superbook_pdf/

image_extract.rs

//! Image Extraction module
//!
//! Provides functionality to extract page images from PDF files.
//!
//! # Features
//!
//! - Extract pages as PNG, JPEG, or TIFF
//! - Configurable DPI (72-1200)
//! - Color space conversion (RGB, Grayscale, CMYK)
//! - Parallel extraction with progress callbacks
//! - Transparent background handling
//!
//! # Example
//!
//! ```rust,no_run
//! use superbook_pdf::{ExtractOptions, MagickExtractor, ImageFormat, ColorSpace};
//! use std::path::Path;
//!
//! // Create options
//! let options = ExtractOptions::builder()
//!     .dpi(300)
//!     .format(ImageFormat::Png)
//!     .colorspace(ColorSpace::Rgb)
//!     .parallel(4)
//!     .build();
//!
//! // Extract a single page
//! // let result = MagickExtractor::extract_page(
//! //     Path::new("input.pdf"),
//! //     0,
//! //     Path::new("output/page_0.png"),
//! //     &options,
//! // );
//! ```

use std::path::{Path, PathBuf};
use std::process::Command;
use thiserror::Error;

// ============================================================
// Constants
// ============================================================

/// Standard DPI for document scanning
const DEFAULT_DPI: u32 = 300;

/// High quality DPI for archival purposes
const HIGH_QUALITY_DPI: u32 = 600;

/// Low DPI for fast previews
const FAST_DPI: u32 = 150;

/// Minimum allowed DPI
const MIN_DPI: u32 = 72;

/// Maximum allowed DPI
const MAX_DPI: u32 = 1200;

/// Default white background color
const WHITE_BACKGROUND: [u8; 3] = [255, 255, 255];

/// Image extraction error types
#[derive(Debug, Error)]
pub enum ExtractError {
    #[error("PDF file not found: {0}")]
    PdfNotFound(PathBuf),

    #[error("Output directory not writable: {0}")]
    OutputNotWritable(PathBuf),

    #[error("Extraction failed for page {page}: {reason}")]
    ExtractionFailed { page: usize, reason: String },

    #[error("External tool error: {0}")]
    ExternalToolError(String),

    #[error("IO error: {0}")]
    IoError(#[from] std::io::Error),
}

pub type Result<T> = std::result::Result<T, ExtractError>;

/// Image extraction options
pub struct ExtractOptions {
    /// Output DPI
    pub dpi: u32,
    /// Output format
    pub format: ImageFormat,
    /// Color space
    pub colorspace: ColorSpace,
    /// Background color (for transparency handling)
    pub background: Option<[u8; 3]>,
    /// Number of parallel workers
    pub parallel: usize,
    /// Progress callback
    #[allow(clippy::type_complexity)]
    pub progress_callback: Option<Box<dyn Fn(usize, usize) + Send + Sync>>,
}

impl std::fmt::Debug for ExtractOptions {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        f.debug_struct("ExtractOptions")
            .field("dpi", &self.dpi)
            .field("format", &self.format)
            .field("colorspace", &self.colorspace)
            .field("background", &self.background)
            .field("parallel", &self.parallel)
            .field(
                "progress_callback",
                &self.progress_callback.as_ref().map(|_| "<callback>"),
            )
            .finish()
    }
}

impl Default for ExtractOptions {
    fn default() -> Self {
        Self {
            dpi: DEFAULT_DPI,
            format: ImageFormat::Png,
            colorspace: ColorSpace::Rgb,
            background: Some(WHITE_BACKGROUND),
            parallel: num_cpus::get(),
            progress_callback: None,
        }
    }
}

impl ExtractOptions {
    /// Create a new options builder
    pub fn builder() -> ExtractOptionsBuilder {
        ExtractOptionsBuilder::default()
    }

    /// Create options for high quality extraction
    pub fn high_quality() -> Self {
        Self {
            dpi: HIGH_QUALITY_DPI,
            format: ImageFormat::Png,
            ..Default::default()
        }
    }

    /// Create options for fast extraction (lower quality)
    pub fn fast() -> Self {
        Self {
            dpi: FAST_DPI,
            format: ImageFormat::Jpeg { quality: 80 },
            ..Default::default()
        }
    }

    /// Create options for grayscale documents
    pub fn grayscale() -> Self {
        Self {
            colorspace: ColorSpace::Grayscale,
            ..Default::default()
        }
    }
}

/// Builder for ExtractOptions
#[derive(Debug, Default)]
pub struct ExtractOptionsBuilder {
    options: ExtractOptions,
}

impl ExtractOptionsBuilder {
    /// Set output DPI (clamped to MIN_DPI-MAX_DPI)
    #[must_use]
    pub fn dpi(mut self, dpi: u32) -> Self {
        self.options.dpi = dpi.clamp(MIN_DPI, MAX_DPI);
        self
    }

    /// Set output format
    #[must_use]
    pub fn format(mut self, format: ImageFormat) -> Self {
        self.options.format = format;
        self
    }

    /// Set color space
    #[must_use]
    pub fn colorspace(mut self, colorspace: ColorSpace) -> Self {
        self.options.colorspace = colorspace;
        self
    }

    /// Set background color for transparency handling
    #[must_use]
    pub fn background(mut self, rgb: [u8; 3]) -> Self {
        self.options.background = Some(rgb);
        self
    }

    /// Disable background (keep transparency)
    #[must_use]
    pub fn no_background(mut self) -> Self {
        self.options.background = None;
        self
    }

    /// Set number of parallel workers
    #[must_use]
    pub fn parallel(mut self, workers: usize) -> Self {
        self.options.parallel = workers.max(1);
        self
    }

    /// Set progress callback
    #[must_use]
    pub fn progress_callback(mut self, callback: Box<dyn Fn(usize, usize) + Send + Sync>) -> Self {
        self.options.progress_callback = Some(callback);
        self
    }

    /// Build the options
    #[must_use]
    pub fn build(self) -> ExtractOptions {
        self.options
    }
}

/// Output image formats
#[derive(Debug, Clone, Copy, Default)]
pub enum ImageFormat {
    #[default]
    Png,
    Jpeg {
        quality: u8,
    },
    Bmp,
    Tiff,
}

impl ImageFormat {
    /// Get file extension for format
    pub fn extension(&self) -> &str {
        match self {
            ImageFormat::Png => "png",
            ImageFormat::Jpeg { .. } => "jpg",
            ImageFormat::Bmp => "bmp",
            ImageFormat::Tiff => "tiff",
        }
    }
}

/// Color space options
#[derive(Debug, Clone, Copy, Default, PartialEq, Eq)]
pub enum ColorSpace {
    #[default]
    Rgb,
    Grayscale,
    Cmyk,
}

/// Extracted page information
#[derive(Debug)]
pub struct ExtractedPage {
    pub page_index: usize,
    pub path: PathBuf,
    pub width: u32,
    pub height: u32,
    pub format: ImageFormat,
}

/// Image extractor trait
pub trait ImageExtractor {
    /// Extract all pages from PDF
    fn extract_all(
        pdf_path: &Path,
        output_dir: &Path,
        options: &ExtractOptions,
    ) -> Result<Vec<ExtractedPage>>;

    /// Extract a single page
    fn extract_page(
        pdf_path: &Path,
        page_index: usize,
        output_path: &Path,
        options: &ExtractOptions,
    ) -> Result<ExtractedPage>;
}

/// ImageMagick-based extractor
pub struct MagickExtractor;

impl MagickExtractor {
    /// Extract a single page from PDF using ImageMagick
    pub fn extract_page(
        pdf_path: &Path,
        page_index: usize,
        output_path: &Path,
        options: &ExtractOptions,
    ) -> Result<ExtractedPage> {
        if !pdf_path.exists() {
            return Err(ExtractError::PdfNotFound(pdf_path.to_path_buf()));
        }

        // Check if output directory is writable
        if let Some(parent) = output_path.parent() {
            if !parent.exists() {
                std::fs::create_dir_all(parent)?;
            }
            // Try to create a test file to verify writability
            let test_file = parent.join(".write_test");
            if std::fs::write(&test_file, b"test").is_err() {
                return Err(ExtractError::OutputNotWritable(parent.to_path_buf()));
            }
            let _ = std::fs::remove_file(test_file);
        }

        let mut cmd = Command::new("magick");
        cmd.arg("-density").arg(options.dpi.to_string());

        // Set background color for transparency
        if let Some(bg) = options.background {
            cmd.arg("-background")
                .arg(format!("rgb({},{},{})", bg[0], bg[1], bg[2]));
            cmd.arg("-alpha").arg("remove");
            cmd.arg("-alpha").arg("off");
        }

        // Set colorspace
        match options.colorspace {
            ColorSpace::Grayscale => {
                cmd.arg("-colorspace").arg("gray");
            }
            ColorSpace::Cmyk => {
                cmd.arg("-colorspace").arg("CMYK");
            }
            ColorSpace::Rgb => {
                cmd.arg("-colorspace").arg("sRGB");
            }
        }

        // Input file with page index
        cmd.arg(format!("{}[{}]", pdf_path.display(), page_index));

        // Set output quality for JPEG
        if let ImageFormat::Jpeg { quality } = options.format {
            cmd.arg("-quality").arg(quality.to_string());
        }

        // Output file
        cmd.arg(output_path);

        let output = cmd.output()?;

        if !output.status.success() {
            let stderr = String::from_utf8_lossy(&output.stderr);
            return Err(ExtractError::ExternalToolError(stderr.to_string()));
        }

        // Get image dimensions
        let img = image::open(output_path).map_err(|e| ExtractError::ExtractionFailed {
            page: page_index,
            reason: e.to_string(),
        })?;

        Ok(ExtractedPage {
            page_index,
            path: output_path.to_path_buf(),
            width: img.width(),
            height: img.height(),
            format: options.format,
        })
    }

    /// Extract all pages from PDF
    pub fn extract_all(
        pdf_path: &Path,
        output_dir: &Path,
        options: &ExtractOptions,
    ) -> Result<Vec<ExtractedPage>> {
        if !pdf_path.exists() {
            return Err(ExtractError::PdfNotFound(pdf_path.to_path_buf()));
        }

        // Create output directory if it doesn't exist
        if !output_dir.exists() {
            std::fs::create_dir_all(output_dir)?;
        }

        // Check writability
        let test_file = output_dir.join(".write_test");
        if std::fs::write(&test_file, b"test").is_err() {
            return Err(ExtractError::OutputNotWritable(output_dir.to_path_buf()));
        }
        let _ = std::fs::remove_file(test_file);

        // Get page count using pdfinfo or similar
        let page_count = Self::get_page_count(pdf_path)?;

        // Extract pages (optionally in parallel)
        let extension = options.format.extension();
        let mut results = Vec::with_capacity(page_count);

        // Sequential extraction for now (parallel would require more complex handling)
        for i in 0..page_count {
            let output_path = output_dir.join(format!("page_{:05}.{}", i, extension));

            let result = Self::extract_page(pdf_path, i, &output_path, options)?;
            results.push(result);

            // Call progress callback if provided
            if let Some(ref callback) = options.progress_callback {
                callback(i + 1, page_count);
            }
        }

        Ok(results)
    }

    /// Get the number of pages in a PDF
    fn get_page_count(pdf_path: &Path) -> Result<usize> {
        // Try using pdfinfo first
        if let Ok(output) = Command::new("pdfinfo").arg(pdf_path).output() {
            if output.status.success() {
                let stdout = String::from_utf8_lossy(&output.stdout);
                for line in stdout.lines() {
                    if line.starts_with("Pages:") {
                        if let Some(count_str) = line.split(':').nth(1) {
                            if let Ok(count) = count_str.trim().parse() {
                                return Ok(count);
                            }
                        }
                    }
                }
            }
        }

        // Fallback: use ImageMagick identify
        let output = Command::new("magick")
            .args(["identify", "-format", "%n\n"])
            .arg(pdf_path)
            .output()?;

        if output.status.success() {
            let stdout = String::from_utf8_lossy(&output.stdout);
            if let Some(line) = stdout.lines().next() {
                if let Ok(count) = line.trim().parse() {
                    return Ok(count);
                }
            }
        }

        // Last resort: try lopdf
        let doc = lopdf::Document::load(pdf_path).map_err(|e| ExtractError::ExtractionFailed {
            page: 0,
            reason: e.to_string(),
        })?;

        Ok(doc.get_pages().len())
    }
}

/// Pure Rust PDF image extractor using lopdf
///
/// This extractor works without external tools by directly extracting
/// embedded JPEG images from the PDF. Works best with scanned PDFs where
/// each page is a single JPEG image (DCTDecode filter).
pub struct LopdfExtractor;

impl LopdfExtractor {
    /// Extract all embedded JPEG images from a PDF
    ///
    /// This method extracts XObject images with DCTDecode filter (JPEG).
    /// For scanned PDFs, this typically means one JPEG per page.
    pub fn extract_all(
        pdf_path: &Path,
        output_dir: &Path,
        _options: &ExtractOptions,
    ) -> Result<Vec<ExtractedPage>> {
        if !pdf_path.exists() {
            return Err(ExtractError::PdfNotFound(pdf_path.to_path_buf()));
        }

        // Create output directory
        if !output_dir.exists() {
            std::fs::create_dir_all(output_dir)?;
        }

        let doc = lopdf::Document::load(pdf_path).map_err(|e| ExtractError::ExtractionFailed {
            page: 0,
            reason: format!("Failed to load PDF: {}", e),
        })?;

        let mut results = Vec::new();
        let mut image_count = 0;

        // Iterate through all objects to find images
        for (obj_id, object) in doc.objects.iter() {
            if let Ok(stream) = object.as_stream() {
                // Check if it's an Image XObject
                if let Ok(subtype) = stream.dict.get(b"Subtype") {
                    if let Ok(subtype_name) = subtype.as_name_str() {
                        if subtype_name == "Image" {
                            if let Ok(extracted) =
                                Self::extract_image_stream(stream, image_count, obj_id, output_dir)
                            {
                                results.push(extracted);
                                image_count += 1;
                            }
                        }
                    }
                }
            }
        }

        if results.is_empty() {
            return Err(ExtractError::ExtractionFailed {
                page: 0,
                reason: "No extractable images found. This PDF may require ImageMagick (install with: sudo apt install imagemagick).".to_string(),
            });
        }

        // Sort by page index for consistent ordering
        results.sort_by_key(|r| r.page_index);

        Ok(results)
    }

    /// Extract a single image stream to file
    fn extract_image_stream(
        stream: &lopdf::Stream,
        index: usize,
        obj_id: &lopdf::ObjectId,
        output_dir: &Path,
    ) -> Result<ExtractedPage> {
        // Get image dimensions
        let width = stream
            .dict
            .get(b"Width")
            .ok()
            .and_then(|w| w.as_i64().ok())
            .unwrap_or(0) as u32;
        let height = stream
            .dict
            .get(b"Height")
            .ok()
            .and_then(|h| h.as_i64().ok())
            .unwrap_or(0) as u32;

        // Determine filter type
        let filter = stream
            .dict
            .get(b"Filter")
            .ok()
            .and_then(|f| f.as_name_str().ok())
            .unwrap_or("");

        // Only extract JPEG images (DCTDecode) - these are most common in scanned PDFs
        if filter == "DCTDecode" {
            let output_path = output_dir.join(format!(
                "page_{:04}_obj{}_{}.jpg",
                index, obj_id.0, obj_id.1
            ));

            // JPEG data can be saved directly (no decompression needed)
            std::fs::write(&output_path, &stream.content)?;

            return Ok(ExtractedPage {
                page_index: index,
                path: output_path,
                width,
                height,
                format: ImageFormat::Jpeg { quality: 95 },
            });
        }

        // Try to decompress and save other formats
        if let Ok(decoded) = stream.decompressed_content() {
            if width > 0 && height > 0 {
                // Determine channels from ColorSpace
                let channels = stream
                    .dict
                    .get(b"ColorSpace")
                    .ok()
                    .and_then(|cs| cs.as_name_str().ok())
                    .map(|name| match name {
                        "DeviceGray" | "CalGray" => 1,
                        "DeviceRGB" | "CalRGB" => 3,
                        "DeviceCMYK" => 4,
                        _ => 3,
                    })
                    .unwrap_or(3);

                let expected_size = (width as usize) * (height as usize) * channels;
                if decoded.len() >= expected_size {
                    let output_path = output_dir.join(format!(
                        "page_{:04}_obj{}_{}.png",
                        index, obj_id.0, obj_id.1
                    ));

                    let img_opt = match channels {
                        1 => image::GrayImage::from_raw(
                            width,
                            height,
                            decoded[..expected_size].to_vec(),
                        )
                        .map(image::DynamicImage::ImageLuma8),
                        3 => image::RgbImage::from_raw(
                            width,
                            height,
                            decoded[..expected_size].to_vec(),
                        )
                        .map(image::DynamicImage::ImageRgb8),
                        4 => {
                            // CMYK to RGB conversion
                            let rgb: Vec<u8> = decoded[..expected_size]
                                .chunks_exact(4)
                                .flat_map(|cmyk| {
                                    let (c, m, y, k) = (
                                        cmyk[0] as f32 / 255.0,
                                        cmyk[1] as f32 / 255.0,
                                        cmyk[2] as f32 / 255.0,
                                        cmyk[3] as f32 / 255.0,
                                    );
                                    [
                                        ((1.0 - c) * (1.0 - k) * 255.0) as u8,
                                        ((1.0 - m) * (1.0 - k) * 255.0) as u8,
                                        ((1.0 - y) * (1.0 - k) * 255.0) as u8,
                                    ]
                                })
                                .collect();
                            image::RgbImage::from_raw(width, height, rgb)
                                .map(image::DynamicImage::ImageRgb8)
                        }
                        _ => None,
                    };

                    if let Some(img) = img_opt {
                        img.save(&output_path)
                            .map_err(|e| ExtractError::ExtractionFailed {
                                page: index,
                                reason: format!("Failed to save: {}", e),
                            })?;
                        return Ok(ExtractedPage {
                            page_index: index,
                            path: output_path,
                            width,
                            height,
                            format: ImageFormat::Png,
                        });
                    }
                }
            }
        }

        Err(ExtractError::ExtractionFailed {
            page: index,
            reason: format!("Unsupported image filter: {}", filter),
        })
    }

    /// Check if ImageMagick is available
    pub fn magick_available() -> bool {
        which::which("magick").is_ok() || which::which("convert").is_ok()
    }

    /// Check if pdftoppm (poppler-utils) is available
    pub fn pdftoppm_available() -> bool {
        which::which("pdftoppm").is_ok()
    }

    /// Extract using best available method
    pub fn extract_auto(
        pdf_path: &Path,
        output_dir: &Path,
        options: &ExtractOptions,
    ) -> Result<Vec<ExtractedPage>> {
        // Try ImageMagick first if available (better quality for complex PDFs)
        if Self::magick_available() {
            return MagickExtractor::extract_all(pdf_path, output_dir, options);
        }

        // Try pdftoppm (poppler-utils) as second option
        if Self::pdftoppm_available() {
            return PopplerExtractor::extract_all(pdf_path, output_dir, options);
        }

        // Fall back to pure Rust extraction
        Self::extract_all(pdf_path, output_dir, options)
    }
}

/// Poppler-based extractor using pdftoppm
pub struct PopplerExtractor;

impl PopplerExtractor {
    /// Extract a single page from PDF using pdftoppm
    pub fn extract_page(
        pdf_path: &Path,
        page_index: usize,
        output_path: &Path,
        options: &ExtractOptions,
    ) -> Result<ExtractedPage> {
        if !pdf_path.exists() {
            return Err(ExtractError::PdfNotFound(pdf_path.to_path_buf()));
        }

        // Create output directory if needed
        if let Some(parent) = output_path.parent() {
            if !parent.exists() {
                std::fs::create_dir_all(parent)?;
            }
        }

        // pdftoppm uses 1-based page numbers
        let page_num = page_index + 1;

        // Get output path without extension (pdftoppm adds its own)
        let output_stem = output_path.with_extension("");
        let output_stem_str = output_stem.to_string_lossy();

        let mut cmd = Command::new("pdftoppm");
        cmd.arg("-r").arg(options.dpi.to_string()); // Resolution
        cmd.arg("-f").arg(page_num.to_string()); // First page
        cmd.arg("-l").arg(page_num.to_string()); // Last page
        cmd.arg("-singlefile"); // Single file output (no suffix)

        // Set output format (pdftoppm doesn't support BMP, fallback to PNG)
        match options.format {
            ImageFormat::Png | ImageFormat::Bmp => {
                cmd.arg("-png");
            }
            ImageFormat::Jpeg { quality } => {
                cmd.arg("-jpeg");
                cmd.arg("-jpegopt")
                    .arg(format!("quality={}", quality));
            }
            ImageFormat::Tiff => {
                cmd.arg("-tiff");
            }
        }

        // Set colorspace
        match options.colorspace {
            ColorSpace::Grayscale => {
                cmd.arg("-gray");
            }
            ColorSpace::Rgb | ColorSpace::Cmyk => {
                // RGB is default for pdftoppm
            }
        }

        // Input PDF and output prefix
        cmd.arg(pdf_path);
        cmd.arg(&*output_stem_str);

        let output = cmd.output()?;

        if !output.status.success() {
            let stderr = String::from_utf8_lossy(&output.stderr);
            return Err(ExtractError::ExternalToolError(format!(
                "pdftoppm failed: {}",
                stderr
            )));
        }

        // pdftoppm creates file with extension based on format
        // (BMP outputs as PNG since pdftoppm doesn't support BMP)
        let actual_output = match options.format {
            ImageFormat::Png | ImageFormat::Bmp => output_stem.with_extension("png"),
            ImageFormat::Jpeg { .. } => output_stem.with_extension("jpg"),
            ImageFormat::Tiff => output_stem.with_extension("tif"),
        };

        // Rename to expected output path if different
        if actual_output != output_path {
            std::fs::rename(&actual_output, output_path)?;
        }

        // Get image dimensions
        let img = image::open(output_path).map_err(|e| ExtractError::ExtractionFailed {
            page: page_index,
            reason: e.to_string(),
        })?;

        Ok(ExtractedPage {
            page_index,
            path: output_path.to_path_buf(),
            width: img.width(),
            height: img.height(),
            format: options.format,
        })
    }

    /// Extract all pages from PDF using pdftoppm
    pub fn extract_all(
        pdf_path: &Path,
        output_dir: &Path,
        options: &ExtractOptions,
    ) -> Result<Vec<ExtractedPage>> {
        if !pdf_path.exists() {
            return Err(ExtractError::PdfNotFound(pdf_path.to_path_buf()));
        }

        // Create output directory
        if !output_dir.exists() {
            std::fs::create_dir_all(output_dir)?;
        }

        // Get page count using pdfinfo
        let page_count = Self::get_page_count(pdf_path)?;

        // Extract pages
        let extension = options.format.extension();
        let mut results = Vec::with_capacity(page_count);

        for i in 0..page_count {
            let output_path = output_dir.join(format!("page_{:05}.{}", i, extension));

            let result = Self::extract_page(pdf_path, i, &output_path, options)?;
            results.push(result);

            // Call progress callback if provided
            if let Some(ref callback) = options.progress_callback {
                callback(i + 1, page_count);
            }
        }

        Ok(results)
    }

    /// Get page count using pdfinfo
    fn get_page_count(pdf_path: &Path) -> Result<usize> {
        let output = Command::new("pdfinfo").arg(pdf_path).output()?;

        if output.status.success() {
            let stdout = String::from_utf8_lossy(&output.stdout);
            for line in stdout.lines() {
                if line.starts_with("Pages:") {
                    if let Some(count_str) = line.split_whitespace().nth(1) {
                        if let Ok(count) = count_str.parse::<usize>() {
                            return Ok(count);
                        }
                    }
                }
            }
        }

        // Fallback: try lopdf
        let doc = lopdf::Document::load(pdf_path).map_err(|e| ExtractError::ExtractionFailed {
            page: 0,
            reason: format!("Failed to load PDF: {}", e),
        })?;
        Ok(doc.get_pages().len())
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use tempfile::tempdir;

    // TC-EXT-009: 存在しないPDFエラー
    #[test]
    fn test_nonexistent_pdf_error() {
        let temp_dir = tempdir().unwrap();

        let result = MagickExtractor::extract_all(
            Path::new("/nonexistent/file.pdf"),
            temp_dir.path(),
            &ExtractOptions::default(),
        );

        assert!(matches!(result, Err(ExtractError::PdfNotFound(_))));
    }

    // TC-EXT-003: DPI設定
    #[test]
    fn test_default_options() {
        let opts = ExtractOptions::default();

        assert_eq!(opts.dpi, 300);
        assert!(matches!(opts.format, ImageFormat::Png));
        assert!(matches!(opts.colorspace, ColorSpace::Rgb));
        assert_eq!(opts.background, Some([255, 255, 255]));
        assert!(opts.parallel > 0);
    }

    #[test]
    fn test_image_format_extension() {
        assert_eq!(ImageFormat::Png.extension(), "png");
        assert_eq!(ImageFormat::Jpeg { quality: 90 }.extension(), "jpg");
        assert_eq!(ImageFormat::Bmp.extension(), "bmp");
        assert_eq!(ImageFormat::Tiff.extension(), "tiff");
    }

    #[test]
    fn test_builder_pattern() {
        let options = ExtractOptions::builder()
            .dpi(600)
            .format(ImageFormat::Jpeg { quality: 95 })
            .colorspace(ColorSpace::Grayscale)
            .background([0, 0, 0])
            .parallel(4)
            .build();

        assert_eq!(options.dpi, 600);
        assert!(matches!(options.format, ImageFormat::Jpeg { quality: 95 }));
        assert!(matches!(options.colorspace, ColorSpace::Grayscale));
        assert_eq!(options.background, Some([0, 0, 0]));
        assert_eq!(options.parallel, 4);
    }

    #[test]
    fn test_builder_dpi_clamping() {
        // DPI should be clamped to 72-1200
        let options = ExtractOptions::builder().dpi(50).build();
        assert_eq!(options.dpi, 72);

        let options = ExtractOptions::builder().dpi(2000).build();
        assert_eq!(options.dpi, 1200);

        let options = ExtractOptions::builder().dpi(300).build();
        assert_eq!(options.dpi, 300);
    }

    #[test]
    fn test_builder_parallel_minimum() {
        // Parallel workers should be at least 1
        let options = ExtractOptions::builder().parallel(0).build();
        assert_eq!(options.parallel, 1);
    }

    #[test]
    fn test_builder_no_background() {
        let options = ExtractOptions::builder().no_background().build();
        assert!(options.background.is_none());
    }

    #[test]
    fn test_high_quality_preset() {
        let options = ExtractOptions::high_quality();

        assert_eq!(options.dpi, 600);
        assert!(matches!(options.format, ImageFormat::Png));
    }

    #[test]
    fn test_fast_preset() {
        let options = ExtractOptions::fast();

        assert_eq!(options.dpi, 150);
        assert!(matches!(options.format, ImageFormat::Jpeg { quality: 80 }));
    }

    #[test]
    fn test_grayscale_preset() {
        let options = ExtractOptions::grayscale();

        assert!(matches!(options.colorspace, ColorSpace::Grayscale));
    }

    // Note: The following tests require ImageMagick and actual PDF fixtures
    // They are marked with #[ignore] until fixtures are available

    // TC-EXT-001: 単一ページ抽出
    #[test]
    #[ignore = "requires external tool"]
    fn test_extract_single_page() {
        let temp_dir = tempdir().unwrap();
        let output = temp_dir.path().join("page_0.png");

        let result = MagickExtractor::extract_page(
            Path::new("tests/fixtures/sample.pdf"),
            0,
            &output,
            &ExtractOptions::default(),
        )
        .unwrap();

        assert!(output.exists());
        assert_eq!(result.page_index, 0);
        assert!(result.width > 0);
        assert!(result.height > 0);
    }

    // TC-EXT-002: 全ページ抽出
    #[test]
    #[ignore = "requires external tool"]
    fn test_extract_all_pages() {
        let temp_dir = tempdir().unwrap();

        let results = MagickExtractor::extract_all(
            Path::new("tests/fixtures/10pages.pdf"),
            temp_dir.path(),
            &ExtractOptions::default(),
        )
        .unwrap();

        assert_eq!(results.len(), 10);
        for (i, result) in results.iter().enumerate() {
            assert_eq!(result.page_index, i);
            assert!(result.path.exists());
        }
    }

    // TC-EXT-003: DPI設定（詳細テスト）
    #[test]
    #[ignore = "requires external tool"]
    fn test_dpi_setting() {
        let temp_dir = tempdir().unwrap();

        // 72 DPI
        let output_72 = temp_dir.path().join("72dpi.png");
        let result_72 = MagickExtractor::extract_page(
            Path::new("tests/fixtures/a4.pdf"),
            0,
            &output_72,
            &ExtractOptions {
                dpi: 72,
                ..Default::default()
            },
        )
        .unwrap();

        // 300 DPI
        let output_300 = temp_dir.path().join("300dpi.png");
        let result_300 = MagickExtractor::extract_page(
            Path::new("tests/fixtures/a4.pdf"),
            0,
            &output_300,
            &ExtractOptions {
                dpi: 300,
                ..Default::default()
            },
        )
        .unwrap();

        // 300 DPI image should be ~4x larger in each dimension
        assert!(result_300.width > result_72.width * 3);
        assert!(result_300.height > result_72.height * 3);
    }

    // TC-EXT-004: JPEG出力
    #[test]
    #[ignore = "requires external tool"]
    fn test_jpeg_output() {
        let temp_dir = tempdir().unwrap();
        let output = temp_dir.path().join("page_0.jpg");

        MagickExtractor::extract_page(
            Path::new("tests/fixtures/sample.pdf"),
            0,
            &output,
            &ExtractOptions {
                format: ImageFormat::Jpeg { quality: 85 },
                ..Default::default()
            },
        )
        .unwrap();

        assert!(output.exists());

        // Check JPEG magic bytes
        let bytes = std::fs::read(&output).unwrap();
        assert_eq!(&bytes[0..2], &[0xFF, 0xD8]);
    }

    // TC-EXT-005: グレースケール変換
    #[test]
    #[ignore = "requires external tool"]
    fn test_grayscale_extraction() {
        let temp_dir = tempdir().unwrap();
        let output = temp_dir.path().join("gray.png");

        MagickExtractor::extract_page(
            Path::new("tests/fixtures/color.pdf"),
            0,
            &output,
            &ExtractOptions {
                colorspace: ColorSpace::Grayscale,
                ..Default::default()
            },
        )
        .unwrap();

        // Verify image is grayscale
        let img = image::open(&output).unwrap();
        let rgb = img.to_rgb8();

        // Check that R=G=B for each pixel (grayscale property)
        for pixel in rgb.pixels() {
            assert_eq!(pixel[0], pixel[1]);
            assert_eq!(pixel[1], pixel[2]);
        }
    }

    // Additional structure tests

    #[test]
    fn test_extracted_page_construction() {
        let page = ExtractedPage {
            page_index: 5,
            path: PathBuf::from("/test/page_5.png"),
            width: 2480,
            height: 3508,
            format: ImageFormat::Png,
        };

        assert_eq!(page.page_index, 5);
        assert_eq!(page.path, PathBuf::from("/test/page_5.png"));
        assert_eq!(page.width, 2480);
        assert_eq!(page.height, 3508);
        assert!(matches!(page.format, ImageFormat::Png));
    }

    #[test]
    fn test_all_image_formats() {
        let formats = [
            ImageFormat::Png,
            ImageFormat::Jpeg { quality: 90 },
            ImageFormat::Bmp,
            ImageFormat::Tiff,
        ];

        let expected_ext = ["png", "jpg", "bmp", "tiff"];

        for (format, ext) in formats.iter().zip(expected_ext.iter()) {
            assert_eq!(format.extension(), *ext);
        }
    }

    #[test]
    fn test_all_colorspaces() {
        let colorspaces = vec![ColorSpace::Rgb, ColorSpace::Grayscale, ColorSpace::Cmyk];

        // Verify all colorspaces can be constructed and roundtrip through builder
        for cs in colorspaces {
            let options = ExtractOptions::builder().colorspace(cs).build();
            match (cs, options.colorspace) {
                (ColorSpace::Rgb, ColorSpace::Rgb) => {}
                (ColorSpace::Grayscale, ColorSpace::Grayscale) => {}
                (ColorSpace::Cmyk, ColorSpace::Cmyk) => {}
                _ => panic!("Colorspace mismatch"),
            }
        }
    }

    #[test]
    fn test_error_types() {
        // Test all error variants can be constructed
        let _err1 = ExtractError::PdfNotFound(PathBuf::from("/test/path"));
        let _err2 = ExtractError::OutputNotWritable(PathBuf::from("/readonly/dir"));
        let _err3 = ExtractError::ExternalToolError("ImageMagick not found".to_string());
        let _err4 = ExtractError::ExtractionFailed {
            page: 3,
            reason: "Test error".to_string(),
        };
        let _err5: ExtractError = std::io::Error::new(std::io::ErrorKind::NotFound, "test").into();
    }

    #[test]
    fn test_output_not_writable_error_message() {
        let err = ExtractError::OutputNotWritable(PathBuf::from("/readonly/output"));

        let msg = err.to_string();
        assert!(msg.contains("/readonly/output"));
        assert!(msg.contains("not writable"));
    }

    #[test]
    fn test_extraction_failed_error_message() {
        let err = ExtractError::ExtractionFailed {
            page: 5,
            reason: "ImageMagick crashed".to_string(),
        };

        let msg = err.to_string();
        assert!(msg.contains("5"));
        assert!(msg.contains("ImageMagick"));
    }

    #[test]
    fn test_format_builder() {
        // Test different JPEG qualities
        let options_low = ExtractOptions::builder()
            .format(ImageFormat::Jpeg { quality: 50 })
            .build();
        let options_high = ExtractOptions::builder()
            .format(ImageFormat::Jpeg { quality: 95 })
            .build();

        match (options_low.format, options_high.format) {
            (ImageFormat::Jpeg { quality: q1 }, ImageFormat::Jpeg { quality: q2 }) => {
                assert_eq!(q1, 50);
                assert_eq!(q2, 95);
            }
            _ => panic!("Expected JPEG format"),
        }
    }

    // TC-EXT-006: 透明部分の処理
    #[test]
    fn test_background_color_setting() {
        // White background (default)
        let options = ExtractOptions::builder()
            .background([255, 255, 255])
            .build();
        assert_eq!(options.background, Some([255, 255, 255]));

        // Black background
        let options = ExtractOptions::builder().background([0, 0, 0]).build();
        assert_eq!(options.background, Some([0, 0, 0]));

        // Transparent (no background)
        let options = ExtractOptions::builder().no_background().build();
        assert!(options.background.is_none());
    }

    // TC-EXT-007: 並列抽出
    #[test]
    fn test_parallel_extraction_config() {
        // Test parallel thread configuration
        let options_single = ExtractOptions::builder().parallel(1).build();
        assert_eq!(options_single.parallel, 1);

        let options_multi = ExtractOptions::builder().parallel(4).build();
        assert_eq!(options_multi.parallel, 4);

        let options_max = ExtractOptions::builder().parallel(16).build();
        assert_eq!(options_max.parallel, 16);

        // parallel(0) should be clamped to 1
        let options_zero = ExtractOptions::builder().parallel(0).build();
        assert_eq!(options_zero.parallel, 1);
    }

    // TC-EXT-008: 進捗コールバック
    #[test]
    fn test_progress_callback_structure() {
        use std::sync::atomic::{AtomicUsize, Ordering};
        use std::sync::Arc;

        // Test that progress callback can be set
        let progress_count = Arc::new(AtomicUsize::new(0));
        let progress_clone = progress_count.clone();

        let options = ExtractOptions::builder()
            .progress_callback(Box::new(move |current, total| {
                progress_clone.fetch_add(1, Ordering::SeqCst);
                assert!(current <= total);
            }))
            .build();

        // Verify callback is set
        assert!(options.progress_callback.is_some());

        // Call the callback to verify it works
        if let Some(callback) = &options.progress_callback {
            callback(1, 10);
            callback(5, 10);
            callback(10, 10);
        }

        assert_eq!(progress_count.load(Ordering::SeqCst), 3);
    }

    // TC-EXT-010: 書き込み不可ディレクトリエラー追加テスト
    #[test]
    fn test_output_not_writable_error_display() {
        let err = ExtractError::OutputNotWritable(std::path::PathBuf::from("/root/protected"));
        let display = format!("{}", err);
        assert!(display.contains("/root/protected"));
        assert!(display.contains("not writable") || display.contains("writable"));
    }

    #[test]
    fn test_extracted_page_display() {
        let page = ExtractedPage {
            page_index: 0,
            path: std::path::PathBuf::from("/tmp/page_001.png"),
            width: 2480,
            height: 3508,
            format: ImageFormat::Png,
        };

        assert_eq!(page.page_index, 0);
        assert_eq!(page.width, 2480);
        assert_eq!(page.height, 3508);
        assert!(page.path.to_string_lossy().contains("page_001"));
    }

    #[test]
    fn test_colorspace_all_variants() {
        // Test all colorspace variants exist and can be used
        let colorspaces = [ColorSpace::Rgb, ColorSpace::Grayscale, ColorSpace::Cmyk];

        for cs in &colorspaces {
            let options = ExtractOptions::builder().colorspace(*cs).build();
            assert_eq!(options.colorspace, *cs);
        }
    }

    #[test]
    fn test_image_format_all_variants() {
        // Test all image format variants
        let formats = [
            ImageFormat::Png,
            ImageFormat::Jpeg { quality: 85 },
            ImageFormat::Bmp,
            ImageFormat::Tiff,
        ];

        for fmt in &formats {
            let options = ExtractOptions::builder().format(*fmt).build();
            match (&options.format, fmt) {
                (ImageFormat::Png, ImageFormat::Png) => {}
                (ImageFormat::Tiff, ImageFormat::Tiff) => {}
                (ImageFormat::Bmp, ImageFormat::Bmp) => {}
                (ImageFormat::Jpeg { quality: q1 }, ImageFormat::Jpeg { quality: q2 }) => {
                    assert_eq!(q1, q2);
                }
                _ => panic!("Format mismatch"),
            }
        }
    }

    // Additional comprehensive tests

    #[test]
    fn test_dpi_boundary_values() {
        // Minimum boundary (should clamp to 72)
        let options_below = ExtractOptions::builder().dpi(50).build();
        assert_eq!(options_below.dpi, 72);

        // Exact minimum
        let options_min = ExtractOptions::builder().dpi(72).build();
        assert_eq!(options_min.dpi, 72);

        // Normal range
        let options_normal = ExtractOptions::builder().dpi(300).build();
        assert_eq!(options_normal.dpi, 300);

        // Maximum boundary
        let options_max = ExtractOptions::builder().dpi(1200).build();
        assert_eq!(options_max.dpi, 1200);

        // Above maximum (should clamp to 1200)
        let options_above = ExtractOptions::builder().dpi(2400).build();
        assert_eq!(options_above.dpi, 1200);
    }

    #[test]
    fn test_jpeg_quality_edge_cases() {
        // Minimum quality
        let opts_min = ExtractOptions::builder()
            .format(ImageFormat::Jpeg { quality: 0 })
            .build();
        if let ImageFormat::Jpeg { quality } = opts_min.format {
            assert_eq!(quality, 0);
        } else {
            panic!("Expected JPEG format");
        }

        // Maximum quality
        let opts_max = ExtractOptions::builder()
            .format(ImageFormat::Jpeg { quality: 100 })
            .build();
        if let ImageFormat::Jpeg { quality } = opts_max.format {
            assert_eq!(quality, 100);
        } else {
            panic!("Expected JPEG format");
        }

        // Typical quality values
        for q in [1, 50, 75, 85, 99] {
            let opts = ExtractOptions::builder()
                .format(ImageFormat::Jpeg { quality: q })
                .build();
            if let ImageFormat::Jpeg { quality } = opts.format {
                assert_eq!(quality, q);
            }
        }
    }

    #[test]
    fn test_builder_method_chaining() {
        // Test that all builder methods can be chained
        let options = ExtractOptions::builder()
            .dpi(400)
            .format(ImageFormat::Tiff)
            .colorspace(ColorSpace::Cmyk)
            .background([128, 128, 128])
            .parallel(8)
            .build();

        assert_eq!(options.dpi, 400);
        assert!(matches!(options.format, ImageFormat::Tiff));
        assert_eq!(options.colorspace, ColorSpace::Cmyk);
        assert_eq!(options.background, Some([128, 128, 128]));
        assert_eq!(options.parallel, 8);
    }

    #[test]
    fn test_extracted_page_various_sizes() {
        // Standard A4 at 300 DPI
        let a4_page = ExtractedPage {
            page_index: 0,
            path: PathBuf::from("/tmp/a4.png"),
            width: 2480,
            height: 3508,
            format: ImageFormat::Png,
        };
        assert_eq!(a4_page.width, 2480);
        assert_eq!(a4_page.height, 3508);

        // Letter size at 300 DPI
        let letter_page = ExtractedPage {
            page_index: 1,
            path: PathBuf::from("/tmp/letter.png"),
            width: 2550,
            height: 3300,
            format: ImageFormat::Png,
        };
        assert_eq!(letter_page.width, 2550);
        assert_eq!(letter_page.height, 3300);

        // Square thumbnail
        let thumb = ExtractedPage {
            page_index: 99,
            path: PathBuf::from("/tmp/thumb.jpg"),
            width: 150,
            height: 150,
            format: ImageFormat::Jpeg { quality: 70 },
        };
        assert_eq!(thumb.width, thumb.height);
    }

    #[test]
    fn test_error_from_io_error() {
        // Test From<std::io::Error> conversion
        let io_err = std::io::Error::new(std::io::ErrorKind::NotFound, "file not found");
        let extract_err: ExtractError = io_err.into();
        let msg = extract_err.to_string();
        assert!(msg.contains("file not found") || msg.contains("IO error"));
    }

    #[test]
    fn test_preset_high_quality_details() {
        let hq = ExtractOptions::high_quality();
        assert_eq!(hq.dpi, 600);
        assert!(matches!(hq.format, ImageFormat::Png));
        // Should inherit other defaults
        assert_eq!(hq.colorspace, ColorSpace::Rgb);
        assert!(hq.background.is_some());
    }

    #[test]
    fn test_preset_fast_details() {
        let fast = ExtractOptions::fast();
        assert_eq!(fast.dpi, 150);
        if let ImageFormat::Jpeg { quality } = fast.format {
            assert_eq!(quality, 80);
        } else {
            panic!("Fast preset should use JPEG");
        }
    }

    #[test]
    fn test_preset_grayscale_details() {
        let gray = ExtractOptions::grayscale();
        assert_eq!(gray.colorspace, ColorSpace::Grayscale);
        // Should have default DPI
        assert_eq!(gray.dpi, 300);
    }

    #[test]
    fn test_background_color_extremes() {
        // Pure black
        let black = ExtractOptions::builder().background([0, 0, 0]).build();
        assert_eq!(black.background, Some([0, 0, 0]));

        // Pure white
        let white = ExtractOptions::builder()
            .background([255, 255, 255])
            .build();
        assert_eq!(white.background, Some([255, 255, 255]));

        // Gray
        let gray = ExtractOptions::builder()
            .background([128, 128, 128])
            .build();
        assert_eq!(gray.background, Some([128, 128, 128]));

        // Primary colors
        let red = ExtractOptions::builder().background([255, 0, 0]).build();
        assert_eq!(red.background, Some([255, 0, 0]));

        let green = ExtractOptions::builder().background([0, 255, 0]).build();
        assert_eq!(green.background, Some([0, 255, 0]));

        let blue = ExtractOptions::builder().background([0, 0, 255]).build();
        assert_eq!(blue.background, Some([0, 0, 255]));
    }

    #[test]
    fn test_extract_options_debug_impl() {
        let options = ExtractOptions::builder()
            .dpi(300)
            .format(ImageFormat::Png)
            .build();

        let debug_str = format!("{:?}", options);
        assert!(debug_str.contains("ExtractOptions"));
        assert!(debug_str.contains("dpi"));
        assert!(debug_str.contains("300"));
    }

    #[test]
    fn test_extract_options_with_callback_debug() {
        let options = ExtractOptions::builder()
            .progress_callback(Box::new(|_, _| {}))
            .build();

        let debug_str = format!("{:?}", options);
        assert!(debug_str.contains("<callback>"));
    }

    #[test]
    fn test_image_format_default() {
        let format: ImageFormat = Default::default();
        assert!(matches!(format, ImageFormat::Png));
    }

    #[test]
    fn test_colorspace_default() {
        let cs: ColorSpace = Default::default();
        assert_eq!(cs, ColorSpace::Rgb);
    }

    #[test]
    fn test_parallel_workers_various_values() {
        // Test various worker counts
        for workers in [1, 2, 4, 8, 16, 32, 64] {
            let options = ExtractOptions::builder().parallel(workers).build();
            assert_eq!(options.parallel, workers);
        }
    }

    #[test]
    fn test_extracted_page_with_all_formats() {
        let formats = [
            (ImageFormat::Png, "png"),
            (ImageFormat::Jpeg { quality: 85 }, "jpg"),
            (ImageFormat::Bmp, "bmp"),
            (ImageFormat::Tiff, "tiff"),
        ];

        for (idx, (format, ext)) in formats.iter().enumerate() {
            let page = ExtractedPage {
                page_index: idx,
                path: PathBuf::from(format!("/tmp/page.{}", ext)),
                width: 1000,
                height: 1500,
                format: *format,
            };
            assert_eq!(page.page_index, idx);
            assert!(page.path.to_string_lossy().ends_with(ext));
        }
    }

    #[test]
    fn test_error_display_all_variants() {
        let errors = [
            ExtractError::PdfNotFound(PathBuf::from("/test.pdf")),
            ExtractError::OutputNotWritable(PathBuf::from("/output")),
            ExtractError::ExtractionFailed {
                page: 1,
                reason: "test reason".to_string(),
            },
            ExtractError::ExternalToolError("tool error".to_string()),
        ];

        for err in &errors {
            let display = format!("{}", err);
            assert!(!display.is_empty());
        }
    }

    #[test]
    fn test_options_builder_default_state() {
        let builder = ExtractOptionsBuilder::default();
        let options = builder.build();

        // Should have default values
        assert_eq!(options.dpi, 300);
        assert!(matches!(options.format, ImageFormat::Png));
        assert_eq!(options.colorspace, ColorSpace::Rgb);
    }

    #[test]
    fn test_colorspace_partial_eq() {
        assert_eq!(ColorSpace::Rgb, ColorSpace::Rgb);
        assert_eq!(ColorSpace::Grayscale, ColorSpace::Grayscale);
        assert_eq!(ColorSpace::Cmyk, ColorSpace::Cmyk);
        assert_ne!(ColorSpace::Rgb, ColorSpace::Grayscale);
        assert_ne!(ColorSpace::Rgb, ColorSpace::Cmyk);
        assert_ne!(ColorSpace::Grayscale, ColorSpace::Cmyk);
    }

    // Additional comprehensive Debug/Clone tests

    #[test]
    fn test_image_format_debug_impl() {
        let png = ImageFormat::Png;
        let debug_str = format!("{:?}", png);
        assert!(debug_str.contains("Png"));

        let jpeg = ImageFormat::Jpeg { quality: 85 };
        let debug_str = format!("{:?}", jpeg);
        assert!(debug_str.contains("Jpeg"));
        assert!(debug_str.contains("85"));

        let tiff = ImageFormat::Tiff;
        let debug_str = format!("{:?}", tiff);
        assert!(debug_str.contains("Tiff"));
    }

    #[test]
    fn test_image_format_clone() {
        let original = ImageFormat::Jpeg { quality: 92 };
        let cloned = original;
        if let ImageFormat::Jpeg { quality } = cloned {
            assert_eq!(quality, 92);
        } else {
            panic!("Clone should preserve JPEG format");
        }

        let original_png = ImageFormat::Png;
        let cloned_png = original_png;
        assert!(matches!(cloned_png, ImageFormat::Png));
    }

    #[test]
    fn test_image_format_copy() {
        let original = ImageFormat::Bmp;
        let copied = original; // Copy, not move
        let _still_valid = original; // Original still valid
        assert!(matches!(copied, ImageFormat::Bmp));
    }

    #[test]
    fn test_colorspace_debug_impl() {
        let rgb = ColorSpace::Rgb;
        let debug_str = format!("{:?}", rgb);
        assert!(debug_str.contains("Rgb"));

        let gray = ColorSpace::Grayscale;
        let debug_str = format!("{:?}", gray);
        assert!(debug_str.contains("Grayscale"));

        let cmyk = ColorSpace::Cmyk;
        let debug_str = format!("{:?}", cmyk);
        assert!(debug_str.contains("Cmyk"));
    }

    #[test]
    fn test_colorspace_clone() {
        let original = ColorSpace::Cmyk;
        let cloned = original;
        assert_eq!(cloned, ColorSpace::Cmyk);
    }

    #[test]
    fn test_colorspace_copy() {
        let original = ColorSpace::Grayscale;
        let copied = original; // Copy
        let _still_valid = original; // Original still valid
        assert_eq!(copied, ColorSpace::Grayscale);
    }

    #[test]
    fn test_extracted_page_debug_impl() {
        let page = ExtractedPage {
            page_index: 3,
            path: PathBuf::from("/tmp/test.png"),
            width: 1920,
            height: 1080,
            format: ImageFormat::Png,
        };
        let debug_str = format!("{:?}", page);
        assert!(debug_str.contains("ExtractedPage"));
        assert!(debug_str.contains("3"));
        assert!(debug_str.contains("1920"));
        assert!(debug_str.contains("1080"));
    }

    #[test]
    fn test_error_debug_impl() {
        let err = ExtractError::PdfNotFound(PathBuf::from("/test.pdf"));
        let debug_str = format!("{:?}", err);
        assert!(debug_str.contains("PdfNotFound"));

        let err2 = ExtractError::ExtractionFailed {
            page: 5,
            reason: "test reason".to_string(),
        };
        let debug_str2 = format!("{:?}", err2);
        assert!(debug_str2.contains("ExtractionFailed"));
    }

    #[test]
    fn test_extract_options_builder_debug_impl() {
        let builder = ExtractOptionsBuilder::default();
        let debug_str = format!("{:?}", builder);
        assert!(debug_str.contains("ExtractOptionsBuilder"));
    }

    #[test]
    fn test_error_path_extraction() {
        let path = PathBuf::from("/some/pdf/file.pdf");
        let err = ExtractError::PdfNotFound(path.clone());

        if let ExtractError::PdfNotFound(p) = err {
            assert_eq!(p, path);
        } else {
            panic!("Wrong error variant");
        }
    }

    #[test]
    fn test_error_page_extraction() {
        let err = ExtractError::ExtractionFailed {
            page: 42,
            reason: "Out of memory".to_string(),
        };

        if let ExtractError::ExtractionFailed { page, reason } = err {
            assert_eq!(page, 42);
            assert!(reason.contains("memory"));
        } else {
            panic!("Wrong error variant");
        }
    }

    #[test]
    fn test_page_index_sequential() {
        let pages: Vec<ExtractedPage> = (0..100)
            .map(|i| ExtractedPage {
                page_index: i,
                path: PathBuf::from(format!("/tmp/page_{:05}.png", i)),
                width: 1000,
                height: 1500,
                format: ImageFormat::Png,
            })
            .collect();

        for (i, page) in pages.iter().enumerate() {
            assert_eq!(page.page_index, i);
        }
    }

    #[test]
    fn test_large_page_dimensions() {
        // A0 at 600 DPI
        let large_page = ExtractedPage {
            page_index: 0,
            path: PathBuf::from("/tmp/a0.png"),
            width: 19842,
            height: 28067,
            format: ImageFormat::Png,
        };
        assert!(large_page.width > 10000);
        assert!(large_page.height > 20000);
    }

    #[test]
    fn test_small_page_dimensions() {
        // Tiny thumbnail
        let tiny_page = ExtractedPage {
            page_index: 0,
            path: PathBuf::from("/tmp/tiny.png"),
            width: 16,
            height: 16,
            format: ImageFormat::Png,
        };
        assert!(tiny_page.width <= 100);
        assert!(tiny_page.height <= 100);
    }

    #[test]
    fn test_preset_consistency() {
        let high = ExtractOptions::high_quality();
        let fast = ExtractOptions::fast();
        let gray = ExtractOptions::grayscale();

        // High quality should have higher DPI than fast
        assert!(high.dpi > fast.dpi);

        // Grayscale should have grayscale colorspace
        assert_eq!(gray.colorspace, ColorSpace::Grayscale);

        // All presets should have valid backgrounds
        assert!(high.background.is_some() || high.background.is_none()); // Either is valid
    }

    #[test]
    fn test_output_path_types() {
        // Absolute path
        let abs_page = ExtractedPage {
            page_index: 0,
            path: PathBuf::from("/absolute/path/page.png"),
            width: 100,
            height: 100,
            format: ImageFormat::Png,
        };
        assert!(abs_page.path.is_absolute());

        // Relative path
        let rel_page = ExtractedPage {
            page_index: 0,
            path: PathBuf::from("relative/path/page.png"),
            width: 100,
            height: 100,
            format: ImageFormat::Png,
        };
        assert!(rel_page.path.is_relative());
    }

    #[test]
    fn test_jpeg_quality_boundary() {
        // Test quality 1 (minimum realistic)
        let opts_1 = ExtractOptions::builder()
            .format(ImageFormat::Jpeg { quality: 1 })
            .build();
        if let ImageFormat::Jpeg { quality } = opts_1.format {
            assert_eq!(quality, 1);
        }

        // Test quality values across range
        for q in (0..=100).step_by(10) {
            let opts = ExtractOptions::builder()
                .format(ImageFormat::Jpeg { quality: q })
                .build();
            if let ImageFormat::Jpeg { quality } = opts.format {
                assert_eq!(quality, q);
            }
        }
    }

    #[test]
    fn test_magick_extractor_marker() {
        // Verify MagickExtractor type exists
        let _ = std::any::type_name::<MagickExtractor>();
    }

    #[test]
    fn test_error_io_details_preserved() {
        let io_err = std::io::Error::new(
            std::io::ErrorKind::PermissionDenied,
            "access denied to file",
        );
        let extract_err: ExtractError = io_err.into();

        let msg = extract_err.to_string().to_lowercase();
        // The error message should contain IO-related info
        assert!(msg.contains("io") || msg.contains("error") || msg.contains("access"));
    }

    #[test]
    fn test_all_dpi_presets() {
        let dpi_values = [72, 96, 150, 200, 300, 400, 600, 1200];

        for dpi in dpi_values {
            let opts = ExtractOptions::builder().dpi(dpi).build();
            assert_eq!(opts.dpi, dpi);
        }
    }

    #[test]
    fn test_background_none_vs_some() {
        let with_bg = ExtractOptions::builder()
            .background([255, 255, 255])
            .build();
        assert!(with_bg.background.is_some());

        let without_bg = ExtractOptions::builder().no_background().build();
        assert!(without_bg.background.is_none());
    }

    // ============ Concurrency Tests ============

    #[test]
    fn test_image_extract_types_send_sync() {
        fn assert_send_sync<T: Send + Sync>() {}
        assert_send_sync::<ExtractOptions>();
        assert_send_sync::<ExtractedPage>();
        assert_send_sync::<ImageFormat>();
        assert_send_sync::<ColorSpace>();
    }

    #[test]
    fn test_concurrent_options_building() {
        use std::thread;
        let handles: Vec<_> = (0..8)
            .map(|i| {
                thread::spawn(move || {
                    ExtractOptions::builder()
                        .dpi(150 + (i as u32 * 50))
                        .colorspace(if i % 2 == 0 {
                            ColorSpace::Rgb
                        } else {
                            ColorSpace::Grayscale
                        })
                        .build()
                })
            })
            .collect();

        let results: Vec<_> = handles
            .into_iter()
            .map(|h: std::thread::JoinHandle<ExtractOptions>| h.join().unwrap())
            .collect();
        assert_eq!(results.len(), 8);
        for (i, opt) in results.iter().enumerate() {
            assert_eq!(opt.dpi, 150 + (i as u32 * 50));
        }
    }

    #[test]
    fn test_parallel_extracted_page_creation() {
        use rayon::prelude::*;

        let pages: Vec<_> = (0..100)
            .into_par_iter()
            .map(|i| ExtractedPage {
                page_index: i,
                path: PathBuf::from(format!("page_{:04}.png", i)),
                width: 1000 + i as u32,
                height: 1500 + i as u32,
                format: ImageFormat::Png,
            })
            .collect();

        assert_eq!(pages.len(), 100);
        for (i, page) in pages.iter().enumerate() {
            assert_eq!(page.page_index, i);
            assert_eq!(page.width, 1000 + i as u32);
        }
    }

    #[test]
    fn test_extracted_page_thread_transfer() {
        use std::thread;

        let page = ExtractedPage {
            page_index: 42,
            path: PathBuf::from("/tmp/test_page.png"),
            width: 2480,
            height: 3508,
            format: ImageFormat::Jpeg { quality: 95 },
        };

        let handle = thread::spawn(move || {
            assert_eq!(page.page_index, 42);
            assert_eq!(page.width, 2480);
            page.path.to_string_lossy().to_string()
        });

        let result = handle.join().unwrap();
        assert!(result.contains("test_page"));
    }

    #[test]
    fn test_options_shared_across_threads() {
        use std::sync::Arc;
        use std::thread;

        let options = Arc::new(
            ExtractOptions::builder()
                .dpi(600)
                .format(ImageFormat::Png)
                .colorspace(ColorSpace::Rgb)
                .build(),
        );

        let handles: Vec<_> = (0..4)
            .map(|_| {
                let opts = Arc::clone(&options);
                thread::spawn(move || {
                    assert_eq!(opts.dpi, 600);
                    opts.dpi
                })
            })
            .collect();

        for handle in handles {
            let result: u32 = handle.join().unwrap();
            assert_eq!(result, 600);
        }
    }

    #[test]
    fn test_image_format_thread_safe() {
        use std::thread;

        let formats = vec![
            ImageFormat::Png,
            ImageFormat::Jpeg { quality: 90 },
            ImageFormat::Tiff,
            ImageFormat::Bmp,
        ];

        let handles: Vec<_> = formats
            .into_iter()
            .map(|format| {
                thread::spawn(move || {
                    let ext = format.extension();
                    ext.to_string()
                })
            })
            .collect();

        let extensions: Vec<_> = handles.into_iter().map(|h| h.join().unwrap()).collect();
        assert_eq!(extensions.len(), 4);
        assert!(extensions.contains(&"png".to_string()));
        assert!(extensions.contains(&"jpg".to_string()));
    }

    // ============ Additional Boundary Tests ============

    #[test]
    fn test_dpi_boundary_minimum() {
        // Values below MIN_DPI (72) should be clamped to MIN_DPI
        let opts = ExtractOptions::builder().dpi(1).build();
        assert_eq!(opts.dpi, MIN_DPI);
    }

    #[test]
    fn test_dpi_boundary_maximum() {
        // Values above MAX_DPI (1200) should be clamped to MAX_DPI
        let opts = ExtractOptions::builder().dpi(2400).build();
        assert_eq!(opts.dpi, MAX_DPI);
    }

    #[test]
    fn test_page_index_zero() {
        let page = ExtractedPage {
            page_index: 0,
            path: PathBuf::from("first.png"),
            width: 100,
            height: 100,
            format: ImageFormat::Png,
        };
        assert_eq!(page.page_index, 0);
    }

    #[test]
    fn test_page_index_large() {
        let page = ExtractedPage {
            page_index: 10000,
            path: PathBuf::from("page_10000.png"),
            width: 100,
            height: 100,
            format: ImageFormat::Png,
        };
        assert_eq!(page.page_index, 10000);
    }

    #[test]
    fn test_page_dimensions_zero() {
        let page = ExtractedPage {
            page_index: 0,
            path: PathBuf::from("empty.png"),
            width: 0,
            height: 0,
            format: ImageFormat::Png,
        };
        assert_eq!(page.width, 0);
        assert_eq!(page.height, 0);
    }

    #[test]
    fn test_page_dimensions_large() {
        let page = ExtractedPage {
            page_index: 0,
            path: PathBuf::from("huge.png"),
            width: 32768,
            height: 32768,
            format: ImageFormat::Png,
        };
        assert_eq!(page.width, 32768);
        assert_eq!(page.height, 32768);
    }

    #[test]
    fn test_background_color_black() {
        let opts = ExtractOptions::builder().background([0, 0, 0]).build();
        assert_eq!(opts.background, Some([0, 0, 0]));
    }

    #[test]
    fn test_background_color_white() {
        let opts = ExtractOptions::builder()
            .background([255, 255, 255])
            .build();
        assert_eq!(opts.background, Some([255, 255, 255]));
    }

    #[test]
    fn test_all_color_spaces() {
        let spaces = [ColorSpace::Rgb, ColorSpace::Grayscale, ColorSpace::Cmyk];
        for space in spaces {
            let opts = ExtractOptions::builder().colorspace(space).build();
            assert_eq!(opts.colorspace, space);
        }
    }
}