/** Accessible multimodal UI. It emits intents but never fetches, uploads, or opens devices. */

import { Camera, FileText, Image as ImageIcon, Mic2, MonitorUp, Pencil, Upload } from "lucide-react";
import { useMemo, useRef, useState } from "react";

import {
  buildAnnotation, buildCaptureIntent, buildImageEdit, buildTranscriptCorrection,
  captureAuthorization, multimodalEnabled, normalizeMultimodalPage,
} from "./model.ts";
import { validateUpload } from "./security.ts";
import type { FileCandidate, MediaView, MultimodalProps } from "./types.ts";

function MediaPreview({item}: {item: MediaView}) {
  if (item.kind === "image" && item.previewUrl) return <figure className="hux-mm-image">
    <img src={item.previewUrl} alt={item.altText} />
    <figcaption>{item.fileName} · version {item.artifactVersion}</figcaption>
  </figure>;
  if (item.kind === "document" && item.previewText) return <div className="hux-mm-document">
    <strong>{item.fileName}</strong>
    <pre tabIndex={0}><code>{item.previewText}</code></pre>
    <small>Safe text preview; active document content is not executed.</small>
  </div>;
  const Icon = item.kind === "image" ? ImageIcon : item.kind === "audio" ? Mic2 : FileText;
  return <div className="hux-mm-safe-preview" role="img" aria-label={`${item.kind} preview unavailable`}>
    <Icon aria-hidden />
    <strong>{item.fileName}</strong>
    <span>{item.mime} · {Math.ceil(item.bytes / 1024)} KB</span>
    <small>Content is not executed. Open an authorized artifact preview to inspect it.</small>
  </div>;
}

function UploadPanel({props, authorization, setNotice}: {
  props: MultimodalProps;
  authorization: MultimodalProps["page"]["upload_authorization"];
  setNotice: (message: string) => void;
}) {
  const input = useRef<HTMLInputElement>(null);
  const authorized = authorization === "authorized";

  function handle(files: FileList | readonly File[]) {
    const accepted: FileCandidate[] = [];
    const rejected: string[] = [];
    for (const file of Array.from(files).slice(0, 20)) {
      const result = validateUpload(file, String(authorization));
      if (result.ok) accepted.push(result.file);
      else rejected.push(`${file.name || "File"}: ${result.reason}`);
    }
    if (accepted.length) props.onUpload?.(accepted);
    setNotice(rejected.length ? rejected.join(" ") : `${accepted.length} file${accepted.length === 1 ? "" : "s"} ready to upload.`);
  }

  return <section className="hux-mm-upload" aria-labelledby="hux-mm-upload-title"
    onDragOver={(event) => event.preventDefault()} onDrop={(event) => {
      event.preventDefault(); handle(event.dataTransfer.files);
    }}>
    <Upload aria-hidden />
    <h3 id="hux-mm-upload-title">Add files or images</h3>
    <p>Drop authorized PNG, JPEG, WebP, PDF, text, Markdown, or audio files here.</p>
    <input ref={input} className="sr-only" type="file" multiple
      accept="image/png,image/jpeg,image/webp,application/pdf,text/plain,text/markdown,audio/webm,audio/wav,audio/mpeg,audio/ogg"
      onChange={(event) => event.currentTarget.files && handle(event.currentTarget.files)} />
    {authorized ? <button type="button" disabled={props.busy} onClick={() => input.current?.click()}>
      Choose files
    </button> : <button type="button" disabled={props.busy || authorization === "denied"}
      onClick={() => props.onRequestAuthorization?.("upload")}>
      {authorization === "denied" ? "Uploads denied" : "Ask before uploading"}
    </button>}
  </section>;
}

function MediaEditor({item, props}: {item: MediaView; props: MultimodalProps}) {
  const [draft, setDraft] = useState("");
  const [page, setPage] = useState("");
  if (item.kind === "audio") return null;
  const image = item.kind === "image";
  return <form className="hux-mm-editor" onSubmit={(event) => {
    event.preventDefault();
    if (image) props.onImageEdit?.(buildImageEdit(item, props.scope, draft));
    else props.onAnnotate?.(buildAnnotation(item, props.scope, draft, page ? Number(page) : null));
    setDraft(""); setPage("");
  }}>
    <label htmlFor={`hux-mm-edit-${item.id}`}>{image ? "Describe an image edit" : "Add a document annotation"}</label>
    <textarea id={`hux-mm-edit-${item.id}`} value={draft} maxLength={image ? 2000 : 1000}
      onChange={(event) => setDraft(event.currentTarget.value)} required />
    {!image && <label>Page (optional)<input type="number" min="1" max="100000" value={page}
      onChange={(event) => setPage(event.currentTarget.value)} /></label>}
    <button type="submit" disabled={props.busy || !draft.trim()}>
      <Pencil aria-hidden /> {image ? "Create linked variant" : "Save annotation intent"}
    </button>
    {image && <small>The next version retains artifact and variant lineage.</small>}
  </form>;
}

function TranscriptEditor({props, page}: {props: MultimodalProps; page: ReturnType<typeof normalizeMultimodalPage>}) {
  const transcript = page?.transcript;
  const [text, setText] = useState(transcript?.text || "");
  if (!transcript) return <p>No voice transcript is attached to this turn.</p>;
  return <form className="hux-mm-transcript" onSubmit={(event) => {
    event.preventDefault();
    props.onCorrectTranscript?.(buildTranscriptCorrection(transcript, text, props.identity, props.scope));
  }}>
    <label htmlFor="hux-mm-transcript-text">Voice transcript · {transcript.language}</label>
    <textarea id="hux-mm-transcript-text" value={text} maxLength={20000}
      readOnly={!transcript.finalized} onChange={(event) => setText(event.currentTarget.value)} />
    <button type="submit" disabled={props.busy || !transcript.finalized || !text.trim() || text === transcript.text}>
      Correct transcript
    </button>
    {!transcript.finalized && <small>Correction unlocks when transcription is finalized.</small>}
  </form>;
}

function CaptureButton({kind, props}: {kind: "camera" | "screen"; props: MultimodalProps}) {
  const decision = captureAuthorization(props.autonomyPolicy, null, props.identity);
  const Icon = kind === "camera" ? Camera : MonitorUp;
  return <button type="button" disabled={props.busy || decision === "deny"} onClick={() => {
    props.onCapture?.(buildCaptureIntent(kind, props.autonomyPolicy, props.identity, props.scope));
  }}>
    <Icon aria-hidden /> {decision === "deny" ? `${kind} denied` : `Ask to use ${kind}`}
  </button>;
}

/** Render nothing unless foundation, projects, artifacts, autonomy, and multimodal are active. */
export function MultimodalChat(props: MultimodalProps) {
  const enabled = multimodalEnabled(props.flags);
  const page = useMemo(() => enabled ? normalizeMultimodalPage(props.page, props.identity, props.scope) : null,
    [enabled, props.identity, props.page, props.scope]);
  const [selectedId, setSelectedId] = useState<string | null>(null);
  const [notice, setNotice] = useState("");
  if (!enabled || !page) return null;
  const selected = page.media.find((item) => item.id === selectedId) || page.media[0] || null;

  return <section className="hux-multimodal" aria-label="Multimodal chat" aria-busy={props.busy}>
    <header><div><span className="hux-mm-kicker">HUX-07</span><h2>Multimodal workspace</h2>
      <p>Files, voice, and generated variants remain bound to this conversation.</p></div>
      <div className="hux-mm-capture" aria-label="Live media permissions">
        <CaptureButton kind="camera" props={props} /><CaptureButton kind="screen" props={props} />
      </div>
    </header>
    {props.error && <p className="hux-mm-error" role="alert">{props.error}</p>}
    {page.rejected > 0 && <p className="hux-mm-warning" role="status">
      Some media was withheld because its owner, binding, type, or lineage was invalid.
    </p>}
    <UploadPanel props={props} authorization={page.uploadAuthorization} setNotice={setNotice} />
    <div className="hux-mm-workspace">
      <nav aria-label="Conversation media"><ul>{page.media.map((item) => <li key={item.id}>
        <button type="button" aria-current={selected?.id === item.id ? "page" : undefined}
          onClick={() => setSelectedId(item.id)}>{item.kind === "image" ? <ImageIcon aria-hidden /> :
            <FileText aria-hidden />}<span>{item.fileName}</span></button>
      </li>)}</ul>{!page.media.length && <p>No media is attached.</p>}</nav>
      <main>{selected ? <><MediaPreview item={selected} /><MediaEditor key={selected.id} item={selected} props={props} /></> :
        <p>Select media to preview or annotate it.</p>}</main>
      <aside aria-label="Generation history"><h3>Variant history</h3>
        {page.threads.map((thread) => <section key={thread.id}><h4>{thread.prompt}</h4><ol>
          {thread.variants.map((variant, index) => <li key={variant.id}>
            Variant {index + 1} · artifact v{variant.artifactVersion}
            {variant.parentVariantId && <small>Linked to an earlier variant</small>}
          </li>)}</ol></section>)}
        {!page.threads.length && <p>No generated variants yet.</p>}
      </aside>
    </div>
    <TranscriptEditor key={`${page.transcript?.id || "none"}:${page.transcript?.revision || 0}`}
      props={props} page={page} />
    <p className="sr-only" role="status" aria-live="polite">{notice ||
      `${page.media.length} media items and ${page.threads.length} generation threads available`}</p>
  </section>;
}