/** Accessible HUX-05 UI. Parent callbacks own every request and side effect. */

import { Ban, Hand, Octagon, ShieldCheck } from "lucide-react";
import { useMemo, useState } from "react";

import {
  AUTONOMY_LEVELS, BUDGET_MAX, CAPABILITIES, GRANT_DECISIONS,
  autonomyControlsEnabled, buildApprovalDecision, buildPolicyUpdate,
  buildStopIntent, normalizeAutonomyPage, normalizeStopReceipt,
} from "./model.ts";
import type {
  ActiveRun, ApprovalChoice, ApprovalDecisionIntent, ApprovalView, AutonomyLevel,
  BudgetDraft, Capability, GrantDecision, HuxIdentity, PolicyUpdateIntent,
  RawAutonomyEnvelope, StopIntent,
} from "./types.ts";

interface AutonomyControlsProps {
  flags?: Iterable<string>;
  identity: HuxIdentity;
  conversationId: string;
  page: RawAutonomyEnvelope;
  activeRun?: ActiveRun | null;
  stopReceipt?: Record<string, unknown> | null;
  now?: number;
  busy?: boolean;
  onUpdatePolicy?: (intent: PolicyUpdateIntent) => void;
  onDecideApproval?: (intent: ApprovalDecisionIntent) => void;
  onStop?: (intent: StopIntent) => void;
}

const LABELS: Readonly<Record<Capability, string>> = {
  read_files: "Read files", write_files: "Write files", shell: "Run commands",
  network: "Use network", web_search: "Search the web", send_message: "Send messages",
  memory_write: "Save memory", artifact_write: "Change artifacts",
  spend_tokens: "Spend model tokens", delegate: "Delegate to agents", deploy: "Deploy changes",
};

const MODES: Readonly<Record<AutonomyLevel, {label: string; help: string}>> = {
  ask_first: {label: "Ask First", help: "Pause before actions until you approve."},
  safe: {label: "Safe Actions", help: "Read-only work may proceed; external effects still pause."},
  autonomous: {label: "Autonomous", help: "Explicitly allowed capabilities may proceed within every budget."},
};

function startingBudget(page: ReturnType<typeof normalizeAutonomyPage>): BudgetDraft {
  return {...page!.policy.budgets, spendCentsPerRun: 0, scopeLimit: "current_task"};
}

function CapabilityMatrix({grants, setGrant, busy}: {
  grants: Readonly<Record<Capability, GrantDecision>>;
  setGrant: (capability: Capability, decision: GrantDecision) => void;
  busy: boolean;
}) {
  return <fieldset className="hux-autonomy-matrix"><legend>Capability matrix</legend>
    <p id="hux-autonomy-matrix-help">Missing or invalid grants are denied.</p>
    <table><thead><tr><th scope="col">Capability</th><th scope="col">Decision</th></tr></thead>
      <tbody>{CAPABILITIES.map((capability) => <tr key={capability}>
        <th scope="row">{LABELS[capability]}</th><td><select
          aria-label={`${LABELS[capability]} decision`} aria-describedby="hux-autonomy-matrix-help"
          value={grants[capability]} disabled={busy}
          onChange={(event) => setGrant(capability, event.target.value as GrantDecision)}>
          {GRANT_DECISIONS.map((decision) => <option key={decision} value={decision}>
            {decision === "allow" ? "Allow" : decision === "ask" ? "Ask" : "Deny"}
          </option>)}</select></td>
      </tr>)}</tbody></table>
  </fieldset>;
}

function BudgetControls({budget, setBudget, busy}: {
  budget: BudgetDraft;
  setBudget: (next: BudgetDraft) => void;
  busy: boolean;
}) {
  const number = (field: keyof typeof BUDGET_MAX, label: string, step = 1) =>
    <label>{label}<input type="number" min="0" max={BUDGET_MAX[field]} step={step}
      value={budget[field]} disabled={busy} onChange={(event) => setBudget({...budget,
        [field]: Number(event.target.value)})} /></label>;
  return <fieldset className="hux-autonomy-budgets"><legend>Per-run budgets</legend>
    <p id="hux-autonomy-budget-help">Zero blocks that resource. Limits are enforced together.</p>
    <div aria-describedby="hux-autonomy-budget-help">
      {number("wallClockSeconds", "Time (seconds)")}
      {number("spendCentsPerRun", "Spend (cents)")}
      {number("tokensPerRun", "Tokens", 1000)}
      {number("toolCallsPerRun", "Tool calls")}
      {number("delegationsPerRun", "Subagents")}
      <label>Maximum scope<select value={budget.scopeLimit} disabled={busy}
        onChange={(event) => setBudget({...budget, scopeLimit: event.target.value as BudgetDraft["scopeLimit"]})}>
        <option value="current_task">Current task</option><option value="conversation">Conversation</option>
        <option value="project">Project</option></select></label>
    </div>
  </fieldset>;
}

function ApprovalQueue({items, busy, decide}: {
  items: readonly ApprovalView[];
  busy: boolean;
  decide: (approval: ApprovalView, choice: ApprovalChoice) => void;
}) {
  return <section className="hux-autonomy-approvals" aria-labelledby="hux-approval-title">
    <h3 id="hux-approval-title"><Hand aria-hidden /> Review external side effects</h3>
    {items.length ? <ol>{items.map((approval) => <li key={approval.id} data-risk={approval.risk}>
      <strong>{LABELS[approval.capability]}</strong><p>{approval.summary}</p>
      <small>Risk: {approval.risk}. Expires <time dateTime={approval.expiresAt}>
        {new Date(approval.expiresAt).toLocaleTimeString()}</time>.</small>
      <div aria-label="Approval choices">
        <button type="button" disabled={busy} onClick={() => decide(approval, "once")}>Allow once</button>
        <button type="button" disabled={busy} onClick={() => decide(approval, "session")}>This session</button>
        <button type="button" disabled={busy} onClick={() => decide(approval, "always")}>Always</button>
        <button type="button" disabled={busy} onClick={() => decide(approval, "deny")}><Ban aria-hidden /> Deny</button>
      </div>
    </li>)}</ol> : <p>No actions are waiting for approval.</p>}
  </section>;
}

/** Render nothing unless foundation, timeline, and autonomy are negotiated. */
export function AutonomyControls(props: AutonomyControlsProps) {
  const enabled = autonomyControlsEnabled(props.flags);
  const page = useMemo(() => enabled ? normalizeAutonomyPage(props.page, props.identity,
    props.conversationId, props.now) : null,
  [enabled, props.page, props.identity, props.conversationId, props.now]);
  const [autonomy, setAutonomy] = useState<AutonomyLevel>("ask_first");
  const [grants, setGrants] = useState<Readonly<Record<Capability, GrantDecision>> | null>(null);
  const [budget, setBudget] = useState<BudgetDraft | null>(null);
  if (!enabled) return null;
  if (!page) return <section className="hux-autonomy" role="alert">
    Autonomy controls are unavailable because identity or policy scope could not be verified.
  </section>;
  const selectedAutonomy = grants ? autonomy : page.policy.autonomy;
  const selectedGrants = grants || page.policy.grants;
  const selectedBudget = budget || startingBudget(page);
  const receipt = props.stopReceipt && props.activeRun ?
    normalizeStopReceipt(props.stopReceipt, props.activeRun, props.identity) : null;

  function decide(approval: ApprovalView, choice: ApprovalChoice) {
    try { props.onDecideApproval?.(buildApprovalDecision(approval, choice, props.identity,
      approval.requestedAt, props.now)); } catch { /* a stale approval remains denied */ }
  }

  function stop() {
    if (!props.activeRun) return;
    try { props.onStop?.(buildStopIntent(props.activeRun, props.identity, props.activeRun.runId)); }
    catch { /* an unowned run is never stopped */ }
  }

  return <section className="hux-autonomy" aria-labelledby="hux-autonomy-title" aria-busy={props.busy}>
    <header><div><h2 id="hux-autonomy-title"><ShieldCheck aria-hidden /> Autonomy</h2>
      <p>Control what Hermes may do, how far it may go, and what always pauses.</p></div>
      <button className="hux-autonomy-stop" type="button" disabled={props.busy || !props.activeRun}
        onClick={stop}><Octagon aria-hidden /> Stop current run</button>
    </header>
    <form onSubmit={(event) => { event.preventDefault();
      try { props.onUpdatePolicy?.(buildPolicyUpdate(page.policy, props.identity,
        selectedAutonomy, selectedGrants, selectedBudget)); } catch { /* invalid budgets fail closed */ }
    }}>
      <fieldset className="hux-autonomy-levels"><legend>Autonomy level</legend>
        {AUTONOMY_LEVELS.map((level) => <label key={level}>
          <input type="radio" name="hux-autonomy-level" value={level}
            checked={selectedAutonomy === level} disabled={props.busy}
            onChange={() => {setAutonomy(level); setGrants({...selectedGrants});}} />
          <span><strong>{MODES[level].label}</strong><small>{MODES[level].help}</small></span>
        </label>)}
      </fieldset>
      <CapabilityMatrix grants={selectedGrants} busy={!!props.busy}
        setGrant={(capability, decision) => setGrants({...selectedGrants, [capability]: decision})} />
      <BudgetControls budget={selectedBudget} busy={!!props.busy} setBudget={setBudget} />
      <button className="hux-autonomy-save" type="submit" disabled={props.busy}>Save controls</button>
    </form>
    {page.rejectedApprovals > 0 && <p role="status" className="hux-autonomy-warning">
      Some approval requests were withheld because they were stale or out of scope.</p>}
    <ApprovalQueue items={page.approvals} busy={!!props.busy} decide={decide} />
    {receipt && <section className="hux-autonomy-receipt" aria-labelledby="hux-stop-receipt-title">
      <h3 id="hux-stop-receipt-title">Stop receipt</h3><p>Outcome: {receipt.outcome}.</p>
      <p>{receipt.stopped} effects reverted; {receipt.remaining} remain.</p>
      <ul>{receipt.effects.map((effect, index) => <li key={index}>
        {effect.description} — {effect.reverted ? "reverted" : "remaining"}</li>)}</ul>
      {receipt.omittedEffects > 0 && <p>{receipt.omittedEffects} additional effects omitted.</p>}
    </section>}
    <p className="sr-only" role="status" aria-live="polite">
      {props.busy ? "Updating autonomy controls" : `${page.approvals.length} approvals waiting`}
    </p>
  </section>;
}