import Elementary
import Foundation
import Testing

@testable import Infrastructure

@Suite(
    "Page protocol",
    .tags(.`protocol`)
)
struct PageTests {

    // MARK: Functional tests

    @Test
    func `assembles the document around the page's parts`() {
        let html = StubPage().render()

        #expect(html.contains("<title>Stub Page</title>"))
        #expect(html.contains(#"lang="en""#))
        #expect(html.contains(#"name="viewport""#))
        #expect(html.contains(#"<meta name="stub" content="marker">"#))
        #expect(html.contains(#"<link rel="stylesheet" href="/css/stub.css">"#))
        #expect(html.contains(#"<script defer src="/js/stub.js"></script>"#))
        #expect(html.contains("Stub content"))
    }

    @Test
    func `places the metadata between the viewport and the stylesheets`() throws {
        let html = StubPage().render()

        let viewport = try #require(html.range(of: #"name="viewport""#))
        let metadata = try #require(html.range(of: #"name="stub""#))
        let stylesheet = try #require(html.range(of: "/css/stub.css"))

        #expect(viewport.lowerBound < metadata.lowerBound)
        #expect(metadata.lowerBound < stylesheet.lowerBound)
    }

    @Test
    func `renders the scripts deferred in the head, after the stylesheets`() throws {
        let html = StubPage().render()

        let stylesheet = try #require(html.range(of: "/css/stub.css"))
        let script = try #require(html.range(of: "/js/stub.js"))
        let content = try #require(html.range(of: "Stub content"))

        // Deferred head scripts start downloading during head parsing but still execute, in order, only after the
        // document is parsed — the semantics end-of-body tags gave, minus the late download start.
        #expect(stylesheet.lowerBound < script.lowerBound)
        #expect(script.lowerBound < content.lowerBound)
    }

    @Test
    func `omits the summary and canonical tags by default`() {
        let html = StubPage().render()

        #expect(!html.contains(#"name="description""#))
        #expect(!html.contains(#"rel="canonical""#))
    }

    @Test
    func `renders the summary and canonical tags when provided`() {
        let html = StubPage(
            canonicalURL: "https://stub.example/",
            summary: "A stub page."
        ).render()

        #expect(html.contains(#"<meta name="description" content="A stub page.">"#))
        #expect(html.contains(#"<link rel="canonical" href="https://stub.example/">"#))
    }

    @Test
    func `omits the social card tags by default`() {
        let html = StubPage().render()

        #expect(!html.contains(#"property="og:"#))
        #expect(!html.contains(#"name="twitter:card""#))
    }

    @Test
    func `renders the social card tags when provided`() {
        let html = StubPage(socialCard: .init(
            title: "Stub Page",
            summary: "A stub page.",
            url: "https://stub.example/",
            image: .init(
                url: "https://stub.example/img/card.png",
                width: 2400,
                height: 1260
            )
        )).render()

        #expect(html.contains(#"<meta property="og:type" content="website">"#))
        #expect(html.contains(#"<meta property="og:title" content="Stub Page">"#))
        #expect(html.contains(#"<meta property="og:description" content="A stub page.">"#))
        #expect(html.contains(#"<meta property="og:url" content="https://stub.example/">"#))
        #expect(html.contains(#"<meta property="og:image" content="https://stub.example/img/card.png">"#))
        #expect(html.contains(#"<meta property="og:image:width" content="2400">"#))
        #expect(html.contains(#"<meta property="og:image:height" content="1260">"#))
        #expect(html.contains(#"<meta name="twitter:card" content="summary_large_image">"#))
    }

    @Test
    func `omits the structured data script by default`() {
        let html = StubPage().render()

        #expect(!html.contains("application/ld+json"))
    }

    @Test
    func `renders the structured data script when provided`() {
        let html = StubPage(structuredData: .init(
            name: "Stub Site",
            url: "https://stub.example/",
            logo: "https://stub.example/logo.png",
            profiles: ["https://social.example/stub"]
        )).render()

        #expect(html.contains(
            #"<script type="application/ld+json">"# +
            #"{"@context":"https://schema.org","@graph":["# +
            #"{"@type":"Organization","@id":"https://stub.example/#organization","name":"Stub Site","url":"https://stub.example/","logo":"https://stub.example/logo.png","sameAs":["https://social.example/stub"]},"# +
            #"{"@type":"WebSite","name":"Stub Site","url":"https://stub.example/","publisher":{"@id":"https://stub.example/#organization"}}]}"# +
            #"</script>"#
        ))
    }

    @Test
    func `omits the analytics tracker by default`() {
        let html = StubPage().render()

        #expect(!html.contains("data-website-id"))
        #expect(!html.contains(#"rel="preconnect""#))
    }

    @Test
    func `renders the analytics tracker when provided`() throws {
        let html = StubPage(analytics: .init(
            scriptURL: "https://analytics.example.com/script",
            websiteID: "0000-website-id",
            domains: "example.com"
        )).render()

        #expect(html.contains(#"<script defer src="https://analytics.example.com/script" data-website-id="0000-website-id" data-domains="example.com" data-exclude-hash="true" data-do-not-track="true" data-performance="true"></script>"#))

        // The preconnect hint warms the tracker origin's connection before the parser reaches the script tag.
        let preconnect = try #require(html.range(of: #"<link rel="preconnect" href="https://analytics.example.com">"#))
        let script = try #require(html.range(of: #"<script defer src="https://analytics.example.com/script""#))

        #expect(preconnect.lowerBound < script.lowerBound)
    }

    @Test
    func `omits the analytics behavior flags that are disabled`() {
        let html = StubPage(analytics: .init(
            scriptURL: "https://analytics.example.com/script",
            websiteID: "0000-website-id",
            domains: "example.com",
            excludeHash: true,
            doNotTrack: false,
            performance: false
        )).render()

        #expect(html.contains(#"<script defer src="https://analytics.example.com/script" data-website-id="0000-website-id" data-domains="example.com" data-exclude-hash="true"></script>"#))
        #expect(!html.contains("data-do-not-track"))
        #expect(!html.contains("data-performance"))
    }

    @Test
    func `appends the version token to the asset URLs`() {
        let html = StubPage(assetVersion: "0123456789abcdef").render()

        #expect(html.contains("/css/stub.css?v=0123456789abcdef"))
        #expect(html.contains("/js/stub.js?v=0123456789abcdef"))
    }

    @Test
    func `derives the document language from the locale`() {
        let html = StubPage(locale: .init(identifier: "de-DE")).render()

        #expect(html.contains(#"lang="de""#))
    }

}