import Foundation
import XCTest
@testable import DocsKit

final class DocumentCompositionTests: XCTestCase {
    @MainActor func testCommittedReplacementUsesScalarSafeUTF16() throws {
        let (range, text) = try XCTUnwrap(DocumentComposition.replacement(before: "A😀draftZ", after: "A😀日本語Z"))
        XCTAssertEqual(range, NSRange(location: 3, length: 5))
        XCTAssertEqual(text, "日本語")
        XCTAssertNil(DocumentComposition.replacement(before: "😀", after: "😀"))
        let changed = try XCTUnwrap(DocumentComposition.replacement(before: "😀", after: "😁"))
        XCTAssertEqual(changed.0, NSRange(location: 0, length: 2))
        XCTAssertEqual(changed.1, "😁")
    }
    #if os(macOS)
    @MainActor func testNativeMarkedTextCommitsOnceAgainstOriginalString() {
        let view = DocsTextView(frame: .zero)
        view.textStorage?.setAttributedString(NSAttributedString(string: "A😀Z"))
        view.setSelectedRange(NSRange(location: 3, length: 0))
        var states: [Bool] = []; var commits: [(String, String)] = []
        view.compositionChanged = { states.append($0) }
        view.compositionCommitted = { before, after in commits.append((before.string, after)); return true }
        view.setMarkedText("に", selectedRange: NSRange(location: 1, length: 0), replacementRange: NSRange(location: NSNotFound, length: 0))
        view.setMarkedText("日本", selectedRange: NSRange(location: 2, length: 0), replacementRange: NSRange(location: NSNotFound, length: 0))
        XCTAssertTrue(view.isComposing)
        XCTAssertEqual(commits.count, 0)
        view.unmarkText()
        XCTAssertEqual(states, [true, false])
        XCTAssertEqual(commits.count, 1)
        XCTAssertEqual(commits.first?.0, "A😀Z")
        XCTAssertEqual(commits.first?.1, "A😀日本Z")
    }
    #endif
}