<?php

declare(strict_types=1);

namespace App\Service;

use Symfony\Component\Process\Process;

final readonly class LogService
{
    public function __construct(
        private AppPathResolver $pathResolver,
    ) {}

    public function getDockerLogs(string $containerName, int $lines = 100, ?string $since = null): string
    {
        $check = new Process(['which', 'docker']);
        $check->setTimeout(5);
        $check->run();

        if (!$check->isSuccessful()) {
            return 'Docker CLI is not available in this environment.';
        }

        $args = ['docker', 'logs', '--tail', (string) $lines];

        if (null !== $since) {
            $args[] = '--since';
            $args[] = $since;
        }

        $args[] = $containerName;

        $process = new Process($args);
        $process->setTimeout(10);
        $process->run();

        $output = $process->getOutput() . $process->getErrorOutput();

        return $this->formatDockerOutput($output);
    }

    private function formatDockerOutput(string $output): string
    {
        $rawLines = explode("\n", trim($output));
        $formatted = [];

        foreach ($rawLines as $line) {
            if ('' === $line) {
                continue;
            }

            // Try parsing as Symfony monolog JSON format
            $parsed = $this->parseSymfonyLogLine($line);

            if (null !== $parsed) {
                if ('doctrine' === $parsed['channel']) {
                    continue;
                }
                $formatted[] = sprintf('[%s] %s.%s: %s', $parsed['date'], $parsed['channel'], $parsed['level'], $parsed['message']);
                continue;
            }

            // Try parsing as JSON log ({"message":"...","level":...})
            $json = json_decode($line, true);
            if (\is_array($json) && isset($json['message'])) {
                $date = isset($json['datetime']) ? substr($json['datetime'], 0, 19) : '';
                $date = str_replace('T', ' ', $date);
                $channel = $json['channel'] ?? 'app';
                $level = $json['level_name'] ?? 'INFO';

                if ('doctrine' === $channel) {
                    continue;
                }

                $formatted[] = sprintf('[%s] %s.%s: %s', $date, $channel, $level, $json['message']);
                continue;
            }

            // Keep raw lines that don't match any format (nginx access logs, etc.)
            $formatted[] = $line;
        }

        return implode("\n", $formatted);
    }

    public function getSymfonyLog(string $containerName, string $logPath, int $lines = 100, ?string $level = null): string
    {
        $check = new Process(['which', 'docker']);
        $check->setTimeout(5);
        $check->run();

        if (!$check->isSuccessful()) {
            // Fallback: try reading from filesystem (dev mode)
            $localPath = $this->pathResolver->resolve($logPath);
            if (!file_exists($localPath)) {
                return sprintf('Log file not found: %s (Docker CLI unavailable, local path: %s)', $logPath, $localPath);
            }
            $readLines = (null !== $level && '' !== $level) ? $lines * 5 : $lines;
            $process = new Process(['tail', '-n', (string) $readLines, $localPath]);
            $process->setTimeout(10);
            $process->run();
            return $this->formatSymfonyOutput($process->getOutput(), $lines, $level);
        }

        // Read more lines than requested to compensate for filtering
        $readLines = (null !== $level && '' !== $level) ? $lines * 5 : $lines;

        $process = new Process(['docker', 'exec', $containerName, 'tail', '-n', (string) $readLines, $logPath]);
        $process->setTimeout(10);
        $process->run();

        if (!$process->isSuccessful()) {
            return sprintf('Error reading log: %s', trim($process->getErrorOutput()));
        }

        return $this->formatSymfonyOutput($process->getOutput(), $lines, $level);
    }

    private function formatSymfonyOutput(string $output, int $lines, ?string $level): string
    {
        $rawLines = explode("\n", trim($output));
        $formatted = [];

        foreach ($rawLines as $line) {
            if ('' === $line) {
                continue;
            }

            $parsed = $this->parseSymfonyLogLine($line);

            if (null === $parsed) {
                continue;
            }

            // Skip noisy channels
            if ('doctrine' === $parsed['channel']) {
                continue;
            }

            if (null !== $level && '' !== $level && !str_contains(strtoupper($parsed['level']), strtoupper($level))) {
                continue;
            }

            $formatted[] = sprintf('[%s] %s.%s: %s', $parsed['date'], $parsed['channel'], $parsed['level'], $parsed['message']);
        }

        // Keep only the last N lines after filtering
        $formatted = \array_slice($formatted, -$lines);

        return implode("\n", $formatted);
    }

    /**
     * @return array{date: string, level: string, channel: string, message: string}|null
     */
    private function parseSymfonyLogLine(string $line): ?array
    {
        // Standard Symfony monolog format: [2026-04-03T15:33:19.304937+02:00] channel.LEVEL: message {context} []
        if (preg_match('/^\[([^\]]+)\]\s+(\w+)\.(\w+):\s+(.+)$/', $line, $matches)) {
            $date = substr($matches[1], 0, 19); // Trim to YYYY-MM-DDTHH:MM:SS
            $message = $matches[4];

            // Remove JSON context at the end: {"key":"value"} []
            $message = preg_replace('/\s*\{.*\}\s*\[\]\s*$/', '', $message) ?? $message;
            // Remove trailing []
            $message = preg_replace('/\s*\[\]\s*$/', '', $message) ?? $message;

            return [
                'date' => str_replace('T', ' ', $date),
                'level' => $matches[3],
                'channel' => $matches[2],
                'message' => $message,
            ];
        }

        return null;
    }
}