<?php

declare(strict_types=1);

namespace App\Models;

use App\Support\MediaDisk;
use Illuminate\Database\Eloquent\Builder;
use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Relations\BelongsTo;
use Illuminate\Database\Eloquent\Relations\HasMany;
use Spatie\MediaLibrary\HasMedia;
use Spatie\MediaLibrary\InteractsWithMedia;
use Spatie\MediaLibrary\MediaCollections\Models\Media;
use Spatie\Tags\HasTags;
use Xpier\FilamentMediaLibrary\Models\MediaLibrary;

class Post extends Model implements HasMedia
{
    use HasFactory;
    use HasTags;
    use InteractsWithMedia;

    protected $fillable = [
        'category_id',
        'user_id',
        'title',
        'slug',
        'excerpt',
        'content',
        'content_format',
        'keywords',
        'cover_media_id',
        'status',
        'is_sticky',
        'sticky_level',
        'close_comment',
        'read_password',
        'views',
        'comment_count',
        'meta',
        'published_at',
    ];

    protected $casts = [
        'meta' => 'array',
        'is_sticky' => 'boolean',
        'sticky_level' => 'integer',
        'close_comment' => 'boolean',
        'published_at' => 'datetime',
    ];

    public const STICKY_NONE = 0;

    public const STICKY_LIGHT = 1;

    public const STICKY_STRONG = 2;

    public const STICKY_HEADLINE = 3;

    /**
     * @return array<int, string>
     */
    public static function stickyLevelOptions(): array
    {
        return [
            self::STICKY_NONE => '不置顶',
            self::STICKY_LIGHT => '轻置顶',
            self::STICKY_STRONG => '强置顶',
            self::STICKY_HEADLINE => '置顶头条',
        ];
    }

    public function stickyLabel(): ?string
    {
        $level = (int) $this->sticky_level;

        return $level > 0 ? (self::stickyLevelOptions()[$level] ?? '置顶') : null;
    }

    public function isPinned(): bool
    {
        return (int) $this->sticky_level > 0 || $this->is_sticky;
    }

    protected static function booted(): void
    {
        static::saving(function (Post $post): void {
            $level = (int) ($post->sticky_level ?? 0);
            $post->sticky_level = max(self::STICKY_NONE, min(self::STICKY_HEADLINE, $level));

            if ($post->is_sticky && $post->sticky_level < self::STICKY_LIGHT) {
                $post->sticky_level = self::STICKY_LIGHT;
            }

            $post->is_sticky = $post->sticky_level > self::STICKY_NONE;
        });
    }

    public function scopeOrderedForList(Builder $query): Builder
    {
        return $query->orderByDesc('sticky_level')->latest('published_at');
    }

    public function category(): BelongsTo
    {
        return $this->belongsTo(Category::class);
    }

    public function author(): BelongsTo
    {
        return $this->belongsTo(User::class, 'user_id');
    }

    public function coverMedia(): BelongsTo
    {
        return $this->belongsTo(MediaLibrary::class, 'cover_media_id');
    }

    public function coverImageUrl(?string $conversion = 'card'): ?string
    {
        $libraryUrl = $this->coverMedia?->url;
        if (filled($libraryUrl)) {
            return (string) $libraryUrl;
        }

        $cover = $this->getFirstMedia('cover');
        if ($cover === null) {
            return null;
        }

        return $cover->getUrl($conversion) ?: $cover->getUrl();
    }

    /**
     * 封面回退链：显式封面 → 附件/正文里的第一张图。
     * 都没有时返回 null，由调用方决定兜底（占位图或不显示）。
     */
    public function coverOrFirstImageUrl(): ?string
    {
        if ($url = $this->coverImageUrl()) {
            return $url;
        }

        // 附件里的第一张图片
        $attachment = $this->getMedia('attachments')
            ->first(fn ($m) => str_starts_with((string) $m->mime_type, 'image/'));
        if ($attachment) {
            return $attachment->getUrl();
        }

        // 正文 HTML/Markdown 里的第一张图片地址
        $content = (string) $this->content;
        if (preg_match('/<img[^>]+src=["\']([^"\']+)["\']/i', $content, $m)) {
            return $m[1];
        }
        if (preg_match('/!\[[^\]]*\]\((https?:\/\/[^)\s]+)[^)]*\)/i', $content, $m)) {
            return $m[1];
        }

        return null;
    }

    public function comments(): HasMany
    {
        return $this->hasMany(Comment::class);
    }

    public function scopePublished(Builder $query): Builder
    {
        return $query->where('status', 'published')
            ->whereNotNull('published_at')
            ->where('published_at', '<=', now());
    }

    public function scopeSearch(Builder $query, ?string $keyword): Builder
    {
        if (! $keyword) {
            return $query;
        }

        return $query->where(function (Builder $q) use ($keyword) {
            $q->where('title', 'like', "%{$keyword}%")
                ->orWhere('content', 'like', "%{$keyword}%")
                ->orWhere('excerpt', 'like', "%{$keyword}%")
                ->orWhere('keywords', 'like', "%{$keyword}%");
        });
    }

    public function registerMediaCollections(): void
    {
        $this->addMediaCollection('attachments')->useDisk(MediaDisk::name());
        $this->addMediaCollection('cover')->useDisk(MediaDisk::name())
            ->singleFile()
            ->registerMediaConversions(function () {
                $this->addMediaConversion('card')->width(1200)->height(630)->sharpen(1);
            });
    }

    public function registerMediaConversions(?Media $media = null): void
    {
        [$tw, $th] = array_pad(explode('x', strtolower((string) blog_setting('attachments_thumbs_size', '500x500'))), 2, '500');
        $this->addMediaConversion('thumb')
            ->width((int) $tw)
            ->height((int) $th)
            ->performOnCollections('attachments');
    }

    public function getUrlAttribute(): string
    {
        return route('posts.show', $this->id);
    }

    /**
     * 作为可购买实体（单篇解锁）的展示约定。
     */
    public function payableLabel(): string
    {
        return '文章：'.$this->title;
    }

    public function payableUrl(): ?string
    {
        return route('filament.admin.resources.posts.edit', $this);
    }

    public function getExcerptOrFallbackAttribute(): string
    {
        if ($this->excerpt) {
            return $this->excerpt;
        }

        // 会员专享文章不落入内容摘要，避免泄漏到 paywall/SEO meta
        if (! empty(($this->meta ?? [])['members_only'])) {
            return '';
        }

        $text = (new \App\Blog\Support\SablogHtmlNormalizer)->plainText((string) $this->content);
        // 付费块不进入摘要，避免付费内容泄漏到列表页/SEO meta
        $text = preg_replace('/\[paid\].*?\[\/paid\]/s', '', $text) ?? $text;
        $text = preg_replace('/!\[([^\]]*)\]\((?:media|attach):\d+\)/i', '$1', $text) ?? $text;
        $text = preg_replace('/\[([^\]]*)\]\((?:media|attach):\d+\)/i', '$1', $text) ?? $text;
        $text = preg_replace('/\[[^\]]*\]/', '', $text) ?? $text;

        return mb_substr(trim($text), 0, 200);
    }
}