import Elementary
import Foundation
import Infrastructure
import Testing

@testable import WebsiteLibrary

@Suite(
    "Page+Defaults extension",
    .tags(.extensionTests)
)
struct PageDefaultsTests {

    // MARK: Computed tests

    @Test
    func `pairs english with a territory for its social card locale`() {
        #expect(StubPage().ogLocale == "en_US")
    }

    /// Open Graph prefers `language_TERRITORY`, but a scraper accepts the bare code — better than pinning a territory the site never named.
    @Test
    func `leaves an unpaired language as a bare code`() {
        #expect(StubPage(locale: .init(identifier: "nl")).ogLocale == "nl")
    }

    // MARK: Method tests

    @Test
    func `renders no language alternates without an origin`() {
        let html = StubPage().languageAlternates(
            origin: nil,
            path: "/",
            languages: Self.languages
        ).render()

        #expect(html.isEmpty)
    }

    @Test
    func `renders no language alternates for a single language`() {
        let html = StubPage().languageAlternates(
            origin: "https://example.com",
            path: "/",
            languages: [.default]
        ).render()

        #expect(html.isEmpty)
    }

    /// The default language keeps the bare root; the prefixed edition collapses onto its prefix rather than carrying a trailing slash.
    @Test
    func `renders an alternate per language and an x-default at the root`() {
        let html = StubPage().languageAlternates(
            origin: "https://example.com",
            path: "/",
            languages: Self.languages
        ).render()

        #expect(html.contains(#"<link rel="alternate" hreflang="en" href="https://example.com">"#))
        #expect(html.contains(#"<link rel="alternate" hreflang="nl" href="https://example.com/nl">"#))
        #expect(html.contains(#"<link rel="alternate" hreflang="x-default" href="https://example.com">"#))
    }

    @Test
    func `prefixes the alternates of a nested page`() {
        let html = StubPage().languageAlternates(
            origin: "https://example.com",
            path: "/privacy",
            languages: Self.languages
        ).render()

        #expect(html.contains(#"<link rel="alternate" hreflang="en" href="https://example.com/privacy">"#))
        #expect(html.contains(#"<link rel="alternate" hreflang="nl" href="https://example.com/nl/privacy">"#))
        #expect(html.contains(#"<link rel="alternate" hreflang="x-default" href="https://example.com/privacy">"#))
    }

}

// MARK: - Helpers

private extension PageDefaultsTests {

    // MARK: Constants

    /// A two-language set, standing in for the multi-language catalog the template itself does not ship.
    static let languages: [Language] = [
        .default,
        .init(identifier: "nl")
    ]

    // MARK: Types

    /// The barest ``Page`` conformance, so the shared defaults can be exercised without a real page's content.
    struct StubPage: Page {

        // MARK: Properties

        let assetVersion: String? = nil
        let locale: Locale

        // MARK: Initializers

        init(locale: Locale = .init(identifier: "en")) {
            self.locale = locale
        }

        // MARK: Properties

        var content: some HTML {
            HTMLRaw("")
        }

        var scripts: [any Asset] {
            []
        }

        var stylesheets: [any Asset] {
            []
        }

        var title: String {
            "Stub"
        }

    }

}