# Update documentation on Read the docs
# -----------------------------------
# This GitHub Actions workflow runs on push commits. It detects commit's target branch and project,
# then triggers the corresponding build on Read the Docs.
# Key Steps:
# 1. Compare the current commit to the last commit and obtain the path of changed files
# 2. Extract a set of project names from changed file path
# 3. Obtain the target branch name and convert it into Read the Docs format
# 4. Use Read the Docs V3 API to trigger the build for the corresponding docs:
#    Github project name -> Read the docs project name
#    Github branch name -> Read the docs version
#
# This ensures live documentation is synchronized with the latest change.

name: RTD Docs Synchronization

on:
  push:
    branches:
      - 'develop'
      - 'docs/**'
    paths:
     - 'projects/**'
     - 'shared/**'

jobs:
  trigger-rtd:
    runs-on: ubuntu-latest
    steps:
      - name: Get changed files using GitHub REST API
        id: diff
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        run: |
          echo "Fetching changed files between ${{ github.event.before }} and ${{ github.event.after }}"

          changed_files=$(gh api \
            repos/${{ github.repository }}/compare/${{ github.event.before }}...${{ github.event.after }} \
            --jq '.files[].filename')

          echo "Changed files:"
          echo "$changed_files"

          # Extract project names from paths like projects/rocprim/...
          project_names=$(echo "$changed_files" \
            | grep '^projects/' \
            | awk -F/ '{print $2}' \
            | sort -u)

          echo "Detected changed projects:"
          echo "$project_names"

          echo "changed_projects<<EOF" >> $GITHUB_OUTPUT
          echo "$project_names" >> $GITHUB_OUTPUT
          echo "EOF" >> $GITHUB_OUTPUT

      - name: Trigger RTD build
        if: steps.diff.outputs.changed_projects
        env:
          changed_projects: ${{ steps.diff.outputs.changed_projects }}
          RTD_TOKEN: ${{ secrets.RTD_TOKEN }}
        run: |
          branch_name="${GITHUB_REF#refs/heads/}"
          version_slug="${branch_name//\//-}"
          echo "Target github branch: $branch_name"
          echo "Read the Docs version slug: $version_slug"

          # List of project slugs on RTD
          project_list=$( curl \
                 -H "Authorization: Token $RTD_TOKEN" \
                 "https://app.readthedocs.com/api/v3/projects/?expand=advanced-micro-devices&limit=300" \
                 | jq -r '.results[].slug'
          )

          for project in $changed_projects; do
            slug="advanced-micro-devices-$project"
            if echo "$project_list" | grep -Fxq "$slug"; then
              latest_branch=$(curl -s \
                  -H "Authorization: Token $RTD_TOKEN" \
                  "https://app.readthedocs.com/api/v3/projects/$slug/" \
                  | jq -r ".default_branch" \
                  | tr -d '[:space:]')
              echo "Latest branch for $project: $latest_branch"
              if [ "$branch_name" = "$latest_branch" ]; then
                echo "Detected latest release branch, trigger builds for 'latest' version"
                response=$(curl -f -s -X POST \
                      -H "Authorization: Token $RTD_TOKEN" \
                      "https://readthedocs.com/api/v3/projects/$slug/versions/latest/builds/") || {
                      echo "Failed to trigger RTD build for $project. Response: $response"
                      exit 1
                    }
                echo "Successfully triggered RTD build for $project 'latest' version. Response: $response"
              fi
              echo "Triggering RTD build for $project, version: $version_slug"
              response=$(curl -f -s -X POST \
                  -H "Authorization: Token $RTD_TOKEN" \
                  "https://readthedocs.com/api/v3/projects/$slug/versions/$version_slug/builds/") || {
                  echo "Failed to trigger RTD build for $project. Response: $response"
                  exit 1
              }
              echo "Successfully triggered RTD build for $project. Response: $response"
            else
              echo "Skipping $project - Does not exist on Read the Docs"
            fi
          done