//
//  LogStore.swift
//  secant-testnet
//
//  Created by Lukáš Korba on 23.01.2023.
//

import Foundation
import OSLog
    
enum LogStore {
    static func exportCategory(
        _ category: String,
        hoursToThePast: TimeInterval = 168,
        fileSize: Int = 1_000_000
    ) async throws -> [String]? {
        guard let bundle = Bundle.main.bundleIdentifier else { return nil }
        
        let store = try OSLogStore(scope: .currentProcessIdentifier)
        let date = Date.now.addingTimeInterval(-hoursToThePast * 3600)
        let position = store.position(date: date)
        var res: [String] = []
        var size = 0
        
        let entries = try store.getEntries(at: position).reversed()
        for entry in entries {
            guard let logEntry = entry as? OSLogEntryLog else { continue }
            guard logEntry.subsystem == bundle && logEntry.category == category else { continue }
            
            guard size < fileSize else { break }
            
            size += logEntry.composedMessage.utf8.count
            res.append("[\(logEntry.date.timestamp())] \(logEntry.composedMessage)")
        }
        
        return res
    }
}