---
# Non-Arch installer logic:
# Download the official Nix installer and its SHA256 from releases.nixos.org
# and run the daemon (multi-user) installer.

# 1) Fetch the official SHA256 from releases.nixos.org on the control node
- name: ⬇️ Fetch official Nix installer SHA256
  uri_retry:
    url: "{{ dev_nix_installer_sha256_url }}"
    return_content: true
  register: dev_nix_official_sha_response
  delegate_to: localhost
  run_once: true
  become: false

- name: 🔧 Set expected installer checksum from official SHA256
  ansible.builtin.set_fact:
    dev_nix_installer_sha256: >-
      {{ dev_nix_official_sha_response.content.split()[0] | trim }}
  run_once: true

- name: ⬇️ Download Nix installer script from official releases
  get_url_retry:
    url: "{{ dev_nix_installer_url }}"
    dest: "{{ dev_nix_installer_dest }}"
    mode: "0755"
    timeout: "{{ lookup('timeout', 30) | int }}"
    checksum: "sha256:{{ dev_nix_installer_sha256 }}"
  register: dev_nix_installer_download_result
  become: true

- name: 🔍 Probe common nix binary paths before installation
  ansible.builtin.stat:
    path: "{{ item }}"
  loop: "{{ dev_nix_binary_candidates }}"
  register: dev_nix_binary_probe_before
  become: true

- name: 🔧 Set nix binary path detected before installation
  ansible.builtin.set_fact:
    dev_nix_binary_path_before: >-
      {{
        (
          dev_nix_binary_probe_before.results
          | selectattr("stat.exists")
          | map(attribute="item")
          | list
          | first
        ) | default("", true)
      }}

- name: 📦 Install Nix via official installer when no Nix binary is present
  ansible.builtin.include_tasks: 02_install_official.yml
  when: dev_nix_binary_path_before | length == 0

- name: 🔍 Probe common nix binary paths after installation
  ansible.builtin.stat:
    path: "{{ item }}"
  loop: "{{ dev_nix_binary_candidates }}"
  register: dev_nix_binary_probe_after
  become: true

- name: 🔧 Set nix binary path for systemd usage
  ansible.builtin.set_fact:
    dev_nix_binary_path: >-
      {{
        (
          dev_nix_binary_probe_after.results
          | selectattr("stat.exists")
          | map(attribute="item")
          | list
          | first
        ) | default("", true)
      }}

- name: 🛑 Fail if nix binary is missing after installation
  ansible.builtin.fail:
    msg: >-
      Nix binary could not be found after installation.
      Checked: {{ dev_nix_binary_candidates | join(', ') }}
  when: dev_nix_binary_path | length == 0

- name: ✅ Ensure nix is reachable in PATH for systemd services
  ansible.builtin.file:
    src: "{{ dev_nix_binary_path }}"
    dest: /usr/local/bin/nix
    state: link
  become: true
  when: dev_nix_binary_path != "/usr/local/bin/nix"

- name: 🗑️ Optionally drop shell snippet for Nix
  ansible.builtin.script:
    cmd: >-
      {{ role_path }}/files/shell/write_nix_shell_snippet.sh
      {{ dev_nix_shell_snippet_path | quote }}
  register: dev_nix_shell_snippet_result
  changed_when: >
    dev_nix_shell_snippet_result.stdout is search('\\[CHANGED\\]')
  failed_when: >
    dev_nix_shell_snippet_result.rc != 0 or
    dev_nix_shell_snippet_result.stdout is search('\\[FAIL\\]')
  when: dev_nix_enable_shell_snippet | bool
  become: true

- name: 🧹 Aggressively prune Nix data (GC + optimise)
  become: true
  ansible.builtin.script: >
    shell/aggressive_prune_nix.sh
    {{ dev_nix_binary_path | quote }}
  changed_when: true
  when:
    - MODE_CLEANUP | bool
    - DOCKER_IN_CONTAINER | bool