<?php

namespace App\Services;

use App\Http\Requests\LambdaRequest;
use App\Models\Session;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Log;

class SessionCommunicationService
{
    public const EMAIL_SUBJECT_PREFIX = 'CREST Research and Training Support';

    protected static $feedbackTemplateCodes = [
        'crest_thankyou_and_feedback',
        'crest_feedback_new',
        'post_impact_assessment',
        'pre_impact_assessment',
    ];

    /**
     * Normalize Lambda contact/get_all response items to a foreach-safe array.
     */
    public static function extractContactItems($response): array
    {
        if (!is_object($response) || !isset($response->data)) {
            return [];
        }

        if (!isset($response->data->items)) {
            return [];
        }

        $items = $response->data->items;

        if (is_array($items)) {
            return $items;
        }

        if (!is_object($items)) {
            return [];
        }

        // Single contact object stored in items (not a list wrapper).
        if (isset($items->id) && (isset($items->phone) || isset($items->name) || isset($items->email))) {
            return [$items];
        }

        return array_values((array) $items);
    }

    public function resolveSessionForMode($session): ?Session
    {
        if ($session instanceof Session) {
            return $session;
        }

        if (is_numeric($session)) {
            return Session::find((int) $session);
        }

        if (!is_object($session)) {
            return null;
        }

        if (!empty($session->session_id)) {
            $loaded = Session::find($session->session_id);
            if ($loaded) {
                return $loaded;
            }
        }

        if (!empty($session->code)) {
            $loaded = Session::where('code', $session->code)->first();
            if ($loaded) {
                return $loaded;
            }
        }

        if (!empty($session->id) && empty($session->template_code ?? null)) {
            return Session::find($session->id);
        }

        return null;
    }

    public function resolveMode($session): string
    {
        $sessionModel = $this->resolveSessionForMode($session);

        if (!$sessionModel) {
            if (is_object($session) && !empty($session->communication_mode)) {
                $mode = strtolower(trim((string) $session->communication_mode));
                if (in_array($mode, [Session::MODE_WHATSAPP, Session::MODE_EMAIL, Session::MODE_BOTH], true)) {
                    return $mode;
                }
            }

            return Session::MODE_WHATSAPP;
        }

        $mode = strtolower(trim((string) ($sessionModel->communication_mode ?? '')));

        if (!in_array($mode, [Session::MODE_WHATSAPP, Session::MODE_EMAIL, Session::MODE_BOTH], true)) {
            return Session::MODE_WHATSAPP;
        }

        return $mode;
    }

    public function resolveSessionId($session): int
    {
        $sessionModel = $this->resolveSessionForMode($session);
        if ($sessionModel) {
            return (int) $sessionModel->id;
        }

        if (is_object($session)) {
            return (int) ($session->session_id ?? $session->id ?? 0);
        }

        return (int) ($session['session_id'] ?? $session['id'] ?? 0);
    }

    public function shouldSendWhatsApp(string $mode): bool
    {
        return in_array($mode, [Session::MODE_WHATSAPP, Session::MODE_BOTH], true);
    }

    public function shouldSendEmail(string $mode): bool
    {
        return in_array($mode, [Session::MODE_EMAIL, Session::MODE_BOTH], true);
    }

    public function normalizeModeForSave(?string $mode): string
    {
        $mode = strtolower(trim((string) $mode));

        if (!in_array($mode, [Session::MODE_WHATSAPP, Session::MODE_EMAIL, Session::MODE_BOTH], true)) {
            return Session::MODE_WHATSAPP;
        }

        return $mode;
    }

    public function buildSessionVariables($session, $sendRow = null): array
    {
        $sessionModel = $this->resolveSessionForMode($session);
        $session = $sessionModel ?: (is_object($session) ? $session : (object) $session);

        return [
            'SESSION_NAME' => $session->number ?? '',
            'SESSION_DATE' => isset($session->start_date)
                ? date('d M, Y', strtotime($session->start_date))
                : '',
            'SESSION_TYPE' => strtoupper($session->type ?? ''),
            'SESSION_BROCHURE' => 'https://road.xltr.in/brochure/' . ($session->code ?? ''),
            'SESSION_CODE' => $session->code ?? '',
        ];
    }

    public function applyFeedbackSessionCode(string $sessionCode, $contact, string $templateCode): string
    {
        if (!in_array($templateCode, self::$feedbackTemplateCodes, true)) {
            return $sessionCode;
        }

        $contactId = is_object($contact) ? ($contact->id ?? '') : ($contact['id'] ?? '');

        return $sessionCode . '_' . $contactId;
    }

    public function buildContactVariables($contact, $session, $sendRow): array
    {
        $sessionVars = $this->buildSessionVariables($session, $sendRow);
        $templateCode = is_object($sendRow)
            ? ($sendRow->template_code ?? '')
            : ($sendRow['template_code'] ?? '');

        $sessionCode = $this->applyFeedbackSessionCode(
            $sessionVars['SESSION_CODE'],
            $contact,
            $templateCode
        );

        $sendId = is_object($sendRow) ? ($sendRow->id ?? 0) : ($sendRow['id'] ?? 0);

        $vars = array_merge($sessionVars, [
            'SESSION_CODE' => $sessionCode,
            'RECIPIENT_NAME' => is_object($contact) ? ($contact->name ?? '') : ($contact['name'] ?? ''),
            'CERT_PARAM' => (is_object($contact) ? ($contact->phone ?? '') : ($contact['phone'] ?? '')) . '_' . $sendId,
        ]);

        if (is_object($contact)) {
            foreach (get_object_vars($contact) as $key => $value) {
                if (is_string($key) && $key !== '' && !is_array($value) && !is_object($value)) {
                    $vars[strtoupper($key)] = (string) $value;
                }
            }
        }

        return $vars;
    }

    public function substituteParams(?string $pipeList, array $vars): array
    {
        if ($pipeList === null || $pipeList === '') {
            return [];
        }

        $params = explode('||', $pipeList);
        foreach ($params as &$var) {
            if (isset($vars[$var]) && $vars[$var] !== '') {
                $var = $vars[$var];
            }
        }

        return $params;
    }

    public function renderTemplateBody(string $body, array $vars, array $numericValues = []): string
    {
        $rendered = $body;

        foreach ($vars as $key => $value) {
            $rendered = str_replace('{{' . $key . '}}', $value, $rendered);
            $rendered = str_replace('{' . $key . '}', $value, $rendered);
        }

        foreach ($numericValues as $index => $value) {
            $placeholder = '{{' . ($index + 1) . '}}';
            $rendered = str_replace($placeholder, (string) $value, $rendered);
        }

        return $rendered;
    }

    /**
     * Ensure absolute URLs (e.g. road.xltr.in/path → https://road.xltr.in/path).
     */
    public function normalizeUrlScheme(string $url): string
    {
        $url = trim($url);
        if ($url === '') {
            return '';
        }

        if (!preg_match('#^https?://#i', $url)) {
            $url = 'https://' . ltrim($url, '/');
        }

        return $url;
    }

    public function buildButtonSection(array $buttonValues): string
    {
        if (empty($buttonValues)) {
            return '';
        }

        $lines = ["\n"];
        foreach ($buttonValues as $i => $value) {
            $value = trim((string) $value);
            if ($value === '') {
                continue;
            }
            if (filter_var($value, FILTER_VALIDATE_URL)) {
                $lines[] = 'Link: ' . $value;
            } else {
                $lines[] = $value;
            }
        }

        return implode("\n", $lines);
    }

    /**
     * Build email CTA button from template button_url / button_label + substituted params.
     */
    public function buildEmailCallToAction(array $config, array $vars, array $buttonParamValues = []): string
    {
        $urlTemplate = trim($config['button_url'] ?? '');
        $label = trim($config['button_label'] ?? '');

        if ($urlTemplate === '') {
            return '';
        }

        $url = $this->renderTemplateBody($urlTemplate, $vars, $buttonParamValues);
        $url = $this->normalizeUrlScheme($url);

        if (!filter_var($url, FILTER_VALIDATE_URL)) {
            $paramValue = trim((string) ($buttonParamValues[0] ?? ''));
            if ($paramValue !== '' && filter_var($this->normalizeUrlScheme($paramValue), FILTER_VALIDATE_URL)) {
                $url = $this->normalizeUrlScheme($paramValue);
            } elseif ($paramValue !== '') {
                $base = $this->normalizeUrlScheme(
                    $this->renderTemplateBody(rtrim($urlTemplate, '/'), $vars, $buttonParamValues)
                );
                $url = rtrim($base, '/') . '/' . ltrim($paramValue, '/');
            }
        }

        $url = $this->normalizeUrlScheme($url);

        if ($url === '' || !filter_var($url, FILTER_VALIDATE_URL)) {
            return '';
        }

        if ($label === '') {
            $label = 'Click here';
        }
        $label = $this->renderTemplateBody($label, $vars, $buttonParamValues);

        return '<table role="presentation" cellspacing="0" cellpadding="0" border="0" style="margin:28px auto 8px;">'
            . '<tr><td align="center" style="border-radius:6px;background-color:#1a3a5c;">'
            . '<a href="' . e($url) . '" target="_blank" rel="noopener noreferrer" '
            . 'style="display:inline-block;padding:14px 28px;font-size:15px;font-weight:bold;color:#ffffff;text-decoration:none;">'
            . e($label)
            . '</a></td></tr></table>';
    }

    public function buildInteraktTemplate(array $config, array $vars): array
    {
        if (!empty($config['header_values']) && is_array($config['header_values'])) {
            $headerParams = $config['header_values'];
        } else {
            $headerParams = $this->substituteParams($config['header_params'] ?? '', $vars);
        }

        $bodyParams = $this->substituteParams($config['body_params'] ?? '', $vars);
        $buttonParams = $this->substituteParams($config['button_params'] ?? '', $vars);

        $template = [
            'name' => $config['template_code'],
            'languageCode' => 'en',
        ];

        if (count($headerParams) > 0) {
            $template['headerValues'] = $headerParams;
        }
        if (count($bodyParams) > 0) {
            $template['bodyValues'] = $bodyParams;
        }
        if (count($buttonParams) > 0) {
            $template['buttonValues'] = (object) ['0' => $buttonParams];
        }

        return $template;
    }

    public function buildEmailBody(string $templateBody, array $vars, array $buttonValues = [], array $headerValues = [], array $numericValues = [], array $config = []): string
    {
        $body = $this->renderTemplateBody($templateBody, $vars, $numericValues);

        $imageHtml = '';
        foreach ($headerValues as $headerValue) {
            if (filter_var($headerValue, FILTER_VALIDATE_URL)) {
                $imageHtml .= '<p><img src="' . e($headerValue) . '" alt="Crest" style="max-width:100%;height:auto;" /></p>';
            }
        }

        $ctaHtml = $this->buildEmailCallToAction($config, $vars, $buttonValues);
        if ($ctaHtml === '') {
            $body .= $this->buildButtonSection($buttonValues);
        }

        return $imageHtml . nl2br(e($body)) . $ctaHtml;
    }

    public function buildEmailSubject($session, $sendRow): string
    {
        $sessionName = is_object($session) ? ($session->number ?? 'Session') : ($session['number'] ?? 'Session');
        $title = is_object($sendRow) ? ($sendRow->template_title ?? null) : ($sendRow['template_title'] ?? null);
        $prefix = self::EMAIL_SUBJECT_PREFIX;

        if (!empty($title)) {
            return $prefix . ' – ' . $title;
        }

        return $prefix . ' – ' . $sessionName;
    }

    public function contactEmail($contact): ?string
    {
        $candidates = [];
        if (is_object($contact)) {
            $candidates = [
                $contact->email ?? null,
                $contact->user_email ?? null,
                $contact->Email ?? null,
            ];
        } elseif (is_array($contact)) {
            $candidates = [
                $contact['email'] ?? null,
                $contact['user_email'] ?? null,
            ];
        }

        foreach ($candidates as $email) {
            $email = trim((string) $email);
            if ($email !== '' && filter_var($email, FILTER_VALIDATE_EMAIL)) {
                return $email;
            }
        }

        return null;
    }

    /**
     * Load full contact from Lambda when get_all omitted email (fields projection).
     */
    public function enrichContactEmail($contact)
    {
        if ($this->contactEmail($contact)) {
            return $contact;
        }

        $contactId = is_object($contact) ? ($contact->id ?? null) : ($contact['id'] ?? null);
        if (!$contactId) {
            return $contact;
        }

        try {
            $response = LambdaRequest::getrequest(
                'contact',
                'contact/get_one',
                ['id' => $contactId],
                env('LAMBDA_ACCESS_TOKEN', 'default_value')
            );

            if (!empty($response->data->item->email) && is_object($contact)) {
                $contact->email = $response->data->item->email;
            }
        } catch (\Throwable $e) {
            Log::warning('enrichContactEmail failed for contact ' . $contactId . ': ' . $e->getMessage());
        }

        return $contact;
    }

    public function queueWhatsApp($contact, int $sessionId, array $interaktPayload): void
    {
        $phone = is_object($contact) ? ($contact->phone ?? '') : ($contact['phone'] ?? '');
        $contactId = is_object($contact) ? ($contact->id ?? null) : ($contact['id'] ?? null);

        DB::table('raphiwa_send')->insert([
            'to' => $phone,
            'text' => json_encode($interaktPayload),
            'contact_id' => $contactId,
            'session_id' => $sessionId,
            'is_sent' => 0,
            'status' => 1,
            'created_at' => now(),
            'updated_at' => now(),
        ]);
    }

    public function queueEmail($contact, int $sessionId, string $subject, string $bodyHtml, ?string $templateCode = null): bool
    {
        $contact = $this->enrichContactEmail($contact);
        $email = $this->contactEmail($contact);
        if (!$email) {
            $contactId = is_object($contact) ? ($contact->id ?? 'unknown') : 'unknown';
            Log::info('email_send skipped: no valid email on contact', [
                'contact_id' => $contactId,
                'session_id' => $sessionId,
            ]);
            return false;
        }

        $contactId = is_object($contact) ? ($contact->id ?? null) : ($contact['id'] ?? null);

        DB::table('email_send')->insert([
            'to' => $email,
            'subject' => $subject,
            'body_html' => $bodyHtml,
            'contact_id' => $contactId,
            'session_id' => $sessionId,
            'template_code' => $templateCode,
            'is_sent' => 0,
            'status' => 1,
            'created_at' => now(),
            'updated_at' => now(),
        ]);

        return true;
    }

    public function queueEmailFromText($session, $contact, string $plainText, ?string $templateCode = null): bool
    {
        if (!$this->shouldSendEmail($this->resolveMode($session))) {
            return false;
        }

        $sessionId = is_object($session) ? (int) ($session->id ?? 0) : (int) ($session['id'] ?? 0);
        $subject = 'Crest – ' . (is_object($session) ? ($session->number ?? 'Message') : ($session['number'] ?? 'Message'));
        $bodyHtml = nl2br(e($plainText));

        return $this->queueEmail($contact, $sessionId, $subject, $bodyHtml, $templateCode);
    }

    public function dispatchForContact($session, $contact, array $config): void
    {
        $sessionModel = $this->resolveSessionForMode($session);
        $mode = $this->resolveMode($session);
        $sessionId = $this->resolveSessionId($session);
        $vars = $this->buildContactVariables($contact, $sessionModel ?: $session, $config);

        if (!empty($config['header_values']) && is_array($config['header_values'])) {
            $headerParams = $config['header_values'];
        } else {
            $headerParams = $this->substituteParams($config['header_params'] ?? '', $vars);
        }

        $bodyParams = $this->substituteParams($config['body_params'] ?? '', $vars);
        $buttonParams = $this->substituteParams($config['button_params'] ?? '', $vars);

        if ($this->shouldSendWhatsApp($mode)) {
            $phone = is_object($contact) ? ($contact->phone ?? '') : ($contact['phone'] ?? '');
            $contactId = is_object($contact) ? ($contact->id ?? '') : ($contact['id'] ?? '');

            $template = $this->buildInteraktTemplate($config, $vars);
            $params = [
                'countryCode' => '+91',
                'phoneNumber' => $phone,
                'callbackData' => $phone . '_' . $contactId,
                'type' => 'Template',
                'template' => $template,
            ];

            $this->queueWhatsApp($contact, $sessionId, $params);
        }

        if ($this->shouldSendEmail($mode)) {
            $templateBody = trim($config['template_body'] ?? '');
            if ($templateBody !== '') {
                $bodyHtml = $this->buildEmailBody($templateBody, $vars, $buttonParams, $headerParams, $bodyParams, $config);
                $subject = $this->buildEmailSubject($sessionModel ?: $session, $config);
                $this->queueEmail(
                    $contact,
                    $sessionId,
                    $subject,
                    $bodyHtml,
                    $config['template_code'] ?? null
                );
            } else {
                Log::warning('email_send skipped: empty template_body', [
                    'session_id' => $sessionId,
                    'template_code' => $config['template_code'] ?? null,
                ]);
            }
        }
    }

    public function dispatchPlainText($session, $contact, string $message, bool $sendWhatsApp = true): void
    {
        $mode = $this->resolveMode($session);
        $sessionId = is_object($session) ? (int) ($session->id ?? 0) : (int) ($session['id'] ?? 0);

        if ($sendWhatsApp && $this->shouldSendWhatsApp($mode)) {
            $phone = is_object($contact) ? ($contact->phone ?? '') : ($contact['phone'] ?? '');
            $params = [
                'countryCode' => '+91',
                'phoneNumber' => $phone,
                'callbackData' => 'email_mirror',
                'type' => 'Text',
                'data' => ['message' => $message],
            ];
            $this->queueWhatsApp($contact, $sessionId, $params);
        }

        if ($this->shouldSendEmail($mode)) {
            $this->queueEmailFromText($session, $contact, $message);
        }
    }
}