use std::fs::File;
use std::io::Read;

use cbz2pdf::formats::cbz::CbzWriter;
use cbz2pdf::formats::FormatWriter;
use cbz2pdf::model::{Document, ImagePage};

fn make_tiny_jpeg() -> (Vec<u8>, image::DynamicImage) {
    let img = image::DynamicImage::new_rgb8(1, 1).to_rgb8();
    let mut buf = Vec::new();
    {
        let mut cursor = std::io::Cursor::new(&mut buf);
        let mut enc = image::codecs::jpeg::JpegEncoder::new_with_quality(&mut cursor, 80);
        enc.encode(&img, 1, 1, image::ColorType::Rgb8.into())
            .unwrap();
    }
    let decoded = image::load_from_memory(&buf).unwrap();
    (buf, decoded)
}

#[test]
fn cbz_writer_preserves_dct_and_renames_non_jpg() {
    // Prepare a page with original JPEG DCT data but a non-jpg name.
    let (jpeg_dct, decoded) = make_tiny_jpeg();
    let page = ImagePage {
        name: "cover.png".to_string(),
        image: decoded,
        jpeg_dct: Some(jpeg_dct.clone()),
    };
    let doc = Document::new(vec![page]);

    let temp_dir = tempfile::tempdir().expect("create temp dir");
    let cbz_path = temp_dir.path().join("out.cbz");

    let writer = CbzWriter;
    writer.write(&doc, &cbz_path).expect("write cbz");

    // Open the CBZ and verify it contains 001.jpg with the exact JPEG data.
    let f = File::open(&cbz_path).unwrap();
    let mut zip = zip::ZipArchive::new(f).unwrap();

    // There should be exactly one file named 001.jpg
    let mut found = false;
    for i in 0..zip.len() {
        let mut file = zip.by_index(i).unwrap();
        let name = file.enclosed_name().unwrap().to_owned();
        if name.file_name().unwrap() == "001.jpg" {
            let mut data = Vec::new();
            file.read_to_end(&mut data).unwrap();
            assert_eq!(
                data, jpeg_dct,
                "writer should preserve original JPEG DCT bytes"
            );
            found = true;
        }
    }
    assert!(found, "001.jpg not found in zip");
}

#[test]
fn cbz_writer_keeps_jpg_name() {
    // If the page already has a .jpg name, the writer should keep it.
    let (jpeg_dct, decoded) = make_tiny_jpeg();
    let page = ImagePage {
        name: "page01.jpg".to_string(),
        image: decoded,
        jpeg_dct: Some(jpeg_dct),
    };
    let doc = Document::new(vec![page]);

    let temp_dir = tempfile::tempdir().expect("create temp dir");
    let cbz_path = temp_dir.path().join("out.cbz");

    let writer = CbzWriter;
    writer.write(&doc, &cbz_path).expect("write cbz");

    let f = File::open(&cbz_path).unwrap();
    let mut zip = zip::ZipArchive::new(f).unwrap();

    let mut names = Vec::new();
    for i in 0..zip.len() {
        let file = zip.by_index(i).unwrap();
        let name = file
            .enclosed_name()
            .unwrap()
            .file_name()
            .unwrap()
            .to_owned();
        names.push(name.to_string_lossy().to_string());
    }
    assert_eq!(
        names,
        vec!["page01.jpg"],
        "existing .jpg name should be kept"
    );
}