---
# =============================================================================
# DRIFT-CHECK PLAYBOOK
# Purpose: Check file drift and output detailed file-level JSON report
# Usage: ansible-playbook drift-check.yml
# Output: Structured JSON with sync status and drifted files info
# Registers: drift_detected, drifted_files_json for consumption by update script
# =============================================================================

- name: Check file drift
  hosts: all
  gather_facts: false
  vars_files:
    - ../deploy-config.yml

  tasks:
    # ─────────────────────────────────────────────────────────────────────
    # TASK 1: Initialize drift tracking variables
    # ─────────────────────────────────────────────────────────────────────
    - name: Initialize drift tracking
      set_fact:
        drift_detected: false
        drifted_items: []

    # ─────────────────────────────────────────────────────────────────────
    # TASK 2: Check drift for each configured file
    # Loops through deploy_items and compares local vs server files
    # ─────────────────────────────────────────────────────────────────────
    - name: Check drift for each file
      block:
        # Read local file from repo
        - name: Read local file
          slurp:
            src: "{{ playbook_dir }}/{{ '../../' + item.src }}"
          delegate_to: localhost
          register: local_file_content
          failed_when: false

        # Read file from server
        - name: Read server file
          slurp:
            src: "{{ item.dest }}"
          register: server_file_content
          failed_when: false

        # Build drift info if file is missing
        - name: Add to drifted items if missing
          set_fact:
            drifted_items: "{{ drifted_items + [drift_info] }}"
          vars:
            drift_info:
              name: "{{ item.name }}"
              destination: "{{ item.dest }}"
              status: "MISSING"
              reason: "File not found on server"
          when: server_file_content.rc != 0

        # Build drift info if file content differs
        - name: Add to drifted items if content differs
          set_fact:
            drifted_items: "{{ drifted_items + [drift_info] }}"
          vars:
            drift_info:
              name: "{{ item.name }}"
              destination: "{{ item.dest }}"
              status: "CONTENT_DIFFERS"
              reason: "File content differs from repository"
          when:
            - server_file_content.rc == 0
            - local_file_content.content | b64decode != server_file_content.content | b64decode

      loop: "{{ deploy_items }}"
      loop_control:
        loop_var: item
        label: "{{ item.name }}"

    # ─────────────────────────────────────────────────────────────────────
    # TASK 3: Update drift detection flag
    # ─────────────────────────────────────────────────────────────────────
    - name: Set drift_detected flag
      set_fact:
        drift_detected: "{{ drifted_items | length > 0 }}"

    # ─────────────────────────────────────────────────────────────────────
    # TASK 4: Generate JSON report with drift details
    # ─────────────────────────────────────────────────────────────────────
    - name: Generate drift detection JSON report
      set_fact:
        drifted_files_json: "{{ drifted_items | to_nice_json }}"

    # ─────────────────────────────────────────────────────────────────────
    # TASK 5: Save drift report to file for script consumption
    # ─────────────────────────────────────────────────────────────────────
    - name: Save drift report to file
      copy:
        content: "{{ drifted_files_json }}"
        dest: "/tmp/drifted_files_{{ inventory_hostname }}.json"
        owner: root
        group: root
        mode: "0644"
      delegate_to: localhost

    # ─────────────────────────────────────────────────────────────────────
    # TASK 6: Output status summary
    # ─────────────────────────────────────────────────────────────────────
    - name: Output SYNCED status
      debug:
        msg: |
          ✓ All files are in sync
          Total files monitored: {{ deploy_items | length }}
      when: not drift_detected

    - name: Output OUT_OF_SYNC status with details
      debug:
        msg: |
          ✗ Configuration drift detected!
          Drifted files: {{ drifted_items | length }}
          Details: {{ drifted_files_json }}
      when: drift_detected

    # ─────────────────────────────────────────────────────────────────────
    # TASK 7: Fail if drift detected (for CI/CD pipeline)
    # ─────────────────────────────────────────────────────────────────────
    - name: Fail if drift detected
      fail:
        msg: "Configuration drift detected. {{ drifted_items | length }} file(s) out of sync."
      when: drift_detected