<?php

namespace App\Services;

use App\Clients\SlsClient;
use Carbon\Carbon;
use Illuminate\Support\Collection;

class SlsService
{
    public function __construct(
        private readonly SlsClient $client,
        private readonly ConfigService $configService
    ) {}

    /**
     * 检查 SLS 是否已配置
     */
    public function isConfigured(): bool
    {
        return $this->client->isConfigured();
    }

    /**
     * 获取日志
     *
     * @param Carbon $from 开始时间
     * @param Carbon $to 结束时间
     * @param string|null $query SLS 查询语句
     * @param int|null $limit 最大返回数量
     * @return Collection
     */
    public function fetchLogs(
        Carbon $from,
        Carbon $to,
        ?string $query = null,
        ?int $limit = null
    ): Collection {
        $settings = $this->configService->get('log_analysis.settings', []);
        $maxLogs = $limit ?? ($settings['max_logs_per_batch'] ?? 1000);

        $logs = $this->client->getAllLogs(
            $from->timestamp,
            $to->timestamp,
            $query,
            $maxLogs
        );

        return collect($logs)->map(function ($log) {
            return $this->normalizeLog($log);
        });
    }

    /**
     * 从多个 logstore 获取日志
     *
     * @param Carbon $from 开始时间
     * @param Carbon $to 结束时间
     * @param string|null $query SLS 查询语句
     * @param int|null $limit 最大返回数量
     * @param array|null $logstores 要查询的 logstore 列表
     * @return array 按 logstore 分组的日志数据
     */
    public function fetchLogsFromMultipleStores(
        Carbon $from,
        Carbon $to,
        ?string $query = null,
        ?int $limit = null,
        ?array $logstores = null
    ): array {
        $settings = $this->configService->get('log_analysis.settings', []);
        $maxLogs = $limit ?? ($settings['max_logs_per_batch'] ?? 1000);

        $results = $this->client->getAllLogsFromMultipleStores(
            $from->timestamp,
            $to->timestamp,
            $query,
            $maxLogs,
            $logstores
        );

        // 标准化每个 logstore 的日志
        $normalized = [];
        foreach ($results as $logstore => $data) {
            $normalized[$logstore] = [
                'logs' => collect($data['logs'])->map(function ($log) use ($logstore) {
                    $normalizedLog = $this->normalizeLog($log);
                    $normalizedLog['_logstore'] = $logstore;
                    return $normalizedLog;
                }),
                'count' => $data['count'],
                'success' => $data['success'],
                'error' => $data['error'] ?? null,
            ];
        }

        return $normalized;
    }

    /**
     * 获取配置的所有 logstore
     */
    public function getLogstores(): array
    {
        return $this->client->getLogstores();
    }

    /**
     * 按 app_name 分组日志
     *
     * @param Collection $logs
     * @return array<string, Collection>
     */
    public function groupByAppName(Collection $logs): array
    {
        $grouped = $logs->groupBy(function ($log) {
            return $log['app_name'] ?? $log['__source__'] ?? 'unknown';
        });

        return $grouped->map(function ($group) {
            return $group->values();
        })->toArray();
    }

    /**
     * 按日志级别过滤
     *
     * @param Collection $logs
     * @param array $levels 要保留的级别 ['ERROR', 'WARN', 'INFO']
     * @return Collection
     */
    public function filterByLevel(Collection $logs, array $levels): Collection
    {
        $levels = array_map('strtoupper', $levels);

        return $logs->filter(function ($log) use ($levels) {
            $level = strtoupper($log['level'] ?? $log['__level__'] ?? '');
            return in_array($level, $levels);
        });
    }

    /**
     * 获取日志分布直方图
     *
     * @param Carbon $from
     * @param Carbon $to
     * @param string|null $query
     * @return array
     */
    public function getHistogram(Carbon $from, Carbon $to, ?string $query = null): array
    {
        return $this->client->getHistograms(
            $from->timestamp,
            $to->timestamp,
            $query
        );
    }

    /**
     * 获取日志统计信息
     *
     * @param Collection $logs
     * @return array
     */
    public function getStatistics(Collection $logs): array
    {
        $byLevel = $logs->groupBy(function ($log) {
            return strtoupper($log['level'] ?? $log['__level__'] ?? 'UNKNOWN');
        })->map(fn ($group) => $group->count());

        $byApp = $logs->groupBy(function ($log) {
            return $log['app_name'] ?? $log['__source__'] ?? 'unknown';
        })->map(fn ($group) => $group->count());

        return [
            'total' => $logs->count(),
            'by_level' => $byLevel->toArray(),
            'by_app' => $byApp->toArray(),
        ];
    }

    /**
     * 获取多 logstore 的统计信息
     *
     * @param array $logstoreData 按 logstore 分组的日志数据
     * @return array
     */
    public function getMultiStoreStatistics(array $logstoreData): array
    {
        $totalCount = 0;
        $byLogstore = [];
        $byLevel = [];
        $byApp = [];

        foreach ($logstoreData as $logstore => $data) {
            if (!$data['success']) {
                $byLogstore[$logstore] = [
                    'count' => 0,
                    'success' => false,
                    'error' => $data['error'],
                ];
                continue;
            }

            $logs = $data['logs'];
            $count = $logs->count();
            $totalCount += $count;

            $byLogstore[$logstore] = [
                'count' => $count,
                'success' => true,
            ];

            // 按级别统计
            $logs->groupBy(function ($log) {
                return strtoupper($log['level'] ?? $log['__level__'] ?? 'UNKNOWN');
            })->each(function ($group, $level) use (&$byLevel) {
                $byLevel[$level] = ($byLevel[$level] ?? 0) + $group->count();
            });

            // 按应用统计
            $logs->groupBy(function ($log) {
                return $log['app_name'] ?? $log['__source__'] ?? 'unknown';
            })->each(function ($group, $app) use (&$byApp) {
                $byApp[$app] = ($byApp[$app] ?? 0) + $group->count();
            });
        }

        return [
            'total' => $totalCount,
            'by_logstore' => $byLogstore,
            'by_level' => $byLevel,
            'by_app' => $byApp,
        ];
    }

    /**
     * 测试连接
     */
    public function testConnection(): bool
    {
        return $this->client->testConnection();
    }

    /**
     * 标准化日志格式
     */
    private function normalizeLog(array $log): array
    {
        // 如果日志内容是 JSON 字符串（某些情况下 SLS 会将整条日志作为一个字段返回）
        // 尝试解析 content 或 message 字段
        if (isset($log['content']) && is_string($log['content']) && str_starts_with(trim($log['content']), '{')) {
            $decoded = json_decode($log['content'], true);
            if (json_last_error() === JSON_ERROR_NONE && is_array($decoded)) {
                $log = array_merge($log, $decoded);
            }
        }

        // 尝试提取常见字段，优先使用业务字段，其次使用 SLS 系统字段
        $normalized = [
            'time' => $log['date'] ?? $log['time'] ?? $log['timestamp'] ?? $log['__time__'] ?? null,
            'level' => $log['level'] ?? $log['__level__'] ?? $log['severity'] ?? null,
            'message' => $log['message'] ?? $log['msg'] ?? $log['content'] ?? null,
            'app_name' => $log['app_name'] ?? $log['application'] ?? $log['service'] ?? $log['__source__'] ?? null,
            'trace' => $log['stack_trace'] ?? $log['trace'] ?? $log['exception'] ?? null,
            'file' => $log['file'] ?? $log['filename'] ?? null,
            'line' => $log['line'] ?? $log['lineno'] ?? null,
        ];

        // 格式化时间
        if (is_numeric($normalized['time'])) {
            // Unix 时间戳
            $normalized['time'] = Carbon::createFromTimestamp($normalized['time'])->format('Y-m-d H:i:s');
        } elseif (is_string($normalized['time']) && !empty($normalized['time'])) {
            // ISO 8601 格式或其他字符串格式
            try {
                $normalized['time'] = Carbon::parse($normalized['time'])->format('Y-m-d H:i:s');
            } catch (\Exception $e) {
                // 如果解析失败，保持原样
            }
        }

        // 保留原始数据
        $normalized['_raw'] = $log;

        return $normalized;
    }
}