ansible/roles/pi_slint_frontend/tasks/main.yml

---
- name: Packages needed to build the front-end
  ansible.builtin.apt:
    name:
      - build-essential
      - pkg-config
      # The only C libraries the binary links: everything else - X11, Wayland, EGL,
      # GL - is dlopen'd at runtime by winit and glutin, so it is not needed to build.
      - libfontconfig1-dev
      - libfreetype-dev
      - curl
      # Runtime, not build: winit and glutin dlopen all of these, so they never show
      # up in `ldd` and the binary links happily without them - it then aborts on
      # first run with "Library libxkbcommon-x11.so could not be loaded".
      - libxkbcommon0
      - libxkbcommon-x11-0
      - libx11-xcb1
      - libxcb-xkb1
      - libxcursor1
      - libxi6
      - libxrandr2
      - libgl1
      - libegl1
      - libgles2
      # The design uses emoji as iconography - the shelf badges, the figurine marker,
      # the scene sparkle. Raspbian ships no font that has them, so without these they
      # render as empty boxes. Symbola is the monochrome fallback for the glyphs Noto
      # does not cover.
      - fonts-noto-color-emoji
      - fonts-symbola
    cache_valid_time: 7200

- name: Check for a rust toolchain
  ansible.builtin.stat:
    path: /root/.cargo/bin/cargo
  register: pi_slint_frontend_cargo

- name: Fetch the rustup installer
  ansible.builtin.get_url:
    url: https://sh.rustup.rs
    dest: /tmp/rustup-init.sh
    mode: "0755"
  when: not pi_slint_frontend_cargo.stat.exists

- name: Install the rust toolchain
  # Debian 12 ships rustc 1.63, which is far too old for Slint, so this comes from
  # rustup rather than apt.
  ansible.builtin.command:
    cmd: "/tmp/rustup-init.sh -y --profile minimal --default-toolchain {{ pi_slint_frontend_toolchain }}"
    creates: /root/.cargo/bin/cargo
  when: not pi_slint_frontend_cargo.stat.exists

- name: Check the checkout has a slint-frontend
  ansible.builtin.stat:
    path: "{{ pi_slint_frontend_root }}/Cargo.toml"
  register: pi_slint_frontend_manifest
  when: not ansible_check_mode

- name: Fail on a checkout without the front-end
  ansible.builtin.fail:
    msg: >-
      {{ musicmouse_version }} has no slint-frontend/, so it predates the native
      front-end. Point musicmouse_version at a branch that has it, or set
      mediapi_install_slint_frontend to false for this host.
  when: not ansible_check_mode and not pi_slint_frontend_manifest.stat.exists

- name: Fail when the checkout's commit is unknown
  # This role builds what pi_musicmouse checked out, and reuses its record of which
  # commit that was. With mediapi_install_kidsmusic false that role never ran, so
  # there is no checkout to build and no commit to stamp - and the stamp comparison
  # below would compare against an empty string and rebuild on every run.
  ansible.builtin.fail:
    msg: >-
      pi_slint_frontend needs pi_musicmouse to have run first - it builds the
      slint-frontend/ inside the checkout that role owns. Set
      mediapi_install_kidsmusic to true for this host, or
      mediapi_install_slint_frontend to false.
  when: not ansible_check_mode and pi_musicmouse_commit | length == 0

- name: Read which commit the binary was built from
  # The same guard pi_musicmouse uses for the venv and the web dist, for the same
  # reason: hanging a 40-minute build off "the checkout changed" strands the device
  # when a run fails after the checkout, because the next run finds it current and
  # rebuilds nothing.
  ansible.builtin.command:
    cmd: "cat {{ pi_slint_frontend_root }}/.built-commit"
  register: pi_slint_frontend_stamp
  changed_when: false
  failed_when: false

- name: Build the front-end
  # First build takes roughly 40 minutes on a Pi 4 - 570 crates, two jobs. Later ones
  # are incremental. `async` keeps the SSH connection from idling out underneath it.
  ansible.builtin.command:
    cmd: >-
      nice -n 10 /root/.cargo/bin/cargo build --release
      --no-default-features --features {{ pi_slint_frontend_features }}
      -j {{ pi_slint_frontend_jobs }}
    chdir: "{{ pi_slint_frontend_root }}"
  environment:
    # The committed release profile is tuned for a workstation. Thin LTO with
    # codegen-units=1 is a memory risk on 1.8 GB and buys nothing that matters here.
    CARGO_PROFILE_RELEASE_LTO: "false"
    CARGO_PROFILE_RELEASE_CODEGEN_UNITS: "16"
    PATH: "/root/.cargo/bin:{{ ansible_facts['env']['PATH'] }}"
  async: 7200
  poll: 30
  changed_when: true
  when: >-
    not ansible_check_mode
    and pi_slint_frontend_stamp.stdout | trim != pi_musicmouse_commit

- name: Record which commit the binary was built from
  ansible.builtin.copy:
    content: "{{ pi_musicmouse_commit }}\n"
    dest: "{{ pi_slint_frontend_root }}/.built-commit"
    mode: "0644"
  when: not ansible_check_mode

- name: Find the X session user's home directory
  ansible.builtin.getent:
    database: passwd
    key: "{{ pi_slint_frontend_x_user }}"

- name: Note where the X cookie lives
  ansible.builtin.set_fact:
    pi_slint_frontend_x_home: "{{ ansible_facts.getent_passwd[pi_slint_frontend_x_user][4] }}"

- name: Install the launcher
  ansible.builtin.template:
    src: musikdelfin.sh.j2
    dest: /usr/local/bin/musikdelfin
    mode: "0755"

- name: Install the systemd unit
  # Installed but deliberately not enabled: this is the thing under test, and the
  # kiosk browser is still what the device shows on boot. Start it by hand -
  # `systemctl start musikdelfin` - or run /usr/local/bin/musikdelfin over SSH.
  ansible.builtin.template:
    src: musikdelfin.service.j2
    dest: /etc/systemd/system/musikdelfin.service
    mode: "0644"
  notify: Reload systemd