import XCTest
@testable import MarkBase

final class TokenizerTest: XCTestCase {

    var tokenizer: Tokenizing!

    override func setUp() {
        super.setUp()
        let modelDir = "/Users/accusys/MarkBaseEngine/models/E4B-MarkBase"
        guard FileManager.default.fileExists(atPath: modelDir) else {
            return
        }
        tokenizer = try? TokenizerFactory.load(modelDir: modelDir)
    }

    func testTokenizerAvailable() {
        let modelDir = "/Users/accusys/MarkBaseEngine/models/E4B-MarkBase"
        guard FileManager.default.fileExists(atPath: modelDir) else {
            throw XCTSkip("E4B-MarkBase model not found")
        }
        XCTAssertNotNil(tokenizer, "Tokenizer should load successfully")
    }

    func testEncodeDecodeRoundtrip() throws {
        try XCTSkipIf(tokenizer == nil, "Tokenizer not available")
        let inputs = ["Hello", "Hello World", "test", "123", "你好"]
        for input in inputs {
            let tokens = tokenizer.encode(text: input)
            let decoded = tokenizer.decode(tokens: tokens)
            XCTAssertEqual(decoded.lowercased(), input.lowercased(),
                           "Roundtrip failed for '\(input)': got '\(decoded)'")
        }
    }

    func testSpacePreservation() throws {
        try XCTSkipIf(tokenizer == nil, "Tokenizer not available")
        let input = "Hello World"
        let tokens = tokenizer.encode(text: input)
        let decoded = tokenizer.decode(tokens: tokens)
        XCTAssertTrue(decoded.contains(" "), "Spaces should be preserved in '\(decoded)'")
    }

    func testSpecialTokens() throws {
        try XCTSkipIf(tokenizer == nil, "Tokenizer not available")
        // BOS token should exist
        let bosToken = tokenizer.encode(text: "")
        XCTAssertFalse(bosToken.isEmpty, "BOS token should be prepended")
    }

    func testEmptyString() throws {
        try XCTSkipIf(tokenizer == nil, "Tokenizer not available")
        let tokens = tokenizer.encode(text: "")
        let decoded = tokenizer.decode(tokens: tokens)
        XCTAssertNotNil(decoded)
    }
}