Generate a PDF out of the images

Cargo.toml

@@ -13,6 +13,8 @@ calamine = "0.26.1"
 chrono = "0.4.40"
 image = "0.25.6"
 imageproc = "0.25.0"
+printpdf = { version = "0.8.2", features = ["png"] }
 serde = "1.0.217"
 small_uid = "0.2.4"
 structopt = "0.3.26"
+tempfile = "3.19.1"

main.rs

@@ -1,13 +1,19 @@
 use calamine::{open_workbook, Data, Reader, Xlsx};
 
+use printpdf::image::RawImage;
+use printpdf::{
+    Mm, Op, PdfDocument, PdfPage, PdfSaveOptions, PdfWarnMsg, RawImageData, RawImageFormat,
+    XObjectTransform,
+};
 use structopt::StructOpt;
 
 use ab_glyph::{FontRef, PxScale};
-use image::{ImageBuffer, Rgba};
+use image::{EncodableLayout, ImageBuffer, Rgba};
 use imageproc::drawing::draw_text_mut;
-use small_uid::SmallUid;
-use std::path::{Path, PathBuf};
 
+// A4 dimensions
+const A4_WIDTH: f32 = 210.0;
+const A4_HEIGHT: f32 = 297.0;
 // Configuration for the label
 const DPI: f32 = 300.0;
 const MM_TO_PX: f32 = DPI / 25.4;
@@ -98,24 +104,13 @@ fn parse_xlsx(delivery_week_filter: &str) -> Result<Vec<Record>, Box<dyn std::er
     Ok(records)
 }
 
-// The label looks like this:
-//
-//  Tomate (Solanum lycopersicum) (species)                                             /^\
-//  Variété: San Marzano (variety)                                                     / j \
-//                                                                                    / ard \
-//                                                                                   / iflore\
-//                                                                                   ---------
-// SEMAINE DE LIVRAISON: 22
-//
-//                                                                       123 Allée des Récoltes
-//                                                                       Tél: Téléphone.
-//
-fn generate_label(output_dir: &String, record: Record) -> PathBuf {
+fn generate_label(record: Record) -> ImageBuffer<Rgba<u8>, Vec<u8>> {
     let font_data = include_bytes!("./assets/DejaVuSans.ttf");
     let font = FontRef::try_from_slice(font_data).unwrap();
     let logo = image::open("./assets/logo.png").unwrap();
 
-    let mut label = ImageBuffer::new(LABEL_WIDTH as u32, LABEL_HEIGHT as u32);
+    let mut label: ImageBuffer<Rgba<u8>, Vec<u8>> =
+        ImageBuffer::new(LABEL_WIDTH as u32, LABEL_HEIGHT as u32);
 
     // Fill in the background
     for pixel in label.pixels_mut() {
@@ -167,13 +162,62 @@ fn generate_label(output_dir: &String, record: Record) -> PathBuf {
         &font,
         &species_varieties,
     );
+    return label;
+}
 
-    // Save the label
+fn combine_labels(
+    labels: &[ImageBuffer<Rgba<u8>, Vec<u8>>],
+    output_dir: &str,
+) -> Result<(), Box<dyn std::error::Error>> {
+    let labels_per_page = (A4_HEIGHT / LABEL_HEIGHT).floor() as usize;
 
-    let output_path = Path::new(output_dir).join(format!("label_{}.png", SmallUid::new()));
-    label.save(output_path.clone()).unwrap();
+    // Create a new PDF document
+    let mut doc = PdfDocument::new("Labels Document");
+    let mut pages = Vec::new();
+    let mut warnings: Vec<PdfWarnMsg> = Vec::new();
 
-    return output_path;
+    // Group labels by page
+    for chunk in labels.chunks(labels_per_page) {
+        let mut page_contents = Vec::new();
+        let mut y_position = A4_HEIGHT - LABEL_HEIGHT;
+
+        for label in chunk {
+            // let image = RawImage::decode_from_bytes(label.as_raw(), &mut Vec::new()).unwrap();
+            // let bytes = include_bytes!("output/label_GV-Ek9pYRis.png");
+            let pixels = label.clone().into_raw();
+            let image = RawImage {
+                pixels: RawImageData::U8(pixels),
+                width: LABEL_WIDTH as usize,
+                height: LABEL_HEIGHT as usize,
+                data_format: RawImageFormat::RGBA8,
+                tag: Vec::new(),
+            };
+            let image_id = doc.add_image(&image);
+
+            // Add image to page at current y position
+            page_contents.push(Op::UseXobject {
+                id: image_id,
+                transform: XObjectTransform::default(),
+            });
+
+            // Move y position up for next label
+            y_position -= LABEL_HEIGHT;
+        }
+
+        // Create page and add to pages list
+        let page = PdfPage::new(Mm(A4_WIDTH), Mm(A4_HEIGHT), page_contents);
+        pages.push(page);
+    }
+
+    // Add all pages to document and save
+    let pdf_bytes: Vec<u8> = doc
+        .with_pages(pages)
+        .save(&PdfSaveOptions::default(), &mut warnings);
+
+    // Write PDF bytes to file
+    std::fs::write("test.pdf", pdf_bytes)?;
+
+    Ok(())
 }
 
 #[derive(StructOpt)]
@@ -190,10 +234,9 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
     let week_number = "s".to_owned() + &opts.week;
     let records = parse_xlsx(&week_number)?;
 
+    let mut labels = Vec::new();
     for record in records {
-        let path = generate_label(&opts.output_dir, record);
-        println!("{}", path.into_os_string().into_string().unwrap())
+        labels.push(generate_label(record));
     }
-
-    Ok(())
+    combine_labels(&labels, &opts.output_dir)
 }