@testable import PureXML
import Testing

@Suite("XSD top-level attribute applicability (topLevelAttribute)")
struct SchemaTopLevelAttributeTests {
    private let xsd = "xmlns:xs=\"http://www.w3.org/2001/XMLSchema\""

    private func compiles(_ body: String) -> Bool {
        (try? PureXML.Schema.Document("<xs:schema \(xsd)>\(body)</xs:schema>")) != nil
    }

    @Test("A top-level attribute with use is rejected")
    func test_topLevelUseRejected() {
        #expect(!compiles("<xs:attribute name=\"a\" type=\"xs:string\" use=\"required\"/>"))
        #expect(!compiles("<xs:attribute name=\"a\" type=\"xs:string\" use=\"optional\"/>"))
        #expect(!compiles("<xs:attribute name=\"a\" type=\"xs:string\" use=\"prohibited\"/>"))
    }

    @Test("A top-level attribute with form is rejected")
    func test_topLevelFormRejected() {
        #expect(!compiles("<xs:attribute name=\"a\" type=\"xs:string\" form=\"qualified\"/>"))
    }

    @Test("A plain top-level attribute declaration compiles")
    func test_plainTopLevelAccepted() {
        #expect(compiles("<xs:attribute name=\"a\" type=\"xs:string\"/>"))
        #expect(compiles("<xs:attribute name=\"a\" type=\"xs:string\" default=\"x\"/>"))
    }

    /// `use`, `form`, and a `ref` are legitimate on a LOCAL attribute use inside a
    /// complex type; the rule applies only to top-level declarations.
    @Test("A local attribute use with use/form compiles")
    func test_localUseAccepted() {
        #expect(compiles(
            "<xs:element name=\"e\"><xs:complexType>"
                + "<xs:attribute name=\"a\" type=\"xs:string\" use=\"required\" form=\"qualified\"/>"
                + "</xs:complexType></xs:element>",
        ))
        // A local ref with use is fine.
        #expect(compiles(
            "<xs:attribute name=\"g\" type=\"xs:string\"/>"
                + "<xs:element name=\"e\"><xs:complexType>"
                + "<xs:attribute ref=\"g\" use=\"required\"/>"
                + "</xs:complexType></xs:element>",
        ))
    }
}