import { Link, useFetcher } from "react-router";
import { auth } from "~/lib/auth.server";
import type { Route } from "./+types/admin.tournaments.$id";

import { logger } from "~/lib/logger";
import {
  getTournamentById,
  updateTournamentStatus,
} from "~/models/tournament";
import {
  getTournamentResults,
  upsertTournamentResult,
} from "~/models/tournament-result";
import { findCanonicalParticipantsBySport } from "~/models/participant";
import { isUserAdmin } from "~/models/user";
import {
  syncTournamentResults,
  type SyncReport,
} from "~/services/sync-tournament-results";
import {
  getSportsSeasonsByTournament,
  getPrimaryEventForTournament,
  setPrimaryEvent,
  deleteScoringEvent,
} from "~/models/scoring-event";
import { isBracketMajor } from "~/lib/event-utils";
import {
  Card,
  CardContent,
  CardDescription,
  CardHeader,
  CardTitle,
} from "~/components/ui/card";
import {
  AlertDialog,
  AlertDialogAction,
  AlertDialogCancel,
  AlertDialogContent,
  AlertDialogDescription,
  AlertDialogFooter,
  AlertDialogHeader,
  AlertDialogTitle,
  AlertDialogTrigger,
} from "~/components/ui/alert-dialog";
import { Badge } from "~/components/ui/badge";
import { Button } from "~/components/ui/button";
import {
  Table,
  TableBody,
  TableCell,
  TableHead,
  TableHeader,
  TableRow,
} from "~/components/ui/table";
import { ArrowLeft, CheckCircle2, AlertTriangle } from "lucide-react";
import { BatchResultEntry } from "~/components/BatchResultEntry";

export function meta({ data }: Route.MetaArgs): Route.MetaDescriptors {
  return [
    {
      title: `${data?.tournament?.name ?? "Tournament"} - Brackt Admin`,
    },
  ];
}

export async function loader({ params }: Route.LoaderArgs) {
  const tournament = await getTournamentById(params.id);
  if (!tournament) {
    throw new Response("Not Found", { status: 404 });
  }

  const [results, canonicalParticipants, linkedSportsSeasons, primaryEvent] =
    await Promise.all([
      getTournamentResults(tournament.id),
      findCanonicalParticipantsBySport(tournament.sportId),
      getSportsSeasonsByTournament(tournament.id),
      getPrimaryEventForTournament(tournament.id),
    ]);

  // Bracket majors (tennis, CS2) are scored on their primary window's bracket /
  // stage UI; golf is entered right here. Surface a link for the bracket case.
  const simulatorType =
    linkedSportsSeasons[0]?.sportsSeason?.sport?.simulatorType ?? null;
  const bracketMajor = isBracketMajor(simulatorType);
  const isCs2 = simulatorType === "cs2_major_qualifying_points";

  return {
    tournament,
    results,
    canonicalParticipants,
    linkedSportsSeasons,
    primaryEvent,
    bracketMajor,
    isCs2,
  };
}

export async function action(args: Route.ActionArgs) {
  const { request, params } = args;
  const session = await auth.api.getSession({ headers: request.headers });
  const userId = session?.user.id ?? null;
  const isAdmin = userId ? await isUserAdmin(userId) : false;
  if (!isAdmin) {
    throw new Response("Forbidden", { status: 403 });
  }

  const tournament = await getTournamentById(params.id);
  if (!tournament) {
    throw new Response("Not Found", { status: 404 });
  }

  const formData = await request.formData();
  const intent = formData.get("intent");

  if (intent === "batch-upsert-results") {
    const resultsRaw = formData.get("results");
    if (typeof resultsRaw !== "string" || !resultsRaw) {
      return {
        success: false as const,
        error: "Missing results payload",
        syncReport: null,
      };
    }

    let parsed: Array<{ participantId: string; placement: number }>;
    try {
      parsed = JSON.parse(resultsRaw);
    } catch {
      return {
        success: false as const,
        error: "Invalid JSON in results payload",
        syncReport: null,
      };
    }

    if (!Array.isArray(parsed)) {
      return {
        success: false as const,
        error: "Results payload must be an array",
        syncReport: null,
      };
    }

    try {
      for (const row of parsed) {
        if (
          !row ||
          typeof row.participantId !== "string" ||
          typeof row.placement !== "number"
        ) {
          return {
            success: false as const,
            error: "Each result must have participantId and placement",
            syncReport: null,
          };
        }
        await upsertTournamentResult({
          tournamentId: tournament.id,
          participantId: row.participantId,
          placement: row.placement,
        });
      }

      const syncReport = await syncTournamentResults(tournament.id);

      // Status reflects reality: completed only when every linked window synced.
      // If any window failed, leave it in_progress so the failure is visible and
      // retryable rather than masked by a green "completed" badge.
      const newStatus =
        syncReport.windowsFailed === 0 ? "completed" : "in_progress";
      if (tournament.status !== newStatus) {
        await updateTournamentStatus(tournament.id, newStatus);
      }

      return {
        success: true as const,
        error: null,
        syncReport,
      };
    } catch (error) {
      logger.error("batch-upsert-results failed:", error);
      return {
        success: false as const,
        error:
          error instanceof Error ? error.message : "Failed to save results",
        syncReport: null,
      };
    }
  }

  if (intent === "retry-window-sync") {
    try {
      const syncReport = await syncTournamentResults(tournament.id);
      const newStatus =
        syncReport.windowsFailed === 0 ? "completed" : "in_progress";
      if (tournament.status !== newStatus) {
        await updateTournamentStatus(tournament.id, newStatus);
      }
      return { success: true as const, error: null, syncReport };
    } catch (error) {
      logger.error("retry-window-sync failed:", error);
      return {
        success: false as const,
        error:
          error instanceof Error ? error.message : "Failed to retry sync",
        syncReport: null,
      };
    }
  }

  if (intent === "set-primary") {
    const eventId = formData.get("eventId");
    if (typeof eventId !== "string" || !eventId) {
      return { success: false as const, error: "Event ID is required", syncReport: null };
    }
    try {
      await setPrimaryEvent(eventId);
      return { success: true as const, error: null, syncReport: null };
    } catch (error) {
      logger.error("set-primary failed:", error);
      return {
        success: false as const,
        error: error instanceof Error ? error.message : "Failed to set primary window",
        syncReport: null,
      };
    }
  }

  if (intent === "unlink-window") {
    const eventId = formData.get("eventId");
    if (typeof eventId !== "string" || !eventId) {
      return { success: false as const, error: "Event ID is required", syncReport: null };
    }
    try {
      // Remove that season's scoring event. The tournament stays (we're on its
      // page); if this was the primary window, another is auto-promoted.
      await deleteScoringEvent(eventId);
      return { success: true as const, error: null, syncReport: null };
    } catch (error) {
      logger.error("unlink-window failed:", error);
      return {
        success: false as const,
        error: error instanceof Error ? error.message : "Failed to remove season",
        syncReport: null,
      };
    }
  }

  return {
    success: false as const,
    error: "Invalid intent",
    syncReport: null,
  };
}

export default function AdminTournamentDetail({
  loaderData,
  actionData,
}: Route.ComponentProps) {
  const {
    tournament,
    results,
    canonicalParticipants,
    linkedSportsSeasons,
    primaryEvent,
    bracketMajor,
    isCs2,
  } = loaderData;
  const retryFetcher = useFetcher<typeof action>();
  const primaryFetcher = useFetcher<typeof action>();
  const unlinkFetcher = useFetcher<typeof action>();

  // For bracket majors, scoring lives on the primary window's bracket/stage UI.
  const primaryScoringHref =
    bracketMajor && primaryEvent
      ? isCs2
        ? `/admin/sports-seasons/${primaryEvent.sportsSeasonId}/events/${primaryEvent.id}/cs2-setup`
        : `/admin/sports-seasons/${primaryEvent.sportsSeasonId}/events/${primaryEvent.id}/bracket`
      : null;

  // Prefer the latest action/retry response for the sync report
  const liveReport: SyncReport | null =
    (retryFetcher.data?.syncReport ?? actionData?.syncReport) ?? null;

  const participantById = new Map(
    canonicalParticipants.map((p) => [p.id, p])
  );

  return (
    <div className="p-8">
      <div className="max-w-5xl">
        <div className="mb-6">
          <Button variant="ghost" size="sm" asChild className="mb-2">
            <Link to="/admin/tournaments">
              <ArrowLeft className="mr-2 h-4 w-4" />
              Back to tournaments
            </Link>
          </Button>
          <div className="flex items-center justify-between gap-3">
            <div className="flex items-center gap-3">
              <h1 className="text-3xl font-bold">{tournament.name}</h1>
              <Badge
                variant={
                  tournament.status === "completed"
                    ? "default"
                    : tournament.status === "in_progress"
                    ? "secondary"
                    : "outline"
                }
              >
                {tournament.status}
              </Badge>
            </div>
            {primaryScoringHref && (
              <Button asChild>
                <Link to={primaryScoringHref}>
                  {isCs2 ? "Manage stages & bracket →" : "Manage bracket →"}
                </Link>
              </Button>
            )}
          </div>
          <p className="text-muted-foreground mt-1">
            {tournament.year}
            {tournament.location ? ` — ${tournament.location}` : ""}
            {tournament.surface ? ` — ${tournament.surface}` : ""}
          </p>
        </div>

        {liveReport && (
          <Card className="mb-6 border-emerald-500/30">
            <CardHeader>
              <CardTitle className="flex items-center gap-2 text-emerald-500">
                <CheckCircle2 className="h-5 w-5" />
                Synced to {liveReport.windowsSynced}{" "}
                {liveReport.windowsSynced === 1 ? "window" : "windows"}
              </CardTitle>
              <CardDescription>
                Canonical results were fanned out to every linked scoring
                window.
              </CardDescription>
            </CardHeader>
            {liveReport.failures.length > 0 && (
              <CardContent>
                <div className="rounded-md border border-destructive/50 bg-destructive/10 p-4 space-y-3">
                  <div className="flex items-center gap-2 text-destructive font-medium">
                    <AlertTriangle className="h-4 w-4" />
                    {liveReport.failures.length}{" "}
                    {liveReport.failures.length === 1 ? "window" : "windows"}{" "}
                    failed to sync
                  </div>
                  <div className="space-y-2">
                    {liveReport.failures.map((f) => (
                      <div
                        key={f.scoringEventId}
                        className="flex items-start justify-between gap-4 text-sm"
                      >
                        <div className="space-y-1">
                          <div className="font-mono text-xs text-muted-foreground">
                            event: {f.scoringEventId}
                          </div>
                          <div className="font-mono text-xs text-muted-foreground">
                            season: {f.sportsSeasonId}
                          </div>
                          <div className="text-destructive">{f.error}</div>
                        </div>
                        <retryFetcher.Form method="post">
                          <input
                            type="hidden"
                            name="intent"
                            value="retry-window-sync"
                          />
                          <input
                            type="hidden"
                            name="scoringEventId"
                            value={f.scoringEventId}
                          />
                          <Button
                            type="submit"
                            size="sm"
                            variant="outline"
                            disabled={retryFetcher.state !== "idle"}
                          >
                            {retryFetcher.state !== "idle"
                              ? "Retrying…"
                              : "Retry"}
                          </Button>
                        </retryFetcher.Form>
                      </div>
                    ))}
                  </div>
                </div>
              </CardContent>
            )}
          </Card>
        )}

        <Card className="mb-6">
          <CardHeader>
            <CardTitle>Linked Sports Seasons</CardTitle>
            <CardDescription>
              {linkedSportsSeasons.length}{" "}
              {linkedSportsSeasons.length === 1
                ? "sports season"
                : "sports seasons"}{" "}
              use this tournament as a scoring event
            </CardDescription>
          </CardHeader>
          <CardContent>
            {linkedSportsSeasons.length > 0 ? (
              <div className="space-y-2">
                {linkedSportsSeasons.map((link) => (
                  <div
                    key={link.id}
                    className="flex items-center justify-between p-3 border rounded-lg"
                  >
                    <div>
                      <p className="font-medium">
                        {link.sportsSeason.sport.name} -{" "}
                        {link.sportsSeason.name}
                      </p>
                      <p className="text-sm text-muted-foreground">
                        {link.sportsSeason.year} &bull;{" "}
                        {link.sportsSeason.scoringType.replace("_", " ")}
                      </p>
                    </div>
                    <div className="flex items-center gap-2">
                      {bracketMajor &&
                        (link.isPrimary ? (
                          <Badge variant="default">Primary</Badge>
                        ) : (
                          <primaryFetcher.Form method="post">
                            <input type="hidden" name="intent" value="set-primary" />
                            <input type="hidden" name="eventId" value={link.id} />
                            <Button
                              type="submit"
                              variant="outline"
                              size="sm"
                              disabled={primaryFetcher.state !== "idle"}
                            >
                              Make primary
                            </Button>
                          </primaryFetcher.Form>
                        ))}
                      <Badge
                        variant={
                          link.sportsSeason.status === "completed"
                            ? "default"
                            : link.sportsSeason.status === "active"
                            ? "secondary"
                            : "outline"
                        }
                      >
                        {link.sportsSeason.status}
                      </Badge>
                      <AlertDialog>
                        <AlertDialogTrigger asChild>
                          <Button
                            type="button"
                            variant="ghost"
                            size="sm"
                            className="text-destructive hover:text-destructive"
                            disabled={unlinkFetcher.state !== "idle"}
                          >
                            Remove
                          </Button>
                        </AlertDialogTrigger>
                        <AlertDialogContent>
                          <AlertDialogHeader>
                            <AlertDialogTitle>
                              Remove {link.sportsSeason.sport.name} - {link.sportsSeason.name}?
                            </AlertDialogTitle>
                            <AlertDialogDescription asChild>
                              <span>
                                This deletes that season's scoring event (and its results) but keeps{" "}
                                <span className="font-medium">{tournament.name}</span> and the other linked seasons.
                                {link.isPrimary && linkedSportsSeasons.length > 1 && (
                                  <> Because this is the primary scoring window, another season will be promoted to primary automatically.</>
                                )}
                                {linkedSportsSeasons.length === 1 && (
                                  <> This is the only linked season — the tournament will remain but have no windows until you link one again.</>
                                )}
                              </span>
                            </AlertDialogDescription>
                          </AlertDialogHeader>
                          <AlertDialogFooter>
                            <AlertDialogCancel>Cancel</AlertDialogCancel>
                            <unlinkFetcher.Form method="post">
                              <input type="hidden" name="intent" value="unlink-window" />
                              <input type="hidden" name="eventId" value={link.id} />
                              <AlertDialogAction
                                type="submit"
                                className="bg-destructive text-destructive-foreground hover:bg-destructive/90"
                              >
                                Remove
                              </AlertDialogAction>
                            </unlinkFetcher.Form>
                          </AlertDialogFooter>
                        </AlertDialogContent>
                      </AlertDialog>
                    </div>
                  </div>
                ))}
              </div>
            ) : (
              <p className="text-sm text-muted-foreground text-center py-4">
                No sports seasons are using this tournament yet.
              </p>
            )}
          </CardContent>
        </Card>

        <div className="grid gap-6 md:grid-cols-2">
          <Card>
            <CardHeader>
              <CardTitle>Current Results</CardTitle>
              <CardDescription>
                {results.length}{" "}
                {results.length === 1 ? "result" : "results"} recorded
              </CardDescription>
            </CardHeader>
            <CardContent>
              {results.length === 0 ? (
                <p className="text-sm text-muted-foreground py-6 text-center">
                  No results recorded yet. Paste a ranked list to the right to
                  import.
                </p>
              ) : (
                <Table>
                  <TableHeader>
                    <TableRow>
                      <TableHead className="w-24">Placement</TableHead>
                      <TableHead>Participant</TableHead>
                    </TableRow>
                  </TableHeader>
                  <TableBody>
                    {results.map((r) => {
                      const p = participantById.get(r.participantId);
                      return (
                        <TableRow key={r.id}>
                          <TableCell className="font-semibold">
                            {r.placement ?? "—"}
                          </TableCell>
                          <TableCell>
                            {p?.name ?? (
                              <span className="text-muted-foreground font-mono text-xs">
                                {r.participantId}
                              </span>
                            )}
                          </TableCell>
                        </TableRow>
                      );
                    })}
                  </TableBody>
                </Table>
              )}
            </CardContent>
          </Card>

          {bracketMajor ? (
            <Card>
              <CardHeader>
                <CardTitle>Scoring</CardTitle>
                <CardDescription>
                  This is a bracket major. Results are derived from the
                  bracket/stage workflow on the primary window and fan out here
                  automatically.
                </CardDescription>
              </CardHeader>
              <CardContent>
                {primaryScoringHref ? (
                  <Button asChild>
                    <Link to={primaryScoringHref}>
                      {isCs2 ? "Manage stages & bracket →" : "Manage bracket →"}
                    </Link>
                  </Button>
                ) : (
                  <p className="text-sm text-muted-foreground">
                    No primary window is set up yet for this tournament.
                  </p>
                )}
              </CardContent>
            </Card>
          ) : (
            <BatchResultEntry
              participants={canonicalParticipants.map((p) => ({
                id: p.id,
                name: p.name,
              }))}
              sportsSeasonId=""
              existingResultParticipantIds={
                new Set(results.map((r) => r.participantId))
              }
              intent="batch-upsert-results"
            />
          )}
        </div>
      </div>
    </div>
  );
}