"use client";

import { useEffect, useRef, useState } from "react";
import PinballCanvas from "./PinballCanvas";
import { takePendingTable } from "@/lib/pinball/tableSelectionStore";
import { getLibraryEntry, saveToLibrary } from "@/lib/pinball/tableLibrary";
import { romGameNameFromFileName } from "@/lib/pinball/rom";
import type { RomSelection } from "@/lib/pinball/usePinballInstance";
import type { TableInfo } from "@/lib/pinball/types";

interface ResolvedTable {
  tableData?: ArrayBuffer;
  rom?: RomSelection;
  tableInfo: TableInfo;
}

async function toRomSelection(romFile: File): Promise<RomSelection> {
  return { gameName: romGameNameFromFileName(romFile.name), romData: await romFile.arrayBuffer() };
}

export default function PlayView() {
  const [resolved, setResolved] = useState<ResolvedTable | null>(null);
  // takePendingTable() pops the store on read, so it must run at most once
  // per real mount — React's dev-mode double-invoke of effects would
  // otherwise have the second call see an already-emptied store (the first
  // call already popped the selection) and silently fall back to the demo
  // table. No unmount-cancellation guard here: this ref makes the
  // double-invoke's second pass a full no-op, so the async work below only
  // ever runs once for a given component instance — a cleanup-driven cancel
  // flag would incorrectly cancel that one real run's own result, since the
  // phantom unmount's cleanup fires for whichever pass actually started it.
  const hasResolvedRef = useRef(false);

  useEffect(() => {
    if (hasResolvedRef.current) return;
    hasResolvedRef.current = true;

    (async () => {
      const selection = takePendingTable();

      if (selection?.kind === "upload") {
        const { vpxFile, romFile, saveToLibrary: shouldSave } = selection;
        const [tableData, rom] = await Promise.all([
          vpxFile.arrayBuffer(),
          romFile ? toRomSelection(romFile) : Promise.resolve(undefined),
        ]);
        if (shouldSave) {
          saveToLibrary({
            id: crypto.randomUUID(),
            name: vpxFile.name,
            sizeBytes: vpxFile.size,
            addedAt: Date.now(),
            vpxBlob: vpxFile,
            romFileName: romFile?.name,
            romBlob: romFile,
          }).catch((err) => console.error("Failed to save table to library:", err));
        }
        setResolved({
          tableData,
          rom,
          tableInfo: { name: vpxFile.name, sizeBytes: vpxFile.size, isDemo: false, romFileName: romFile?.name },
        });
        return;
      }

      if (selection?.kind === "library") {
        const entry = await getLibraryEntry(selection.id);
        if (entry) {
          const [tableData, rom] = await Promise.all([
            entry.vpxBlob.arrayBuffer(),
            entry.romBlob
              ? entry.romBlob.arrayBuffer().then((romData) => ({
                  gameName: romGameNameFromFileName(entry.romFileName ?? ""),
                  romData,
                }))
              : Promise.resolve(undefined),
          ]);
          setResolved({
            tableData,
            rom,
            tableInfo: {
              name: entry.name,
              sizeBytes: entry.sizeBytes,
              isDemo: false,
              romFileName: entry.romFileName,
            },
          });
          return;
        }
        // Fall through to the demo table if the library entry was removed
        // (e.g. deleted in another tab) between selecting it and arriving here.
      }

      // No pending upload/library selection (fresh visit, or a hard refresh
      // of /play) — fall back to the bundled demo table rather than
      // dead-ending the route.
      setResolved({
        tableInfo: { name: "Demo table", sizeBytes: 0, isDemo: true },
      });
    })();
  }, []);

  if (!resolved) {
    return (
      <div className="flex h-full w-full items-center justify-center bg-ink font-mono text-chrome">
        Preparing table…
      </div>
    );
  }

  return (
    <PinballCanvas
      tableData={resolved.tableData}
      rom={resolved.rom}
      tableInfo={resolved.tableInfo}
      key={resolved.tableInfo.name}
    />
  );
}