import Foundation

@MainActor
protocol LeadDetailRemoteService {
    func fetchDetail(id: String, salesCode: String) async throws -> LeadDetailDTO
    func download(_ reference: LeadFileReference, leadID: String, salesCode: String) async throws -> Data
}

/// Transport boundary. A future HTTP adapter maps its response into this payload.
struct LeadDetailDTO {
    let detail: LeadDetail

    func toDomain(expectedID: String) throws -> LeadDetail {
        let documents = detail.offers.flatMap(\.documents)
        let groups = detail.offers.flatMap(\.groups)
        guard detail.lead.id == expectedID,
              Set(detail.offers.map(\.id)).count == detail.offers.count,
              Set(groups.map(\.id)).count == groups.count,
              Set(documents.map(\.id)).count == documents.count,
              Set(detail.photos.map(\.id)).count == detail.photos.count,
              Set(detail.tankOptions.map(\.id)).count == detail.tankOptions.count,
              detail.offers.allSatisfy({ !$0.id.isEmpty && !$0.title.isEmpty && $0.amount >= 0 }),
              documents.allSatisfy({ !$0.id.isEmpty && !$0.title.isEmpty && $0.pageCount > 0
                  && $0.file.kind == .pdf && !$0.file.id.isEmpty && !$0.file.version.isEmpty }),
              detail.photos.allSatisfy({ $0.thumbnail.kind == .image && $0.original.kind == .image })
        else { throw LeadError.invalidResponse }
        return detail
    }
}