#!/usr/bin/env php
<?php
require_once dirname(__DIR__).'/includes/boot.php';
require_once dirname(__DIR__).'/includes/facebook_event_importer.php';

if (PHP_SAPI !== 'cli') {
    fwrite(STDERR, "This script must be run from the command line.\n");
    exit(1);
}

const FB_GRAPH_DEFAULT_VERSION = 'v23.0';
const FB_GRAPH_EVENT_FIELDS = 'id,name,description,start_time,end_time,place{id,name,location},cover{source},ticket_uri';
const FB_GRAPH_PLACE_FIELDS = 'id,name,location';

function fbCliUsage(): void {
    echo "Facebook Graph API event importer for My Keyser\n\n";
    echo "Usage:\n";
    echo "  FACEBOOK_GRAPH_ACCESS_TOKEN=... php scripts/facebook-events-import.php --area=\"Keyser, WV\" --page-id=123456789\n";
    echo "  php scripts/facebook-events-import.php --access-token=... --event-id=123456789012345\n";
    echo "  php scripts/facebook-events-import.php --access-token=... --pages-file=/path/to/page-ids.txt\n";
    echo "  php scripts/facebook-events-import.php --access-token=... --area=\"Keyser, WV\" --center=39.4364,-78.9762 --distance=25000 --query=\"Keyser\" --discover-pages\n\n";
    echo "Required:\n";
    echo "  --access-token=TOKEN       Graph API access token, or set FACEBOOK_GRAPH_ACCESS_TOKEN.\n\n";
    echo "Sources:\n";
    echo "  --page-id=ID[,ID]          Facebook Page IDs to read through /{page-id}/events.\n";
    echo "  --pages-file=FILE          Plain-text Page ID file, one ID per line.\n";
    echo "  --event-id=ID[,ID]         Specific Facebook Event IDs to read through /{event-id}.\n";
    echo "  --events-file=FILE         Plain-text Event ID file, one ID per line.\n";
    echo "  --discover-pages           Use Graph place search for --center/--distance/--query, then read events for matching Page/place IDs.\n\n";
    echo "Options:\n";
    echo "  --area=TEXT                Label shown in the admin import review queue.\n";
    echo "  --center=LAT,LNG           Center point for Graph place search.\n";
    echo "  --distance=METERS          Radius for Graph place search. Default: 25000.\n";
    echo "  --query=TEXT               Place search query. Defaults to --area.\n";
    echo "  --place-limit=N            Maximum places to discover. Default: 50.\n";
    echo "  --limit=N                  Maximum events to stage total. Default: 100.\n";
    echo "  --since=YYYY-MM-DD         Start date for Page event reads. Default: today.\n";
    echo "  --until=YYYY-MM-DD         End date for Page event reads. Default: +1 year.\n";
    echo "  --graph-version=vNN.0      Graph API version. Default: ".FB_GRAPH_DEFAULT_VERSION." or FACEBOOK_GRAPH_VERSION.\n";
    echo "  --no-images                Stage Graph cover URLs but skip downloading cover photos.\n";
    echo "  --dry-run                  Fetch and print candidates without writing to the database.\n";
    echo "  --help                     Show this help.\n\n";
    echo "Notes:\n";
    echo "  This script uses only official Graph API endpoints. It does not scrape HTML, log in,\n";
    echo "  solve challenges, or bypass Facebook access controls. Your Meta app/token must have\n";
    echo "  permission to read the requested Page or Event data.\n";
}

function fbCliOptions(array $argv): array {
    $options = [];
    for ($i = 1; $i < count($argv); $i++) {
        $arg = $argv[$i];
        if (!str_starts_with($arg, '--')) continue;
        $arg = substr($arg, 2);
        if (str_contains($arg, '=')) {
            [$key, $value] = explode('=', $arg, 2);
        } else {
            $key = $arg;
            $value = true;
            if ($i + 1 < count($argv) && !str_starts_with($argv[$i + 1], '--')) $value = $argv[++$i];
        }
        if (isset($options[$key])) {
            if (!is_array($options[$key])) $options[$key] = [$options[$key]];
            $options[$key][] = $value;
        } else {
            $options[$key] = $value;
        }
    }
    return $options;
}

function fbCliValues(array $options, string $key): array {
    if (!isset($options[$key])) return [];
    $value = $options[$key];
    if (!is_array($value)) $value = [$value];
    $out = [];
    foreach ($value as $item) {
        foreach (explode(',', (string)$item) as $part) {
            $part = trim($part);
            if ($part !== '') $out[] = $part;
        }
    }
    return $out;
}

function fbCliFileValues(array $options, string $key): array {
    $out = [];
    foreach (fbCliValues($options, $key) as $file) {
        if (!is_file($file) || !is_readable($file)) {
            throw new RuntimeException("File is not readable: ".$file);
        }
        foreach (file($file, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES) ?: [] as $line) {
            $line = trim(preg_replace('/#.*/', '', $line));
            if ($line !== '') $out[] = $line;
        }
    }
    return $out;
}

function fbCliLine(string $message = ''): void {
    echo $message."\n";
}

function fbCliGraphVersion(array $options): string {
    $version = trim((string)($options['graph-version'] ?? getenv('FACEBOOK_GRAPH_VERSION') ?: FB_GRAPH_DEFAULT_VERSION));
    if ($version === '') $version = FB_GRAPH_DEFAULT_VERSION;
    return str_starts_with($version, 'v') ? $version : 'v'.$version;
}

function fbCliGraphBase(string $version): string {
    return 'https://graph.facebook.com/'.rawurlencode($version).'/';
}

function fbCliGraphRequest(string $path, array $params, string $token, string $version): array {
    $path = ltrim($path, '/');
    $url = fbCliGraphBase($version).$path;
    if ($params) $url .= '?'.http_build_query($params);

    if (function_exists('curl_init')) {
        $ch = curl_init($url);
        curl_setopt_array($ch, [
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_FOLLOWLOCATION => true,
            CURLOPT_MAXREDIRS => 4,
            CURLOPT_TIMEOUT => 30,
            CURLOPT_CONNECTTIMEOUT => 10,
            CURLOPT_USERAGENT => facebookEventImporterUserAgent(),
            CURLOPT_HTTPHEADER => [
                'Accept: application/json',
                'Authorization: Bearer '.$token,
            ],
        ]);
        $body = curl_exec($ch);
        $errno = curl_errno($ch);
        $error = curl_error($ch);
        $status = (int)curl_getinfo($ch, CURLINFO_RESPONSE_CODE);
        if (PHP_VERSION_ID < 80000) curl_close($ch);
        if ($errno) throw new RuntimeException($error ?: 'Graph API request failed.');
    } else {
        $context = stream_context_create([
            'http' => [
                'method' => 'GET',
                'timeout' => 30,
                'ignore_errors' => true,
                'header' => "Accept: application/json\r\nAuthorization: Bearer ".$token."\r\nUser-Agent: ".facebookEventImporterUserAgent()."\r\n",
            ],
        ]);
        $body = @file_get_contents($url, false, $context);
        $statusLine = $http_response_header[0] ?? '';
        $status = preg_match('/\s(\d{3})\s/', $statusLine, $match) ? (int)$match[1] : 0;
        if ($body === false) throw new RuntimeException($statusLine ?: 'Graph API request failed.');
    }

    $json = json_decode((string)$body, true);
    if (!is_array($json)) throw new RuntimeException('Graph API returned invalid JSON.');
    if ($status < 200 || $status >= 300 || isset($json['error'])) {
        $err = $json['error'] ?? [];
        $message = is_array($err) ? ($err['message'] ?? 'Graph API error') : 'Graph API error';
        $code = is_array($err) && isset($err['code']) ? ' (code '.$err['code'].')' : '';
        throw new RuntimeException($message.$code);
    }
    return $json;
}

function fbCliDateToTimestamp(string $date, string $fallback): int {
    $date = trim($date);
    $ts = strtotime($date !== '' ? $date : $fallback);
    if ($ts === false) throw new RuntimeException("Invalid date: ".$date);
    return $ts;
}

function fbCliDiscoverPages(array $options, string $token, string $version): array {
    if (empty($options['discover-pages'])) return [];
    $center = trim((string)($options['center'] ?? ''));
    if ($center === '' || !preg_match('/^-?\d+(?:\.\d+)?,-?\d+(?:\.\d+)?$/', $center)) {
        throw new RuntimeException('--discover-pages requires --center=LAT,LNG.');
    }
    $area = trim((string)($options['area'] ?? ''));
    $query = trim((string)($options['query'] ?? $area));
    if ($query === '') throw new RuntimeException('--discover-pages requires --query or --area.');

    $limit = max(1, min(100, (int)($options['place-limit'] ?? 50)));
    $distance = max(1, (int)($options['distance'] ?? 25000));
    $json = fbCliGraphRequest('search', [
        'type' => 'place',
        'q' => $query,
        'center' => $center,
        'distance' => $distance,
        'fields' => FB_GRAPH_PLACE_FIELDS,
        'limit' => $limit,
    ], $token, $version);

    $ids = [];
    foreach (($json['data'] ?? []) as $place) {
        if (!empty($place['id'])) $ids[(string)$place['id']] = (string)$place['id'];
    }
    fbCliLine('Discovered '.count($ids).' Page/place ID'.(count($ids) === 1 ? '' : 's').' from Graph place search.');
    return array_values($ids);
}

function fbCliFetchPageEvents(string $pageId, string $token, string $version, int $since, int $until, int $remaining): array {
    $events = [];
    $after = '';
    while ($remaining > count($events)) {
        $params = [
            'fields' => FB_GRAPH_EVENT_FIELDS,
            'since' => $since,
            'until' => $until,
            'limit' => min(100, $remaining - count($events)),
        ];
        if ($after !== '') $params['after'] = $after;
        $json = fbCliGraphRequest(rawurlencode($pageId).'/events', $params, $token, $version);
        foreach (($json['data'] ?? []) as $event) {
            if (is_array($event)) $events[] = $event + ['_source_page_id' => $pageId];
        }
        $after = (string)($json['paging']['cursors']['after'] ?? '');
        if ($after === '' || empty($json['data'])) break;
    }
    return $events;
}

function fbCliFetchEvent(string $eventId, string $token, string $version): array {
    $json = fbCliGraphRequest(rawurlencode($eventId), ['fields' => FB_GRAPH_EVENT_FIELDS], $token, $version);
    return $json + ['_source_event_id' => $eventId];
}

function fbCliStageGraphEvent(array $event, string $area, bool $downloadImages, bool $dryRun, array &$summary): void {
    $candidate = facebookGraphEventToCandidate($event, $area);
    $title = $candidate['title'] ?: '(untitled)';
    if ($dryRun) {
        $summary['dry_run']++;
        fbCliLine('DRY RUN: '.$title.' | '.($candidate['event_date'] ?: 'no date').' | '.($candidate['source_url'] ?: 'no source URL'));
        return;
    }

    $result = facebookEventStageCandidate($candidate, $downloadImages);
    if ($result['ok']) {
        $summary[$result['action']] = ($summary[$result['action']] ?? 0) + 1;
        fbCliLine(strtoupper(str_replace('_', ' ', $result['action'])).': #'.$result['id'].' '.$title);
    } else {
        $summary['failed']++;
        fbCliLine('FAILED: '.$title.' - '.$result['error']);
    }
}

$options = fbCliOptions($argv);
if (isset($options['help']) || $options === []) {
    fbCliUsage();
    exit(0);
}

$token = trim((string)($options['access-token'] ?? getenv('FACEBOOK_GRAPH_ACCESS_TOKEN') ?: ''));
if ($token === '') {
    fwrite(STDERR, "Missing Graph API access token. Use --access-token or FACEBOOK_GRAPH_ACCESS_TOKEN.\n\n");
    fbCliUsage();
    exit(2);
}

try {
    $version = fbCliGraphVersion($options);
    $area = trim((string)($options['area'] ?? ''));
    $limit = max(1, (int)($options['limit'] ?? 100));
    $downloadImages = !isset($options['no-images']);
    $dryRun = isset($options['dry-run']);
    $summary = ['created' => 0, 'updated' => 0, 'already_imported' => 0, 'dry_run' => 0, 'failed' => 0, 'graph_failed' => 0];

    $pageIds = array_values(array_unique(array_merge(
        fbCliValues($options, 'page-id'),
        fbCliFileValues($options, 'pages-file'),
        fbCliDiscoverPages($options, $token, $version)
    )));
    $eventIds = array_values(array_unique(array_merge(
        fbCliValues($options, 'event-id'),
        fbCliFileValues($options, 'events-file')
    )));

    if (!$pageIds && !$eventIds) {
        throw new RuntimeException('Provide at least one --page-id, --pages-file, --event-id, --events-file, or --discover-pages source.');
    }

    $since = fbCliDateToTimestamp((string)($options['since'] ?? ''), 'today');
    $until = fbCliDateToTimestamp((string)($options['until'] ?? ''), '+1 year');
    $staged = 0;

    foreach ($eventIds as $eventId) {
        if ($staged >= $limit) break;
        fbCliLine('Fetching Graph event: '.$eventId);
        try {
            $event = fbCliFetchEvent($eventId, $token, $version);
            fbCliStageGraphEvent($event, $area, $downloadImages, $dryRun, $summary);
            $staged++;
        } catch (Throwable $e) {
            $summary['graph_failed']++;
            fbCliLine('GRAPH FAILED: event '.$eventId.' - '.$e->getMessage());
        }
    }

    foreach ($pageIds as $pageId) {
        if ($staged >= $limit) break;
        $remaining = $limit - $staged;
        fbCliLine('Fetching Graph Page events: '.$pageId);
        try {
            $events = fbCliFetchPageEvents($pageId, $token, $version, $since, $until, $remaining);
        } catch (Throwable $e) {
            $summary['graph_failed']++;
            fbCliLine('GRAPH FAILED: page '.$pageId.' - '.$e->getMessage());
            continue;
        }
        foreach ($events as $event) {
            if ($staged >= $limit) break;
            fbCliStageGraphEvent($event, $area, $downloadImages, $dryRun, $summary);
            $staged++;
        }
    }

    fbCliLine();
    fbCliLine('Summary:');
    fbCliLine('  Created: '.$summary['created']);
    fbCliLine('  Updated: '.$summary['updated']);
    fbCliLine('  Already imported: '.$summary['already_imported']);
    if ($dryRun) fbCliLine('  Dry-run candidates: '.$summary['dry_run']);
    fbCliLine('  Stage failures: '.$summary['failed']);
    fbCliLine('  Graph failures: '.$summary['graph_failed']);
    fbCliLine();
    fbCliLine('Review staged imports at: /admin/event_imports.php');
} catch (Throwable $e) {
    fwrite(STDERR, "Error: ".$e->getMessage()."\n");
    exit(1);
}