<?php
/**
 * AJAX API voor AI Co-Pilot (Release v1.5)
 */

require_once __DIR__ . '/../includes/auth.php';
require_once __DIR__ . '/../includes/ai.php';
require_once __DIR__ . '/../includes/settings.php';

$user = require_auth();
$db = get_db_connection();

header('Content-Type: application/json');

$action = $_GET['action'] ?? ($_POST['action'] ?? '');

try {
    // 1. Auto-categoriseer kaartjes in een brainstormsessie
    if ($action === 'categorize_cards') {
        $data = json_decode(file_get_contents('php://input'), true);
        $sessionId = (int)($data['session_id'] ?? 0);

        if (!$sessionId) {
            echo json_encode(['error' => 'Sessie ID ontbreekt']);
            exit;
        }

        $stmtSession = $db->prepare("SELECT * FROM brainstorm_sessions WHERE id = ?");
        $stmtSession->execute([$sessionId]);
        $session = $stmtSession->fetch();

        if (!$session) {
            echo json_encode(['error' => 'Sessie niet gevonden']);
            exit;
        }

        $stmtCards = $db->prepare("SELECT id, content, category FROM brainstorm_cards WHERE session_id = ?");
        $stmtCards->execute([$sessionId]);
        $cards = $stmtCards->fetchAll();

        if (empty($cards)) {
            echo json_encode(['error' => 'Er zijn nog geen kaartjes op het canvas om te categoriseren']);
            exit;
        }

        $aiRes = fociz_ai_categorize_cards($session['title'], $session['theme'] ?? 'Algemeen', $cards, $user['id']);

        if (!$aiRes['success']) {
            echo json_encode(['error' => $aiRes['error']]);
            exit;
        }

        $validCategories = ['Ideeën', 'Knelpunten', 'Oplossingen', 'Quick Wins'];
        $updateStmt = $db->prepare("UPDATE brainstorm_cards SET category = ? WHERE id = ? AND session_id = ?");
        $updatedCount = 0;

        foreach ($aiRes['categorized'] as $item) {
            $cardId = (int)($item['id'] ?? 0);
            $newCat = trim($item['category'] ?? '');
            if ($cardId > 0 && in_array($newCat, $validCategories)) {
                $updateStmt->execute([$newCat, $cardId, $sessionId]);
                $updatedCount++;
            }
        }

        echo json_encode(['success' => true, 'updated' => $updatedCount]);
        exit;
    }

    // 2. Automatisch ideeën genereren voor een sessie
    if ($action === 'generate_ideas') {
        $data = json_decode(file_get_contents('php://input'), true);
        $sessionId = (int)($data['session_id'] ?? 0);
        $count = min(6, max(2, (int)($data['count'] ?? 4)));

        if (!$sessionId) {
            echo json_encode(['error' => 'Sessie ID ontbreekt']);
            exit;
        }

        $stmtSession = $db->prepare("SELECT * FROM brainstorm_sessions WHERE id = ?");
        $stmtSession->execute([$sessionId]);
        $session = $stmtSession->fetch();

        if (!$session) {
            echo json_encode(['error' => 'Sessie niet gevonden']);
            exit;
        }

        $aiRes = fociz_ai_generate_ideas($session['title'], $session['theme'] ?? 'Algemeen', $count, $user['id']);

        if (!$aiRes['success']) {
            echo json_encode(['error' => $aiRes['error']]);
            exit;
        }

        $insertStmt = $db->prepare("
            INSERT INTO brainstorm_cards (session_id, content, category, color, author_name, votes)
            VALUES (?, ?, 'Ideeën', 'amber', ?, 1)
        ");

        $createdCards = [];
        $authorName = 'AI Co-Pilot';

        foreach ($aiRes['ideas'] as $ideaText) {
            $ideaText = trim($ideaText);
            if (!empty($ideaText)) {
                $insertStmt->execute([$sessionId, $ideaText, $authorName]);
                $createdCards[] = [
                    'id'          => (int)$db->lastInsertId(),
                    'content'     => $ideaText,
                    'category'    => 'Ideeën',
                    'color'       => 'amber',
                    'author_name' => $authorName,
                    'votes'       => 1,
                ];
            }
        }

        echo json_encode(['success' => true, 'cards' => $createdCards]);
        exit;
    }

    // 3. Brainstorm notitie omzetten naar Roadmap Item
    if ($action === 'summarize_to_roadmap') {
        $data = json_decode(file_get_contents('php://input'), true);
        $content = trim($data['content'] ?? '');
        $sessionTitle = trim($data['session_title'] ?? '');

        if (empty($content)) {
            echo json_encode(['error' => 'Geen inhoud opgegeven om samen te vatten']);
            exit;
        }

        $aiRes = fociz_ai_summarize_to_roadmap($content, $sessionTitle, $user['id']);

        if (!$aiRes['success']) {
            echo json_encode(['error' => $aiRes['error']]);
            exit;
        }

        echo json_encode(['success' => true, 'item' => $aiRes['item']]);
        exit;
    }

    // 3b. AI Brainstorm Idee Uitwerken tot concrete behapbare items
    if ($action === 'breakdown_idea') {
        $data = json_decode(file_get_contents('php://input'), true) ?: $_POST;
        $content = trim($data['content'] ?? '');
        $sessionId = (int)($data['session_id'] ?? 0);
        $sessionTitle = trim($data['session_title'] ?? '');
        $theme = trim($data['theme'] ?? '');

        if (empty($content)) {
            echo json_encode(['error' => 'Geen inhoud opgegeven om uit te werken.']);
            exit;
        }

        if ($sessionId > 0 && (empty($sessionTitle) || empty($theme))) {
            $stmtS = $db->prepare("SELECT title, theme FROM brainstorm_sessions WHERE id = ?");
            $stmtS->execute([$sessionId]);
            $sRow = $stmtS->fetch();
            if ($sRow) {
                if (empty($sessionTitle)) $sessionTitle = $sRow['title'] ?? '';
                if (empty($theme)) $theme = $sRow['theme'] ?? '';
            }
        }

        $aiRes = fociz_ai_breakdown_idea($content, $sessionTitle, $theme, $user['id']);

        if (!$aiRes['success']) {
            echo json_encode(['error' => $aiRes['error']]);
            exit;
        }

        echo json_encode([
            'success' => true,
            'summary' => $aiRes['summary'],
            'items'   => $aiRes['items'],
            'model'   => $aiRes['model'] ?? 'Gemini Pro',
        ]);
        exit;
    }

    // 3c. Opgesplitste AI items exporteren naar Kanban Bord, Tijdlijn of Dagplanner
    if ($action === 'save_breakdown_items') {
        $data = json_decode(file_get_contents('php://input'), true) ?: $_POST;
        $destination = trim($data['destination'] ?? 'kanban'); // 'kanban', 'timeline', 'planner'
        $items = $data['items'] ?? [];

        if (empty($items) || !is_array($items)) {
            echo json_encode(['error' => 'Geen items geselecteerd om op te slaan.']);
            exit;
        }

        $isAdmin = ($user['role'] === 'ADMIN');
        $createdCount = 0;

        if ($destination === 'kanban' || $destination === 'timeline') {
            $boardId = (int)($data['board_id'] ?? 0);
            $laneId  = (int)($data['lane_id'] ?? 0);

            if ($boardId <= 0) {
                // Pak het eerste actieve bord van de gebruiker
                if ($isAdmin) {
                    $boardId = (int)$db->query("SELECT id FROM boards WHERE is_archived = 0 ORDER BY id ASC LIMIT 1")->fetchColumn();
                } else {
                    $stmtB = $db->prepare("SELECT b.id FROM boards b JOIN board_members bm ON b.id = bm.board_id WHERE bm.user_id = ? AND b.is_archived = 0 ORDER BY b.id ASC LIMIT 1");
                    $stmtB->execute([$user['id']]);
                    $boardId = (int)$stmtB->fetchColumn();
                }
            }

            if ($boardId <= 0) {
                echo json_encode(['error' => 'Geen actief Kanban-bord gevonden om taken aan toe te voegen.']);
                exit;
            }

            // Toegangscontrole
            if (!$isAdmin) {
                $stmtCheck = $db->prepare("SELECT COUNT(*) FROM board_members WHERE board_id = ? AND user_id = ?");
                $stmtCheck->execute([$boardId, $user['id']]);
                if ((int)$stmtCheck->fetchColumn() === 0) {
                    http_response_code(403);
                    echo json_encode(['error' => 'Geen toegang tot dit bord.']);
                    exit;
                }
            }

            // Als lane_id niet geldig is, pak de eerste kolom (bijv. 'To Do' of 'Backlog')
            if ($laneId <= 0) {
                $stmtLane = $db->prepare("SELECT id FROM board_lanes WHERE board_id = ? ORDER BY position ASC, id ASC LIMIT 1");
                $stmtLane->execute([$boardId]);
                $laneId = (int)$stmtLane->fetchColumn();
            }

            if ($laneId <= 0) {
                echo json_encode(['error' => 'Het geselecteerde bord heeft geen kolommen.']);
                exit;
            }

            // Datumbereik voor Tijdlijn
            $startDate = !empty($data['start_date']) ? trim($data['start_date']) : date('Y-m-d');
            $endDate = !empty($data['end_date']) ? trim($data['end_date']) : date('Y-m-d', strtotime('+3 days'));

            $stmtMax = $db->prepare("SELECT COALESCE(MAX(position), -1) FROM board_cards WHERE lane_id = ?");
            $stmtInsertCard = $db->prepare("
                INSERT INTO board_cards (board_id, lane_id, title, description, assignee_id, priority, color, position, created_by_id)
                VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)
            ");

            $stmtSchedule = $db->prepare("
                INSERT INTO board_card_schedules (card_id, schedule_type, start_date, end_date, start_time, end_time, days_of_week)
                VALUES (?, 'DAILY_RANGE', ?, ?, '09:00', '17:00', '1,2,3,4,5')
            ");

            $priorityMap = ['P1' => 'HIGH', 'P2' => 'MEDIUM', 'P3' => 'LOW'];

            foreach ($items as $item) {
                $title = trim($item['title'] ?? '');
                if (empty($title)) continue;

                $desc = trim($item['description'] ?? '');
                $rawPri = strtoupper(trim($item['priority'] ?? 'P2'));
                $priority = $priorityMap[$rawPri] ?? ($rawPri === 'HIGH' || $rawPri === 'LOW' ? $rawPri : 'MEDIUM');
                $color = trim($item['color'] ?? 'indigo');

                $stmtMax->execute([$laneId]);
                $maxPos = (int)$stmtMax->fetchColumn();

                $stmtInsertCard->execute([
                    $boardId,
                    $laneId,
                    $title,
                    $desc,
                    $user['id'],
                    $priority,
                    $color,
                    $maxPos + 1,
                    $user['id'],
                ]);

                $cardId = (int)$db->lastInsertId();

                if ($destination === 'timeline' && $cardId > 0) {
                    $stmtSchedule->execute([$cardId, $startDate, $endDate]);
                }

                $createdCount++;
            }

            echo json_encode([
                'success'       => true,
                'destination'   => $destination,
                'created_count' => $createdCount,
                'board_id'      => $boardId,
            ]);
            exit;
        }

        if ($destination === 'planner') {
            $planDate = !empty($data['plan_date']) ? trim($data['plan_date']) : date('Y-m-d');

            // Zoek of maak daily plan
            $stmtPlan = $db->prepare("SELECT id FROM daily_plans WHERE user_id = ? AND plan_date = ?");
            $stmtPlan->execute([$user['id'], $planDate]);
            $planId = (int)$stmtPlan->fetchColumn();

            if ($planId <= 0) {
                $stmtNewPlan = $db->prepare("INSERT INTO daily_plans (user_id, plan_date, focus_goal) VALUES (?, ?, 'Brainstorm actiepunten oppakken')");
                $stmtNewPlan->execute([$user['id'], $planDate]);
                $planId = (int)$db->lastInsertId();
            }

            $stmtInsertTask = $db->prepare("
                INSERT INTO tasks (user_id, daily_plan_id, title, priority, duration_minutes, status, source)
                VALUES (?, ?, ?, ?, ?, 'TODO', 'BRAINSTORM')
            ");

            foreach ($items as $item) {
                $title = trim($item['title'] ?? '');
                if (empty($title)) continue;

                $rawPri = strtoupper(trim($item['priority'] ?? 'P2'));
                $priority = in_array($rawPri, ['P1', 'P2', 'P3']) ? $rawPri : 'P2';
                $duration = max(15, min(240, (int)($item['estimated_minutes'] ?? 30)));

                $stmtInsertTask->execute([
                    $user['id'],
                    $planId,
                    $title,
                    $priority,
                    $duration,
                ]);

                $createdCount++;
            }

            echo json_encode([
                'success'       => true,
                'destination'   => 'planner',
                'created_count' => $createdCount,
                'plan_date'     => $planDate,
            ]);
            exit;
        }

        echo json_encode(['error' => 'Onbekende bestemming: ' . htmlspecialchars($destination)]);
        exit;
    }

    // 3d. Test AI Verbinding (Gemini Pro / OpenAI)
    if ($action === 'test_connection') {
        $data = json_decode(file_get_contents('php://input'), true) ?: $_POST;
        
        $tempProvider = !empty($data['provider']) ? trim($data['provider']) : null;
        $tempKey = !empty($data['api_key']) ? trim($data['api_key']) : null;
        $tempModel = !empty($data['model']) ? trim($data['model']) : null;

        // Als er test credentials zijn meegegeven, test direct met die credentials
        if (!empty($tempKey)) {
            $testSettings = [
                'ai_provider' => $tempProvider ?: 'gemini',
                'ai_api_key'  => $tempKey,
                'ai_model'    => $tempModel ?: ($tempProvider === 'openai' ? 'gpt-4o-mini' : 'gemini-1.5-pro'),
            ];
        } else {
            // Anders haal de geconfigureerde instellingen op van user of org
            $testSettings = get_ai_settings($user['id']);
        }

        if (empty($testSettings['ai_api_key'])) {
            echo json_encode([
                'success' => false,
                'error'   => 'Geen API-sleutel ingevuld of geconfigureerd om te testen.',
            ]);
            exit;
        }

        $provider = strtolower($testSettings['ai_provider'] ?? 'gemini');
        $model = $testSettings['ai_model'] ?? ($provider === 'openai' ? 'gpt-4o-mini' : 'gemini-1.5-pro');

        $t0 = microtime(true);

        $testMessages = [
            ['role' => 'user', 'content' => 'Fociz connectiviteitstest. Reageer enkel met het woord OK.'],
        ];

        if ($provider === 'gemini' || strpos(strtolower($model), 'gemini') !== false) {
            $aiRes = fociz_ai_chat_gemini($testMessages, ['max_tokens' => 20, 'temperature' => 0.1], $testSettings);
        } else {
            $aiRes = fociz_ai_chat_openai($testMessages, ['max_tokens' => 20, 'temperature' => 0.1], $testSettings);
        }

        $latency = round((microtime(true) - $t0) * 1000);

        if (!$aiRes['success']) {
            echo json_encode([
                'success'    => false,
                'error'      => $aiRes['error'] ?? 'Verbindingstest mislukt.',
                'latency_ms' => $latency,
                'provider'   => $provider,
                'model'      => $model,
            ]);
            exit;
        }

        $providerName = ($provider === 'gemini' || strpos(strtolower($model), 'gemini') !== false) ? 'Google Gemini Pro' : 'OpenAI';

        echo json_encode([
            'success'     => true,
            'message'     => "Verbinding met {$providerName} is succesvol tot stand gebracht! (Response tijd: {$latency}ms)",
            'latency_ms'  => $latency,
            'provider'    => $provider,
            'model'       => $aiRes['model'] ?? $model,
            'zero_leak'   => true,
        ]);
        exit;
    }

    // 4. Slimme dagindeling berekenen voor taken rondom bezette tijdblokken
    // ZERO-DATA LEAKAGE: Geen meetingsdetails of externe tickets worden verzonden!
    if ($action === 'smart_schedule') {
        $data = json_decode(file_get_contents('php://input'), true);
        $date = !empty($data['date']) ? trim($data['date']) : date('Y-m-d');

        // Haal daily plan op
        $stmtPlan = $db->prepare("SELECT id FROM daily_plans WHERE user_id = ? AND plan_date = ?");
        $stmtPlan->execute([$user['id'], $date]);
        $plan = $stmtPlan->fetch();
        $planId = $plan['id'] ?? 0;

        // ZERO-DATA LEAKAGE: Sluit expliciet alle taken uit die afkomstig zijn van Jira, Mail of Teams!
        $isToday = ($date === date('Y-m-d'));
        $stmtTasks = $db->prepare("
            SELECT t.id, t.title, t.priority, t.duration_minutes
            FROM tasks t
            WHERE t.user_id = ? 
              AND (t.daily_plan_id = ? " . ($isToday ? "OR t.daily_plan_id IS NULL" : "") . ") 
              AND t.is_completed = 0
              AND (t.source IS NULL OR t.source NOT IN ('JIRA', 'MAIL', 'EMAIL', 'OUTLOOK', 'TEAMS'))
              AND t.external_id IS NULL
            ORDER BY t.priority ASC, t.created_at ASC
        ");
        $stmtTasks->execute([$user['id'], $planId]);
        $tasks = $stmtTasks->fetchAll();

        if (empty($tasks)) {
            echo json_encode(['error' => 'Geen openstaande Fociz taken gevonden om in te delen']);
            exit;
        }

        // ZERO-DATA LEAKAGE: Haal meetings op maar geef UITSLUITEND start/eindtijd door (geen titel/deelnemers)
        $busyBlocks = [];
        try {
            require_once __DIR__ . '/../includes/integrations/microsoft.php';
            $rawEvents = microsoft_fetch_today_events($user['id'], $date);
            foreach ($rawEvents as $ev) {
                if (!empty($ev['start']) && !empty($ev['end'])) {
                    $busyBlocks[] = [
                        'start' => substr($ev['start'], 0, 5),
                        'end'   => substr($ev['end'], 0, 5),
                    ];
                }
            }
        } catch (Throwable $e) {
            // Microsoft niet gekoppeld
        }

        $workdaySettings = get_workday_settings();

        $aiRes = fociz_ai_smart_schedule($tasks, $busyBlocks, $workdaySettings, $user['id']);

        if (!$aiRes['success']) {
            echo json_encode(['error' => $aiRes['error']]);
            exit;
        }

        // Werk de tijdsblokken bij in MariaDB
        $updateStmt = $db->prepare("
            UPDATE tasks 
            SET time_block_start = ?, 
                duration_minutes = COALESCE(?, duration_minutes)
            WHERE id = ? AND user_id = ?
        ");

        $scheduledCount = 0;
        foreach ($aiRes['scheduled'] as $s) {
            $taskId = (int)($s['id'] ?? 0);
            $startTime = trim($s['time_block_start'] ?? '');
            $duration = !empty($s['duration_minutes']) ? (int)$s['duration_minutes'] : null;

            if ($taskId > 0 && preg_match('/^\d{1,2}:\d{2}$/', $startTime)) {
                $updateStmt->execute([$startTime, $duration, $taskId, $user['id']]);
                $scheduledCount++;
            }
        }

        echo json_encode(['success' => true, 'scheduled_count' => $scheduledCount]);
        exit;
    }

    // 5. Persoonlijke AI Dagbriefing genereren
    // ZERO-DATA LEAKAGE: Absoluut GEEN Jira, Mail of Teams data!
    if ($action === 'daily_briefing') {
        $data = json_decode(file_get_contents('php://input'), true);
        $date = !empty($data['date']) ? trim($data['date']) : date('Y-m-d');
        $today = date('Y-m-d');

        // Haal openstaande taken van vandaag op (ZERO-DATA LEAKAGE: GEEN externe Jira/Mail taken)
        $stmtPlan = $db->prepare("SELECT id FROM daily_plans WHERE user_id = ? AND plan_date = ?");
        $stmtPlan->execute([$user['id'], $date]);
        $planId = $stmtPlan->fetchColumn();

        $isToday = ($date === $today);
        $taskFilter = $planId
            ? "t.daily_plan_id = " . (int)$planId . ($isToday ? " OR t.daily_plan_id IS NULL" : "")
            : ($isToday ? "t.daily_plan_id IS NULL" : "1=0");

        $stmtTasks = $db->prepare("
            SELECT id, title, priority, time_block_start, duration_minutes
            FROM tasks t
            WHERE t.user_id = ? 
              AND t.is_completed = 0 
              AND ({$taskFilter})
              AND (t.source IS NULL OR t.source NOT IN ('JIRA', 'MAIL', 'EMAIL', 'OUTLOOK', 'TEAMS'))
              AND t.external_id IS NULL
            ORDER BY t.priority ASC, t.time_block_start ASC
            LIMIT 15
        ");
        $stmtTasks->execute([$user['id']]);
        $tasks = $stmtTasks->fetchAll();

        // Haal gisteren niet-voltooide interne taken op
        $yesterday = date('Y-m-d', strtotime('-1 day', strtotime($date)));
        $stmtYest = $db->prepare("SELECT id FROM daily_plans WHERE user_id = ? AND plan_date = ?");
        $stmtYest->execute([$user['id'], $yesterday]);
        $yesterdayPlanId = $stmtYest->fetchColumn();
        $unfinishedYest = [];
        if ($yesterdayPlanId) {
            $stmtUnf = $db->prepare("
                SELECT title FROM tasks
                WHERE user_id = ? AND daily_plan_id = ? AND is_completed = 0
                  AND (source IS NULL OR source NOT IN ('JIRA', 'MAIL', 'EMAIL', 'OUTLOOK', 'TEAMS'))
                  AND external_id IS NULL
                LIMIT 5
            ");
            $stmtUnf->execute([$user['id'], $yesterdayPlanId]);
            $unfinishedYest = $stmtUnf->fetchAll();
        }

        // ZERO-DATA LEAKAGE: Alleen geanonimiseerde bezette tijdblokken (geen subject/afzender)
        $busyBlocks = [];
        try {
            require_once __DIR__ . '/../includes/integrations/microsoft.php';
            $rawEvents = microsoft_fetch_today_events($user['id'], $date);
            foreach ($rawEvents as $ev) {
                if (!empty($ev['start']) && !empty($ev['end'])) {
                    $busyBlocks[] = [
                        'start' => substr($ev['start'], 0, 5),
                        'end'   => substr($ev['end'], 0, 5),
                    ];
                }
            }
        } catch (Throwable $e) {
            // Geen agenda beschikbaar
        }

        $aiSettings = get_ai_settings($user['id']);
        if (empty($aiSettings['ai_enabled']) || empty($aiSettings['has_key'])) {
            echo json_encode(['error' => 'AI Co-Pilot is niet geconfigureerd']);
            exit;
        }

        $aiRes = fociz_ai_daily_briefing(
            $user['name'] ?? 'Jij',
            $date,
            $tasks,
            $busyBlocks,
            $unfinishedYest,
            $user['id']
        );

        if (!$aiRes['success']) {
            echo json_encode(['error' => $aiRes['error']]);
            exit;
        }

        echo json_encode([
            'success'    => true,
            'greeting'   => $aiRes['greeting'],
            'focus_task' => $aiRes['focus_task'],
            'tip'        => $aiRes['tip'],
            'warnings'   => $aiRes['warnings'],
            'date'       => $date,
            'model'      => $aiRes['model'] ?? 'Gemini Pro',
        ]);
        exit;
    }

    echo json_encode(['error' => 'Onbekende actie']);
} catch (Exception $e) {
    http_response_code(500);
    echo json_encode(['error' => $e->getMessage()]);
}