---
- name: Configure WireGuard split tunnel routing
  hosts: production
  become: true
  gather_facts: true

  vars:
    wg_interface: wg0
    wg_addr: 10.8.0.1/24
    wg_net: 10.8.0.0/24
    wan_interface: eth0
    listening_port: 51820
    extra_nets:
      - 192.168.178.0/24
      - 172.20.0.0/16
    firewall_backend: iptables   # or nftables
    manage_ufw: false
    manage_firewalld: false
    firewalld_zone: public

  pre_tasks:
    - name: Ensure required collections are installed (documentation note)
      debug:
        msg: >
          Install collections if missing:
          ansible-galaxy collection install ansible.posix community.general
      when: false

  tasks:
    - name: Ensure WireGuard config directory exists
      ansible.builtin.file:
        path: "/etc/wireguard"
        state: directory
        mode: "0700"
        owner: root
        group: root

    - name: Persist IPv4 forwarding
      ansible.builtin.copy:
        dest: "/etc/sysctl.d/99-{{ wg_interface }}-forward.conf"
        owner: root
        group: root
        mode: "0644"
        content: |
          # Managed by Ansible - WireGuard {{ wg_interface }}
          net.ipv4.ip_forward=1

    - name: Enable IPv4 forwarding runtime
      ansible.posix.sysctl:
        name: net.ipv4.ip_forward
        value: "1"
        state: present
        reload: true

    - name: Configure MASQUERADE (iptables)
      community.general.iptables:
        table: nat
        chain: POSTROUTING
        out_interface: "{{ wan_interface }}"
        source: "{{ wg_net }}"
        jump: MASQUERADE
        state: present
      when: firewall_backend == "iptables"

    - name: Allow forwarding wg -> wan (iptables)
      community.general.iptables:
        table: filter
        chain: FORWARD
        in_interface: "{{ wg_interface }}"
        out_interface: "{{ wan_interface }}"
        source: "{{ wg_net }}"
        jump: ACCEPT
        state: present
      when: firewall_backend == "iptables"

    - name: Allow forwarding wan -> wg (iptables)
      community.general.iptables:
        table: filter
        chain: FORWARD
        out_interface: "{{ wg_interface }}"
        destination: "{{ wg_net }}"
        ctstate: RELATED,ESTABLISHED
        jump: ACCEPT
        state: present
      when: firewall_backend == "iptables"

    - name: Allow forwarding to extra nets (iptables)
      community.general.iptables:
        table: filter
        chain: FORWARD
        in_interface: "{{ wg_interface }}"
        destination: "{{ item }}"
        jump: ACCEPT
        state: present
      loop: "{{ extra_nets }}"
      when: firewall_backend == "iptables"

    - name: Allow return from extra nets (iptables)
      community.general.iptables:
        table: filter
        chain: FORWARD
        source: "{{ item }}"
        out_interface: "{{ wg_interface }}"
        ctstate: RELATED,ESTABLISHED
        jump: ACCEPT
        state: present
      loop: "{{ extra_nets }}"
      when: firewall_backend == "iptables"

    - name: Deploy nftables WireGuard rules
      ansible.builtin.template:
        src: "{{ playbook_dir }}/../templates/wireguard-nftables.nft.j2"
        dest: "/etc/nftables.d/wireguard-{{ wg_interface }}.nft"
        owner: root
        group: root
        mode: "0644"
      when: firewall_backend == "nftables"
      notify: Reload nftables

    - name: Ensure nftables main config includes WireGuard rules
      ansible.builtin.lineinfile:
        path: /etc/nftables.conf
        regexp: '^include "/etc/nftables.d/wireguard-{{ wg_interface }}.nft";$'
        line: 'include "/etc/nftables.d/wireguard-{{ wg_interface }}.nft";'
        create: true
      when: firewall_backend == "nftables"
      notify: Reload nftables

    - name: Manage UFW forward policy
      ansible.builtin.lineinfile:
        path: /etc/default/ufw
        regexp: '^DEFAULT_FORWARD_POLICY='
        line: 'DEFAULT_FORWARD_POLICY="ACCEPT"'
      when: manage_ufw

    - name: Allow WireGuard port in UFW
      community.general.ufw:
        rule: allow
        port: "{{ listening_port }}"
        proto: udp
        comment: "WireGuard VPN"
      when: manage_ufw

    - name: Allow routed traffic via UFW (wg -> wan)
      ansible.builtin.command:
        cmd: "ufw route allow in on {{ wg_interface }} out on {{ wan_interface }} to any"
      register: ufw_route_result
      changed_when: "'Skipping' not in ufw_route_result.stdout"
      when: manage_ufw

    - name: Allow extra nets via UFW
      ansible.builtin.command:
        cmd: "ufw route allow in on {{ wg_interface }} to {{ item }}"
      loop: "{{ extra_nets }}"
      register: ufw_extra_result
      changed_when: "'Skipping' not in ufw_extra_result.stdout"
      when: manage_ufw

    - name: Allow WireGuard port in firewalld
      ansible.posix.firewalld:
        zone: "{{ firewalld_zone }}"
        port: "{{ listening_port }}/udp"
        permanent: true
        state: enabled
      when: manage_firewalld

    - name: Enable firewalld masquerade
      ansible.posix.firewalld:
        zone: "{{ firewalld_zone }}"
        masquerade: true
        permanent: true
        state: enabled
      when: manage_firewalld

    - name: Allow forwarding from WireGuard via firewalld
      ansible.posix.firewalld:
        permanent: true
        state: enabled
        immediate: false
        rich_rule: 'rule family="ipv4" source address="{{ wg_net }}" accept'
      when: manage_firewalld

    - name: Allow extra nets via firewalld
      ansible.posix.firewalld:
        permanent: true
        state: enabled
        immediate: false
        rich_rule: 'rule family="ipv4" source address="{{ item }}" accept'
      loop: "{{ extra_nets }}"
      when: manage_firewalld

    - name: Ensure wg-quick service enabled and restarted
      ansible.builtin.systemd:
        name: "wg-quick@{{ wg_interface }}"
        enabled: true
        state: restarted

    - name: Show WireGuard status
      ansible.builtin.command: "wg show {{ wg_interface }}"
      register: wg_status
      changed_when: false
      failed_when: false

    - name: Render routing summary
      ansible.builtin.debug:
        msg: |
          WireGuard routing updated for {{ wg_interface }}
          {{ wg_status.stdout }}

  handlers:
    - name: Reload nftables
      ansible.builtin.command: nft -f /etc/nftables.conf