/** Accessible HUX-02 ledger UI. No network request is made by this module. */

import { EyeOff, History, Pencil, ShieldCheck, Trash2 } from "lucide-react";
import { useMemo, useState } from "react";

import {
  MEMORY_TOPICS,
  memoryControlEnabled,
  normalizeMemoryPage,
} from "./model.ts";
import { isControlReference } from "./security.ts";
import type {
  DoNotRememberTarget,
  HuxIdentity,
  MemoryItem,
  MemoryTopic,
  RawMemoryPage,
} from "./types.ts";

interface MemoryControlCenterProps {
  flags?: Iterable<string>;
  identity: HuxIdentity;
  page: RawMemoryPage;
  conversationId?: string;
  messageId?: string;
  busyId?: string;
  onApprove?: (memoryId: string) => void;
  onReject?: (memoryId: string) => void;
  onEditAsNew?: (memoryId: string, content: string) => void;
  onForget?: (memoryId: string) => void;
  onOpenSourceMessage?: (memoryId: string) => void;
  onDoNotRemember?: (target: DoNotRememberTarget) => void;
  onRequireSuggestOnly?: () => void;
}

function LedgerActions({
  item,
  busy,
  onApprove,
  onReject,
  onEdit,
  onForget,
  onOpenSource,
}: {
  item: MemoryItem;
  busy: boolean;
  onApprove?: () => void;
  onReject?: () => void;
  onEdit?: () => void;
  onForget?: () => void;
  onOpenSource?: () => void;
}) {
  if (item.status === "forgotten" || item.status === "expired") return null;
  if (item.status === "proposed") {
    return (
      <div className="hux-memory-actions" aria-label="Approval choices">
        {item.sourceIsMessage && onOpenSource && (
          <button type="button" disabled={busy} onClick={onOpenSource}>
            View source message
          </button>
        )}
        <button type="button" disabled={busy} onClick={onApprove}>
          Remember
        </button>
        <button type="button" disabled={busy} onClick={onReject}>
          Reject
        </button>
      </div>
    );
  }
  return (
    <div className="hux-memory-actions">
      {item.sourceIsMessage && onOpenSource && (
        <button type="button" disabled={busy} onClick={onOpenSource}>
          View source message
        </button>
      )}
      {item.content !== null && (
        <button type="button" disabled={busy} onClick={onEdit}>
          <Pencil aria-hidden /> Edit as new entry
        </button>
      )}
      <button type="button" disabled={busy} onClick={onForget}>
        <Trash2 aria-hidden /> Delete &amp; forget
      </button>
    </div>
  );
}

function MemoryCard({
  item,
  busy,
  editing,
  draft,
  setDraft,
  beginEdit,
  cancelEdit,
  saveEdit,
  approve,
  reject,
  forget,
  openSource,
}: {
  item: MemoryItem;
  busy: boolean;
  editing: boolean;
  draft: string;
  setDraft: (value: string) => void;
  beginEdit: () => void;
  cancelEdit: () => void;
  saveEdit: () => void;
  approve: () => void;
  reject: () => void;
  forget: () => void;
  openSource?: () => void;
}) {
  return (
    <li className="hux-memory-card" data-status={item.status}>
      <header>
        <span className="hux-memory-kind">{item.kind}</span>
        <span className="hux-memory-status">{item.status}</span>
      </header>
      {item.content === null ? (
        <p className="hux-memory-hidden">
          <EyeOff aria-hidden /> {item.contentNotice}
        </p>
      ) : (
        <p className="hux-memory-content">{item.content}</p>
      )}
      <dl className="hux-memory-meta">
        <div>
          <dt>Why</dt><dd>{item.reason}</dd>
        </div>
        <div>
          <dt>Source</dt><dd>{item.sourceLabel}</dd>
        </div>
        <div>
          <dt>Recorded by</dt><dd>{item.provenanceLabel}</dd>
        </div>
        <div>
          <dt>Scope</dt><dd>{item.scopeLabel}</dd>
        </div>
        <div>
          <dt>Sensitivity</dt><dd>{item.sensitivity}</dd>
        </div>
        <div>
          <dt>Approval</dt>
          <dd>{item.approvalMode === "ask" ? "Ask first" : "Automatic (historical)"}</dd>
        </div>
        <div>
          <dt>Retention</dt><dd>{item.ttlLabel}</dd>
        </div>
        <div>
          <dt>Saved</dt>
          <dd>
            <time dateTime={item.savedAt}>
              {new Date(item.savedAt).toLocaleString()}
            </time>
          </dd>
        </div>
      </dl>
      {editing && (
        <form
          className="hux-memory-edit"
          onSubmit={(event) => {
            event.preventDefault();
            saveEdit();
          }}
        >
          <label htmlFor={`hux-memory-edit-${item.id}`}>Proposed replacement</label>
          <textarea
            id={`hux-memory-edit-${item.id}`}
            value={draft}
            maxLength={2000}
            required
            autoFocus
            onChange={(event) => setDraft(event.target.value)}
          />
          <p>
            The original stays in the audit ledger. This replacement needs
            approval.
          </p>
          <div className="hux-memory-actions">
            <button type="submit" disabled={busy || !draft.trim()}>
              Propose change
            </button>
            <button type="button" onClick={cancelEdit}>Cancel</button>
          </div>
        </form>
      )}
      {!editing && (
        <LedgerActions
          item={item}
          busy={busy}
          onApprove={approve}
          onReject={reject}
          onEdit={beginEdit}
          onForget={forget}
          onOpenSource={openSource}
        />
      )}
    </li>
  );
}

/** Render nothing unless foundation, privacy, and memory-control are enabled. */
export function MemoryControlCenter(props: MemoryControlCenterProps) {
  const [editingId, setEditingId] = useState<string | null>(null);
  const [draft, setDraft] = useState("");
  const [topic, setTopic] = useState<MemoryTopic>("general");
  const enabled = memoryControlEnabled(props.flags);
  const page = useMemo(
    () => {
      if (!enabled) return null;
      try {
        return normalizeMemoryPage(props.page, props.identity);
      } catch {
        return null;
      }
    },
    [enabled, props.identity, props.page],
  );
  if (!enabled) return null;
  if (!page) {
    return (
      <section className="hux-memory" role="alert">
        Memory is unavailable because its workspace scope could not be verified.
      </section>
    );
  }

  function beginEdit(item: MemoryItem) {
    setEditingId(item.id);
    setDraft(item.content || "");
  }

  function saveEdit(item: MemoryItem) {
    const value = draft.trim();
    if (value) props.onEditAsNew?.(item.id, value);
    setEditingId(null);
    setDraft("");
  }

  return (
    <section className="hux-memory" aria-labelledby="hux-memory-title">
      <header className="hux-memory-heading">
        <div>
          <h2 id="hux-memory-title">
            <History aria-hidden /> Memory
          </h2>
          <p>
            An append-only record of what Hermes may use in future
            conversations.
          </p>
        </div>
        <div className="hux-memory-approval" role="status">
          <ShieldCheck aria-hidden />
          <span>Suggest only — nothing new is saved without your approval.</span>
          <button type="button" onClick={props.onRequireSuggestOnly}>Enforce</button>
        </div>
      </header>

      <fieldset className="hux-memory-blocks">
        <legend>Do not remember</legend>
        {isControlReference(props.messageId) && (
          <button
            type="button"
            onClick={() =>
              props.onDoNotRemember?.({
                kind: "message",
                messageId: props.messageId as string,
              })
            }
          >
            This message
          </button>
        )}
        {isControlReference(props.conversationId, "conv") && (
          <button
            type="button"
            onClick={() =>
              props.onDoNotRemember?.({
                kind: "conversation",
                conversationId: props.conversationId as string,
              })
            }
          >
            This conversation
          </button>
        )}
        <label htmlFor="hux-memory-topic">Topic</label>
        <select
          id="hux-memory-topic"
          value={topic}
          onChange={(event) => setTopic(event.target.value as MemoryTopic)}
        >
          {MEMORY_TOPICS.map((value) => (
            <option key={value} value={value}>{value}</option>
          ))}
        </select>
        <button
          type="button"
          onClick={() => props.onDoNotRemember?.({ kind: "topic", topic })}
        >
          Block topic
        </button>
      </fieldset>

      {(page.invalid > 0 || page.truncated > 0) && (
        <p className="hux-memory-warning" role="status">
          Some entries were withheld because they were unsafe, out of scope, or
          beyond this page.
        </p>
      )}
      <ol className="hux-memory-ledger" aria-label="Memory ledger">
        {page.entries.map((item) => (
          <MemoryCard
            key={item.id}
            item={item}
            busy={props.busyId === item.id}
            editing={editingId === item.id}
            draft={draft}
            setDraft={setDraft}
            beginEdit={() => beginEdit(item)}
            cancelEdit={() => {
              setEditingId(null);
              setDraft("");
            }}
            saveEdit={() => saveEdit(item)}
            approve={() => props.onApprove?.(item.id)}
            reject={() => props.onReject?.(item.id)}
            forget={() => props.onForget?.(item.id)}
            openSource={
              props.onOpenSourceMessage
                ? () => props.onOpenSourceMessage?.(item.id)
                : undefined
            }
          />
        ))}
      </ol>
      {page.entries.length === 0 && (
        <p className="hux-memory-empty">Hermes has no memory entries to show.</p>
      )}
    </section>
  );
}