//
//  TokenizerTests.swift
//  
//
//  Created by Shadowfacts on 11/22/23.
//

import XCTest
@testable import HTMLStreamer

final class TokenizerTests: XCTestCase {
    
    private func tokenize(_ s: String) -> [Token] {
        let iterator = Tokenizer(chars: s.unicodeScalars.makeIterator())
//        let iterator = PrintIterator(inner: Tokenizer(chars: s.makeIterator()))
        return Array(AnySequence({ iterator }))
    }

    func testNamedCharacterReferences() {
        XCTAssertEqual(tokenize("&amp;"), [.characterSequence("&")])
        // missing-semicolon-after-character-reference:
        XCTAssertEqual(tokenize("&not;in"), [.characterSequence("¬"), .characterSequence("in")])
        XCTAssertEqual(tokenize("&notin"), [.characterSequence("¬"), .characterSequence("in")])
        // unknown-named-character-reference:
        XCTAssertEqual(tokenize("&notit;"), [.characterSequence("¬"), .characterSequence("it;")])
        XCTAssertEqual(tokenize("&asdf"), [.characterSequence("&asdf")])
        XCTAssertEqual(tokenize("&a"), [.characterSequence("&a")])
        
        // attribute special case
        XCTAssertEqual(tokenize("<a a='&nota' />"), [.startTag("a", selfClosing: true, attributes: [Attribute(name: "a", value: "&nota")])])
    }
    
    func testNumericCharacterReference() {
        XCTAssertEqual(tokenize("&#33;"), [.characterSequence("!")])
        XCTAssertEqual(tokenize("&#x21;"), [.characterSequence("!")])
        XCTAssertEqual(tokenize("&#x4A;"), [.characterSequence("J")])
        XCTAssertEqual(tokenize("&#x4a;"), [.characterSequence("J")])
    }
    
    func testStartTag() {
        XCTAssertEqual(tokenize("<asdf>"), [.startTag("asdf", selfClosing: false, attributes: [])])
        XCTAssertEqual(tokenize("<asdf/>"), [.startTag("asdf", selfClosing: true, attributes: [])])
        XCTAssertEqual(tokenize("<asdf />"), [.startTag("asdf", selfClosing: true, attributes: [])])
        
        // double-quoted attributes
        XCTAssertEqual(tokenize("<asdf a=\"b\" />"), [.startTag("asdf", selfClosing: true, attributes: [.init(name: "a", value: "b")])])
        XCTAssertEqual(tokenize("<asdf a=\"&amp;\" />"), [.startTag("asdf", selfClosing: true, attributes: [.init(name: "a", value: "&")])])
        
        // single-quoted attributes
        XCTAssertEqual(tokenize("<asdf a='b' />"), [.startTag("asdf", selfClosing: true, attributes: [.init(name: "a", value: "b")])])
        XCTAssertEqual(tokenize("<asdf a='&#x20;' />"), [.startTag("asdf", selfClosing: true, attributes: [.init(name: "a", value: " ")])])
        
        // unquoted attributes
        XCTAssertEqual(tokenize("<asdf a=b />"), [.startTag("asdf", selfClosing: true, attributes: [.init(name: "a", value: "b")])])
        XCTAssertEqual(tokenize("<asdf a=&#32; />"), [.startTag("asdf", selfClosing: true, attributes: [.init(name: "a", value: " ")])])
    }
    
    func testEndTag() {
        XCTAssertEqual(tokenize("</asdf>"), [.endTag("asdf")])
        XCTAssertEqual(tokenize("</asdf a b='c'>"), [.endTag("asdf")])
    }
    
    func testComment() {
        XCTAssertEqual(tokenize("<!-- hello -->"), [.comment(" hello ")])
        XCTAssertEqual(tokenize("<!- hello -->"), [.comment("- hello --")])
        XCTAssertEqual(tokenize("<!-- hello ->"), [.comment(" hello ->")])
    }
    
    func testDoctype() {
        XCTAssertEqual(tokenize("<!DOCTYPE html>"), [.doctype("html", forceQuirks: false, publicIdentifier: nil, systemIdentifier: nil)])
        XCTAssertEqual(tokenize(#"<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">"#), [.doctype("html", forceQuirks: false, publicIdentifier: "-//W3C//DTD HTML 4.01//EN", systemIdentifier: nil)])
        XCTAssertEqual(tokenize(#"<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">"#), [.doctype("html", forceQuirks: false, publicIdentifier: "-//W3C//DTD HTML 4.01//EN", systemIdentifier: "http://www.w3.org/TR/html4/strict.dtd")])
    }
    
    func testMultiScalar() {
        XCTAssertEqual(tokenize("🇺🇸"), [.characterSequence("\u{1F1FA}\u{1F1F8}")])
    }
    
    func testWhitespaceAfterAttributeName() {
        XCTAssertEqual(tokenize("<a foo >"), [.startTag("a", selfClosing: false, attributes: [.init(name: "foo", value: "")])])
    }
    
}

private struct PrintIterator<Inner: IteratorProtocol>: IteratorProtocol {
    typealias Element = Inner.Element
    var inner: Inner
    
    mutating func next() -> Inner.Element? {
        let next = inner.next()
        print(String(describing: next))
        return next
    }
}