import FluentKit
import Foundation

/// A FluentKit model of a single `offers` row.
final class OfferRecord: Model, @unchecked Sendable {

    // MARK: Properties

    static let schema = "offers"

    @ID(key: .id)
    var id: UUID?

    @Parent(key: "conversation_id")
    var conversation: ConversationRecord

    @Parent(key: "listing_id")
    var listing: ListingRecord

    @Parent(key: "buyer_id")
    var buyer: UserRecord

    @Field(key: "amount_cents")
    var amountCents: Int

    @Field(key: "status")
    var status: String

    @Field(key: "created_at")
    var createdAt: Date

    @Field(key: "expires_at")
    var expiresAt: Date

    // MARK: Initializers

    init() {}

    init(
        conversationID: UUID,
        listingID: UUID,
        buyerID: UUID,
        amountCents: Int,
        at date: Date
    ) {
        self.$conversation.id = conversationID
        self.$listing.id = listingID
        self.$buyer.id = buyerID
        self.amountCents = amountCents
        self.status = Offer.Status.open.rawValue
        self.createdAt = date
        self.expiresAt = date.addingTimeInterval(Offer.lifetime)
    }

}

// MARK: - Extensions

extension OfferRecord {

    // MARK: Methods

    /// The `Sendable` snapshot of the saved record; its buyer, and its listing with its shop, must be eager-loaded.
    /// - Parameter now: the moment an open offer's expiry is judged at.
    func snapshot(
        at now: Date
    ) throws -> Offer {
        let stored = Offer.Status(rawValue: status) ?? .declined

        return .init(
            id: try requireID(),
            conversationID: $conversation.id,
            listing: listing.snapshot,
            buyer: try buyer.snapshot,
            amountCents: amountCents,
            status: stored == .open && expiresAt <= now ? .expired : stored,
            createdAt: createdAt,
            expiresAt: expiresAt
        )
    }

}