name: "Star History Chart"
description: "Generate a star history chart (PNG, SVG or Mermaid) for a GitHub repository, ready to embed in a README."
author: "emanuelef"

branding:
  icon: "trending-up"
  color: "blue"

inputs:
  repo:
    description: "Repository to chart, as owner/name. Defaults to the repository running the workflow."
    required: false
    default: ${{ github.repository }}
  output:
    description: "Path to write. The extension picks the format unless `format` is set: .png, .svg, .md."
    required: false
    default: "star-history.png"
  format:
    description: "png, svg or mermaid. Defaults to whatever the output extension implies."
    required: false
    default: ""
  theme:
    description: "light, dark, or transparent (transparent adapts to the reader's GitHub theme)."
    required: false
    default: "light"
  width:
    description: "Image width in pixels. Ignored for mermaid."
    required: false
    default: "800"
  height:
    description: "Image height in pixels. Ignored for mermaid."
    required: false
    default: "400"
  daily:
    description: "Overlay per-day counts on a second axis in addition to the cumulative curve."
    required: false
    default: "false"
  caption:
    description: "Small attribution text in the bottom-right corner. Empty for none."
    required: false
    default: ""
  token:
    description: >-
      GitHub token. Optional: the star history endpoint serves public repositories
      unauthenticated at 60 requests/hour, and one chart costs ~1-33 requests. A token
      raises that to 5000/hour.
    required: false
    default: ${{ github.token }}
  version:
    description: "Version of the starchart tool to run (a git tag, or 'latest')."
    required: false
    default: "latest"
  go-version:
    description: "Go version used to build the tool."
    required: false
    default: "1.27"

outputs:
  stars:
    description: "Total stars in the rendered history."
    value: ${{ steps.render.outputs.stars }}
  days:
    description: "Number of days in the rendered history."
    value: ${{ steps.render.outputs.days }}
  file:
    description: "Path that was written."
    value: ${{ steps.render.outputs.file }}

runs:
  using: composite
  steps:
    - name: Set up Go
      uses: actions/setup-go@v7
      with:
        go-version: ${{ inputs.go-version }}
        cache: false

    - name: Render star history chart
      id: render
      shell: bash
      env:
        GITHUB_TOKEN: ${{ inputs.token }}
        STARCHART_REPO: ${{ inputs.repo }}
        STARCHART_OUT: ${{ inputs.output }}
        STARCHART_FORMAT: ${{ inputs.format }}
        STARCHART_THEME: ${{ inputs.theme }}
        STARCHART_WIDTH: ${{ inputs.width }}
        STARCHART_HEIGHT: ${{ inputs.height }}
        STARCHART_DAILY: ${{ inputs.daily }}
        STARCHART_CAPTION: ${{ inputs.caption }}
        STARCHART_VERSION: ${{ inputs.version }}
      run: |
        set -euo pipefail

        args=(
          -repo "$STARCHART_REPO"
          -out "$STARCHART_OUT"
          -theme "$STARCHART_THEME"
          -width "$STARCHART_WIDTH"
          -height "$STARCHART_HEIGHT"
        )
        [ -n "$STARCHART_FORMAT" ] && args+=(-format "$STARCHART_FORMAT")
        [ -n "$STARCHART_CAPTION" ] && args+=(-caption "$STARCHART_CAPTION")
        [ "$STARCHART_DAILY" = "true" ] && args+=(-daily)

        go run "github.com/emanuelef/gh-repo-stats-server/cmd/starchart@${STARCHART_VERSION}" "${args[@]}"