#if os(macOS)
import AppKit
import SwiftUI
import XCTest
@testable import DocsKit

@MainActor private final class RenderState {
    var pending = false
    var allowed: UInt64 = 1
    var selection = NSRange(location: 0, length: 0)
    var acknowledgements: [UInt64] = []
    var commands: [[String: JSONValue]] = []
    func candidate(_ content: NSAttributedString, generation: UInt64) -> NativeDocumentTextView {
        NativeDocumentTextView(content: content, generation: generation,
            didRender: { self.acknowledgements.append($0) }, compositionChanged: { _ in },
            isEditable: true, paged: false, pendingInput: pending,
            canRender: { !self.pending && self.allowed == $0 }, currentSelection: { self.selection },
            selection: Binding(get: { self.selection }, set: { self.selection = $0 }),
            edit: { self.pending = true; self.commands.append($0); return true })
    }
}
final class NativeRenderTests: XCTestCase {
    @MainActor func testDelayedCandidateCannotOverwriteAcceptedNativeTyping() {
        let state = RenderState()
        let initial = state.candidate(NSAttributedString(string: "a😀b\n"), generation: 1)
        let coordinator = initial.makeCoordinator()
        let text = DocsTextView(frame: CGRect(x: 0, y: 0, width: 500, height: 700))
        text.delegate = coordinator
        coordinator.applyRender(initial, to: text)
        state.allowed = 2
        let delayed = state.candidate(NSAttributedString(string: "older server view\n"), generation: 2)
        XCTAssertFalse(delayed.pendingInput)
        text.insertText("X", replacementRange: NSRange(location: 4, length: 0))
        XCTAssertTrue(state.pending)
        XCTAssertEqual(text.string, "a😀bX\n")
        XCTAssertEqual(state.commands.last?["generation"], .number(1))
        coordinator.applyRender(delayed, to: text)
        XCTAssertEqual(text.string, "a😀bX\n")
        XCTAssertEqual(state.acknowledgements, [1])
        state.pending = false; state.allowed = 3
        coordinator.applyRender(delayed, to: text)
        XCTAssertEqual(text.string, "a😀bX\n")
        state.selection = NSRange(location: 6, length: 0)
        let current = state.candidate(NSAttributedString(string: "a😀bX!\n"), generation: 3)
        coordinator.applyRender(current, to: text)
        XCTAssertEqual(text.string, "a😀bX!\n")
        XCTAssertEqual(text.selectedRange(), NSRange(location: 6, length: 0))
        XCTAssertEqual(state.acknowledgements, [1, 3])
    }
    @MainActor func testMarkedTextSurvivesPeerPresentationAndCommitsOnce() {
        let state = RenderState()
        let initial = state.candidate(NSAttributedString(string: "a😀b\n"), generation: 1)
        let coordinator = initial.makeCoordinator()
        let text = DocsTextView(frame: CGRect(x: 0, y: 0, width: 500, height: 700))
        text.delegate = coordinator
        text.compositionCommitted = { coordinator.commitComposition(before: $0, after: $1) }
        coordinator.applyRender(initial, to: text)
        text.setMarkedText("に", selectedRange: NSRange(location: 1, length: 0), replacementRange: NSRange(location: 1, length: 2))
        XCTAssertTrue(text.hasMarkedText())
        XCTAssertTrue(state.commands.isEmpty)
        state.allowed = 2
        coordinator.applyRender(state.candidate(NSAttributedString(string: "peer update\n"), generation: 2), to: text)
        XCTAssertEqual(text.string, "aにb\n")
        XCTAssertEqual(state.acknowledgements, [1])
        text.unmarkText()
        XCTAssertEqual(state.commands.count, 1)
        XCTAssertEqual(state.commands.first?["generation"], .number(1))
        XCTAssertEqual(state.commands.first?["at"], .number(1))
        XCTAssertEqual(state.commands.first?["length"], .number(2))
        XCTAssertEqual(state.commands.first?["text"], .string("に"))
    }

    @MainActor func testAttributeOnlyRefreshPreservesNativeCaret() {
        let state = RenderState()
        let initial = state.candidate(NSAttributedString(string: "abcdef\n"), generation: 1)
        let coordinator = initial.makeCoordinator()
        let text = DocsTextView(frame: CGRect(x: 0, y: 0, width: 500, height: 700))
        coordinator.applyRender(initial, to: text)
        text.setSelectedRange(NSRange(location: 4, length: 0))
        state.selection = NSRange(location: 0, length: 0)
        let changed = NSAttributedString(string: "abcdef\n", attributes: [.foregroundColor: NSColor.red])
        coordinator.applyRender(state.candidate(changed, generation: 1), to: text)
        XCTAssertEqual(text.selectedRange(), NSRange(location: 4, length: 0))
        XCTAssertEqual(text.textStorage?.attribute(.foregroundColor, at: 0, effectiveRange: nil) as? NSColor, .red)
    }
}
#endif