import XCTest
@testable import AIStudyApp

final class MaterialPathResolverTests: XCTestCase {

    // MARK: - materialTypeFrom (infer from apiType + title)

    func test_materialTypeFrom_knowledge_source_with_md_title_returns_markdown() {
        let result = MaterialPathResolver.resolve(materialId: "m1", apiType: "knowledge_source", title: "note.md")
        // Path won't exist, but we test the type inference via the file system cascade
        XCTAssertNil(result) // File doesn't exist
    }

    // MARK: - resolve returns nil for nonexistent file

    func test_resolve_returns_nil_for_nonexistent_material() {
        let result = MaterialPathResolver.resolve(
            materialId: UUID().uuidString,
            apiType: nil,
            title: nil
        )
        XCTAssertNil(result)
    }

    // MARK: - resolve finds file in Documents

    func test_resolve_finds_file_in_documents() {
        let docs = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
        let fileId = "test-resolve-\(UUID().uuidString)"
        let fileURL = docs.appendingPathComponent(fileId)
        defer { try? FileManager.default.removeItem(at: fileURL) }

        // Create a temp file in Documents
        FileManager.default.createFile(atPath: fileURL.path, contents: "test".data(using: .utf8))

        let result = MaterialPathResolver.resolve(materialId: fileId, apiType: nil, title: nil)
        XCTAssertNotNil(result)
        XCTAssertEqual(result?.filePath, fileURL.path)
    }

    // MARK: - resolve finds file in Caches

    func test_resolve_finds_file_in_caches() {
        let cache = FileManager.default.urls(for: .cachesDirectory, in: .userDomainMask).first!
        let fileId = "test-cache-\(UUID().uuidString)"
        let fileURL = cache.appendingPathComponent(fileId)
        defer { try? FileManager.default.removeItem(at: fileURL) }

        FileManager.default.createFile(atPath: fileURL.path, contents: "test".data(using: .utf8))

        let result = MaterialPathResolver.resolve(materialId: fileId, apiType: nil, title: nil)
        XCTAssertNotNil(result)
        XCTAssertEqual(result?.filePath, fileURL.path)
    }

    // MARK: - materialType inference via file cascade

    func test_resolve_infers_type_from_title_extension() {
        let docs = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
        let fileId = "test-type-\(UUID().uuidString)"
        let fileURL = docs.appendingPathComponent(fileId)
        defer { try? FileManager.default.removeItem(at: fileURL) }

        FileManager.default.createFile(atPath: fileURL.path, contents: "test".data(using: .utf8))

        // .md title → markdown
        let result = MaterialPathResolver.resolve(materialId: fileId, apiType: "knowledge_source", title: "doc.md")
        XCTAssertNotNil(result)
        XCTAssertEqual(result?.materialType, .markdown)
    }

    func test_resolve_pdf_title_infers_pdf_type() {
        let docs = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
        let fileId = "test-pdf-\(UUID().uuidString)"
        let fileURL = docs.appendingPathComponent(fileId)
        defer { try? FileManager.default.removeItem(at: fileURL) }

        FileManager.default.createFile(atPath: fileURL.path, contents: "test".data(using: .utf8))

        let result = MaterialPathResolver.resolve(materialId: fileId, apiType: "temporary_file", title: "book.pdf")
        XCTAssertNotNil(result)
        XCTAssertEqual(result?.materialType, .pdf)
    }

    func test_resolve_unknown_apiType_defaults_to_unknown_materialType() {
        let docs = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
        let fileId = "test-unknown-\(UUID().uuidString)"
        let fileURL = docs.appendingPathComponent(fileId)
        defer { try? FileManager.default.removeItem(at: fileURL) }

        FileManager.default.createFile(atPath: fileURL.path, contents: "test".data(using: .utf8))

        let result = MaterialPathResolver.resolve(materialId: fileId, apiType: "other_type", title: "file.bin")
        XCTAssertNotNil(result)
        XCTAssertEqual(result?.materialType, .unknown)
    }
}