import Elementary
import Persistence

/// A listing in a card grid: its cover, title, price, grade chip, and — depending on the ``Context`` — the shop selling it.
struct ListingCard: HTML {

    // MARK: Properties

    /// Where the card is shown.
    let context: Context

    /// The listing the card shows.
    let listing: Listing

    // MARK: Initializers

    /// Creates a listing card.
    /// - Parameters:
    ///   - listing: the listing the card shows.
    ///   - context: where the card is shown; a browsing row by default.
    init(
        _ listing: Listing,
        context: Context = .browse
    ) {
        self.context = context
        self.listing = listing
    }

    // MARK: Computed

    var body: some HTML {
        article(.class("listing-card")) {
            // Saving is a gated action: signed out, it leads to the sign-in screen.
            a(
                .class("listing-card__save"),
                .href(.Route.signIn(returningTo: listing.path)),
                .custom(
                    name: "aria-label",
                    value: "Save \(listing.title) to watchlist"
                )
            ) {
                Icon(.bookmark, size: 18)
            }
            a(
                .class("listing-card__cover"),
                .href(listing.path),
                .custom(
                    name: "tabindex",
                    value: "-1"
                ),
                .custom(
                    name: "aria-hidden",
                    value: "true"
                )
            ) {
                ListingImage(listing)
            }
            div {
                h3(.class("type-card-title")) {
                    a(
                        .class("listing-card__title"),
                        .href(listing.path)
                    ) {
                        listing.title
                    }
                }
                p(.class("listing-card__meta")) {
                    listing.summary
                }
            }
            div(.class("listing-card__row")) {
                span(.class("type-price-card")) {
                    listing.priceCents.euros
                }
                Chip(
                    listing.chip.label,
                    tone: listing.chip.tone,
                    isCertified: listing.chip.isCertified
                )
            }
            if context != .shop {
                a(
                    .class("listing-card__shop"),
                    .href(listing.shop.path)
                ) {
                    context == .search
                        ? "\(listing.shop.name) · \(listing.shop.country) · ship \(listing.shippingCents.euros)"
                        : listing.shop.name
                }
            }
        }
    }

}

// MARK: - Enumerations

extension ListingCard {
    /// Where a listing card is shown.
    enum Context: Sendable {
        /// A browsing row: the shop is named.
        case browse
        /// Search results: the shop is named with its country and shipping cost.
        case search
        /// The shop's own screen: the shop goes unnamed.
        case shop
    }
}