name: Rename Go module

on:
  workflow_dispatch:
    inputs:
      source:
        description: "Reference or commit on which to base module renaming"
        required: true
        type: string
        default: "main"
      branch:
        description: "Branch to which a commit of the changes is pushed; leave blank for auto-naming. If non-existent, the branch is created."
        type: string
        default: ""

jobs:
  rename-module:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 0 # everything

      - run: git fetch --tags https://github.com/ethereum/go-ethereum.git

      - run: git checkout ${{ inputs.source }}

      - name: References pointing to source
        # NOTE: This step assumes that the source has been checked out, which
        # might not hold if reordered.
        run: |
          git branch --points-at HEAD;
          git tag --points-at HEAD;

      - name: Set up Go
        uses: actions/setup-go@v5
        with:
          go-version-file: "go.mod"

      - name: Detect Go module
        id: go
        run: |
            echo "MODULE=$(go list -m)" >> "$GITHUB_OUTPUT";
            echo "MODULE_SUFFIX=$(go list -m | cut -b 12-)" >> "$GITHUB_OUTPUT"; # Strip github.com/

      - name: Validate Go module
        if: ${{ steps.go.outputs.MODULE != 'github.com/ava-labs/libevm' && steps.go.outputs.MODULE != 'github.com/ethereum/go-ethereum' }}
        run: echo "Unexpected Go module ${{ steps.go.outputs.MODULE }}" && exit 1;

      - name: Set variables
        id: vars
        env:
          # `cond && ifTrue || ifFalse` is effectively a ternary operator, based on short-circuiting Boolean logic (assumes `ifTrue` is truthy)
          RENAME_TO: ${{ steps.go.outputs.MODULE_SUFFIX == 'ava-labs/libevm' && 'ethereum/go-ethereum' || 'ava-labs/libevm' }}
        run: |
          echo "RENAME_FROM=${{ steps.go.outputs.MODULE_SUFFIX}}" >> "$GITHUB_OUTPUT";
          echo "RENAME_TO=${RENAME_TO}" >> "$GITHUB_OUTPUT";
          echo "WORKFLOW_HASH=${WORKFLOW_HASH}" >> "$GITHUB_OUTPUT";
          echo "SOURCE_COMMIT=$(git rev-parse HEAD)" >> "$GITHUB_OUTPUT";
          echo "AUTO_BRANCH_NAME=auto/rename-module/to=${RENAME_TO}/src=$(git rev-parse HEAD)/workflow_sha=${{ github.workflow_sha }}/run=${{ github.run_id }}" \
            >> "$GITHUB_OUTPUT";

      - name: Globally rename module from ${{ steps.vars.outputs.RENAME_FROM }} to ${{ steps.vars.outputs.RENAME_TO }}
        run: |
          go mod edit -module github.com/${{ steps.vars.outputs.RENAME_TO }};
          find . \
            -iname '*.go' \
            -o -iname '*.txt' \
            -o -iname '*.go.tpl' \
            -o -iname '*.proto' \
            -not -wholename '*/libevm/tooling/*' | xargs \
            sed -i -E 's|(["`]github\.com/)${{ steps.vars.outputs.RENAME_FROM }}|\1${{ steps.vars.outputs.RENAME_TO }}|g';

      - name: Remnant references
        run: |
          find . -type f | \
            xargs grep -In github.com/${{ steps.vars.outputs.RENAME_FROM }} | \
            grep -v "https://github.com/${{ steps.vars.outputs.RENAME_FROM }}"

      - name: Smoke tests
        # `go list -m` shows us the module name and grep will non-zero exit on mismatch
        # `go build` is a rudimentary but broad test of correctness
        # The explicitly tested packages are edge cases:
        # - bind generates tests and a go.mod on the fly
        # - rlpgen has testdata with imports that need updating
        run: |
          go list -m | grep github.com/${{ steps.vars.outputs.RENAME_TO }};
          go build ./...;
          go test ./accounts/abi/bind ./rlp/rlpgen

      - name: Set branch name
        id: branch
        env:
          BRANCH: ${{ inputs.branch || steps.vars.outputs.AUTO_BRANCH_NAME }}
        run: echo "NAME=${BRANCH}" >> "$GITHUB_OUTPUT";

      - name: Check out branch (create if non-existent)
        env:
          BRANCH: ${{ steps.branch.outputs.NAME }}
        run: |
          git checkout "${BRANCH}" 2>/dev/null || \
          (git checkout -b "${BRANCH}" && git push origin "${BRANCH}");

      - name: Commit to branch
        uses: planetscale/ghcommit-action@d4176bfacef926cc2db351eab20398dfc2f593b5 # v0.2.0
        env:
          GITHUB_TOKEN: ${{secrets.GITHUB_TOKEN}}
        with:
          # WARNING: mirror any change to the commit_message value below in libevm-delta.yml
          commit_message: |
            [AUTO] rename Go module to ${{ steps.vars.outputs.RENAME_TO }}

            Source: ${{ steps.vars.outputs.SOURCE_COMMIT }} (${{ inputs.source }})
            Workflow: ${{ github.workflow_sha }} (${{ github.workflow_ref }})
            Run ID: ${{ github.run_id }}
          repo: ${{ github.repository }}
          branch: ${{ steps.branch.outputs.NAME }}