<?php
declare(strict_types=1);

class NormalBot
{
    public static function process(array $company, array $context, string $input): ?array
    {
        $config   = self::getConfig($company);
        $permType = (string)($company['_permission_type'] ?? 1);
        $perType  = $config['per_type'][$permType] ?? [];

        $commands = $perType['commands'] ?? $config['commands'] ?? [];
        $flows    = array_merge($config['flows'] ?? [], $perType['flows'] ?? []);
        $menus    = array_merge($config['menus'] ?? [], $perType['menus'] ?? []);

        $botCtx      = ConversationContext::getOrCreate((int)$company['id'], $context['from'], 'normal');
        $ctxId       = (int)$botCtx['id'];
        $currentNode = $botCtx['current_node'];
        $normalized  = self::normalize($input);

        // 1. Commands always win — escape from any state (salir, menu, etc.)
        foreach ($commands as $keyword => $action) {
            if ($normalized === self::normalize((string)$keyword)) {
                ConversationContext::updateNode($ctxId, $action);
                // Commands that match a flow
                if (isset($flows[$action])) {
                    return self::handleFlow($flows[$action], $context, $company, $ctxId, $menus);
                }
                // Commands that match a menu
                if (isset($menus[$action])) {
                    return self::buildMenuResponse($menus[$action], $context['from'], $company);
                }
                return null;
            }
        }

        // 2. Multi-step form: user is currently filling in fields
        $meta = ConversationContext::getMetadata($ctxId);
        if (!empty($meta['collecting'])) {
            return self::handleCollectingInput($meta, $input, 'text', $context, $company, $ctxId, $flows, $menus);
        }

        // 3. Active node — resume conversation
        $sentinels = ['collecting', '__greeted'];
        if ($currentNode !== null && !in_array($currentNode, $sentinels, true) && isset($flows[$currentNode])) {
            return self::handleFlow($flows[$currentNode], $context, $company, $ctxId, $menus);
        }

        // 4. Per-type greeting menu — only for brand-new sessions (currentNode === null)
        $greetingMenuKey = $perType['greeting_menu'] ?? null;
        if ($greetingMenuKey !== null && $currentNode === null && isset($menus[$greetingMenuKey])) {
            ConversationContext::updateNode($ctxId, '__greeted'); // sentinel: evita re-envío del menú
            return self::buildMenuResponse($menus[$greetingMenuKey], $context['from'], $company);
        }

        // 5. Greeting text
        $greeting = $perType['greeting'] ?? $config['greeting'] ?? null;
        if ($greeting !== null && $currentNode === null) {
            $greetingFlowId = $perType['greeting_flow'] ?? 'greeting';
            if (isset($flows[$greetingFlowId])) {
                ConversationContext::updateNode($ctxId, $greetingFlowId);
                return self::handleFlow($flows[$greetingFlowId], $context, $company, $ctxId, $menus);
            }
            $response = self::sendText($greeting, $context['from'], $company);
            ConversationContext::updateNode($ctxId, null);
            return $response;
        }

        // 6. Fallback flow
        $fallbackFlowId = $perType['fallback_flow'] ?? $config['fallback_flow'] ?? null;
        if ($fallbackFlowId !== null && isset($flows[$fallbackFlowId])) {
            ConversationContext::updateNode($ctxId, $fallbackFlowId);
            return self::handleFlow($flows[$fallbackFlowId], $context, $company, $ctxId, $menus);
        }

        // 7. Greeting menu as fallback (texto no reconocido después de estar en __greeted)
        if ($greetingMenuKey !== null && isset($menus[$greetingMenuKey])) {
            ConversationContext::updateNode($ctxId, '__greeted');
            return self::buildMenuResponse($menus[$greetingMenuKey], $context['from'], $company);
        }

        // 8. Static fallback text
        $fallback = $perType['fallback'] ?? $config['fallback'] ?? null;
        if ($fallback !== null) {
            ConversationContext::updateNode($ctxId, null);
            return self::sendText($fallback, $context['from'], $company);
        }

        return null;
    }

    // ── Multi-step collecting ────────────────────────────────────────────────

    private static function handleCollectingInput(
        array $meta, string $input, string $inputType,
        array $context, array $company, int $ctxId, array $flows, array $menus
    ): ?array {
        $col      = $meta['collecting'];
        $group    = $col['meta_group'] ?? '';
        $key      = $col['meta_key']   ?? '';
        $nextNode = $col['next_node']  ?? null;

        $formData        = $meta[$group] ?? [];
        $formData[$key]  = trim($input);
        $meta[$group]    = $formData;
        unset($meta['collecting']);
        ConversationContext::updateMetadata($ctxId, $meta);

        if ($nextNode !== null) {
            ConversationContext::updateNode($ctxId, $nextNode);
            if (isset($flows[$nextNode])) {
                return self::handleFlow($flows[$nextNode], $context, $company, $ctxId, $menus);
            }
        } else {
            ConversationContext::updateNode($ctxId, null);
        }
        return null;
    }

    private static function handleCollectInput(array $flow, array $context, array $company, int $ctxId): ?array
    {
        $meta               = ConversationContext::getMetadata($ctxId);
        $meta['collecting'] = [
            'meta_group' => $flow['meta_group'] ?? '',
            'meta_key'   => $flow['meta_key']   ?? '',
            'next_node'  => $flow['next_node']  ?? null,
        ];
        ConversationContext::updateMetadata($ctxId, $meta);
        ConversationContext::updateNode($ctxId, 'collecting');
        return self::sendText($flow['prompt'] ?? '¿Cuál es el valor?', $context['from'], $company);
    }

    // ── Dynamic list (from endpoint) ─────────────────────────────────────────

    private static function handleDynamicList(array $flow, array $context, array $company, int $ctxId): ?array
    {
        $meta  = ConversationContext::getMetadata($ctxId);
        $items = self::fetchDynamicList($flow['source_endpoint_key'] ?? '', $company, $meta);

        if ($items === null || count($items) === 0) {
            ConversationContext::reset($ctxId);
            return self::sendText(
                'No se pudieron cargar las opciones ahora. Escribe *menu* para volver.',
                $context['from'], $company
            );
        }

        $meta['collecting'] = [
            'meta_group' => $flow['meta_group'] ?? '',
            'meta_key'   => $flow['meta_key']   ?? '',
            'next_node'  => $flow['next_node']  ?? null,
        ];
        ConversationContext::updateMetadata($ctxId, $meta);
        ConversationContext::updateNode($ctxId, 'collecting');

        return self::buildDynamicListResponse($items, $flow, $context['from'], $company);
    }

    // Reemplaza {variable} en la URL con valores del metadata acumulado
    private static function substituteUrlVars(string $url, array $meta): string
    {
        foreach ($meta as $group => $fields) {
            if (!is_array($fields)) continue;
            foreach ($fields as $key => $value) {
                $url = str_replace('{' . $key . '}', urlencode((string)$value), $url);
            }
        }
        return $url;
    }

    private static function fetchDynamicList(string $endpointKey, array $company, array $meta = []): ?array
    {
        if ($endpointKey === '') return null;

        $stmt = db()->prepare(
            'SELECT url, method FROM company_endpoints WHERE company_id=? AND endpoint_key=? AND is_active=1 LIMIT 1'
        );
        $stmt->execute([(int)$company['id'], $endpointKey]);
        $ep = $stmt->fetch();
        if (!$ep || empty($ep['url'])) return null;

        $apiKey = $company['api_key'] ?? '';
        $url    = self::substituteUrlVars($ep['url'], $meta);
        $ch = curl_init($url);
        curl_setopt_array($ch, [
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_TIMEOUT        => 10,
            CURLOPT_HTTPHEADER     => [
                'Authorization: Bearer ' . $apiKey,
                'X-API-Key: ' . $apiKey,
            ],
        ]);
        $body = curl_exec($ch);
        $code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        curl_close($ch);

        if ($code !== 200 || !$body) return null;
        $data = json_decode($body, true);
        if (!is_array($data)) return null;
        // Accept both top-level array and {data: [...]}
        return isset($data['data']) && is_array($data['data']) ? $data['data'] : $data;
    }

    private static function buildDynamicListResponse(array $items, array $flow, string $to, array $company): ?array
    {
        $valueField = $flow['value_field'] ?? 'id';
        $labelField = $flow['label_field'] ?? 'name';

        $rows = [];
        foreach (array_slice($items, 0, 10) as $item) {
            $id    = (string)($item[$valueField] ?? '');
            $title = mb_substr((string)($item[$labelField] ?? $id), 0, 24);
            if ($id === '') continue;
            $rows[] = ['id' => $id, 'title' => $title];
        }

        if (empty($rows)) return null;

        $interactive = [
            'type'   => 'list',
            'header' => ['type' => 'text', 'text' => mb_substr($flow['header'] ?? 'Selecciona', 0, 60)],
            'body'   => ['text' => mb_substr($flow['body'] ?? 'Elige una opción:', 0, 1024)],
            'footer' => ['text' => mb_substr($company['display_name'] ?? '', 0, 60)],
            'action' => [
                'button'   => mb_substr($flow['button'] ?? 'Ver opciones', 0, 20),
                'sections' => [[
                    'title' => mb_substr($flow['section_title'] ?? 'Opciones', 0, 24),
                    'rows'  => $rows,
                ]],
            ],
        ];

        return self::enqueueInteractive($to, $interactive, $company);
    }

    // ── Submit form (end of multi-step collection) ───────────────────────────

    private static function handleSubmitForm(array $flow, array $context, array $company, int $ctxId): ?array
    {
        $meta  = ConversationContext::getMetadata($ctxId);
        $group = $flow['meta_group'] ?? '';

        $formData = $meta[$group] ?? [];
        unset($meta[$group], $meta['collecting']);
        ConversationContext::updateMetadata($ctxId, $meta);

        $params = [
            'endpoint_key' => $flow['endpoint_key'] ?? '',
            'caption'      => $flow['caption']       ?? 'Informe generado.',
            'filename'     => $flow['filename']      ?? 'reporte.pdf',
            'query'        => $formData,              // form fields become URL query params
        ];

        return self::executeApiReport($params, $context, $company, $ctxId);
    }

    // ── Flow dispatcher ──────────────────────────────────────────────────────

    private static function resolveMenu($menuRef, array $company, array $allMenus = []): array
    {
        if (is_string($menuRef)) {
            if (isset($allMenus[$menuRef])) return $allMenus[$menuRef];
            $config = self::getConfig($company);
            return ($config['menus'] ?? [])[$menuRef] ?? [];
        }
        return is_array($menuRef) ? $menuRef : [];
    }

    private static function handleFlow(array $flow, array $context, array $company, int $ctxId, array $menus = []): ?array
    {
        $type = $flow['type'] ?? 'text';

        return match ($type) {
            'text'         => self::sendText($flow['message'] ?? '', $context['from'], $company),
            'image'        => self::sendImage($flow['media_id'] ?? '', $flow['caption'] ?? null, $context['from'], $company),
            'menu'         => self::buildMenuResponse(self::resolveMenu($flow['menu'] ?? [], $company, $menus), $context['from'], $company),
            'function'     => self::executeFunction($flow['function'] ?? '', $flow['params'] ?? [], $context, $company, $ctxId),
            'collect_input' => self::handleCollectInput($flow, $context, $company, $ctxId),
            'dynamic_list' => self::handleDynamicList($flow, $context, $company, $ctxId),
            'submit_form'  => self::handleSubmitForm($flow, $context, $company, $ctxId),
            default        => null,
        };
    }

    // ── Functions ────────────────────────────────────────────────────────────

    private static function executeFunction(string $function, array $params, array $context, array $company, int $ctxId): ?array
    {
        return match ($function) {
            'reset' => (function () use ($ctxId, $context, $company) {
                ConversationContext::reset($ctxId);
                return self::sendText('¿En qué más puedo ayudarte?', $context['from'], $company);
            })(),
            'goodbye' => (function () use ($ctxId, $context, $company) {
                ConversationContext::reset($ctxId);
                return self::sendText("Hasta luego 👋\n\nEscribe *menu* cuando quieras volver.", $context['from'], $company);
            })(),
            'forward_to_ai' => null,
            'api_report'    => self::executeApiReport($params, $context, $company, $ctxId),
            default         => null,
        };
    }

    private static function executeApiReport(array $params, array $context, array $company, int $ctxId): ?array
    {
        $endpointKey = $params['endpoint_key'] ?? '';
        $nav = "\n\nEscribe *menu* para ver más opciones o *salir* para terminar.";

        if ($endpointKey === '') {
            ConversationContext::reset($ctxId);
            return self::sendText('Error: endpoint no configurado.' . $nav, $context['from'], $company);
        }

        $stmt = db()->prepare("SELECT url, method FROM company_endpoints WHERE company_id = ? AND endpoint_key = ? AND is_active = 1 LIMIT 1");
        $stmt->execute([(int)$company['id'], $endpointKey]);
        $ep = $stmt->fetch();

        if (!$ep || empty($ep['url'])) {
            self::log("API report: endpoint_key '{$endpointKey}' no configurado para company {$company['id']}");
            ConversationContext::reset($ctxId);
            return self::sendText('El informe solicitado no está configurado. Contacta al administrador.' . $nav, $context['from'], $company);
        }

        $meta   = ConversationContext::getMetadata($ctxId);
        $url    = self::substituteUrlVars($ep['url'], $meta); // reemplaza {var} con valores del formulario
        $method = strtoupper($ep['method'] ?? 'GET');
        $apiKey = $company['api_key'] ?? '';

        $extraQuery = $params['query'] ?? [];
        $dateMode   = $params['date_mode'] ?? '';
        if ($dateMode === 'today') {
            $extraQuery['fecha'] = date('Y-m-d');
        } elseif ($dateMode === 'last_30') {
            $extraQuery['fecha_inicio'] = date('Y-m-d', strtotime('-30 days'));
            $extraQuery['fecha_fin']    = date('Y-m-d');
        }
        $extraQuery['telefono'] = $context['from'];
        $extraQuery['nombre']   = $context['name'] ?? '';

        $glue  = str_contains($url, '?') ? '&' : '?';
        $url  .= $glue . http_build_query($extraQuery);

        $ch = curl_init($url);
        $curlOpts = [
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_FOLLOWLOCATION => true,
            CURLOPT_TIMEOUT        => 15,
            CURLOPT_HTTPHEADER     => [
                'Authorization: Bearer ' . $apiKey,
                'X-API-Key: ' . $apiKey,
                'User-Agent: bot-palmas360/1.0',
            ],
        ];
        if ($method === 'POST') {
            $curlOpts[CURLOPT_POST]       = true;
            $curlOpts[CURLOPT_POSTFIELDS] = '{}';
        }
        curl_setopt_array($ch, $curlOpts);
        $content     = curl_exec($ch);
        $httpCode    = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        $contentType = curl_getinfo($ch, CURLINFO_CONTENT_TYPE);
        $error       = curl_error($ch);
        curl_close($ch);

        if ($error) {
            self::log("API report error [{$endpointKey}]: {$error}");
            ConversationContext::reset($ctxId);
            return self::sendText('Error al obtener el reporte. Intenta de nuevo.' . $nav, $context['from'], $company);
        }

        if ($httpCode >= 400) {
            self::log("API report HTTP {$httpCode} [{$endpointKey}]: " . mb_substr($content, 0, 200));
            ConversationContext::reset($ctxId);
            return self::sendText('Error al obtener el reporte. Intenta de nuevo.' . $nav, $context['from'], $company);
        }

        $mimeMap = [
            'application/pdf'                                                        => ['pdf', 'application/pdf'],
            'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet'     => ['xlsx', 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet'],
            'application/vnd.ms-excel'                                              => ['xls', 'application/vnd.ms-excel'],
            'text/csv'                                                              => ['csv', 'text/csv'],
            'application/vnd.oasis.opendocument.spreadsheet'                        => ['ods', 'application/vnd.oasis.opendocument.spreadsheet'],
        ];

        $ext  = 'pdf';
        $mime = 'application/pdf';
        foreach ($mimeMap as $m => $info) {
            if (str_starts_with($contentType ?? '', $m)) {
                [$ext, $mime] = $info;
                break;
            }
        }

        $phoneNumberId = $company['phone_number_id'] ?? env('WHATSAPP_PHONE_NUMBER_ID', '');
        if ($phoneNumberId === '') {
            return self::sendText('Error: canal de envío no configurado.', $context['from'], $company);
        }

        $tmpFile = sys_get_temp_dir() . '/report_' . bin2hex(random_bytes(8)) . '.' . $ext;
        file_put_contents($tmpFile, $content);

        $upload = WhatsAppSender::uploadMedia($tmpFile, $mime, $phoneNumberId);

        if (!$upload['success'] || !$upload['media_id']) {
            self::log("API report upload failed [{$endpointKey}]: " . ($upload['error'] ?? 'unknown'));
            ConversationContext::reset($ctxId);
            return self::sendText('Error al enviar el reporte. Intenta de nuevo.' . $nav, $context['from'], $company);
        }

        $reportName = $params['filename'] ?? ('reporte.' . $ext);
        $caption    = $params['caption'] ?? 'Aquí tienes el reporte solicitado.';

        WhatsAppSender::sendDocument($context['from'], $upload['media_id'], $phoneNumberId, $caption, $reportName);
        ConversationContext::reset($ctxId);

        return self::sendText('✅ Reporte enviado.' . $nav, $context['from'], $company);
    }

    // ── Public helpers ───────────────────────────────────────────────────────

    public static function buildGreetingMenu(array $menu, string $to, array $company): ?array
    {
        return self::buildMenuResponse($menu, $to, $company);
    }

    // ── Interactive messages ─────────────────────────────────────────────────

    public static function processInteractive(array $company, array $context, string $input): ?array
    {
        $config   = self::getConfig($company);
        $permType = (string)($company['_permission_type'] ?? 1);
        $perType  = $config['per_type'][$permType] ?? [];
        $flows    = array_merge($config['flows'] ?? [], $perType['flows'] ?? []);
        $menus    = array_merge($config['menus'] ?? [], $perType['menus'] ?? []);

        $botCtx = ConversationContext::getOrCreate((int)$company['id'], $context['from'], 'normal');
        $ctxId  = (int)$botCtx['id'];

        // Multi-step form: interactive selection is the collected value
        $meta = ConversationContext::getMetadata($ctxId);
        if (!empty($meta['collecting'])) {
            return self::handleCollectingInput($meta, $input, 'interactive', $context, $company, $ctxId, $flows, $menus);
        }

        // Standard button/row resolution against static menus
        foreach ($flows as $flowId => $flow) {
            if (($flow['type'] ?? '') !== 'menu') continue;

            $menu = self::resolveMenu($flow['menu'] ?? [], $company, $menus);
            foreach ($menu['sections'] ?? [] as $section) {
                foreach ($section['rows'] ?? [] as $row) {
                    if (($row['id'] ?? '') === $input) {
                        ConversationContext::updateNode($ctxId, $row['id']);
                        if (isset($flows[$row['id']])) {
                            return self::handleFlow($flows[$row['id']], $context, $company, $ctxId, $menus);
                        }
                        return null;
                    }
                }
            }
            foreach ($menu['buttons'] ?? [] as $btn) {
                if (($btn['id'] ?? '') === $input) {
                    ConversationContext::updateNode($ctxId, $btn['id']);
                    if (isset($flows[$btn['id']])) {
                        return self::handleFlow($flows[$btn['id']], $context, $company, $ctxId, $menus);
                    }
                    return null;
                }
            }
        }

        // Direct flow match (button id == flow key)
        if (isset($flows[$input])) {
            ConversationContext::updateNode($ctxId, $input);
            return self::handleFlow($flows[$input], $context, $company, $ctxId, $menus);
        }

        return null;
    }

    // ── WhatsApp senders ─────────────────────────────────────────────────────

    private static function buildMenuResponse(array $menu, string $to, array $company): ?array
    {
        $menuType = $menu['type'] ?? 'list';

        if ($menuType === 'list') {
            $interactive = [
                'type'   => 'list',
                'header' => [
                    'type' => 'text',
                    'text' => mb_substr($menu['header'] ?? 'Menú', 0, 60),
                ],
                'body'   => ['text' => mb_substr($menu['body'] ?? 'Selecciona una opción:', 0, 1024)],
                'footer' => ['text' => mb_substr($menu['footer'] ?? $company['display_name'] ?? '', 0, 60)],
                'action' => [
                    'button'   => mb_substr($menu['button'] ?? 'Ver opciones', 0, 20),
                    'sections' => [],
                ],
            ];

            foreach ($menu['sections'] ?? [] as $section) {
                $rows = [];
                foreach ($section['rows'] ?? [] as $row) {
                    $rows[] = [
                        'id'          => mb_substr($row['id'] ?? '', 0, 200),
                        'title'       => mb_substr($row['title'] ?? '', 0, 24),
                        'description' => isset($row['description']) ? mb_substr($row['description'], 0, 72) : null,
                    ];
                }
                $interactive['action']['sections'][] = [
                    'title' => mb_substr($section['title'] ?? '', 0, 24),
                    'rows'  => $rows,
                ];
            }

            return self::enqueueInteractive($to, $interactive, $company);
        }

        if ($menuType === 'button') {
            $buttons = [];
            foreach (array_slice($menu['buttons'] ?? [], 0, 3) as $btn) {
                $buttons[] = [
                    'type'  => 'reply',
                    'reply' => [
                        'id'    => mb_substr($btn['id'] ?? '', 0, 256),
                        'title' => mb_substr($btn['title'] ?? '', 0, 20),
                    ],
                ];
            }

            $interactive = [
                'type'   => 'button',
                'body'   => ['text' => mb_substr($menu['body'] ?? 'Selecciona:', 0, 1024)],
                'action' => ['buttons' => $buttons],
            ];

            return self::enqueueInteractive($to, $interactive, $company);
        }

        return null;
    }

    private static function sendText(string $text, string $to, array $company): array
    {
        return ['action' => 'send', 'type' => 'text', 'to' => $to, 'payload' => json_encode(['text' => $text])];
    }

    private static function sendImage(string $mediaId, ?string $caption, string $to, array $company): array
    {
        return ['action' => 'send', 'type' => 'image', 'to' => $to, 'payload' => json_encode(['media_id' => $mediaId, 'caption' => $caption])];
    }

    private static function enqueueInteractive(string $to, array $interactive, array $company): array
    {
        return ['action' => 'send', 'type' => 'interactive', 'to' => $to, 'payload' => json_encode(['interactive' => $interactive])];
    }

    private static function getConfig(array $company): array
    {
        $json   = $company['config_json'] ?? '';
        $config = $json !== '' ? json_decode($json, true) : null;
        return is_array($config) ? $config : [];
    }

    private static function normalize(string $input): string
    {
        $input = mb_strtolower(trim($input));
        $input = str_replace(['á','é','í','ó','ú','ü','ñ'], ['a','e','i','o','u','u','n'], $input);
        return preg_replace('/[^a-z0-9\s]/', '', $input);
    }

    private static function log(string $msg): void
    {
        if (class_exists('WpWebhook')) WpWebhook::log('NORMALBOT', $msg);
    }
}