import { useEffect, useMemo, useRef, useState } from "react";

import { importFiles } from "../import/importNotes";

/**
 * Runs an import and says plainly what came of it.
 *
 * The report is the point. An import can succeed in the sense that no error was
 * thrown and still not be what the user expected — a drawing arrives as a flat
 * picture, an image the archive did not contain cannot be restored. Those are
 * stated afterwards rather than left to be discovered, because the moment to
 * learn that a drawing is no longer editable is now, while the original export
 * is still on disk.
 */
export function ImportDialog({ files, folderId, onDone, onClose, dark }) {
  const [progress, setProgress] = useState({ done: 0, total: 0, label: "" });
  const [result, setResult] = useState(null);
  const [error, setError] = useState("");
  const started = useRef(false);

  const T = useMemo(
    () => ({
      bg: dark ? "#161b22" : "#fff",
      border: dark ? "#30363d" : "#d0d7de",
      text: dark ? "#e6edf3" : "#1f2328",
      muted: dark ? "#8b949e" : "#656d76",
      accent: dark ? "#388bfd" : "#0969da",
      warning: dark ? "#d29922" : "#9a6700",
      danger: dark ? "#f85149" : "#cf222e",
      track: dark ? "#21262d" : "#e5e7eb",
    }),
    [dark]
  );

  useEffect(() => {
    // React runs effects twice in development; importing twice would create
    // every note a second time.
    if (started.current) return;
    started.current = true;

    importFiles(files, folderId, setProgress)
      .then((r) => {
        setResult(r);
        onDone?.(r);
      })
      .catch((e) => setError(e?.message || "Der Import ist fehlgeschlagen."));
  }, [files, folderId, onDone]);

  const done = result || error;
  const pct = progress.total ? Math.round((progress.done / progress.total) * 100) : 0;

  return (
    <div
      style={{
        position: "fixed",
        inset: 0,
        background: "rgba(0,0,0,0.5)",
        display: "flex",
        alignItems: "center",
        justifyContent: "center",
        zIndex: 2000,
        backdropFilter: "blur(4px)",
      }}
      onClick={done ? onClose : undefined}
    >
      <div
        onClick={(e) => e.stopPropagation()}
        style={{
          background: T.bg,
          borderRadius: 16,
          padding: 24,
          width: 440,
          maxWidth: "92vw",
          border: `1px solid ${T.border}`,
          boxShadow: "0 20px 40px rgba(0,0,0,0.3)",
          fontFamily: "'DM Sans',sans-serif",
          color: T.text,
        }}
      >
        <div
          style={{
            fontSize: 17,
            fontWeight: 600,
            marginBottom: 14,
            fontFamily: "'Newsreader',Georgia,serif",
          }}
        >
          {done ? "Import abgeschlossen" : "Notizen werden importiert…"}
        </div>

        {!done && (
          <>
            <div style={{ height: 6, borderRadius: 3, background: T.track, overflow: "hidden" }}>
              <div
                style={{
                  width: `${pct}%`,
                  height: "100%",
                  background: T.accent,
                  transition: "width .2s",
                }}
              />
            </div>
            <div style={{ fontSize: 12, color: T.muted, marginTop: 8 }}>
              {progress.total ? `${progress.done} von ${progress.total}` : "Archiv wird gelesen…"}
              {progress.label ? ` — ${progress.label}` : ""}
            </div>
          </>
        )}

        {error && <div style={{ fontSize: 13, color: T.danger }}>{error}</div>}

        {result && (
          <div style={{ fontSize: 13, lineHeight: 1.7 }}>
            <div>
              <strong>{result.notes.length}</strong>{" "}
              {result.notes.length === 1 ? "Notiz importiert" : "Notizen importiert"}
            </div>

            {result.flattenedDrawings > 0 && (
              <div style={{ color: T.warning, marginTop: 10, fontSize: 12.5 }}>
                {result.flattenedDrawings === 1
                  ? "Eine Zeichnung kam als Bild zurück"
                  : `${result.flattenedDrawings} Zeichnungen kamen als Bilder zurück`}{" "}
                — im Archiv liegen sie als PNG, und aus Pixeln lassen sich die Striche nicht zurückrechnen.
                Sie sind sichtbar und exportierbar, aber nicht mehr mit dem Stift zu bearbeiten.
              </div>
            )}

            {result.missingImages > 0 && (
              <div style={{ color: T.warning, marginTop: 10, fontSize: 12.5 }}>
                {result.missingImages} {result.missingImages === 1 ? "Bild lag" : "Bilder lagen"} nicht im
                Archiv. Die Stelle in der Notiz bleibt erhalten, das Bild fehlt.
              </div>
            )}

            {result.failed.length > 0 && (
              <div style={{ color: T.danger, marginTop: 10, fontSize: 12.5 }}>
                Nicht gelesen: {result.failed.join(", ")}
              </div>
            )}
          </div>
        )}

        <div style={{ display: "flex", justifyContent: "flex-end", marginTop: 20 }}>
          <button
            onClick={onClose}
            disabled={!done}
            style={{
              padding: "8px 20px",
              borderRadius: 10,
              border: "none",
              background: done ? T.accent : T.track,
              color: done ? "#fff" : T.muted,
              cursor: done ? "pointer" : "default",
              fontSize: 13,
              fontWeight: 600,
            }}
          >
            {done ? "Fertig" : "Läuft…"}
          </button>
        </div>
      </div>
    </div>
  );
}