update-tzdb.yml

name: Update TZDB

on:
  schedule:
    # Run daily at 00:00 UTC
    - cron: '0 0 * * *'
  workflow_dispatch:  # Allow manual trigger
  repository_dispatch:
    types: [tzdb-update]

jobs:
  check-and-update:
    name: Check and Update TZDB
    runs-on: macos-latest
    permissions:
      contents: write
      pull-requests: write
    
    steps:
      - uses: actions/checkout@v4
        with:
          submodules: recursive
      
      - name: Select Xcode
        run: |
          sudo xcode-select -s /Applications/Xcode_16.1.app
          swift --version
      
      - name: Install pkl
        run: |
          brew install pkl
          pkl --version
      
      - name: Download current zonenow.tab
        run: |
          curl -o zonenow.tab.new https://raw.githubusercontent.com/eggert/tz/main/zonenow.tab
          curl -o zone1970.tab.new https://raw.githubusercontent.com/eggert/tz/main/zone1970.tab
          
      - name: Check for changes
        id: check
        run: |
          changes_detected=false
          if [ ! -f "zonenow.tab" ] || ! cmp -s "zonenow.tab" "zonenow.tab.new"; then
            echo "Changes detected in zonenow.tab"
            mv zonenow.tab.new zonenow.tab
            changes_detected=true
          else
            echo "No changes detected in zonenow.tab"
          fi
          
          if [ ! -f "zone1970.tab" ] || ! cmp -s "zone1970.tab" "zone1970.tab.new"; then
            echo "Changes detected in zone1970.tab"
            mv zone1970.tab.new zone1970.tab
            changes_detected=true
          else
            echo "No changes detected in zone1970.tab"
          fi
          
          echo "changes_detected=$changes_detected" >> $GITHUB_OUTPUT

      - name: Build project
        if: steps.check.outputs.changes_detected == 'true'
        run: swift build
      
      - name: Generate updated timezone data
        if: steps.check.outputs.changes_detected == 'true'
        run: swift run SwiftTZGenerator
      
      - name: Create Pull Request
        if: steps.check.outputs.changes_detected == 'true'
        uses: peter-evans/create-pull-request@v5
        with:
          token: ${{ secrets.GITHUB_TOKEN }}
          commit-message: "[Automated] Update Time Zone Database"
          title: "[Automated] Update Time Zone Database"
          body: |
            This PR updates the timezone database based on changes in the IANA tzdb.
            
            Changes were automatically detected and generated using the `SwiftTZGenerator` tool.
            
            ### Changes
            <details>
            <summary>View changes</summary>
            
            ```diff
            # zonenow.tab changes
            $(diff -u zonenow.tab.new zonenow.tab || true)
            
            # zone1970.tab changes
            $(diff -u zone1970.tab.new zone1970.tab || true)
            ```
            
            </details>
            
            - Updated `zonenow.tab` and/or `zone1970.tab` from IANA
            - Regenerated PKL schema
            - Updated Swift generated code
            
            Please review the changes and merge if everything looks correct.
          branch: update-tzdb
          base: main
          labels: |
            automated
            tzdb-update
            patch
            release
          delete-branch: true