import XCTest
import SaplingCore
@testable import SaplingEditor

final class EditorStateTests: XCTestCase {
    func testActiveLineFollowsSelection() {
        let source = "# Heading\nRendered **line**\nRaw source line"
        let document = EditorDocument(
            url: URL(fileURLWithPath: "/tmp/EditorStateTests.md"),
            title: "EditorStateTests",
            source: source
        )
        var state = EditorState(document: document)

        let secondLineLocation = (source as NSString).range(of: "Rendered").location
        state.updateSelection(EditorSelection(location: secondLineLocation, length: 0))

        XCTAssertEqual(state.activeLineIndex, 1)
        XCTAssertEqual(state.lines[0].mode, .rendered)
        XCTAssertEqual(state.lines[1].mode, .source)
        XCTAssertEqual(state.lines[2].mode, .rendered)
    }

    func testUpdatingSourceTracksUnsavedChanges() {
        let document = EditorDocument(
            url: URL(fileURLWithPath: "/tmp/EditorStateTests.md"),
            title: "EditorStateTests",
            source: "Initial"
        )
        var state = EditorState(document: document)

        state.updateSource("Initial\nChanged")

        XCTAssertTrue(state.hasUnsavedChanges)
        XCTAssertEqual(state.lines.count, 2)

        state.markSaved()

        XCTAssertFalse(state.hasUnsavedChanges)
    }

    func testActiveColumnFollowsSelectionWithinLine() {
        let source = "First line\nSecond line"
        let document = EditorDocument(
            url: URL(fileURLWithPath: "/tmp/EditorStateTests.md"),
            title: "EditorStateTests",
            source: source
        )
        var state = EditorState(document: document)

        let secondLineLocation = (source as NSString).range(of: "Second").location
        state.updateSelection(EditorSelection(location: secondLineLocation + 3, length: 0))

        XCTAssertEqual(state.activeLineIndex, 1)
        XCTAssertEqual(state.activeColumnNumber, 4)
    }

    @MainActor
    func testViewModelSavesDocumentToDisk() throws {
        let directory = FileManager.default.temporaryDirectory
            .appendingPathComponent(UUID().uuidString, isDirectory: true)
        try FileManager.default.createDirectory(at: directory, withIntermediateDirectories: true)
        let url = directory.appendingPathComponent("Note.md")
        try "# Note\n".write(to: url, atomically: true, encoding: .utf8)

        let document = try HybridMarkdownEditorViewModel.loadDocument(at: url)
        let viewModel = HybridMarkdownEditorViewModel(document: document)
        viewModel.updateSource("# Note\n\nUpdated")
        try viewModel.save()

        let saved = try String(contentsOf: url, encoding: .utf8)
        XCTAssertEqual(saved, "# Note\n\nUpdated")
        XCTAssertFalse(viewModel.hasUnsavedChanges)
    }
}