# yaml-language-server: $schema=https://json.schemastore.org/github-action.json
# permissions:
#   - contents: write  # Required for creating releases
---
name: Do Monthly Release
description: 'Creates a release for the current month, incrementing patch number if necessary.'
author: 'Ismo Vuorinen'

branding:
  icon: calendar
  color: blue

inputs:
  token:
    description: 'GitHub token with permission to create releases.'
    required: true
    default: ${{ github.token }}
  dry-run:
    description: 'Run in dry-run mode without creating the release.'
    required: false
    default: 'false'
  prefix:
    description: 'Optional prefix for release tags.'
    required: false
    default: ''

outputs:
  release-tag:
    description: 'The tag of the created release'
    value: ${{ steps.create-release.outputs.release_tag }}
  release-url:
    description: 'The URL of the created release'
    value: ${{ steps.create-release.outputs.release_url }}
  previous-tag:
    description: 'The previous release tag'
    value: ${{ steps.create-release.outputs.previous_tag }}

runs:
  using: 'composite'
  steps:
    - name: Validate Inputs
      shell: sh
      env:
        INPUT_TOKEN: ${{ inputs.token }}
        INPUT_DRY_RUN: ${{ inputs.dry-run }}
        INPUT_PREFIX: ${{ inputs.prefix }}
      run: |
        set -eu

        # Validate token
        if [ -z "$INPUT_TOKEN" ]; then
          echo "::error::GitHub token is required"
          exit 1
        fi

        # Validate dry-run option
        if [ "$INPUT_DRY_RUN" != "true" ] && [ "$INPUT_DRY_RUN" != "false" ]; then
          echo "::error::dry-run must be either 'true' or 'false'"
          exit 1
        fi

        # Validate prefix format if provided (alphanumeric, dots, underscores, hyphens)
        if [ -n "$INPUT_PREFIX" ]; then
          # Use case pattern matching for validation
          case "$INPUT_PREFIX" in
            *[!a-zA-Z0-9_.-]*)
              echo "::error::Invalid prefix format. Only alphanumeric characters, dots, underscores, and hyphens are allowed"
              exit 1
              ;;
          esac
        fi

        # Write validated values to GITHUB_ENV for use in subsequent steps
        {
          echo "VALIDATED_TOKEN=$INPUT_TOKEN"
          echo "VALIDATED_DRY_RUN=$INPUT_DRY_RUN"
          echo "VALIDATED_PREFIX=$INPUT_PREFIX"
        } >> "$GITHUB_ENV"

    - name: Checkout Repository
      uses: actions/checkout@71cf2267d89c5cb81562390fa70a37fa40b1305e # v6-beta
      with:
        token: ${{ env.VALIDATED_TOKEN }}
        fetch-depth: 0 # Fetch all history for tag comparison

    - name: Create Release
      id: create-release
      shell: sh
      run: |
        set -eu
        # Use validated environment variables from GITHUB_ENV
        GITHUB_TOKEN="$VALIDATED_TOKEN"
        PREFIX="$VALIDATED_PREFIX"
        DRY_RUN="$VALIDATED_DRY_RUN"

        # Function to validate version format (YYYY.M.N or YYYY.MM.N)
        validate_version() {
          version=$1
          # Check basic format with case statement
          case "$version" in
            [0-9][0-9][0-9][0-9].[0-9].[0-9]*|[0-9][0-9][0-9][0-9].[0-9][0-9].[0-9]*)
              # Extract parts for detailed validation
              year="${version%%.*}"
              rest="${version#*.}"
              month="${rest%%.*}"
              patch="${rest#*.}"

              # Validate year (4 digits)
              if [ ${#year} -ne 4 ]; then
                echo "::error::Invalid version format: $version"
                return 1
              fi

              # Validate month (1 or 2 digits)
              if [ ${#month} -gt 2 ] || [ ${#month} -lt 1 ]; then
                echo "::error::Invalid version format: $version"
                return 1
              fi

              # Validate patch is numeric
              case "$patch" in
                ''|*[!0-9]*)
                  echo "::error::Invalid version format: $version"
                  return 1
                  ;;
              esac
              ;;
            *)
              echo "::error::Invalid version format: $version"
              return 1
              ;;
          esac
        }

        # Function to get previous release tag with error handling
        get_previous_tag() {
          local previous_tag
          previous_tag=$(gh release list --limit 1 2>/dev/null | awk '{ print $1 }') || {
            echo "::warning::No previous releases found"
            return 1
          }
          echo "$previous_tag"
        }

        # Get previous release tag
        previous_tag=$(get_previous_tag) || previous_tag=""
        echo "previous_tag=${previous_tag}" >> $GITHUB_OUTPUT

        if [ -n "$previous_tag" ]; then
          previous_major="${previous_tag%%\.*}"
          previous_minor="${previous_tag#*.}"
          previous_minor="${previous_minor%.*}"
          previous_patch="${previous_tag##*.}"

          # Validate previous tag format
          validate_version "$previous_tag" || {
            echo "::error::Invalid previous tag format: $previous_tag"
            exit 1
          }
        fi

        # Determine next release tag
        next_major_minor="$(date +'%Y').$(date +'%-m')"

        if [ -n "$previous_tag" ] && [ "${previous_major}.${previous_minor}" = "${next_major_minor}" ]; then
          echo "Month release already exists for year, incrementing patch number by 1"
          next_patch="$((previous_patch + 1))"
        else
          echo "Month release does not exist for year, setting patch number to 0"
          next_patch="0"
        fi

        # Construct release tag
        release_tag="${next_major_minor}.${next_patch}"
        if [ -n "$PREFIX" ]; then
          release_tag="${PREFIX}${release_tag}"
        fi

        # Validate final release tag
        validate_version "${release_tag#$PREFIX}" || {
          echo "::error::Invalid release tag format: $release_tag"
          exit 1
        }

        echo "release_tag=${release_tag}" >> $GITHUB_OUTPUT

        # Create release if not in dry-run mode
        if [ "$DRY_RUN" = "false" ]; then
          echo "Creating release ${release_tag}..."
          release_url=$(gh release create "${release_tag}" \
              --repo="${GITHUB_REPOSITORY}" \
              --title="${release_tag}" \
              --generate-notes 2>/dev/null) || {
            echo "::error::Failed to create release"
            exit 1
          }
          echo "release_url=${release_url}" >> $GITHUB_OUTPUT
          echo "Release created successfully: ${release_url}"
        else
          echo "Dry run mode - would create release: ${release_tag}"
          echo "release_url=dry-run" >> $GITHUB_OUTPUT
        fi

    - name: Verify Release
      if: inputs.dry-run == 'false'
      shell: sh
      env:
        RELEASE_TAG: ${{ steps.create-release.outputs.release_tag }}
      run: |-
        set -eu
        # Use validated environment variables from GITHUB_ENV
        GITHUB_TOKEN="$VALIDATED_TOKEN"

        # Verify the release was created
        if ! gh release view "$RELEASE_TAG" >/dev/null 2>&1; then
          echo "::error::Failed to verify release creation"
          exit 1
        fi

        echo "Release verification successful"