifications</Link>{" "}
            and receive real-time alerts on any device with the ntfy app.
          </Item>
          <Item icon={Clock} color="bg-amber-100 text-amber-700 dark:bg-amber-900/30 dark:text-amber-400" title="Quiet hours">
            Pause push notifications during set hours (e.g. 10 PM – 8 AM). Events that arrive
            during quiet hours are queued and sent as a batch when the window ends.
          </Item>
          <Item icon={Calendar} color="bg-green-100 text-green-700 dark:bg-green-900/30 dark:text-green-400" title="Digest mode">
            Instead of one push per event, receive a single bundled summary on a daily or weekly
            schedule. Your RSS feed is always real-time regardless of this setting.
          </Item>
          <Item icon={Rss} color="bg-orange-100 text-orange-600 dark:bg-orange-900/30 dark:text-orange-400" title="RSS feed">
            A private, tokenized RSS feed of all your bill alerts. Subscribe in any RSS reader
            (Feedly, NetNewsWire, etc.). Completely independent of ntfy.
          </Item>
        </div>
      </Section>

      {/* AI Briefs */}
      <Section id="briefs" title="AI Briefs" icon={FileText}>
        <p className="text-sm text-muted-foreground">
          For bills with published official text, PocketVeto generates a plain-English AI brief.
        </p>
        <div className="space-y-3">
          <Item icon={FileText} color="bg-blue-100 text-blue-600 dark:bg-blue-900/30 dark:text-blue-400" title="What's in a brief">
            A plain-English summary, key policy points with references to specific bill sections
            (§ chips), and a risks section that flags potential unintended consequences or contested
            provisions.
          </Item>
          <Item icon={Share2} color="bg-purple-100 text-purple-600 dark:bg-purple-900/30 dark:text-purple-400" title="Sharing a brief">
            Click the share icon in the brief panel to copy a public link. Anyone can read the
            brief at that URL — no login required.
          </Item>
          <Item icon={Zap} color="bg-green-100 text-green-700 dark:bg-green-900/30 dark:text-green-400" title="Draft a letter">
            Use the Draft Letter panel (below the brief) to generate a personalised letter to your
            representative based on the brief&apos;s key points.
          </Item>
        </div>
        <p className="text-xs text-muted-foreground">
          Briefs are only generated for bills where GovInfo has published official text. Bills
          without text show a &ldquo;No text&rdquo; badge on their card.
        </p>
      </Section>

      {/* Bills */}
      <Section id="bills" title="Browsing bills" icon={FileText}>
        <p className="text-sm text-muted-foreground">
          The <Link href="/bills" className="text-primary hover:underline">Bills</Link> page lists
          all tracked legislation. Use the filters to narrow your search.
        </p>
        <div className="space-y-2 text-xs text-muted-foreground">
          <p><strong className="text-foreground">Search</strong> — matches bill ID, title, and short title.</p>
          <p><strong className="text-foreground">Chamber</strong> — House or Senate.</p>
          <p><strong className="text-foreground">Topic</strong> — AI-tagged policy area (healthcare, defense, etc.).</p>
          <p><strong className="text-foreground">Has text</strong> — show only bills with published official text available for AI briefing.</p>
        </div>
        <p className="text-xs text-muted-foreground">
          Clicking a topic tag on any bill or following page takes you directly to that filtered
          view on the Bills page.
        </p>
      </Section>
    </div>
  );
}