<?php

namespace App\Http\Controllers\Api;

use App\Http\Controllers\Controller;
use App\Models\Guide;
use App\Models\GuidePage;
use App\Services\KnowledgeContextService;
use Illuminate\Http\JsonResponse;
use Illuminate\Http\Request;

class TerminalApiController extends Controller
{
    public function __construct(
        private KnowledgeContextService $knowledgeService,
    ) {}

    /**
     * GET /api/terminal/config
     * 返回终端配置
     */
    public function config(Request $request): JsonResponse
    {
        $terminal = $request->attributes->get('terminal');
        $terminal->load('prompt');

        // 返回原始提示词模板（占位符由HMI端替换）
        $systemPrompt = $terminal->prompt?->prompt_template ?? '';

        // 获取终端关联的已发布指引数量
        $guideCount = $terminal->guides()->published()->count();

        return response()->json([
            'terminal' => [
                'id' => $terminal->id,
                'name' => $terminal->name,
                'code' => $terminal->code,
                'station_id' => $terminal->station_id,
                'diagram_url' => $terminal->diagram_url,
                'scada_data_url' => $terminal->scada_data_url,
                'scada_tags_url' => $terminal->scada_tags_url,
                'voice_wakeup_enabled' => $terminal->voice_wakeup_enabled,
                'voice_wakeup_word' => $terminal->voice_wakeup_word,
            ],
            'system_prompt' => $systemPrompt,
            'guide_count' => $guideCount,
        ]);
    }

    /**
     * GET /api/knowledge?query=xxx
     * RAG知识搜索（由AI tool_call触发）
     */
    public function knowledge(Request $request): JsonResponse
    {
        $request->validate([
            'query' => 'required|string|max:500',
        ]);

        $result = $this->knowledgeService->search($request->input('query'));

        return response()->json($result);
    }

    /**
     * GET /api/terminal/guides?category=operation
     * 已发布的指引列表
     */
    public function guides(Request $request): JsonResponse
    {
        $terminal = $request->attributes->get('terminal');
        $query = $terminal->guides()->published()->withCount('pages');

        if ($category = $request->input('category')) {
            $query->where('category', $category);
        }

        $guides = $query->orderBy('name')->get()->map(fn(Guide $guide) => [
            'id' => $guide->id,
            'name' => $guide->name,
            'description' => $guide->description,
            'category' => $guide->category,
            'tags' => $guide->tags,
            'page_count' => $guide->pages_count,
        ]);

        return response()->json(['guides' => $guides]);
    }

    /**
     * POST /api/terminal/guides/pages
     * 组合多个指引的页面，返回递归树形结构
     */
    public function guidePages(Request $request): JsonResponse
    {
        $request->validate([
            'guide_ids' => 'required|array|min:1',
            'guide_ids.*' => 'integer|exists:guides,id',
        ]);

        $terminal = $request->attributes->get('terminal');
        $accessibleIds = $terminal->guides()->published()->pluck('guides.id')->toArray();

        $guideIds = $request->input('guide_ids');
        $pages = [];

        foreach ($guideIds as $guideId) {
            if (!in_array($guideId, $accessibleIds)) {
                continue;
            }

            $guide = Guide::with(
                $this->buildEagerLoadArray('trunkPages', 5)
            )->find($guideId);

            if (!$guide) {
                continue;
            }

            foreach ($guide->trunkPages as $page) {
                $pages = array_merge($pages, $this->flattenSequentialPages($page, $guide->name, $guide->id));
            }
        }

        return response()->json([
            'pages' => $pages,
            'total_pages' => count($pages),
        ]);
    }

    /**
     * 将树形页面结构展平：顺序节点（无 options）平铺，分支节点保留嵌套
     */
    private function flattenSequentialPages(GuidePage $page, string $guideName, int $guideId): array
    {
        $data = [
            'id'          => $page->id,
            'guide_id'    => $guideId,
            'guide_name'  => $guideName,
            'page_number' => $page->page_number,
            'title'       => $page->title,
            'html_url'    => $page->html_url,
        ];

        if ($page->options && $page->branchChildren->isNotEmpty()) {
            $data['options'] = $page->options;
            $branches = [];
            foreach ($page->branchChildren as $child) {
                $branches[$child->branch_option][] =
                    $this->buildPageTree($child, $guideName, $guideId);
            }
            $data['branches'] = $branches;
            return [$data];
        }

        if ($page->branchChildren->isNotEmpty()) {
            $result = [$data];
            foreach ($page->branchChildren as $child) {
                $result = array_merge($result, $this->flattenSequentialPages($child, $guideName, $guideId));
            }
            return $result;
        }

        return [$data];
    }

    private function buildPageTree(GuidePage $page, string $guideName, int $guideId): array
    {
        $data = [
            'id'          => $page->id,
            'guide_id'    => $guideId,
            'guide_name'  => $guideName,
            'page_number' => $page->page_number,
            'title'       => $page->title,
            'html_url'    => $page->html_url,
        ];

        if ($page->options && $page->branchChildren->isNotEmpty()) {
            $data['options'] = $page->options;
            $branches = [];
            foreach ($page->branchChildren as $child) {
                $branches[$child->branch_option][] =
                    $this->buildPageTree($child, $guideName, $guideId);
            }
            $data['branches'] = $branches;
        }

        return $data;
    }

    private function buildEagerLoadArray(string $base, int $depth): array
    {
        $loads = [$base => fn($q) => $q->orderBy('sort_order')];
        $current = $base;
        for ($i = 0; $i < $depth; $i++) {
            $current .= '.branchChildren';
            $loads[$current] = fn($q) => $q->orderBy('sort_order');
        }
        return $loads;
    }

    /**
     * POST /api/terminal/heartbeat
     * 终端心跳上报
     */
    public function heartbeat(Request $request): JsonResponse
    {
        $terminal = $request->attributes->get('terminal');

        $terminal->update([
            'is_online' => true,
            'last_online_at' => now(),
        ]);

        return response()->json(['status' => 'ok']);
    }
}