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

import Foundation

public typealias VehicleWithErrors = (
    vehicle: VehicleDto,
    errors: [Error]
)

public final class VehicleService {
    
    let apiService: ApiServiceProtocol
    let storageService: StorageServiceProtocol
    let locationService: LocationServiceProtocol
    
    public init(apiService: ApiServiceProtocol,
                storageService: StorageServiceProtocol,
                locationService: LocationServiceProtocol) {
        
        self.apiService = apiService
        self.storageService = storageService
        self.locationService = locationService
    }
}

extension VehicleService: VehicleServiceProtocol {
    
    func check(
        number: String,
        forceUpdate: Bool,
        trackLocation: Bool,
        additionalEvents: [VehicleEventDto],
        dbUpdatePolicy: DbUpdatePolicy
    ) async throws -> VehicleWithErrors {
        
        var vehicle = (try? await storageService.loadVehicle(number: number)) ?? VehicleDto(number: number)
        var errors: [Error] = []
        
        // TODO: Check if additionalEvents already was added earlier (avoid duplication)
        let events = vehicle.events + additionalEvents
        let notes = vehicle.notes
        
        if !additionalEvents.isEmpty {
            vehicle.events = events
            vehicle.updatedDate = Date().timeIntervalSince1970
            vehicle.synchronized = false
        }
        
        async let locationTask = trackLocation ? locationService.getRecentLocation() : nil
        async let vehicleTask = apiService.checkVehicle(by: number, notes: notes, events: events, force: forceUpdate)
        
        do {
            vehicle = try await vehicleTask
        } catch {
            errors.append(error)
        }
        
        if trackLocation {
            do {
                if let event = try await locationTask {
                    vehicle.events.append(event)
                    vehicle.updatedDate = Date().timeIntervalSince1970
                    vehicle.synchronized = false
                    if !vehicle.unrecognized {
                        vehicle = try await apiService.add(event: event, to: number)
                    }
                }
            } catch {
                errors.append(error)
            }
        }
        
        await locationService.resetLastEvent()
        try await storageService.updateVehicle(dto: vehicle, policy: dbUpdatePolicy)
        
        return VehicleWithErrors(vehicle: vehicle, errors: errors)
    }
    
    public func check(number: String) async throws -> VehicleWithErrors {
        
#if targetEnvironment(macCatalyst)
        try await check(
            number: number,
            forceUpdate: false,
            trackLocation: false,
            additionalEvents: [],
            dbUpdatePolicy: .always
        )
#else
        try await check(
            number: number,
            forceUpdate: false,
            trackLocation: true,
            additionalEvents: [],
            dbUpdatePolicy: .always
        )
#endif
    }
    
    public func updateHistory(number: String) async throws -> VehicleWithErrors {
        
        try await check(
            number: number,
            forceUpdate: true,
            trackLocation: false,
            additionalEvents: [],
            dbUpdatePolicy: .always
        )
    }
    
    public func updateSearch(number: String) async throws -> VehicleWithErrors {
        
        try await check(
            number: number,
            forceUpdate: true,
            trackLocation: false,
            additionalEvents: [],
            dbUpdatePolicy: .ifExists
        )
    }
    
    public func checkRecord(number: String, event: VehicleEventDto?) async throws -> VehicleWithErrors {
        
        try await check(
            number: number,
            forceUpdate: false,
            trackLocation: false,
            additionalEvents: event.flatMap { [$0] } ?? [],
            dbUpdatePolicy: .always
        )
    }
}