//
//  VehiclesArchive.swift
//  AutoCatCore
//
//  Created by Selim Mustafaev on 19.01.2025.
//  Copyright © 2025 Selim Mustafaev. All rights reserved.
//

import SwiftUI

public enum VehiclesArchiveError: LocalizedError {
    
    case filedCreateCsv
    
    public var errorDescription: String? {
        switch self {
        case .filedCreateCsv: "Failed to create csv data for vehicles"
        }
    }
}

public final class VehiclesArchive {
    
    var vehicles: [VehicleDto]
    let apiService: ApiServiceProtocol?
    let filter: Filter?
    
    public init(vehiles: [VehicleDto]) {
        
        self.vehicles = vehiles
        self.apiService = nil
        self.filter = nil
    }
    
    public init(apiService: ApiServiceProtocol, filter: Filter) {
        
        self.apiService = apiService
        self.filter = filter
        self.vehicles = []
    }
    
    func makeCsvString() throws -> String {
        
        var result = ""
        let newLine: Character = "\r\n"
        result.append(VehicleDto.csvHeader)
        result.append(newLine)
        
        for vehicle in vehicles {
            result.append(vehicle.csvLine)
            result.append(newLine)
        }
        
        return result
    }
    
    func loadVehiclesIfNeeded() async throws {
        if let apiService, let filter {
            let result = try await apiService.getVehicles(with: filter, pageToken: nil, pageSize: 0)
            vehicles = result.items
        }
    }
}

extension VehiclesArchive: Transferable {
    
    public static var fileName: String {
        "autocat.csv"
    }
    
    public static var transferRepresentation: some TransferRepresentation {
        
        DataRepresentation(exportedContentType: .commaSeparatedText) { archive in
            
            try await archive.loadVehiclesIfNeeded()
            let csvString = try archive.makeCsvString()
            
            if let data = csvString.data(using: .utf8){
                return data
            } else {
                throw VehiclesArchiveError.filedCreateCsv
            }
        }
        .suggestedFileName(fileName)
    }
}