<?php

namespace App\Signature;

use App\Models\Assignment;
use App\Models\Campaign;
use App\Models\DirectoryUser;
use App\Models\EditableField;
use App\Models\SharedMailbox;
use App\Models\Template;

/**
 * Calcule la signature d'un agent pour un contexte de rédaction donné.
 * Tout est lu dans la base locale (synchro Graph) : aucun appel Graph en direct.
 */
final class SignatureBuilder
{
    public function __construct(
        private readonly TemplateRenderer $renderer,
        private readonly TemplateSelector $selector,
    ) {}

    /**
     * @param  string  $context  new | reply | forward | appointment
     * @param  string|null  $mailbox  adresse émettrice (boîte partagée éventuelle)
     * @return array{html:string, variant:string, template:string}|null
     */
    public function build(DirectoryUser $user, string $context, ?string $mailbox = null): ?array
    {
        $shared = $this->sharedMailbox($user, $mailbox);
        $template = $shared?->template ?? $this->templateFor($user);
        if (! $template) {
            return null;
        }

        $variant = $this->variant($user, $context);
        if ($variant === 'none') {
            return ['html' => '', 'variant' => 'none', 'template' => $template->name];
        }

        $source = $variant === 'short' ? ($template->html_short ?: $template->html_full) : $template->html_full;
        if (! $source) {
            return null;
        }

        $vars = $this->variables($user, $variant);

        if ($shared) {
            // Boîte partagée : ses propres coordonnées, l'agent seulement si l'admin l'a choisi.
            $vars['boite_nom'] = $shared->display_name;
            $vars['boite_email'] = $shared->address;
            $vars['email'] = $shared->address;
            if (! $shared->include_sender) {
                foreach (['prenom', 'nom', 'nom_complet', 'fonction', 'mobile'] as $k) {
                    $vars[$k] = null;
                }
            }
        }

        return [
            'html' => $this->renderer->render($source, $vars),
            'variant' => $variant,
            'template' => $template->name,
        ];
    }

    /** Variables d'un agent (attributs Entra + surcharges autorisées + bannière en variante complète). */
    public function variables(DirectoryUser $user, string $variant = 'full'): array
    {
        $vars = VariableMap::build($user->getAttributes(), $this->allowedOverrides($user));
        $vars['banniere'] = $variant === 'full' ? $this->bannerHtml($user) : '';
        $vars['site_url'] = config('signature.public_url');

        return $vars;
    }

    /** Aperçu d'un HTML brut (brouillon en cours d'édition) pour un agent donné. */
    public function preview(DirectoryUser $user, string $source, string $variant = 'full'): string
    {
        return $this->renderer->render($source, $this->variables($user, $variant));
    }

    public function templateFor(DirectoryUser $user): ?Template
    {
        $assignments = Assignment::query()
            ->where('tenant_id', $user->tenant_id)
            ->get(['id', 'template_id', 'directory_group_id', 'priority'])
            ->map(fn ($a) => [
                'id' => $a->id,
                'template_id' => $a->template_id,
                'group_id' => $a->directory_group_id,
                'priority' => $a->priority,
            ])->all();

        $default = Template::where('tenant_id', $user->tenant_id)->where('is_default', true)->value('id');
        $id = $this->selector->select($assignments, $user->groups()->pluck('directory_groups.id')->all(), $default);

        return $id ? Template::whereNotNull('html_full')->find($id) : null;
    }

    private function variant(DirectoryUser $user, string $context): string
    {
        if ($context !== 'reply' && $context !== 'forward') {
            return 'full';
        }
        $pref = $user->preference?->reply_variant ?? config('signature.default_reply_variant', 'short');

        return in_array($pref, ['short', 'full', 'none'], true) ? $pref : 'short';
    }

    /** Surcharges saisies par l'agent, limitées aux champs que l'admin a ouverts. */
    private function allowedOverrides(DirectoryUser $user): array
    {
        $enabled = EditableField::where('tenant_id', $user->tenant_id)->where('enabled', true)->pluck('field')->all();

        return $user->overrides()->whereIn('field', $enabled)->pluck('value', 'field')->all();
    }

    private function sharedMailbox(DirectoryUser $user, ?string $mailbox): ?SharedMailbox
    {
        if (! $mailbox) {
            return null;
        }
        $mailbox = strtolower($mailbox);
        if ($mailbox === strtolower((string) $user->mail) || $mailbox === strtolower((string) $user->user_principal_name)) {
            return null;
        }

        return SharedMailbox::with('template')->where('tenant_id', $user->tenant_id)->where('address', $mailbox)->first();
    }

    private function bannerHtml(DirectoryUser $user): string
    {
        $groupIds = $user->groups()->pluck('directory_groups.id')->all();

        $campaign = Campaign::running()
            ->where('tenant_id', $user->tenant_id)
            ->where(fn ($q) => $q->whereDoesntHave('groups')
                ->orWhereHas('groups', fn ($g) => $g->whereIn('directory_groups.id', $groupIds)))
            ->orderByDesc('priority')->orderBy('id')
            ->first();

        if (! $campaign) {
            return '';
        }

        $src = htmlspecialchars(config('signature.public_url').'/img/'.ltrim($campaign->image_path, '/'), ENT_QUOTES);
        $alt = htmlspecialchars($campaign->alt_text, ENT_QUOTES);
        $img = "<img src=\"{$src}\" alt=\"{$alt}\" width=\"600\" style=\"display:block;max-width:100%;height:auto;border:0\">";

        return $campaign->link_url
            ? '<a href="'.htmlspecialchars($campaign->link_url, ENT_QUOTES).'">'.$img.'</a>'
            : $img;
    }
}