## PDFium

Native bindings for pdfium project

## Installing

* for Mix projects, add the following under `deps` in `mix.exs`:

    ```elixir
    {:pdfium, "~> 0.1"}
    ```

* for single-file Elixir scripts, add the following:

    ```elixir
    Mix.install([pdfium: "~> 0.1"])
    ```

## Usage

1. open a PDF file descriptor:

   ```elixir
   {:ok, document} = PDFium.load_document("file.pdf")
   # => {:ok, #Reference<0.2181297728.2193227786.166499>}
   ```

2. get the number of pages in the file:

   ```elixir
   {:ok, pages} = PDFium.get_page_count(document)
   # => {:ok, 1}
   ```

3. render a page to file:

   ```elixir
   {:ok, ref} = PDFium.load_document("/Users/eugene/Downloads/7ade6db09604a8b41104763c6f16a987.pdf")
   {:ok, binary, w, h} = PDFium.get_page_bitmap(ref, 0, 300) # 300 for DPI
   {:ok, image} = Vix.Vips.Image.new_from_binary(binary, w, h, 4, :VIPS_FORMAT_UCHAR)
   {:ok, _image} = Image.write(image, "/tmp/sample.png")
   ```

## Releasing

1. bump version in `VERSION` file. Run:

   ```sh
   echo -n (awk 'BEGIN{FS=OFS="."} {$NF+=1}1' VERSION) > VERSION
   ```

2. commit and push the change:

   ```sh
   git add VERSION
   git commit --message "Bump library version"
   git push origin main
   ```

3. create a PR from `main` to `stable`. Run:

   ```sh
   gh pr create --base stable --fill
   ```

4. wait until the PR checks are green, then merge the PR

## Running CI steps locally

1. Prepare:

   ```sh
   mkdir output
   ```

1. Build:

   ```sh
   dagger call \
     precompile --src-dir . --platform-name linux/arm64 --abi musl \
     export --path output/ --allowParentDirPath
   ```

2. Test:

   ```sh
   dagger call test \
     --precompiled output/pdfium-nif-2.17-aarch64-linux-musl-0.1.23.tar.gz \
     --abi musl --platform-name linux/arm64
   ```

## Releasing manually

1. open PR with a new libpdfium tag:

    ```sh
    env GITHUB_TOKEN=(gh auth token) dagger call prepare-release-pull-request \
      --base stable \
      --libpdfium-tag chromium/7506 \
      --actor 41898282+github-actions[bot] \
      --github-token GITHUB_TOKEN
    ```

2. wait until the PR is green, then merge it and release a package on hex:

    ```sh
    HEX_API_KEY=483a... GITHUB_TOKEN=(gh auth token) dagger call create-release \
      --pr 99 \
      --actor gmile \
      --github-token GITHUB_TOKEN \
      --hex-api-key HEX_API_KEY
    ```

## Updating OTP version (for macOS)

```sh
wget https://github.com/erlef/otp_builds/releases/download/OTP-28.1/OTP-28.1-macos-amd64.tar.gz /tmp
wget https://github.com/erlef/otp_builds/releases/download/OTP-28.1/OTP-28.1-macos-arm64.tar.gz /tmp

shasum -a 256 /tmp/OTP-28.1-macos-amd64.tar.gz
shasum -a 256 /tmp/OTP-28.1-macos-arm64.tar.gz

# Then edit custom/build.json by inserting the hashes
```

## Known issues

* Installing the library was tested and will work in macOS and inside Docker images built by Bob. Installing
  currently doesn't work under Elixir installed via package managers, such as via `apk add elixir` for example.

## License

See [LICENSE].