import XCTest
@testable import AIStudyApp

final class ReadingPositionAdapterTests: XCTestCase {

    // MARK: - fromValue: Markdown

    func test_fromValue_markdown_with_blockId() {
        let v = ReadingPositionValue(type: "Markdown", blockId: "b1", lineNumber: nil,
            pageNumber: nil, chapterId: nil, scrollProgress: 0.5, pageProgress: nil,
            overallProgress: nil, zoomScale: nil, offsetX: nil, offsetY: nil, chapterProgress: nil)
        let pos = ReadingPositionAdapter.fromValue(v)
        guard case let .markdown(blockId, scrollProgress) = pos else {
            return XCTFail("Expected .markdown, got \(String(describing: pos))")
        }
        XCTAssertEqual(blockId, "b1")
        XCTAssertEqual(scrollProgress, 0.5)
    }

    func test_fromValue_markdown_nil_blockId_returns_nil() {
        let v = ReadingPositionValue(type: "Markdown", blockId: nil, lineNumber: nil,
            pageNumber: nil, chapterId: nil, scrollProgress: nil, pageProgress: nil,
            overallProgress: nil, zoomScale: nil, offsetX: nil, offsetY: nil, chapterProgress: nil)
        XCTAssertNil(ReadingPositionAdapter.fromValue(v))
    }

    // MARK: - fromValue: Text

    func test_fromValue_text_with_optional_fields() {
        let v = ReadingPositionValue(type: "Text", blockId: nil, lineNumber: 42,
            pageNumber: nil, chapterId: nil, scrollProgress: 0.8, pageProgress: nil,
            overallProgress: nil, zoomScale: nil, offsetX: nil, offsetY: nil, chapterProgress: nil)
        guard case let .text(lineNumber, scrollProgress) = ReadingPositionAdapter.fromValue(v) else {
            return XCTFail("Expected .text")
        }
        XCTAssertEqual(lineNumber, 42)
        XCTAssertEqual(scrollProgress, 0.8)
    }

    func test_fromValue_text_defaults_lineNumber_to_1() {
        let v = ReadingPositionValue(type: "Text", blockId: nil, lineNumber: nil,
            pageNumber: nil, chapterId: nil, scrollProgress: nil, pageProgress: nil,
            overallProgress: nil, zoomScale: nil, offsetX: nil, offsetY: nil, chapterProgress: nil)
        guard case let .text(lineNumber, _) = ReadingPositionAdapter.fromValue(v) else {
            return XCTFail("Expected .text")
        }
        XCTAssertEqual(lineNumber, 1)
    }

    // MARK: - fromValue: Pdf

    func test_fromValue_pdf_with_all_fields() {
        let v = ReadingPositionValue(type: "Pdf", blockId: nil, lineNumber: nil,
            pageNumber: 5, chapterId: nil, scrollProgress: nil, pageProgress: 0.3,
            overallProgress: 0.15, zoomScale: nil, offsetX: nil, offsetY: nil, chapterProgress: nil)
        guard case let .pdf(pageNumber, pageProgress, overallProgress) = ReadingPositionAdapter.fromValue(v) else {
            return XCTFail("Expected .pdf")
        }
        XCTAssertEqual(pageNumber, 5)
        XCTAssertEqual(pageProgress, 0.3)
        XCTAssertEqual(overallProgress, 0.15)
    }

    func test_fromValue_pdf_defaults_to_page_1() {
        let v = ReadingPositionValue(type: "Pdf", blockId: nil, lineNumber: nil,
            pageNumber: nil, chapterId: nil, scrollProgress: nil, pageProgress: nil,
            overallProgress: nil, zoomScale: nil, offsetX: nil, offsetY: nil, chapterProgress: nil)
        guard case let .pdf(pageNumber, _, _) = ReadingPositionAdapter.fromValue(v) else {
            return XCTFail("Expected .pdf")
        }
        XCTAssertEqual(pageNumber, 1)
    }

    // MARK: - fromValue: Image

    func test_fromValue_image_with_zoom_and_offset() {
        let v = ReadingPositionValue(type: "Image", blockId: nil, lineNumber: nil,
            pageNumber: nil, chapterId: nil, scrollProgress: nil, pageProgress: nil,
            overallProgress: nil, zoomScale: 2.0, offsetX: 100, offsetY: 200, chapterProgress: nil)
        guard case let .image(zoomScale, offsetX, offsetY) = ReadingPositionAdapter.fromValue(v) else {
            return XCTFail("Expected .image")
        }
        XCTAssertEqual(zoomScale, 2.0)
        XCTAssertEqual(offsetX, 100)
        XCTAssertEqual(offsetY, 200)
    }

    func test_fromValue_image_defaults_zoom_to_1() {
        let v = ReadingPositionValue(type: "Image", blockId: nil, lineNumber: nil,
            pageNumber: nil, chapterId: nil, scrollProgress: nil, pageProgress: nil,
            overallProgress: nil, zoomScale: nil, offsetX: nil, offsetY: nil, chapterProgress: nil)
        guard case let .image(zoomScale, _, _) = ReadingPositionAdapter.fromValue(v) else {
            return XCTFail("Expected .image")
        }
        XCTAssertEqual(zoomScale, 1.0)
    }

    // MARK: - fromValue: Epub

    func test_fromValue_epub_with_chapterId() {
        let v = ReadingPositionValue(type: "Epub", blockId: nil, lineNumber: nil,
            pageNumber: nil, chapterId: "ch3", scrollProgress: nil, pageProgress: nil,
            overallProgress: 0.6, zoomScale: nil, offsetX: nil, offsetY: nil, chapterProgress: 0.4)
        guard case let .epub(chapterId, chapterProgress, overallProgress) = ReadingPositionAdapter.fromValue(v) else {
            return XCTFail("Expected .epub")
        }
        XCTAssertEqual(chapterId, "ch3")
        XCTAssertEqual(chapterProgress, 0.4)
        XCTAssertEqual(overallProgress, 0.6)
    }

    func test_fromValue_epub_nil_chapterId_returns_nil() {
        let v = ReadingPositionValue(type: "Epub", blockId: nil, lineNumber: nil,
            pageNumber: nil, chapterId: nil, scrollProgress: nil, pageProgress: nil,
            overallProgress: nil, zoomScale: nil, offsetX: nil, offsetY: nil, chapterProgress: nil)
        XCTAssertNil(ReadingPositionAdapter.fromValue(v))
    }

    // MARK: - fromValue: Unknown / default

    func test_fromValue_unknown_type_returns_unknown() {
        let v = ReadingPositionValue(type: "UnknownType", blockId: nil, lineNumber: nil,
            pageNumber: nil, chapterId: nil, scrollProgress: nil, pageProgress: nil,
            overallProgress: nil, zoomScale: nil, offsetX: nil, offsetY: nil, chapterProgress: nil)
        guard case .unknown = ReadingPositionAdapter.fromValue(v) else {
            return XCTFail("Expected .unknown")
        }
    }

    func test_fromValue_nil_type_returns_unknown() {
        let v = ReadingPositionValue(type: nil, blockId: nil, lineNumber: nil,
            pageNumber: nil, chapterId: nil, scrollProgress: nil, pageProgress: nil,
            overallProgress: nil, zoomScale: nil, offsetX: nil, offsetY: nil, chapterProgress: nil)
        guard case .unknown = ReadingPositionAdapter.fromValue(v) else {
            return XCTFail("Expected .unknown")
        }
    }

    // MARK: - Clamp behavior

    func test_clamp_scrollProgress_above_1() {
        let v = ReadingPositionValue(type: "Text", blockId: nil, lineNumber: nil,
            pageNumber: nil, chapterId: nil, scrollProgress: 1.5, pageProgress: nil,
            overallProgress: nil, zoomScale: nil, offsetX: nil, offsetY: nil, chapterProgress: nil)
        guard case let .text(_, scrollProgress) = ReadingPositionAdapter.fromValue(v) else {
            return XCTFail("Expected .text")
        }
        XCTAssertEqual(scrollProgress, 1.0)
    }

    func test_clamp_progress_negative() {
        let v = ReadingPositionValue(type: "Text", blockId: nil, lineNumber: nil,
            pageNumber: nil, chapterId: nil, scrollProgress: -0.5, pageProgress: nil,
            overallProgress: nil, zoomScale: nil, offsetX: nil, offsetY: nil, chapterProgress: nil)
        guard case let .text(_, scrollProgress) = ReadingPositionAdapter.fromValue(v) else {
            return XCTFail("Expected .text")
        }
        XCTAssertEqual(scrollProgress, 0.0)
    }

    // MARK: - blockId extraction

    func test_blockId_from_heading() {
        let block = DocumentBlock.heading(id: "h1", level: 2, text: "Title")
        XCTAssertEqual(ReadingPositionAdapter.blockId(from: block), "h1")
    }

    func test_blockId_from_paragraph() {
        let block = DocumentBlock.paragraph(id: "p1", text: "Content")
        XCTAssertEqual(ReadingPositionAdapter.blockId(from: block), "p1")
    }

    func test_blockId_from_list() {
        let block = DocumentBlock.list(id: "l1", items: [], ordered: true)
        XCTAssertEqual(ReadingPositionAdapter.blockId(from: block), "l1")
    }

    func test_blockId_from_codeBlock() {
        let block = DocumentBlock.codeBlock(id: "c1", language: "swift", code: "print(\"hi\")")
        XCTAssertEqual(ReadingPositionAdapter.blockId(from: block), "c1")
    }

    func test_blockId_from_quote() {
        let block = DocumentBlock.quote(id: "q1", text: "quote")
        XCTAssertEqual(ReadingPositionAdapter.blockId(from: block), "q1")
    }

    func test_blockId_from_table() {
        let block = DocumentBlock.table(id: "t1", headers: [], rows: [])
        XCTAssertEqual(ReadingPositionAdapter.blockId(from: block), "t1")
    }

    func test_blockId_from_imageBlock() {
        let block = DocumentBlock.imageBlock(id: "img1", alt: "img", source: "file.png")
        XCTAssertEqual(ReadingPositionAdapter.blockId(from: block), "img1")
    }

    func test_blockId_from_horizontalRule() {
        let block = DocumentBlock.horizontalRule(id: "hr1")
        XCTAssertEqual(ReadingPositionAdapter.blockId(from: block), "hr1")
    }
}