<?php

namespace App\Http\Controllers\admin;

use App\Constants\Util;
use App\Constants\HttpStatus;
use App\Http\Controllers\Controller;
use Illuminate\Support\Facades\DB;
use Illuminate\Validation\ValidationException;
use Exception;
use App\Models\Banner as BannerModel;
use App\Services\BannerVisibilityService;
use App\Support\ContentLink;

class Banner extends Controller
{
    public const CLICK_TYPES = ['none' => '无链接', 'activity' => '跳转活动', 'external' => '外站链接', 'internal' => '站内相对路径'];

    /**
     * Resolve the submitted jump target. Omitting every link field keeps the saved one; old clients that
     * only send `link` get the type inferred from it (activity ID, `/path` or full URL).
     */
    private static function clickBehavior(array $params, BannerModel $banner): array
    {
        $current = $banner->exists ? BannerVisibilityService::links($banner->getAttributes())
            : ['click_type' => 'none', 'link' => null, 'link_pc' => null, 'link_h5' => null];
        $input = array_intersect_key($params, array_flip(ContentLink::FIELDS));
        if (!$input) return $current;

        if (array_key_exists('link', $input) && $input['link'] !== null) $input['link'] = trim((string) $input['link']);
        if (!array_key_exists('click_type', $input)) {
            $input['click_type'] = array_key_exists('link', $input)
                ? BannerVisibilityService::clickType(null, $input['link']) : $current['click_type'];
        }

        if ($input['click_type'] === 'activity') {
            $link = array_key_exists('link', $input) ? $input['link'] : ($current['click_type'] === 'activity' ? $current['link'] : null);
            $id = BannerVisibilityService::activityId($link);
            if ($id === null) throw ValidationException::withMessages(['link' => '请填写跳转活动ID']);
            return ['click_type' => 'activity', 'link' => $id, 'link_pc' => null, 'link_h5' => null];
        }
        // An activity-type row has no reusable external/internal link, so forSave sees it as "none".
        return ContentLink::forSave($input, $current['click_type'] === 'activity' ? [] : $current);
    }

    /**
     * @api {get} /admin/banner/index 轮播图列表
     * @apiGroup 轮播图管理
     * @apiUse result
     * @apiUse header
     * @apiVersion 1.0.0
     *
     * @apiParam {int} [page=1]
     * @apiParam {int} [limit=10]
     *
     */
    function index()
    {
        try {
            $params = request()->validate([
                'page' => ['sometimes', 'integer', 'min:1'],
                'limit' => ['sometimes', 'integer', 'min:1', 'max:200'],
                'type' => ['nullable', 'in:pc,app'],
                'platform' => ['nullable', 'in:pc,h5'],
                'status' => ['nullable', 'integer', 'in:0,1'],
                'lang' => ['nullable', 'string', 'max:10'],
            ]);
            $page = request()->input('page', 1);
            $limit = request()->input('limit', 15);
            $type = $params['type'] ?? '';
            if (isset($params['platform']) && $params['platform'] !== '') {
                // The existing mobile banner enum is "app"; H5 filtering preserves that storage contract.
                $platformType = $params['platform'] === 'pc' ? 'pc' : 'app';
                if ($type !== '' && $type !== $platformType) {
                    throw ValidationException::withMessages(['platform' => '平台与原类型筛选不一致']);
                }
                $type = $platformType;
            }

            $query = BannerModel::query();

            if ($type !== '') {
                $query->where('type', $type);
            }
            if (isset($params['lang']) && $params['lang'] !== '') {
                $query->where('lang', $params['lang']);
            }
            $query->orderByDesc('sort')->orderByDesc('id');
            if (isset($params['status']) && $params['status'] !== '') {
                // Stored manual status is not the linked activity's actual status. Filter before pagination.
                $rows = BannerVisibilityService::decorate($query->get());
                $rows = array_values(array_filter($rows, static fn ($row) => $row['status'] === (int) $params['status']));
                $count = count($rows);
                $list = array_slice($rows, ((int) $page - 1) * (int) $limit, (int) $limit);
            } else {
                $count = $query->count();
                $list = BannerVisibilityService::decorate($query->forPage($page, $limit)->get());
            }
        } catch (ValidationException $e) {
            return $this->error(HttpStatus::VALIDATION_FAILED, $e->validator->errors()->first());
        } catch (Exception $e) {
            return $this->error(HttpStatus::CUSTOM_ERROR, $e->getMessage());
        }
        return $this->success(['total' => $count, 'data' => $list]);
    }

    /**
     * @api {post} /admin/banner/update 修改
     * @apiDescription 更新或者新增都用这个接口
     * @apiGroup 轮播图管理
     * @apiUse result
     * @apiUse header
     * @apiVersion 1.0.0
     *
     */
    public function update()
    {
        DB::beginTransaction();
        try {
            $params = request()->validate([
                'id' => ['nullable', 'integer', 'min:1'],
                'title' => ['required'],
                'image' => ['required'],
                'click_type' => ['sometimes', 'string', 'in:' . implode(',', array_keys(self::CLICK_TYPES))],
                'link' => ['nullable', function ($attribute, $value, $fail) {
                    if ((!is_string($value) && !is_int($value)) || strlen((string) $value) > 2048) {
                        $fail('跳转ID或链接格式错误');
                    }
                }],
                'link_pc' => ['nullable', 'string', 'max:2048'],
                'link_h5' => ['nullable', 'string', 'max:2048'],
                'type' => ['required', 'in:pc,app'],
                'sort' => ['nullable', 'integer'],
                'lang' => ['required'],
                'status' => ['sometimes', 'integer', 'in:0,1'],
                'manual_status' => ['nullable', 'integer', 'in:0,1'],
            ], ['click_type.in' => '点击方式仅支持无链接、跳转活动、外站链接、站内相对路径']);
            $id = $params['id'] ?? null;
            $banner = $id === null ? new BannerModel() : BannerModel::where('id', $id)->lockForUpdate()->first();
            if (!$banner) throw new Exception('数据不存在', HttpStatus::CUSTOM_ERROR);

            $links = self::clickBehavior($params, $banner);
            $activityId = BannerVisibilityService::boundActivityId($links['click_type'], $links['link']);
            $previousActivityId = BannerVisibilityService::boundActivityId($banner->click_type, $banner->link);
            if ($activityId !== null && (!$banner->exists || $activityId !== $previousActivityId)) {
                if (!DB::table('activity_rewards')->where('id', $activityId)->exists()) {
                    throw ValidationException::withMessages(['link' => '绑定的活动不存在']);
                }
            }
            $manualStatus = $banner->status ?? 1;
            if ($activityId === null) {
                // Both the row button and the editor write status; a stale compatibility alias must not override it.
                $manualStatus = $params['status'] ?? $params['manual_status'] ?? $manualStatus;
            }
            $banner->fill([
                'title' => $params['title'],
                'image' => Util::replacePartInUrl($params['image']),
                'click_type' => $links['click_type'],
                'link' => $links['link'],
                'link_pc' => $links['link_pc'],
                'link_h5' => $links['link_h5'],
                'type' => $params['type'],
                'sort' => array_key_exists('sort', $params) ? ($params['sort'] ?? 0) : ($banner->sort ?? 0),
                'lang' => $params['lang'],
                'status' => $manualStatus,
            ])->save();
            DB::commit();
        } catch (ValidationException $e) {
            DB::rollBack();
            return $this->error(HttpStatus::VALIDATION_FAILED, $e->validator->errors()->first());
        } catch (Exception $e) {
            DB::rollBack();
            return $this->error(intval($e->getCode()), $e->getMessage());
        }
        return $this->success();
    }

    /** Change manual publication without resubmitting the banner form. */
    public function status()
    {
        try {
            $params = request()->validate([
                'id' => ['required', 'integer', 'min:1'],
                'status' => ['required_without:manual_status', 'integer', 'in:0,1'],
                'manual_status' => ['required_without:status', 'integer', 'in:0,1'],
            ]);
            DB::transaction(function () use ($params) {
                $banner = BannerModel::where('id', $params['id'])->lockForUpdate()->first();
                if (!$banner) throw new Exception('数据不存在', HttpStatus::CUSTOM_ERROR);
                if (BannerVisibilityService::boundActivityId($banner->click_type, $banner->link) !== null) {
                    throw new Exception('关联活动的 Banner 由活动状态自动控制，不能手动上下架', HttpStatus::CUSTOM_ERROR);
                }
                $banner->status = $params['status'] ?? $params['manual_status'];
                $banner->save();
            });
        } catch (ValidationException $e) {
            return $this->error(HttpStatus::VALIDATION_FAILED, $e->validator->errors()->first());
        } catch (Exception $e) {
            return $this->error(HttpStatus::CUSTOM_ERROR, $e->getMessage());
        }

        return $this->success();
    }


    /**
     * @api {post} /admin/banner/delete 删除
     * @apiGroup 轮播图管理
     * @apiUse result
     * @apiUse header
     * @apiVersion 1.0.0
     *
     * @apiParam {int} id 要删除的ID
     *
     */
    function delete()
    {
        DB::beginTransaction();
        try {
            request()->validate([
                'id' => ['required', 'integer', 'min:1', 'max:99999999'],
            ]);
            $id = request()->input('id', 0);
            $info = BannerModel::where('id', $id)->first();
            if (!$info) throw new Exception("数据不存在", HttpStatus::CUSTOM_ERROR);
            $info->delete();
            DB::commit();
        } catch (ValidationException $e) {
            DB::rollBack();
            return $this->error(HttpStatus::VALIDATION_FAILED, $e->validator->errors()->first());
        } catch (Exception $e) {
            DB::rollBack();
            return $this->error(intval($e->getCode()));
        }
        return $this->success();
    }


}