//
//  EditableProfile.swift
//  Passepartout
//
//  Created by Davide De Rosa on 10/6/24.
//  Copyright (c) 2024 Davide De Rosa. All rights reserved.
//
//  https://github.com/passepartoutvpn
//
//  This file is part of Passepartout.
//
//  Passepartout is free software: you can redistribute it and/or modify
//  it under the terms of the GNU General Public License as published by
//  the Free Software Foundation, either version 3 of the License, or
//  (at your option) any later version.
//
//  Passepartout is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU General Public License for more details.
//
//  You should have received a copy of the GNU General Public License
//  along with Passepartout.  If not, see <http://www.gnu.org/licenses/>.
//

import Foundation
import PassepartoutKit

struct EditableProfile: MutableProfileType {
    var id = UUID()

    var name: String = ""

    var modules: [any ModuleBuilder] = []

    var activeModulesIds: Set<UUID> = []

    var modulesMetadata: [UUID: ModuleMetadata]?

    func builder() throws -> Profile.Builder {
        try checkConstraints()

        var builder = Profile.Builder(id: id)
        builder.modules = try modules.compactMap {
            do {
                return try $0.tryBuild()
            } catch {
                throw AppError.malformedModule($0, error: error)
            }
        }
        builder.activeModulesIds = activeModulesIds

        let trimmedName = name.trimmingCharacters(in: .whitespaces)
        guard !trimmedName.isEmpty else {
            throw AppError.emptyProfileName
        }
        builder.name = trimmedName

        builder.modulesMetadata = modulesMetadata?.reduce(into: [:]) {
            var metadata = $1.value
            guard let name = metadata.name else {
                return
            }
            let trimmedName = name.trimmingCharacters(in: .whitespaces)
            guard !trimmedName.isEmpty else {
                return
            }
            metadata.name = trimmedName
            $0[$1.key] = metadata
        }

        return builder
    }
}

extension Profile {
    func editable() -> EditableProfile {
        EditableProfile(
            id: id,
            name: name,
            modules: modulesBuilders,
            activeModulesIds: activeModulesIds,
            modulesMetadata: modulesMetadata
        )
    }

    var modulesBuilders: [any ModuleBuilder] {
        modules.compactMap {
            guard let buildableModule = $0 as? any BuildableType else {
                return nil
            }
            let builder = buildableModule.builder() as any BuilderType
            return builder as? any ModuleBuilder
        }
    }
}

private extension EditableProfile {
    var activeConnectionModule: (any ModuleBuilder)? {
        modules.first {
            isActiveModule(withId: $0.id) && $0.buildsConnectionModule
        }
    }

    func checkConstraints() throws {
        if activeConnectionModule == nil,
           let ipModule = modules.first(where: { activeModulesIds.contains($0.id) && $0 is IPModule.Builder }) {
            throw AppError.ipModuleRequiresConnection(ipModule)
        }

        let connectionModules = modules.filter {
            activeModulesIds.contains($0.id) && $0.buildsConnectionModule
        }
        guard connectionModules.count <= 1 else {
            throw AppError.multipleConnectionModules(connectionModules)
        }
    }
}