<?php
/**
 * Adds session approval-mode instructions to a model request.
 *
 * @package MazeAi
 * @since   0.1.1
 */

declare(strict_types=1);

namespace MazeAi\Chat;

defined('ABSPATH') || exit;

use MazeAi\Ai\ModelRequest;
use MazeAi\Kernel\Support\PermissionMode;
use MazeAi\Tools\Tool;

/**
 * The approval mode is runtime session input, independent of the swappable base context contract. This composer is
 * shared by the built-in context engine and the fallback for engines implementing ContextAssembler v1 only.
 *
 * @since 0.1.1
 */
final class PermissionModePrompt
{
    public static function apply(ModelRequest $request, string $permissionMode): ModelRequest
    {
        $mode = PermissionMode::normalize($permissionMode);
        $writes = array_filter($request->tools, static fn ($tool): bool => $tool instanceof Tool && !$tool->readOnly);
        if ($writes === []) {
            return $request;
        }
        $common = array_filter($writes, static fn (Tool $tool): bool => $tool->autoApprovable) !== [];
        $instruction = match ($mode) {
            PermissionMode::FULL => 'Permission mode: Full. You may use offered undoable write tools without a separate approval when policy allows. Site-content guardrails, the person\'s WordPress permissions and all other policy rules still apply; tools without undo are never available. Explain each change clearly.',
            PermissionMode::AUTO => $common
                ? 'Permission mode: Auto. Only offered tools explicitly marked common may run without a separate approval; other writes require approval. Site-content guardrails still require approval. Explain each change clearly.'
                : 'Permission mode: Auto. No offered write tool is marked common for automatic approval, so every write requires approval. Site-content guardrails still apply.',
            default => 'Permission mode: Ask. Every model-initiated write requires approval for its exact arguments. Explain the intended change before requesting approval.',
        };
        $system = rtrim($request->system) . "\n\n" . $instruction;

        return new ModelRequest($system, $request->messages, $request->tools, $request->model, $request->maxTokens, $request->stats);
    }
}