import { useEffect, useState } from "react";
import { Link, useSearchParams } from "react-router";
import { getAuth } from "@clerk/react-router/server";
import { toast } from "sonner";
import {
  findLeagueById,
  findCurrentSeason,
  findTeamsBySeasonId,
  findCommissionersByLeagueId,
  isUserLeagueMember,
  isCommissioner,
  findUserByClerkId,
} from "~/models";
import type { Route } from "./+types/$leagueId";
import { Button } from "~/components/ui/button";
import {
  Card,
  CardContent,
  CardDescription,
  CardHeader,
  CardTitle,
} from "~/components/ui/card";

export async function loader(args: Route.LoaderArgs) {
  const { userId } = await getAuth(args);
  const { params } = args;
  const { leagueId } = params;

  // Fetch league
  const league = await findLeagueById(leagueId);

  if (!league) {
    throw new Response("League not found", { status: 404 });
  }

  // Fetch current season
  const season = await findCurrentSeason(leagueId);

  // Fetch commissioners
  const commissioners = await findCommissionersByLeagueId(leagueId);

  // Check if current user is a commissioner
  const isUserCommissioner = userId ? await isCommissioner(leagueId, userId) : false;

  // Check if user is a member (has a team in current season)
  const isUserMember = userId ? await isUserLeagueMember(leagueId, userId) : false;

  // Check access: user must be a commissioner, a member, or an admin
  // If not logged in or not authorized, throw 403
  if (!userId) {
    throw new Response("You must be logged in to view this league", { status: 401 });
  }

  if (!isUserCommissioner && !isUserMember) {
    throw new Response("You do not have access to this league", { status: 403 });
  }

  // Fetch teams for current season
  const teams = season ? await findTeamsBySeasonId(season.id) : [];

  // Fetch user data for team owners
  const ownerIds = teams.map(t => t.ownerId).filter((id): id is string => id !== null);
  const uniqueOwnerIds = [...new Set(ownerIds)];
  const owners = await Promise.all(
    uniqueOwnerIds.map(async (ownerId) => {
      const user = await findUserByClerkId(ownerId);
      return user ? { clerkId: ownerId, name: user.username || user.displayName } : null;
    })
  );
  const ownerMap = new Map(
    owners.filter((o): o is NonNullable<typeof o> => o !== null).map(o => [o.clerkId, o.name])
  );

  // Fetch user data for commissioners
  const commissionerIds = commissioners.map(c => c.userId);
  const commissionerUsers = await Promise.all(
    commissionerIds.map(async (commissionerId) => {
      const user = await findUserByClerkId(commissionerId);
      return user ? { clerkId: commissionerId, name: user.username || user.displayName } : null;
    })
  );
  const commissionerMap = new Map(
    commissionerUsers.filter((c): c is NonNullable<typeof c> => c !== null).map(c => [c.clerkId, c.name])
  );

  // Count available teams
  const availableTeamCount = teams.filter(t => !t.ownerId).length;

  return {
    league,
    season,
    teams,
    commissioners,
    currentUserId: userId,
    isUserCommissioner,
    ownerMap: Object.fromEntries(ownerMap),
    commissionerMap: Object.fromEntries(commissionerMap),
    availableTeamCount,
  };
}

export default function LeagueHome({ loaderData }: Route.ComponentProps) {
  const { 
    league, 
    season, 
    teams, 
    commissioners, 
    currentUserId, 
    isUserCommissioner,
    ownerMap,
    commissionerMap,
    availableTeamCount,
  } = loaderData;
  const [searchParams, setSearchParams] = useSearchParams();
  const [copied, setCopied] = useState(false);

  useEffect(() => {
    if (searchParams.get("updated") === "true") {
      toast.success("League updated successfully");
      setSearchParams({});
    }
    if (searchParams.get("joined") === "true") {
      toast.success("Welcome to the league! You've been assigned a team.");
      setSearchParams({});
    }
  }, [searchParams, setSearchParams]);

  const handleCopyInviteLink = async () => {
    if (!season?.inviteCode) return;
    
    const inviteUrl = `${window.location.origin}/i/${season.inviteCode}`;
    try {
      await navigator.clipboard.writeText(inviteUrl);
      setCopied(true);
      toast.success("Invite link copied to clipboard!");
      setTimeout(() => setCopied(false), 2000);
    } catch (err) {
      toast.error("Failed to copy invite link");
    }
  };

  return (
    <div className="container mx-auto py-8 px-4">
      <div className="mb-8">
        <div className="flex items-center justify-between mb-2">
          <h1 className="text-4xl font-bold">{league.name}</h1>
          <div className="flex gap-2">
            {isUserCommissioner && (
              <Button variant="outline" asChild>
                <Link to={`/leagues/${league.id}/settings`}>Settings</Link>
              </Button>
            )}
            <Button variant="outline" asChild>
              <Link to="/">Back to Home</Link>
            </Button>
          </div>
        </div>
        {season && (
          <p className="text-muted-foreground">
            {season.year} Season • Status:{" "}
            <span className="capitalize">
              {season.status.replace("_", " ")}
            </span>
          </p>
        )}
      </div>

      <div className="grid gap-6 md:grid-cols-2 lg:grid-cols-3">
        {isUserCommissioner && season && availableTeamCount > 0 && (
          <Card className="md:col-span-2 lg:col-span-3">
            <CardHeader>
              <CardTitle>Invite Link</CardTitle>
              <CardDescription>
                Share this link to invite people to join your league ({availableTeamCount} spot{availableTeamCount !== 1 ? "s" : ""} available)
              </CardDescription>
            </CardHeader>
            <CardContent className="space-y-3">
              <div className="flex items-center gap-2">
                <input
                  type="text"
                  readOnly
                  value={`${typeof window !== "undefined" ? window.location.origin : ""}/i/${season.inviteCode}`}
                  className="flex-1 px-3 py-2 text-sm border rounded-md bg-muted"
                  onClick={(e) => e.currentTarget.select()}
                />
                <Button
                  onClick={handleCopyInviteLink}
                  variant={copied ? "default" : "outline"}
                  size="sm"
                >
                  {copied ? "Copied!" : "Copy"}
                </Button>
              </div>
              <p className="text-xs text-muted-foreground">
                Anyone with this link can join your league
              </p>
            </CardContent>
          </Card>
        )}

        <Card className="md:col-span-2 lg:col-span-3">
          <CardHeader>
            <CardTitle>Teams</CardTitle>
            <CardDescription>
              {teams.length} team{teams.length !== 1 ? "s" : ""} in this league
            </CardDescription>
          </CardHeader>
          <CardContent>
            <div className="grid gap-4 md:grid-cols-2 lg:grid-cols-3">
              {teams.map((team) => {
                const isOwned = team.ownerId === currentUserId;
                const ownerName = team.ownerId ? ownerMap[team.ownerId] : null;
                return (
                  <Card
                    key={team.id}
                    className={isOwned ? "border-primary" : ""}
                  >
                    <CardHeader>
                      <CardTitle className="text-lg">{team.name}</CardTitle>
                      <CardDescription>
                        {team.ownerId ? (
                          isOwned ? (
                            <span className="text-primary font-medium">
                              Your Team
                            </span>
                          ) : (
                            <span>{ownerName || "Unknown Owner"}</span>
                          )
                        ) : (
                          <span className="text-muted-foreground">
                            Available
                          </span>
                        )}
                      </CardDescription>
                    </CardHeader>
                  </Card>
                );
              })}
            </div>
          </CardContent>
        </Card>

        <Card>
          <CardHeader>
            <CardTitle>League Info</CardTitle>
          </CardHeader>
          <CardContent className="space-y-2">
            <div>
              <p className="text-sm text-muted-foreground">Created</p>
              <p className="font-medium">
                {new Date(league.createdAt).toLocaleDateString()}
              </p>
            </div>
            {season && (
              <div>
                <p className="text-sm text-muted-foreground">Season Status</p>
                <p className="font-medium capitalize">
                  {season.status.replace("_", " ")}
                </p>
              </div>
            )}
          </CardContent>
        </Card>

        <Card>
          <CardHeader>
            <CardTitle>Commissioners</CardTitle>
            <CardDescription>
              {commissioners.length} commissioner{commissioners.length !== 1 ? "s" : ""}
            </CardDescription>
          </CardHeader>
          <CardContent>
            <div className="space-y-2">
              {commissioners.map((commissioner) => {
                const commissionerName = commissionerMap[commissioner.userId];
                return (
                  <div
                    key={commissioner.id}
                    className="py-2 border-b last:border-0"
                  >
                    <p className="font-medium">
                      {commissionerName || "Unknown User"}
                      {commissioner.userId === currentUserId && (
                        <span className="ml-2 text-xs text-primary">(You)</span>
                      )}
                    </p>
                  </div>
                );
              })}
            </div>
          </CardContent>
        </Card>
      </div>
    </div>
  );
}