<?php

namespace App\Http\Controllers\Api\Admin\EmailTemplate;

use App\Http\Controllers\Controller;
use App\Models\Setting;
use App\Models\Template;
use Illuminate\Http\JsonResponse;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\DB;

class EmailTemplateController extends Controller
{
    public function index(Request $request): JsonResponse
    {
        $query = Template::with('invoiceTemplate:id,name,scenario')
            ->orderBy('scenario')
            ->orderBy('id');

        if ($request->filled('scenario')) {
            $query->where('scenario', $request->scenario);
        }

        $templates = $query->get()->map(fn($t) => $this->format($t));

        return response()->json(['error' => false, 'data' => $templates]);
    }

    public function show(int $id): JsonResponse
    {
        $template = Template::with('invoiceTemplate:id,name,scenario')->findOrFail($id);
        return response()->json(['error' => false, 'data' => $this->format($template)]);
    }

    public function store(Request $request): JsonResponse
    {
        $data = $request->validate([
            'name'                => 'nullable|string|max:255',
            'scenario'            => 'nullable|string|in:vm_credentials,renewal_reminder,news_notification,invoice_pdf',
            'format'              => 'nullable|in:html,json',
            'invoice_template_id' => 'nullable|integer|exists:template,id',
            'subject'             => 'nullable|string|max:255',
            'message'             => 'nullable|string',
            'status'              => 'boolean',
        ]);

        $template = DB::transaction(fn() => Template::create([
            'type_id'             => 0,
            'name'                => $data['name']                ?? null,
            'scenario'            => $data['scenario']            ?? null,
            'format'              => $data['format']              ?? 'html',
            'invoice_template_id' => $data['invoice_template_id'] ?? null,
            'subject'             => $data['subject']             ?? null,
            'message'             => $data['message']             ?? null,
            'status'              => $data['status']              ?? 1,
        ]));

        return response()->json([
            'error' => false, 'message' => 'Tạo template thành công.',
            'data'  => $this->format($template),
        ], 201);
    }

    public function update(Request $request, int $id): JsonResponse
    {
        $template = Template::findOrFail($id);

        $data = $request->validate([
            'name'                => 'sometimes|nullable|string|max:255',
            'scenario'            => 'sometimes|nullable|string|in:vm_credentials,renewal_reminder,news_notification,invoice_pdf',
            'format'              => 'sometimes|nullable|in:html,json',
            'invoice_template_id' => 'sometimes|nullable|integer|exists:template,id',
            'subject'             => 'sometimes|nullable|string|max:255',
            'message'             => 'sometimes|nullable|string',
            'status'              => 'sometimes|boolean',
        ]);

        DB::transaction(fn() => $template->update($data));

        return response()->json([
            'error' => false, 'message' => 'Cập nhật template thành công.',
            'data'  => $this->format($template->fresh(['invoiceTemplate'])),
        ]);
    }

    public function destroy(int $id): JsonResponse
    {
        DB::transaction(fn() => Template::findOrFail($id)->delete());
        return response()->json(['error' => false, 'message' => 'Đã xoá template.']);
    }

    // ── Email settings (scenario assignments) ─────────────────────────────────

    public function getEmailSettings(): JsonResponse
    {
        $setting = Setting::where('key', 'email_settings')->first();
        $value   = $setting ? json_decode($setting->value, true) : [];

        // Ensure mail_enabled defaults to true when not set
        if (!isset($value['mail_enabled'])) {
            $value['mail_enabled'] = true;
        }

        return response()->json(['error' => false, 'data' => $value]);
    }

    public function updateEmailSettings(Request $request): JsonResponse
    {
        $data = $request->validate([
            'vm_template_id'      => 'nullable|integer|exists:template,id',
            'renewal_template_id' => 'nullable|integer|exists:template,id',
            'news_template_id'    => 'nullable|integer|exists:template,id',
            'invoice_template_id' => 'nullable|integer|exists:template,id',
            'mail_enabled'        => 'sometimes|boolean',
        ]);

        $setting = Setting::firstOrNew(['key' => 'email_settings']);
        $current = $setting->value ? json_decode($setting->value, true) : [];
        $setting->value = json_encode(array_merge($current, $data));
        $setting->save();

        return response()->json(['error' => false, 'message' => 'Đã lưu cài đặt email.', 'data' => json_decode($setting->value, true)]);
    }

    // ── Invoice PDF preview ───────────────────────────────────────────────────

    public function previewInvoiceJson(int $id): JsonResponse
    {
        $template = Template::findOrFail($id);
        if ($template->scenario !== 'invoice_pdf' || $template->format !== 'json') {
            return response()->json(['error' => true, 'message' => 'Template này không phải invoice JSON.'], 422);
        }

        $config = json_decode($template->message ?? '{}', true);
        // Return the config + blade HTML preview
        $html = view('pdf.invoice-preview', compact('config'))->render();

        return response()->json(['error' => false, 'html' => $html]);
    }

    // ── Helpers ───────────────────────────────────────────────────────────────

    private function format(Template $t): array
    {
        return [
            'id'                  => $t->id,
            'type_id'             => $t->type_id,
            'name'                => $t->name,
            'scenario'            => $t->scenario,
            'scenario_label'      => Template::SCENARIOS[$t->scenario] ?? null,
            'format'              => $t->format ?? 'html',
            'invoice_template_id' => $t->invoice_template_id,
            'invoice_template_name' => $t->invoiceTemplate?->name,
            'subject'             => $t->subject,
            'message'             => $t->message,
            'status'              => $t->status,
            'created_at'          => $t->created_at,
            'updated_at'          => $t->updated_at,
        ];
    }
}