import { useEffect, useRef, useState } from "react";
import { useNavigate, useParams, useSearchParams } from "react-router-dom";
import { ArrowLeft, CreditCard, Mail, Shield, Users, X } from "lucide-react";
import { toast } from "sonner";
import { Avatar, AvatarFallback } from "@/components/ui/avatar";
import { Badge } from "@/components/ui/badge";
import { Button } from "@/components/ui/button";
import { Input } from "@/components/ui/input";
import { ScrollArea } from "@/components/ui/scroll-area";
import { Separator } from "@/components/ui/separator";
import { Muted } from "@/components/ui/typography";
import { WindowControls } from "@/components/window-controls";
import { useNetworks } from "@/hooks/use-networks";
import {
  useNetworkInvitations,
  useInviteMembers,
  useRevokeInvitation,
  useRemoveMember,
} from "@/hooks/use-member-management";
import { useAuthStore } from "@/stores/auth-store";
import { BillingSection } from "@/features/network-billing";
import { ConfirmDestructiveOverlay } from "@/components/confirm-destructive-overlay";
import type { Human } from "@/api/types";

function MemberRow({
  human,
  isAdmin,
  onRemove,
}: {
  human: Human;
  isAdmin: boolean;
  onRemove?: () => void;
}) {
  const initials = human.email_prefix.slice(0, 2).toUpperCase();

  return (
    <div className="flex w-full items-center gap-3 px-4 py-3">
      <Avatar>
        <AvatarFallback className="bg-primary/10 text-primary font-medium">
          {initials}
        </AvatarFallback>
      </Avatar>
      <div className="min-w-0 flex-1">
        <p className="truncate text-sm font-medium">{human.email_prefix}</p>
        <Muted className="text-xs">{human.email}</Muted>
      </div>
      {isAdmin && (
        <Badge variant="secondary" className="shrink-0">
          <Shield className="mr-1 size-3" />
          Admin
        </Badge>
      )}
      {onRemove && (
        <Button
          variant="ghost"
          size="icon-sm"
          onClick={onRemove}
          className="text-muted-foreground hover:text-destructive shrink-0"
          aria-label={`Remove ${human.email}`}
        >
          <X className="size-3.5" />
        </Button>
      )}
    </div>
  );
}

function InviteForm({ networkId }: { networkId: string }) {
  const [email, setEmail] = useState("");
  const inviteMembers = useInviteMembers(networkId);

  const handleSubmit = (e: React.FormEvent) => {
    e.preventDefault();
    const trimmed = email.trim();
    if (!trimmed) return;

    inviteMembers.mutate([trimmed], {
      onSuccess: () => {
        toast.success(`Invitation sent to ${trimmed}`);
        setEmail("");
      },
    });
  };

  return (
    <form onSubmit={handleSubmit} className="flex items-center gap-2 px-4 py-3">
      <Input
        type="email"
        placeholder="name@example.com"
        value={email}
        onChange={(e) => setEmail(e.target.value)}
        className="flex-1"
      />
      <Button
        type="submit"
        size="sm"
        disabled={!email.trim() || inviteMembers.isPending}
      >
        {inviteMembers.isPending ? "Sending..." : "Invite"}
      </Button>
    </form>
  );
}

function PendingInvitationRow({
  email,
  networkId,
}: {
  email: string;
  networkId: string;
}) {
  const revokeInvitation = useRevokeInvitation(networkId);

  const handleRevoke = () => {
    revokeInvitation.mutate(email, {
      onSuccess: () => {
        toast.success(`Invitation to ${email} revoked`);
      },
    });
  };

  return (
    <div className="flex w-full items-center gap-3 px-4 py-3">
      <span className="text-muted-foreground flex size-8 items-center justify-center">
        <Mail className="size-4" />
      </span>
      <div className="min-w-0 flex-1">
        <p className="truncate text-sm">{email}</p>
        <Muted className="text-xs">Pending</Muted>
      </div>
      <Button
        variant="ghost"
        size="icon-sm"
        onClick={handleRevoke}
        disabled={revokeInvitation.isPending}
        className="text-muted-foreground hover:text-destructive shrink-0"
      >
        <X className="size-3.5" />
      </Button>
    </div>
  );
}

function SectionHeader({
  icon,
  title,
  description,
  trailing,
}: {
  icon: React.ReactNode;
  title: string;
  description?: string;
  trailing?: React.ReactNode;
}) {
  return (
    <div className="flex items-start gap-3 px-4 pb-2 pt-6">
      <span className="text-muted-foreground mt-0.5 flex size-4 items-center justify-center">
        {icon}
      </span>
      <div className="min-w-0 flex-1">
        <div className="flex items-center gap-2">
          <h2 className="text-sm font-semibold tracking-tight">{title}</h2>
          {trailing}
        </div>
        {description && <Muted className="text-xs">{description}</Muted>}
      </div>
    </div>
  );
}

function Section({ children }: { children: React.ReactNode }) {
  return (
    <section className="bg-card/40 mx-4 mb-2 overflow-hidden rounded-lg border">
      {children}
    </section>
  );
}

export default function NetworkSettingsPage() {
  const navigate = useNavigate();
  const { networkId } = useParams<{ networkId: string }>();
  const [searchParams] = useSearchParams();
  const { data: networks } = useNetworks();
  const network = networks?.find((n) => n.id === networkId);
  const { data: invitations, error: invitationsError } = useNetworkInvitations(networkId!);
  const currentUser = useAuthStore((s) => s.user);
  const isAdmin = currentUser?.id === network?.admin_human.id;
  const [memberToRemove, setMemberToRemove] = useState<Human | null>(null);
  const removeMember = useRemoveMember(networkId!);

  const billingRef = useRef<HTMLDivElement>(null);

  useEffect(() => {
    if (searchParams.get("section") === "billing") {
      billingRef.current?.scrollIntoView({ behavior: "smooth", block: "start" });
    }
  }, [searchParams]);

  const networkName = network?.name ?? "Network";
  const memberCount = network?.humans.length ?? 0;
  const pendingCount = invitations?.length ?? 0;
  const networkInitials = networkName.slice(0, 2).toUpperCase();

  return (
    <div className="flex h-screen flex-col">
      <div className="drag-region flex items-center gap-3 border-b px-3 py-1">
        <WindowControls />
        <Button
          variant="ghost"
          size="sm"
          className="no-drag text-muted-foreground"
          onClick={() => navigate(`/${networkId}`)}
        >
          <ArrowLeft className="size-3.5" />
        </Button>
        <span className="text-sm font-medium">Settings</span>
        <div className="flex-1" />
      </div>

      <ScrollArea className="min-h-0 flex-1">
        <div className="flex items-center gap-3 px-4 pb-4 pt-6">
          <Avatar size="lg">
            <AvatarFallback className="bg-primary/10 text-primary font-medium">
              {networkInitials}
            </AvatarFallback>
          </Avatar>
          <div className="min-w-0 flex-1">
            <p className="truncate text-base font-semibold">{networkName}</p>
            <Muted className="text-xs">
              {memberCount} {memberCount === 1 ? "member" : "members"}
              {isAdmin ? " · You're an admin" : ""}
            </Muted>
          </div>
        </div>

        <Section>
          <SectionHeader
            icon={<Users className="size-4" />}
            title="Members"
            description="People with access to this network."
            trailing={
              <Badge variant="secondary" className="tabular-nums">
                {memberCount}
              </Badge>
            }
          />
          <Separator />
          {network?.humans.map((human, index) => {
            const isRowAdmin = human.id === network.admin_human.id;
            const canRemove =
              isAdmin && !isRowAdmin && human.id !== currentUser?.id;
            return (
              <div key={human.id}>
                <MemberRow
                  human={human}
                  isAdmin={isRowAdmin}
                  onRemove={canRemove ? () => setMemberToRemove(human) : undefined}
                />
                {index < network.humans.length - 1 && (
                  <Separator className="mx-4" />
                )}
              </div>
            );
          })}
        </Section>

        {isAdmin && network && (
          <Section>
            <SectionHeader
              icon={<Mail className="size-4" />}
              title="Invitations"
              description="Invite teammates by email. They'll get a link to join."
              trailing={
                pendingCount > 0 ? (
                  <Badge variant="secondary" className="tabular-nums">
                    {pendingCount} pending
                  </Badge>
                ) : undefined
              }
            />
            <Separator />
            <InviteForm networkId={networkId!} />
            {invitationsError && (
              <>
                <Separator />
                <p className="text-muted-foreground px-4 py-3 text-xs">
                  Couldn't load pending invitations.
                </p>
              </>
            )}
            {pendingCount > 0 && (
              <>
                <Separator />
                <div className="px-4 pb-1 pt-3">
                  <Muted className="text-xs font-medium uppercase tracking-wider">
                    Pending
                  </Muted>
                </div>
                {invitations!.map((inv, index) => (
                  <div key={inv.email}>
                    <PendingInvitationRow
                      email={inv.email}
                      networkId={networkId!}
                    />
                    {index < invitations!.length - 1 && (
                      <Separator className="mx-4" />
                    )}
                  </div>
                ))}
              </>
            )}
          </Section>
        )}

        <div ref={billingRef}>
          <Section>
            <SectionHeader
              icon={<CreditCard className="size-4" />}
              title="Billing"
              description={
                isAdmin
                  ? "Manage your plan, seats, and payment."
                  : "Your network's current plan and usage."
              }
            />
            <Separator />
            <BillingSection networkId={networkId!} />
          </Section>
        </div>

        <div className="h-6" />
      </ScrollArea>

      {memberToRemove && (
        <ConfirmDestructiveOverlay
          title={`Remove ${memberToRemove.email_prefix}?`}
          description={
            <ul className="list-disc space-y-1 pl-4">
              <li>
                They'll lose access to this network's streams and files within
                seconds.
              </li>
              <li>Any content they posted stays in the network.</li>
              <li>
                If they're in a live huddle, they may remain until the call ends.
              </li>
            </ul>
          }
          confirmLabel="Remove"
          pendingLabel="Removing…"
          isPending={removeMember.isPending}
          onConfirm={() => {
            const target = memberToRemove;
            removeMember.mutate(target.id, {
              onSuccess: () => {
                toast.success(`Removed ${target.email}`);
                setMemberToRemove(null);
              },
            });
          }}
          onClose={() => {
            if (!removeMember.isPending) setMemberToRemove(null);
          }}
        />
      )}
    </div>
  );
}