/**
 * AnnotationToolbar — wires "I selected text" into "evidence appears in
 * the sidebar".
 *
 * Visible only when a `pendingSelection` is set (the viewer publishes
 * captures into context, then this toolbar lets the user attach commentary
 * and commit). On Save it runs the full pipeline:
 *
 *   1. `createSelectors(capture, representation)` — anchor builds the
 *      maximal selector set against the active representation.
 *   2. `engine.annotations.create(...)` — engine mints an Annotation +
 *      emits AnnotationCreated.
 *   3. `engine.evidence.create(...)` — engine mints the EvidenceItem with
 *      the user's commentary, emits EvidenceItemCreated.
 *
 * The sidebar re-renders via the engine event bus, so no other glue is
 * needed.
 */

import { useEffect, useState } from "react";
import { createSelectors } from "@anchor/index";
import {
  useActiveDocument,
  useEngine,
  usePendingSelection,
} from "./EngineContext";

export function AnnotationToolbar() {
  const engine = useEngine();
  const { document, representation } = useActiveDocument();
  const { pending, set } = usePendingSelection();
  const [commentary, setCommentary] = useState("");

  // Reset the commentary box whenever a fresh selection arrives.
  useEffect(() => {
    setCommentary("");
  }, [pending]);

  if (!pending || !document || !representation) return null;

  const handleSave = () => {
    const selectors = createSelectors(pending.capture, representation);
    const annotation = engine.annotations.create({
      documentId: document.id,
      representationId: representation.id,
      selectors,
      quote: pending.capture.text,
    });
    engine.evidence.create({
      annotationIds: [annotation.id],
      ...(commentary.trim().length > 0 ? { commentary: commentary.trim() } : {}),
    });
    set(null);
  };

  const handleDiscard = () => set(null);

  const quote = pending.capture.text;
  const shortQuote = quote.length > 200 ? `${quote.slice(0, 200)}…` : quote;

  return (
    <div
      style={{
        borderBottom: "1px solid #f0c040",
        background: "#fff8d6",
        padding: 8,
        fontFamily: "system-ui, sans-serif",
        fontSize: 12,
      }}
    >
      <div style={{ marginBottom: 6, fontWeight: 600 }}>
        New annotation ({pending.selectors.length} selector{pending.selectors.length === 1 ? "" : "s"})
      </div>
      <div style={{ marginBottom: 6, fontStyle: "italic", color: "#444" }}>
        &ldquo;{shortQuote}&rdquo;
      </div>
      <textarea
        value={commentary}
        onChange={(e) => setCommentary(e.target.value)}
        placeholder="Add a one-line comment (optional)…"
        rows={2}
        style={{
          width: "100%",
          boxSizing: "border-box",
          fontSize: 12,
          padding: 4,
          marginBottom: 6,
        }}
      />
      <div style={{ display: "flex", gap: 6 }}>
        <button onClick={handleSave} style={{ fontSize: 12, padding: "4px 10px" }}>
          Save evidence
        </button>
        <button onClick={handleDiscard} style={{ fontSize: 12, padding: "4px 10px" }}>
          Discard
        </button>
      </div>
    </div>
  );
}