import XCTest
@testable import AIStudyApp

final class PositionAdapterTests: XCTestCase {

    // MARK: - Clamping

    func test_clamp_normal_value() {
        let pos = ReadingPositionAdapter.buildPosition(
            materialType: .markdown,
            blockId: "b1",
            scrollProgress: 0.5
        )
        if case .block(_, let progress, let overallProgress) = pos! {
            XCTAssertEqual(progress, 0.5)
            XCTAssertEqual(overallProgress, 0.5)
        } else {
            XCTFail("Expected block position")
        }
    }

    func test_clamp_below_zero() {
        let pos = ReadingPositionAdapter.buildPosition(
            materialType: .markdown,
            blockId: "b1",
            scrollProgress: -0.5
        )
        if case .block(_, let progress, let overallProgress) = pos! {
            XCTAssertEqual(progress, 0.0, "Negative progress should clamp to 0")
            XCTAssertEqual(overallProgress, 0.0)
        } else {
            XCTFail("Expected block position")
        }
    }

    func test_clamp_above_one() {
        let pos = ReadingPositionAdapter.buildPosition(
            materialType: .markdown,
            blockId: "b1",
            scrollProgress: 1.5
        )
        if case .block(_, let progress, let overallProgress) = pos! {
            XCTAssertEqual(progress, 1.0, "Progress >1 should clamp to 1")
            XCTAssertEqual(overallProgress, 1.0)
        } else {
            XCTFail("Expected block position")
        }
    }

    func test_clamp_nan() {
        let pos = ReadingPositionAdapter.buildPosition(
            materialType: .markdown,
            blockId: "b1",
            scrollProgress: Float.nan
        )
        if case .block(_, let progress, let overallProgress) = pos! {
            XCTAssertEqual(progress, 0.0, "NaN progress should clamp to 0")
            XCTAssertEqual(overallProgress, 0.0)
        } else {
            XCTFail("Expected block position")
        }
    }

    // MARK: - Material types

    func test_pdf_position() {
        let pos = ReadingPositionAdapter.buildPosition(
            materialType: .pdf,
            pageNumber: 3,
            pageProgress: 0.5,
            overallProgress: 0.3
        )
        if case .pdf(let page, let pageProg, let overall) = pos! {
            XCTAssertEqual(page, 3)
            XCTAssertEqual(pageProg, 0.5)
            XCTAssertEqual(overall, 0.3)
        } else {
            XCTFail("Expected PDF position")
        }
    }

    func test_text_position() {
        let pos = ReadingPositionAdapter.buildPosition(
            materialType: .text,
            scrollProgress: 0.7,
            lineNumber: 42
        )
        if case .text(let line, let progress) = pos! {
            XCTAssertEqual(line, 42)
            XCTAssertEqual(progress, 0.7)
        } else {
            XCTFail("Expected text position")
        }
    }

    func test_image_position() {
        let pos = ReadingPositionAdapter.buildPosition(
            materialType: .image,
            zoomScale: 2.0,
            offsetX: 100,
            offsetY: 200
        )
        if case .image(let zoom, let ox, let oy) = pos! {
            XCTAssertEqual(zoom, 2.0)
            XCTAssertEqual(ox, 100)
            XCTAssertEqual(oy, 200)
        } else {
            XCTFail("Expected image position")
        }
    }

    func test_epub_position() {
        let pos = ReadingPositionAdapter.buildPosition(
            materialType: .epub,
            chapterProgress: 0.4,
            overallProgress: 0.2,
            chapterId: "ch3"
        )
        if case .epub(let ch, let chProg, let overall) = pos! {
            XCTAssertEqual(ch, "ch3")
            XCTAssertEqual(chProg, 0.4)
            XCTAssertEqual(overall, 0.2)
        } else {
            XCTFail("Expected epub position")
        }
    }

    func test_unknown_material_returns_unknown() {
        let pos = ReadingPositionAdapter.buildPosition(materialType: .unknown)
        if case .unknown = pos! {
            // Expected
        } else {
            XCTFail("Expected unknown position")
        }
    }

    func test_markdown_missing_block_id_returns_nil() {
        let pos = ReadingPositionAdapter.buildPosition(
            materialType: .markdown,
            blockId: nil,
            scrollProgress: 0.5
        )
        XCTAssertNil(pos, "Markdown without blockId should return nil")
    }

    func test_epub_missing_chapter_id_returns_nil() {
        let pos = ReadingPositionAdapter.buildPosition(
            materialType: .epub,
            chapterId: nil,
            chapterProgress: 0.5
        )
        XCTAssertNil(pos, "Epub without chapterId should return nil")
    }

    // MARK: - blockId extraction

    func test_blockId_from_heading() {
        let block = DocumentBlock.heading(id: "h1", level: 1, text: "Title")
        XCTAssertEqual(ReadingPositionAdapter.blockId(from: block), "h1")
    }

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

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