---
# =============================================================================
# Backup Tasks - Using Official Gitea Dump
# =============================================================================
#
# Uses the official `gitea dump` command for comprehensive backup.
# Reference: https://docs.gitea.com/administration/backup-and-restore
#
# The dump creates a ZIP containing:
#   - app.ini and custom/ directory (configuration)
#   - All git repositories
#   - Database SQL dump (gitea-db.sql)
#   - Attachments, avatars, LFS objects
#
# Note: We run the dump while Gitea is running. The official docs recommend
# stopping Gitea for perfect consistency, but docker exec requires a running
# container. The consistency risk during the brief dump operation is minimal.
# =============================================================================

# Set up variables for this backup run.
# gitea_backup_timestamp: Used in filename for unique identification (e.g., 20260114T143022)
# gitea_backup_dir_path: Where backups are stored on the host filesystem
- name: Set backup variables
  ansible.builtin.set_fact:
    gitea_backup_timestamp: "{{ ansible_facts['date_time']['iso8601_basic_short'] }}"
    gitea_backup_dir_path: "{{ gitea_install_dir }}/{{ gitea_backup_dir }}"

# Ensure the backup directory exists on the host.
# Mode 0750: owner read/write/execute, group read/execute, others no access
- name: Ensure backup directory exists
  ansible.builtin.file:
    path: "{{ gitea_backup_dir_path }}"
    state: directory
    mode: "0750"

# -----------------------------------------------------------------------------
# Create Backup Using Official Gitea Dump
# -----------------------------------------------------------------------------
# Run the official gitea dump command inside the running container.
#
# Command breakdown:
#   docker exec {{ container }}  - Execute command inside the container
#   /usr/local/bin/gitea dump    - The gitea binary with dump subcommand
#   -c /data/gitea/conf/app.ini  - Path to config file (tells gitea where data is)
#   -w /tmp                      - Working directory for temporary files
#   -f /tmp/gitea-backup-*.zip   - Output filename for the backup archive
#
# Note: We write to /tmp inside the container first, then copy out.
# This avoids permission issues with mounted volumes.

- name: Run gitea dump command
  ansible.builtin.command:
    cmd: >-
      docker exec -u git {{ gitea_container_name }}
      /usr/local/bin/gitea dump
      -c /data/gitea/conf/app.ini
      -w /tmp
      -f /tmp/gitea-backup-{{ gitea_backup_timestamp }}.zip
  register: gitea_dump_result
  changed_when: true

# Copy backup from container to host filesystem
# docker cp copies files between container and host.
# Format: docker cp container:/path/in/container /path/on/host
- name: Copy backup from container to host
  ansible.builtin.command:
    cmd: >-
      docker cp
      {{ gitea_container_name }}:/tmp/gitea-backup-{{ gitea_backup_timestamp }}.zip
      {{ gitea_backup_dir_path }}/gitea-backup-{{ gitea_backup_timestamp }}.zip
  changed_when: true

# Clean up the backup file inside the container
# We don't want to leave large files in the container's /tmp
# failed_when: false - Don't fail if cleanup fails (backup already succeeded)
- name: Remove backup file from container
  ansible.builtin.command:
    cmd: >-
      docker exec -u git {{ gitea_container_name }}
      rm /tmp/gitea-backup-{{ gitea_backup_timestamp }}.zip
  changed_when: true
  failed_when: false

# -----------------------------------------------------------------------------
# Backup Verification
# -----------------------------------------------------------------------------
# Verify the backup was actually created and is not empty.
# This catches cases where the command succeeded but produced no output.

- name: Verify backup file exists
  ansible.builtin.stat:
    path: "{{ gitea_backup_dir_path }}/gitea-backup-{{ gitea_backup_timestamp }}.zip"
  register: gitea_backup_file

# Display backup info for operator visibility
# Size calculation: bytes / 1048576 = megabytes (1024*1024)
- name: Display backup info
  ansible.builtin.debug:
    msg: >-
      Backup completed: {{ gitea_backup_dir_path }}/gitea-backup-{{ gitea_backup_timestamp }}.zip
      Size: {{ (gitea_backup_file.stat.size / 1048576) | round(2) }}MB
  when: gitea_backup_file.stat.exists | default(false)

- name: Fail if backup file is missing or empty
  ansible.builtin.fail:
    msg: "Backup file is missing or empty. Cannot proceed."
  when:
    - not ansible_check_mode
    - not gitea_backup_file.stat.exists or gitea_backup_file.stat.size == 0

# -----------------------------------------------------------------------------
# Backup Rotation
# -----------------------------------------------------------------------------
# Keep only the N most recent backups (controlled by gitea_backup_retention).
# This prevents disk space from being exhausted by old backups.

# Find all existing backup files matching our naming pattern
- name: Find old backup files
  ansible.builtin.find:
    paths: "{{ gitea_backup_dir_path }}"
    patterns: "gitea-backup-*.zip"
    file_type: file
  register: gitea_old_backup_files

# Delete old backups, keeping only the most recent ones.
# Logic breakdown:
#   gitea_old_backup_files.files | sort(attribute='mtime')  - Sort by modification time (oldest first)
#   [:-gitea_backup_retention]                    - Slice: all except last N items
#                                                   (Python slice notation: [:-5] = all but last 5)
# Example: If we have 7 backups and retention=5, this deletes the 2 oldest.
- name: Remove old backups beyond retention limit
  ansible.builtin.file:
    path: "{{ item.path }}"
    state: absent
  loop: "{{ (gitea_old_backup_files.files | sort(attribute='mtime'))[:-gitea_backup_retention] }}"
  loop_control:
    label: "{{ item.path | basename }}"
  when: gitea_old_backup_files.files | length > gitea_backup_retention