name: Setup package mirrors
description: Benchmark package mirrors and export the fastest reachable registry for each ecosystem
inputs:
  npm_mirrors:
    description: Newline-separated npm-compatible registries
    required: false
    default: |
      https://npm.reg.darano.ir/
  pypi_mirrors:
    required: false
    default: |
      https://package-mirror.liara.ir/repository/pypi/simple
      https://pypi.reg.darano.ir
      https://pypi-iran.ir/simple/
      https://pypi.org/simple/
  go_mirrors:
    description: Newline-separated Go module proxies
    required: false
    default: |
      https://go.devneeds.ir/
      https://package-mirror.liara.ir/repository/go/
      https://go.reg.darano.ir/
      https://proxy.golang.org/
  debian_mirrors:
    description: Newline-separated Debian package repository base URLs
    required: false
    default: |
      http://repo.iut.ac.ir/debian/
      http://deb.debian.org/debian/
  connect_timeout:
    description: curl connection timeout in seconds
    required: false
    default: "3"
  max_time:
    description: curl request timeout in seconds
    required: false
    default: "10"
outputs:
  npm_registry:
    description: Fastest reachable npm registry
    value: ${{ steps.select.outputs.npm_registry }}
  pypi_index:
    description: Fastest reachable Python package index
    value: ${{ steps.select.outputs.pypi_index }}
  go_proxy:
    description: Fastest reachable Go module proxy
    value: ${{ steps.select.outputs.go_proxy }}
  debian_mirror:
    description: Fastest reachable Debian package repository
    value: ${{ steps.select.outputs.debian_mirror }}
runs:
  using: composite
  steps:
    - name: Rate mirrors and export package environments
      id: select
      shell: bash
      env:
        NPM_MIRRORS: ${{ inputs.npm_mirrors }}
        PYPI_MIRRORS: ${{ inputs.pypi_mirrors }}
        GO_MIRRORS: ${{ inputs.go_mirrors }}
        DEBIAN_MIRRORS: ${{ inputs.debian_mirrors }}
        CONNECT_TIMEOUT: ${{ inputs.connect_timeout }}
        MAX_TIME: ${{ inputs.max_time }}
      run: |
        set -euo pipefail

        if [[ ! "$CONNECT_TIMEOUT" =~ ^[0-9]+([.][0-9]+)?$ ]] ||
           [[ ! "$MAX_TIME" =~ ^[0-9]+([.][0-9]+)?$ ]]; then
          echo "Mirror timeouts must be positive numbers" >&2
          exit 1
        fi

        select_fastest() {
          local ecosystem="$1"
          local mirrors="$2"
          local scores mirror result status duration fallback
          scores="$(mktemp)"
          fallback=""

          while IFS= read -r mirror; do
            mirror="$(printf '%s' "$mirror" | sed -e 's/^[[:space:]]*//' -e 's/[[:space:]]*$//')"
            [[ -z "$mirror" || "$mirror" == \#* ]] && continue

            if [[ ! "$mirror" =~ ^https?:// ]]; then
              echo "[$ecosystem] skipped invalid URL: $mirror" >&2
              continue
            fi
            [[ -z "$fallback" ]] && fallback="$mirror"

            if result="$(curl \
              --location \
              --silent \
              --show-error \
              --output /dev/null \
              --connect-timeout "$CONNECT_TIMEOUT" \
              --max-time "$MAX_TIME" \
              --write-out '%{http_code} %{time_total}' \
              "$mirror" 2>/dev/null)"; then
              read -r status duration <<< "$result"
              if [[ "$status" =~ ^[0-9]{3}$ ]] &&
                 (((10#$status >= 200 && 10#$status < 400) || 10#$status == 404)) &&
                 [[ "$duration" =~ ^[0-9]+([.][0-9]+)?$ ]]; then
                printf '%s\t%s\t%s\n' "$duration" "$status" "$mirror" >> "$scores"
                continue
              fi
            fi

            echo "[$ecosystem] unavailable: $mirror" >&2
          done <<< "$mirrors"

          if [[ ! -s "$scores" ]]; then
            rm -f "$scores"
            if [[ -z "$fallback" ]]; then
              echo "No valid $ecosystem mirror was configured" >&2
              return 1
            fi
            echo "[$ecosystem] no mirror responded; falling back to $fallback" >&2
            printf '%s\n' "$fallback"
            return 0
          fi

          echo "[$ecosystem] mirror ranking (seconds, HTTP status, URL):" >&2
          sort -n -k1,1 "$scores" >&2
          sort -n -k1,1 "$scores" | head -n 1 | cut -f3-
          rm -f "$scores"
        }

        npm_registry="$(select_fastest npm "$NPM_MIRRORS")"
        pypi_index="$(select_fastest pypi "$PYPI_MIRRORS")"
        go_proxy="$(select_fastest go "$GO_MIRRORS")"
        debian_mirror="$(select_fastest debian "$DEBIAN_MIRRORS")"

        {
          echo "NPM_CONFIG_REGISTRY=$npm_registry"
          echo "npm_config_registry=$npm_registry"
          echo "COREPACK_NPM_REGISTRY=$npm_registry"
          echo "YARN_REGISTRY=$npm_registry"
          echo "PNPM_CONFIG_REGISTRY=$npm_registry"
          echo "BUN_CONFIG_REGISTRY=$npm_registry"
          echo "PIP_INDEX_URL=$pypi_index"
          echo "UV_DEFAULT_INDEX=$pypi_index"
          echo "GOPROXY=$go_proxy"
          echo "DEBIAN_MIRROR=$debian_mirror"
        } >> "$GITHUB_ENV"

        {
          echo "npm_registry=$npm_registry"
          echo "pypi_index=$pypi_index"
          echo "go_proxy=$go_proxy"
          echo "debian_mirror=$debian_mirror"
        } >> "$GITHUB_OUTPUT"