<?php

namespace App\Models;

use App\Support\EmailScenarioRegistry;
use App\Support\EmailTemplateShell;
use App\Support\MailGlobals;
use App\Support\MailPlaceholders;
use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;
use Illuminate\Support\Facades\Cache;

class Template extends Model
{
    use HasFactory;

    public const CACHE_PREFIX = 'email_template:';

    protected $table = 'template';

    protected $fillable = [
        'type_id',
        'scenario',
        'key',
        'format',
        'invoice_template_id',
        'name',
        'subject',
        'message',
        'metadata',
        'builder_data',
        'status',
    ];

    protected $casts = [
        'status'       => 'integer',
        'metadata'     => 'array',
        'builder_data' => 'array',
    ];

    protected static function booted(): void
    {
        static::saved(fn (self $template) => $template->forgetCache());
        static::deleted(fn (self $template) => $template->forgetCache());
    }

    public function forgetCache(): void
    {
        if ($this->scenario) {
            Cache::forget(self::CACHE_PREFIX . $this->scenario);
        }
        if ($this->key) {
            Cache::forget(self::CACHE_PREFIX . $this->key);
        }
    }

    public function isMarketing(): bool
    {
        return EmailScenarioRegistry::describe($this->key, $this->scenario)['category'] === EmailScenarioRegistry::MARKETING;
    }

    /** Danh sách variable hợp lệ khai báo trong metadata.variables, key theo variable key. */
    public function variables(): array
    {
        return collect($this->metadata['variables'] ?? [])->keyBy('key')->all();
    }

    /**
     * @param array<int, array{key: string, label?: string|null, example?: string|null}> $overrides
     */
    public function syncVariables(array $overrides = []): void
    {
        $declared = $this->variables();
        $used = MailPlaceholders::extract($this->subject, $this->message);
        $overrides = collect($overrides)->keyBy('key');

        $variables = collect(array_unique([...array_keys($declared), ...$used]))
            ->reject(fn (string $key) => ($declared[$key]['custom'] ?? false) && !in_array($key, $used, true))
            ->map(function (string $key) use ($declared, $overrides) {
                $variable = $declared[$key] ?? ['key' => $key, 'label' => MailGlobals::LABELS[$key] ?? $key, 'type' => 'string', 'custom' => true];
                $override = $overrides->get($key, []);

                if (filled($override['label'] ?? null)) {
                    $variable['label'] = trim($override['label']);
                }
                if (array_key_exists('example', $override)) {
                    $variable['example'] = (string) $override['example'];
                }

                return $variable;
            })
            ->values()
            ->all();

        $this->metadata = [...($this->metadata ?? []), 'variables' => $variables];
    }

    /** Mail sender config khai báo trong metadata.mail (from_email, from_name, reply_to, reply_to_name, cc, bcc). */
    public function mailConfig(): array
    {
        return $this->metadata['mail'] ?? [];
    }

    public function invoiceTemplate()
    {
        return $this->belongsTo(self::class, 'invoice_template_id');
    }

    /**
     * Wrap $contentHtml with the admin-editable "layout" template (scenario=layout),
     * replacing its {{$content}} placeholder.
     *
     * Không còn fallback về blade: mọi email đều render từ tbl.template. Thiếu layout thì
     * dùng khung header/footer chuẩn trong code thay vì gửi ra nội dung trần.
     */
    public static function renderWithLayout(?string $subject, string $contentHtml): string
    {
        return EmailTemplateShell::document($subject, self::layoutBody($contentHtml));
    }

    public static function layoutBody(string $contentHtml): string
    {
        $layout = self::where('scenario', 'layout')->where('status', 1)->first();

        return $layout && $layout->message
            ? str_replace('{{$content}}', $contentHtml, $layout->message)
            : EmailTemplateShell::wrap(EmailTemplateShell::body($contentHtml));
    }

    public function type()
    {
        return $this->belongsTo(\App\Models\Type::class);
    }
}