<?php
declare(strict_types=1);

namespace Plugins\AdvancedReporting;

use Core\Http\Response;
use Core\Services\ApiLayer;
use Core\Services\Auth;
use Core\Services\Database;
use Core\Services\Settings;
use Core\Views\View;
use PDO;
use Throwable;

class ReportsController
{
    private View $view;
    private array $releaseTrackCache = [];
    private array $trackDownloadCountCache = [];

    public function __construct()
    {
        $this->view = new View(__DIR__ . '/views');
    }

    public function adminIndex(): Response
    {
        if ($guard = $this->guard()) {
            return $guard;
        }

        $db = Database::get();
        if (!($db instanceof PDO)) {
            return new Response($this->view->render('admin/index.php', [
                'title' => 'Sales Reports',
                'tab' => 'overview',
                'filters' => $this->filters(),
                'overview' => [],
                'artist_rows' => [],
                'track_rows' => [],
                'artist_options' => [],
                'tables_ready' => false,
                'currency' => Settings::get('store_currency', 'GBP'),
            ]));
        }

        ApiLayer::ensureSchema($db);
        $filters = $this->filters();
        $tab = $filters['tab'];

        return new Response($this->view->render('admin/index.php', [
            'title' => 'Sales Reports',
            'tab' => $tab,
            'filters' => $filters,
            'overview' => $this->overviewPayload($db, $filters),
            'artist_rows' => $tab === 'artists' ? $this->artistRows($db, $filters) : [],
            'track_rows' => $tab === 'tracks' ? $this->trackRows($db, $filters) : [],
            'artist_options' => $this->artistOptions($db),
            'tables_ready' => $this->tablesReady($db),
            'currency' => strtoupper(trim((string)Settings::get('store_currency', 'GBP'))),
        ]));
    }

    public function adminExport(): Response
    {
        if ($guard = $this->guard()) {
            return $guard;
        }

        $db = Database::get();
        if (!($db instanceof PDO)) {
            return new Response('Database unavailable', 500);
        }

        ApiLayer::ensureSchema($db);
        $filters = $this->filters();
        $type = strtolower(trim((string)($_GET['type'] ?? 'artists')));
        if (!in_array($type, ['artists', 'tracks'], true)) {
            $type = 'artists';
        }

        $rows = $type === 'tracks' ? $this->trackRows($db, $filters) : $this->artistRows($db, $filters);
        $stream = fopen('php://temp', 'w+');
        if ($stream === false) {
            return new Response('Unable to create export', 500);
        }

        if ($type === 'tracks') {
            fputcsv($stream, ['Artist', 'Track', 'Release', 'Catalog', 'Units Sold', 'Units Refunded', 'Gross Revenue', 'Refunded Revenue', 'Net Revenue', 'PayPal Fees', 'Net After Fees', 'Downloads']);
            foreach ($rows as $row) {
                fputcsv($stream, [
                    (string)($row['artist_name'] ?? ''),
                    (string)($row['track_display'] ?? ''),
                    (string)($row['release_title'] ?? ''),
                    (string)($row['catalog_no'] ?? ''),
                    (int)($row['units_sold'] ?? 0),
                    (int)($row['units_refunded'] ?? 0),
                    number_format((float)($row['gross_revenue'] ?? 0), 2, '.', ''),
                    number_format((float)($row['refunded_revenue'] ?? 0), 2, '.', ''),
                    number_format((float)($row['net_revenue'] ?? 0), 2, '.', ''),
                    number_format((float)($row['payment_fees'] ?? 0), 2, '.', ''),
                    number_format((float)($row['net_after_fees'] ?? 0), 2, '.', ''),
                    (int)($row['download_count'] ?? 0),
                ]);
            }
        } else {
            fputcsv($stream, ['Artist', 'Paid Orders', 'Units Sold', 'Units Refunded', 'Gross Revenue', 'Refunded Revenue', 'Net Revenue', 'PayPal Fees', 'Net After Fees', 'Releases', 'Tracks']);
            foreach ($rows as $row) {
                fputcsv($stream, [
                    (string)($row['artist_name'] ?? ''),
                    (int)($row['paid_orders'] ?? 0),
                    (int)($row['units_sold'] ?? 0),
                    (int)($row['units_refunded'] ?? 0),
                    number_format((float)($row['gross_revenue'] ?? 0), 2, '.', ''),
                    number_format((float)($row['refunded_revenue'] ?? 0), 2, '.', ''),
                    number_format((float)($row['net_revenue'] ?? 0), 2, '.', ''),
                    number_format((float)($row['payment_fees'] ?? 0), 2, '.', ''),
                    number_format((float)($row['net_after_fees'] ?? 0), 2, '.', ''),
                    (int)($row['release_count'] ?? 0),
                    (int)($row['track_count'] ?? 0),
                ]);
            }
        }

        rewind($stream);
        $csv = stream_get_contents($stream);
        fclose($stream);

        return new Response((string)$csv, 200, [
            'Content-Type' => 'text/csv; charset=UTF-8',
            'Content-Disposition' => 'attachment; filename="sales-report-' . $type . '-' . gmdate('Ymd-His') . '.csv"',
        ]);
    }

    private function guard(): ?Response
    {
        if (!Auth::check()) {
            return new Response('', 302, ['Location' => '/admin/login']);
        }
        if (!Auth::hasRole(['admin', 'manager'])) {
            return new Response('', 302, ['Location' => '/admin']);
        }
        return null;
    }

    private function filters(): array
    {
        $tab = strtolower(trim((string)($_GET['tab'] ?? 'overview')));
        if (!in_array($tab, ['overview', 'artists', 'tracks'], true)) {
            $tab = 'overview';
        }

        return [
            'tab' => $tab,
            'from' => trim((string)($_GET['from'] ?? '')),
            'to' => trim((string)($_GET['to'] ?? '')),
            'q' => trim((string)($_GET['q'] ?? '')),
            'artist_id' => max(0, (int)($_GET['artist_id'] ?? 0)),
        ];
    }

    private function tablesReady(PDO $db): bool
    {
        try {
            $probe = $db->query("SHOW TABLES LIKE 'ac_store_order_item_allocations'");
            return (bool)($probe && $probe->fetch(PDO::FETCH_NUM));
        } catch (Throwable $e) {
            return false;
        }
    }

    private function overviewPayload(PDO $db, array $filters): array
    {
        $stats = [
            'gross_revenue' => 0.0,
            'refunded_revenue' => 0.0,
            'net_revenue' => 0.0,
            'payment_fees' => 0.0,
            'net_after_fees' => 0.0,
            'paid_orders' => 0,
            'refunded_orders' => 0,
            'units_sold' => 0,
            'units_refunded' => 0,
            'top_artists' => [],
            'top_tracks' => [],
        ];

        try {
            [$whereSql, $params] = $this->dateWhere($filters, 'o');
            $stmt = $db->prepare("
                SELECT
                    COALESCE(SUM(CASE WHEN o.status = 'paid' THEN o.total ELSE 0 END), 0) AS gross_revenue,
                    COALESCE(SUM(CASE WHEN o.status = 'refunded' THEN o.total ELSE 0 END), 0) AS refunded_revenue,
                    COALESCE(SUM(CASE WHEN o.status = 'paid' THEN COALESCE(o.payment_fee, 0) ELSE 0 END), 0) AS payment_fees,
                    COUNT(DISTINCT CASE WHEN o.status = 'paid' THEN o.id END) AS paid_orders,
                    COUNT(DISTINCT CASE WHEN o.status = 'refunded' THEN o.id END) AS refunded_orders
                FROM ac_store_orders o
                {$whereSql}
            ");
            $stmt->execute($params);
            $row = $stmt->fetch(PDO::FETCH_ASSOC) ?: [];
            $stats['gross_revenue'] = (float)($row['gross_revenue'] ?? 0);
            $stats['refunded_revenue'] = (float)($row['refunded_revenue'] ?? 0);
            $stats['payment_fees'] = (float)($row['payment_fees'] ?? 0);
            $stats['net_revenue'] = $stats['gross_revenue'] - $stats['refunded_revenue'];
            $stats['net_after_fees'] = $stats['net_revenue'] - $stats['payment_fees'];
            $stats['paid_orders'] = (int)($row['paid_orders'] ?? 0);
            $stats['refunded_orders'] = (int)($row['refunded_orders'] ?? 0);
        } catch (Throwable $e) {
        }

        try {
            [$whereSql, $params] = $this->dateWhere($filters, 'o');
            $stmt = $db->prepare("
                SELECT
                    COALESCE(SUM(CASE WHEN o.status = 'paid' THEN a.qty ELSE 0 END), 0) AS units_sold,
                    COALESCE(SUM(CASE WHEN o.status = 'refunded' THEN a.qty ELSE 0 END), 0) AS units_refunded
                FROM ac_store_order_item_allocations a
                JOIN ac_store_orders o ON o.id = a.order_id
                {$whereSql}
            ");
            $stmt->execute($params);
            $row = $stmt->fetch(PDO::FETCH_ASSOC) ?: [];
            $stats['units_sold'] = (int)($row['units_sold'] ?? 0);
            $stats['units_refunded'] = (int)($row['units_refunded'] ?? 0);
        } catch (Throwable $e) {
        }

        $topFilters = $filters;
        $topFilters['limit'] = 5;
        $stats['top_artists'] = $this->artistRows($db, $topFilters);
        $stats['top_tracks'] = $this->trackRows($db, $topFilters);

        return $stats;
    }

    private function artistRows(PDO $db, array $filters): array
    {
        [$whereSql, $params] = $this->dateWhere($filters, 'o');
        if (!empty($filters['artist_id'])) {
            $whereSql .= ($whereSql === '' ? ' WHERE ' : ' AND ') . 'alloc.artist_id = :artist_id';
            $params[':artist_id'] = (int)$filters['artist_id'];
        }
        $q = trim((string)($filters['q'] ?? ''));
        if ($q !== '') {
            $whereSql .= ($whereSql === '' ? ' WHERE ' : ' AND ') . " (ar.name LIKE :q OR r.artist_name LIKE :q OR alloc.title_snapshot LIKE :q)";
            $params[':q'] = '%' . $q . '%';
        }
        $limitSql = !empty($filters['limit']) ? ' LIMIT ' . max(1, (int)$filters['limit']) : '';

        try {
            $stmt = $db->prepare("
                SELECT
                    COALESCE(alloc.artist_id, 0) AS artist_id,
                    COALESCE(NULLIF(MAX(ar.name), ''), NULLIF(MAX(r.artist_name), ''), 'Unknown Artist') AS artist_name,
                    COUNT(DISTINCT CASE WHEN o.status = 'paid' THEN alloc.order_id END) AS paid_orders,
                    COALESCE(SUM(CASE WHEN o.status = 'paid' THEN alloc.qty ELSE 0 END), 0) AS units_sold,
                    COALESCE(SUM(CASE WHEN o.status = 'refunded' THEN alloc.qty ELSE 0 END), 0) AS units_refunded,
                    COALESCE(SUM(CASE WHEN o.status = 'paid' THEN alloc.gross_amount ELSE 0 END), 0) AS gross_revenue,
                    COALESCE(SUM(CASE WHEN o.status = 'refunded' THEN alloc.gross_amount ELSE 0 END), 0) AS refunded_revenue,
                    COALESCE(SUM(CASE WHEN o.status = 'paid' AND COALESCE(NULLIF(o.payment_gross, 0), NULLIF(o.total, 0), 0) > 0 THEN COALESCE(o.payment_fee, 0) * (alloc.gross_amount / COALESCE(NULLIF(o.payment_gross, 0), NULLIF(o.total, 0))) ELSE 0 END), 0) AS payment_fees,
                    COUNT(DISTINCT CASE WHEN o.status = 'paid' AND alloc.release_id IS NOT NULL THEN alloc.release_id END) AS release_count,
                    COUNT(DISTINCT CASE WHEN o.status = 'paid' AND alloc.track_id IS NOT NULL THEN alloc.track_id END) AS track_count
                FROM ac_store_order_item_allocations alloc
                JOIN ac_store_orders o ON o.id = alloc.order_id
                LEFT JOIN ac_artists ar ON ar.id = alloc.artist_id
                LEFT JOIN ac_releases r ON r.id = alloc.release_id
                {$whereSql}
                GROUP BY COALESCE(alloc.artist_id, 0)
                ORDER BY
                    ((COALESCE(SUM(CASE WHEN o.status = 'paid' THEN alloc.gross_amount ELSE 0 END), 0) - COALESCE(SUM(CASE WHEN o.status = 'refunded' THEN alloc.gross_amount ELSE 0 END), 0)) - COALESCE(SUM(CASE WHEN o.status = 'paid' AND COALESCE(NULLIF(o.payment_gross, 0), NULLIF(o.total, 0), 0) > 0 THEN COALESCE(o.payment_fee, 0) * (alloc.gross_amount / COALESCE(NULLIF(o.payment_gross, 0), NULLIF(o.total, 0))) ELSE 0 END), 0)) DESC,
                    COALESCE(SUM(CASE WHEN o.status = 'paid' THEN alloc.gross_amount ELSE 0 END), 0) DESC,
                    artist_name ASC
                {$limitSql}
            ");
            $stmt->execute($params);
            $rows = array_values(array_filter($stmt->fetchAll(PDO::FETCH_ASSOC) ?: [], static function (array $row): bool {
                return (float)($row['gross_revenue'] ?? 0) > 0 || (float)($row['refunded_revenue'] ?? 0) > 0;
            }));
            foreach ($rows as &$row) {
                $row['payment_fees'] = (float)($row['payment_fees'] ?? 0);
                $row['net_revenue'] = (float)($row['gross_revenue'] ?? 0) - (float)($row['refunded_revenue'] ?? 0);
                $row['net_after_fees'] = $row['net_revenue'] - $row['payment_fees'];
            }
            unset($row);
            return $rows;
        } catch (Throwable $e) {
            return [];
        }
    }

    private function trackRows(PDO $db, array $filters): array
    {
        [$whereSql, $params] = $this->dateWhere($filters, 'o');
        if (!empty($filters['artist_id'])) {
            $whereSql .= ($whereSql === '' ? ' WHERE ' : ' AND ') . 'COALESCE(alloc.artist_id, r.artist_id) = :artist_id';
            $params[':artist_id'] = (int)$filters['artist_id'];
        }
        $q = trim((string)($filters['q'] ?? ''));
        if ($q !== '') {
            $whereSql .= ($whereSql === '' ? ' WHERE ' : ' AND ') . "(t.title LIKE :q OR t.mix_name LIKE :q OR ar.name LIKE :q OR r.title LIKE :q OR r.catalog_no LIKE :q)";
            $params[':q'] = '%' . $q . '%';
        }
        $limitSql = !empty($filters['limit']) ? ' LIMIT ' . max(1, (int)$filters['limit']) : '';

        try {
            $stmt = $db->prepare("
                SELECT
                    alloc.id,
                    alloc.order_id,
                    alloc.track_id,
                    alloc.release_id,
                    alloc.artist_id,
                    alloc.qty,
                    alloc.gross_amount,
                    o.status,
                    COALESCE(o.payment_fee, 0) AS payment_fee,
                    COALESCE(o.payment_gross, 0) AS payment_gross,
                    COALESCE(o.total, 0) AS order_total,
                    COALESCE(NULLIF(MAX(t.title), ''), MAX(alloc.title_snapshot), 'Track') AS track_title,
                    COALESCE(NULLIF(MAX(t.mix_name), ''), '') AS mix_name,
                    COALESCE(NULLIF(MAX(ar.name), ''), NULLIF(MAX(r.artist_name), ''), 'Unknown Artist') AS artist_name,
                    COALESCE(NULLIF(MAX(r.title), ''), 'Release') AS release_title,
                    COALESCE(NULLIF(MAX(r.catalog_no), ''), '') AS catalog_no
                FROM ac_store_order_item_allocations alloc
                JOIN ac_store_orders o ON o.id = alloc.order_id
                LEFT JOIN ac_release_tracks t ON t.id = alloc.track_id
                LEFT JOIN ac_releases r ON r.id = COALESCE(alloc.release_id, t.release_id)
                LEFT JOIN ac_artists ar ON ar.id = COALESCE(alloc.artist_id, r.artist_id)
                {$whereSql}
                GROUP BY alloc.id
                ORDER BY alloc.id DESC
            ");
            $stmt->execute($params);
            $allocations = $stmt->fetchAll(PDO::FETCH_ASSOC) ?: [];
            $rows = [];
            foreach ($allocations as $alloc) {
                $releaseId = (int)($alloc['release_id'] ?? 0);
                $trackId = (int)($alloc['track_id'] ?? 0);
                if ($trackId > 0) {
                    $targets = [[
                        'track_id' => $trackId,
                        'artist_name' => (string)($alloc['artist_name'] ?? 'Unknown Artist'),
                        'release_title' => (string)($alloc['release_title'] ?? 'Release'),
                        'catalog_no' => (string)($alloc['catalog_no'] ?? ''),
                        'track_title' => (string)($alloc['track_title'] ?? 'Track'),
                        'mix_name' => (string)($alloc['mix_name'] ?? ''),
                        'weight' => 1.0,
                    ]];
                } elseif ($releaseId > 0) {
                    $targets = $this->releaseTracks($db, $releaseId, (string)($alloc['artist_name'] ?? 'Unknown Artist'), (string)($alloc['release_title'] ?? 'Release'), (string)($alloc['catalog_no'] ?? ''));
                    if (!$targets) {
                        continue;
                    }
                } else {
                    continue;
                }

                $totalWeight = 0.0;
                foreach ($targets as $target) {
                    $totalWeight += max(0.0, (float)($target['weight'] ?? 0));
                }
                if ($totalWeight <= 0) {
                    $totalWeight = (float)count($targets);
                    foreach ($targets as &$target) {
                        $target['weight'] = 1.0;
                    }
                    unset($target);
                }

                foreach ($targets as $target) {
                    $key = (int)($target['track_id'] ?? 0);
                    if ($key <= 0) {
                        continue;
                    }
                    if (!isset($rows[$key])) {
                        $trackTitle = trim((string)($target['track_title'] ?? 'Track'));
                        $mixName = trim((string)($target['mix_name'] ?? ''));
                        $rows[$key] = [
                            'track_id' => $key,
                            'artist_name' => (string)($target['artist_name'] ?? 'Unknown Artist'),
                            'release_title' => (string)($target['release_title'] ?? 'Release'),
                            'catalog_no' => (string)($target['catalog_no'] ?? ''),
                            'track_title' => $trackTitle,
                            'mix_name' => $mixName,
                            'track_display' => $mixName !== '' ? $trackTitle . ' (' . $mixName . ')' : $trackTitle,
                            'units_sold' => 0,
                            'units_refunded' => 0,
                            'gross_revenue' => 0.0,
                            'refunded_revenue' => 0.0,
                            'download_count' => $this->trackDownloadCount($db, $key),
                            'payment_fees' => 0.0,
                            'net_after_fees' => 0.0,
                        ];
                    }
                    $share = max(0.0, (float)($target['weight'] ?? 0)) / $totalWeight;
                    $amount = (float)($alloc['gross_amount'] ?? 0) * $share;
                    $qty = (int)($alloc['qty'] ?? 0);
                    $feeBase = (float)($alloc['payment_gross'] ?? 0);
                    if ($feeBase <= 0) {
                        $feeBase = (float)($alloc['order_total'] ?? 0);
                    }
                    $feeShare = ((string)($alloc['status'] ?? '') === 'paid' && $feeBase > 0)
                        ? ((float)($alloc['payment_fee'] ?? 0) * (((float)($alloc['gross_amount'] ?? 0)) / $feeBase) * $share)
                        : 0.0;
                    if ((string)($alloc['status'] ?? '') === 'paid') {
                        $rows[$key]['units_sold'] += $qty;
                        $rows[$key]['gross_revenue'] += $amount;
                        $rows[$key]['payment_fees'] += $feeShare;
                    } elseif ((string)($alloc['status'] ?? '') === 'refunded') {
                        $rows[$key]['units_refunded'] += $qty;
                        $rows[$key]['refunded_revenue'] += $amount;
                    }
                }
            }
            $rows = array_values(array_filter($rows, static function (array $row): bool {
                return (float)($row['gross_revenue'] ?? 0) > 0 || (float)($row['refunded_revenue'] ?? 0) > 0;
            }));
            foreach ($rows as &$row) {
                $row['payment_fees'] = (float)($row['payment_fees'] ?? 0);
                $row['net_revenue'] = (float)($row['gross_revenue'] ?? 0) - (float)($row['refunded_revenue'] ?? 0);
                $row['net_after_fees'] = $row['net_revenue'] - $row['payment_fees'];
            }
            unset($row);
            usort($rows, static function (array $a, array $b): int {
                $cmp = ((float)($b['net_revenue'] ?? 0)) <=> ((float)($a['net_revenue'] ?? 0));
                if ($cmp !== 0) {
                    return $cmp;
                }
                $cmp = ((float)($b['net_after_fees'] ?? 0)) <=> ((float)($a['net_after_fees'] ?? 0));
                if ($cmp !== 0) {
                    return $cmp;
                }
                return strcasecmp((string)($a['track_display'] ?? ''), (string)($b['track_display'] ?? ''));
            });
            if (!empty($filters['limit'])) {
                $rows = array_slice($rows, 0, max(1, (int)$filters['limit']));
            }
            return $rows;
        } catch (Throwable $e) {
            return [];
        }
    }

    private function releaseTracks(PDO $db, int $releaseId, string $artistName, string $releaseTitle, string $catalogNo): array
    {
        if ($releaseId <= 0) {
            return [];
        }
        if (isset($this->releaseTrackCache[$releaseId])) {
            return $this->releaseTrackCache[$releaseId];
        }
        try {
            $stmt = $db->prepare("
                SELECT
                    t.id,
                    t.title,
                    COALESCE(t.mix_name, '') AS mix_name,
                    COALESCE(sp.track_price, 0) AS track_price
                FROM ac_release_tracks t
                LEFT JOIN ac_store_track_products sp ON sp.release_track_id = t.id AND sp.is_enabled = 1
                WHERE t.release_id = :release_id
                ORDER BY t.track_no ASC, t.id ASC
            ");
            $stmt->execute([':release_id' => $releaseId]);
            $tracks = $stmt->fetchAll(PDO::FETCH_ASSOC) ?: [];
            $targets = [];
            foreach ($tracks as $track) {
                $targets[] = [
                    'track_id' => (int)($track['id'] ?? 0),
                    'artist_name' => $artistName,
                    'release_title' => $releaseTitle,
                    'catalog_no' => $catalogNo,
                    'track_title' => (string)($track['title'] ?? 'Track'),
                    'mix_name' => (string)($track['mix_name'] ?? ''),
                    'weight' => max(0.0, (float)($track['track_price'] ?? 0)),
                ];
            }
            $this->releaseTrackCache[$releaseId] = $targets;
            return $targets;
        } catch (Throwable $e) {
            return [];
        }
    }

    private function trackDownloadCount(PDO $db, int $trackId): int
    {
        if ($trackId <= 0) {
            return 0;
        }
        if (isset($this->trackDownloadCountCache[$trackId])) {
            return $this->trackDownloadCountCache[$trackId];
        }
        try {
            $stmt = $db->prepare("
                SELECT COUNT(e.id) AS download_count
                FROM ac_store_files f
                LEFT JOIN ac_store_download_events e ON e.file_id = f.id
                WHERE f.scope_type = 'track' AND f.scope_id = :track_id
            ");
            $stmt->execute([':track_id' => $trackId]);
            $count = (int)(($stmt->fetch(PDO::FETCH_ASSOC) ?: [])['download_count'] ?? 0);
            $this->trackDownloadCountCache[$trackId] = $count;
            return $count;
        } catch (Throwable $e) {
            return 0;
        }
    }

    private function artistOptions(PDO $db): array
    {
        try {
            $stmt = $db->query("SELECT id, name FROM ac_artists WHERE name IS NOT NULL AND name <> '' ORDER BY name ASC");
            return $stmt ? ($stmt->fetchAll(PDO::FETCH_ASSOC) ?: []) : [];
        } catch (Throwable $e) {
            return [];
        }
    }

    private function dateWhere(array $filters, string $alias): array
    {
        $where = [];
        $params = [];
        $from = trim((string)($filters['from'] ?? ''));
        $to = trim((string)($filters['to'] ?? ''));
        if ($from !== '' && preg_match('/^\d{4}-\d{2}-\d{2}$/', $from)) {
            $where[] = $alias . '.created_at >= :from_date';
            $params[':from_date'] = $from . ' 00:00:00';
        }
        if ($to !== '' && preg_match('/^\d{4}-\d{2}-\d{2}$/', $to)) {
            $where[] = $alias . '.created_at <= :to_date';
            $params[':to_date'] = $to . ' 23:59:59';
        }
        return [$where ? ' WHERE ' . implode(' AND ', $where) : '', $params];
    }
}