clicktrack/components/TempoMapEditor.tsx

"use client";

/**
 * TempoMapEditor
 *
 * Renders a read-only or editable view of a CTP document's sections.
 * The full interactive editor (drag-to-resize bars, BPM knob, etc.)
 * is a future milestone — this version is a structured table view
 * with inline editing stubs.
 */

import type { CTPDocument, CTPSection } from "@/lib/ctp/schema";
import { isRampSection, sectionStartBpm } from "@/lib/ctp/schema";

interface TempoMapEditorProps {
  ctpDoc: CTPDocument;
  /** When true, all inputs are disabled. */
  readOnly?: boolean;
  onChange?: (doc: CTPDocument) => void;
}

function timeSigLabel(ts: CTPSection["time_signature"]): string {
  return `${ts.numerator}/${ts.denominator}`;
}

function bpmLabel(section: CTPSection): string {
  if (isRampSection(section)) {
    return `${section.bpm_start} → ${section.bpm_end}`;
  }
  return String(section.bpm);
}

export default function TempoMapEditor({
  ctpDoc,
  readOnly = false,
}: TempoMapEditorProps) {
  const { metadata, count_in, sections } = ctpDoc;

  return (
    <div className="space-y-5">
      {/* Metadata strip */}
      <div className="flex flex-wrap gap-x-6 gap-y-1 text-sm text-zinc-500">
        <span>
          Contributed by{" "}
          <span className="text-zinc-300 font-medium">{metadata.contributed_by}</span>
        </span>
        {metadata.verified && (
          <span className="text-green-400 font-medium">✓ Verified</span>
        )}
        <span>CTP v{ctpDoc.version}</span>
        {metadata.mbid && (
          <a
            href={`https://musicbrainz.org/recording/${metadata.mbid}`}
            target="_blank"
            rel="noopener noreferrer"
            className="text-blue-500 hover:underline"
          >
            MusicBrainz
          </a>
        )}
      </div>

      {/* Count-in */}
      <div className="flex items-center gap-3 text-sm">
        <span className="text-zinc-500">Count-in:</span>
        <span className="text-zinc-300">
          {count_in.enabled ? `${count_in.bars} bar${count_in.bars !== 1 ? "s" : ""}` : "Disabled"}
        </span>
      </div>

      {/* Sections table */}
      <div className="overflow-x-auto rounded-lg border border-zinc-800">
        <table className="w-full text-sm">
          <thead>
            <tr className="border-b border-zinc-800 text-left text-xs uppercase tracking-widest text-zinc-600">
              <th className="px-4 py-3">Label</th>
              <th className="px-4 py-3">Start Bar</th>
              <th className="px-4 py-3">BPM</th>
              <th className="px-4 py-3">Time Sig</th>
              <th className="px-4 py-3">Transition</th>
            </tr>
          </thead>
          <tbody>
            {sections.map((section, i) => (
              <tr
                key={i}
                className="border-b border-zinc-800/60 last:border-0 hover:bg-zinc-800/30"
              >
                <td className="px-4 py-3 font-medium text-zinc-200">
                  {section.label}
                </td>
                <td className="px-4 py-3 text-zinc-400">{section.start_bar}</td>
                <td className="px-4 py-3 font-mono text-green-400">
                  {bpmLabel(section)}
                </td>
                <td className="px-4 py-3 text-zinc-400">
                  {timeSigLabel(section.time_signature)}
                </td>
                <td className="px-4 py-3">
                  <span
                    className={`rounded-full px-2 py-0.5 text-xs font-medium ${
                      section.transition === "ramp"
                        ? "bg-amber-900/40 text-amber-400"
                        : "bg-zinc-800 text-zinc-400"
                    }`}
                  >
                    {section.transition}
                  </span>
                </td>
              </tr>
            ))}
          </tbody>
        </table>
      </div>

      {!readOnly && (
        <p className="text-xs text-zinc-600">
          Interactive editor coming soon — contribute via the{" "}
          <a
            href="https://github.com/your-org/clicktrack-registry"
            className="text-blue-500 hover:underline"
          >
            community registry
          </a>{" "}
          in the meantime.
        </p>
      )}
    </div>
  );
}