feat(cli): TUI slash command parsing + local commands (P8-009) (#176)

Co-authored-by: Jason Woltje <[email protected]>
Co-committed-by: Jason Woltje <[email protected]>

packages/cli/src/tui/commands/index.ts

@@ -0,0 +1,5 @@
+export { parseSlashCommand } from './parse.js';
+export { commandRegistry, CommandRegistry } from './registry.js';
+export { executeHelp } from './local/help.js';
+export { executeStatus } from './local/status.js';
+export type { StatusContext } from './local/status.js';

packages/cli/src/tui/commands/local/help.ts

@@ -0,0 +1,19 @@
+import type { ParsedCommand } from '@mosaic/types';
+import { commandRegistry } from '../registry.js';
+
+export function executeHelp(_parsed: ParsedCommand): string {
+  const commands = commandRegistry.getAll();
+  const lines = ['Available commands:', ''];
+
+  for (const cmd of commands) {
+    const aliases =
+      cmd.aliases.length > 0 ? ` (${cmd.aliases.map((a) => `/${a}`).join(', ')})` : '';
+    const argsStr =
+      cmd.args && cmd.args.length > 0
+        ? ' ' + cmd.args.map((a) => (a.optional ? `[${a.name}]` : `<${a.name}>`)).join(' ')
+        : '';
+    lines.push(`  /${cmd.name}${argsStr}${aliases} — ${cmd.description}`);
+  }
+
+  return lines.join('\n').trimEnd();
+}

packages/cli/src/tui/commands/local/status.ts

@@ -0,0 +1,20 @@
+import type { ParsedCommand } from '@mosaic/types';
+
+export interface StatusContext {
+  connected: boolean;
+  model: string | null;
+  provider: string | null;
+  sessionId: string | null;
+  tokenCount: number;
+}
+
+export function executeStatus(_parsed: ParsedCommand, ctx: StatusContext): string {
+  const lines = [
+    `Connection: ${ctx.connected ? 'connected' : 'disconnected'}`,
+    `Model: ${ctx.model ?? 'unknown'}`,
+    `Provider: ${ctx.provider ?? 'unknown'}`,
+    `Session: ${ctx.sessionId ?? 'none'}`,
+    `Tokens (session): ${ctx.tokenCount}`,
+  ];
+  return lines.join('\n');
+}

packages/cli/src/tui/commands/parse.ts

@@ -0,0 +1,11 @@
+import type { ParsedCommand } from '@mosaic/types';
+
+export function parseSlashCommand(input: string): ParsedCommand | null {
+  const match = input.match(/^\/([a-z][a-z0-9:_-]*)\s*(.*)?$/i);
+  if (!match) return null;
+  return {
+    command: match[1]!,
+    args: match[2]?.trim() || null,
+    raw: input,
+  };
+}

packages/cli/src/tui/commands/registry.ts

@@ -0,0 +1,98 @@
+import type { CommandDef, CommandManifest } from '@mosaic/types';
+
+// Local-only commands (work even when gateway is disconnected)
+const LOCAL_COMMANDS: CommandDef[] = [
+  {
+    name: 'help',
+    description: 'Show available commands',
+    aliases: ['h'],
+    args: undefined,
+    execution: 'local',
+    available: true,
+    scope: 'core',
+  },
+  {
+    name: 'stop',
+    description: 'Cancel current streaming response',
+    aliases: [],
+    args: undefined,
+    execution: 'local',
+    available: true,
+    scope: 'core',
+  },
+  {
+    name: 'cost',
+    description: 'Show token usage and cost for current session',
+    aliases: [],
+    args: undefined,
+    execution: 'local',
+    available: true,
+    scope: 'core',
+  },
+  {
+    name: 'status',
+    description: 'Show connection and session status',
+    aliases: ['s'],
+    args: undefined,
+    execution: 'local',
+    available: true,
+    scope: 'core',
+  },
+  {
+    name: 'clear',
+    description: 'Clear the current conversation display',
+    aliases: [],
+    args: undefined,
+    execution: 'local',
+    available: true,
+    scope: 'core',
+  },
+];
+
+const ALIASES: Record<string, string> = {
+  n: 'new',
+  m: 'model',
+  t: 'thinking',
+  a: 'agent',
+  s: 'status',
+  h: 'help',
+  pref: 'preferences',
+};
+
+export class CommandRegistry {
+  private gatewayManifest: CommandManifest | null = null;
+
+  updateManifest(manifest: CommandManifest): void {
+    this.gatewayManifest = manifest;
+  }
+
+  resolveAlias(command: string): string {
+    return ALIASES[command] ?? command;
+  }
+
+  find(command: string): CommandDef | null {
+    const resolved = this.resolveAlias(command);
+    // Search local first, then gateway manifest
+    const local = LOCAL_COMMANDS.find((c) => c.name === resolved || c.aliases.includes(resolved));
+    if (local) return local;
+    if (this.gatewayManifest) {
+      return (
+        this.gatewayManifest.commands.find(
+          (c) => c.name === resolved || c.aliases.includes(resolved),
+        ) ?? null
+      );
+    }
+    return null;
+  }
+
+  getAll(): CommandDef[] {
+    const gateway = this.gatewayManifest?.commands ?? [];
+    return [...LOCAL_COMMANDS, ...gateway];
+  }
+
+  getLocalCommands(): CommandDef[] {
+    return LOCAL_COMMANDS;
+  }
+}
+
+export const commandRegistry = new CommandRegistry();