name: Bootstrapping CI

on:
  workflow_dispatch:
  push:
    paths-ignore:
      - '**.yml'
      - '**.md'
      - '**.vv'
      - '**.out'
      - 'cmd/tools/**'
      - '!cmd/tools/builders/**.v'
      - '!cmd/tools/vup.v'
      - '!**/bootstrapping_ci.yml'
  pull_request:
    paths-ignore:
      - '**.yml'
      - '**.md'
      - '**.vv'
      - '**.out'
      - 'cmd/tools/**'
      - '!cmd/tools/builders/**.v'
      - '!cmd/tools/vup.v'
      - '!**/bootstrapping_ci.yml'

concurrency:
  group: bootstrapping-${{ github.workflow }}-${{ github.ref == 'refs/heads/master' && github.sha || github.ref }}
  cancel-in-progress: true

jobs:
  bootstrap-v:
    strategy:
      matrix:
        os: [ubuntu-latest, macos-14]
      fail-fast: false
    runs-on: ${{ matrix.os }}
    timeout-minutes: 20
    env:
      VFLAGS: -no-parallel
      B_LFLAGS: -lm -lpthread
    steps:
      - uses: actions/checkout@v6
        with:
          fetch-depth: 0
      - name: Build V
        run: make -j4
      - name: Test bootstrapping (v.c can be compiled and run with -os cross)
        run: |
          ls -la v vc/v.c
          ./v -os cross -o vc/v.c cmd/v
          # shellcheck disable=SC2086
          cc -o v_from_vc vc/v.c $B_LFLAGS
          ls -lart v_from_vc
          ./v_from_vc version
          ./v_from_vc run examples/hello_world.v
          ./v_from_vc -o v_from_vc_produced_native_v cmd/v
          ./v_from_vc_produced_native_v run examples/hello_world.v
          ### the next make invocation will simulate building V from scratch
          make local=1
          ls -la v vc/v.c v_from_vc v_from_vc_produced_native_v
          ./v_from_vc_produced_native_v -os cross -o vc/v.c cmd/v
          ### do it a second time, just in case:
          # shellcheck disable=SC2086
          clang -o v_from_vc2 vc/v.c $B_LFLAGS
          ls -lart v_from_vc2
          ./v_from_vc2 version
          ./v_from_vc2 run examples/hello_world.v
          ./v_from_vc2 -o v_from_vc_produced_native_v2 cmd/v
          ./v_from_vc_produced_native_v2 run examples/hello_world.v
          make local=1
          ls -la v vc/v.c
          ls -la v_from_vc v_from_vc_produced_native_v
          ls -la v_from_vc2 v_from_vc_produced_native_v2
      - name: Ensure V master is available
        if: github.ref_name != 'master'
        run: git branch master remotes/origin/master
      - name: Test `v up`
        run: |
          # Derive a commit sha from an older successful fast workflow on master that was able to build V.
          # The workflow used below is `Path Testing CI` (18477644).
          # Fetch several successful runs and pick the first commit that is actually reachable on master.
          # Some runs may reference commits from force-pushed branches that are no longer on master.
          fetch_page() {
            local page="$1"
            local body=""
            for attempt in 1 2 3; do
              body=$(curl -sL --max-time 30 \
                -H "Accept: application/vnd.github+json" \
                -H "Authorization: Bearer ${{ secrets.GITHUB_TOKEN }}" \
                -H "X-GitHub-Api-Version: 2022-11-28" \
                "https://api.github.com/repos/vlang/v/actions/workflows/18477644/runs?branch=master&status=success&event=push&per_page=10&page=$page")
              if [ -n "$body" ] && echo "$body" | jq -e '.workflow_runs' >/dev/null 2>&1; then
                echo "$body" | jq -r '.workflow_runs[].head_sha'
                return 0
              fi
              echo "::warning::page $page attempt $attempt failed, retrying..." >&2
              sleep 5
            done
            return 1
          }
          recent_good_commit=""
          valid_count=0
          for page in 1 2 3; do
            commits=$(fetch_page "$page" || true)
            commit_count=$(printf '%s\n' "$commits" | grep -c . || true)
            echo "page $page: fetched $commit_count commits"
            for sha in $commits; do
              if git merge-base --is-ancestor "$sha" master 2>/dev/null; then
                valid_count=$((valid_count + 1))
                echo "  valid #$valid_count: $sha"
                # Skip the first few valid commits to get an older one for testing upgrades.
                if [ "$valid_count" -ge 5 ]; then
                  recent_good_commit="$sha"
                  break 2
                fi
              fi
            done
          done
          if [ -z "$recent_good_commit" ]; then
            echo "Path Testing CI lookup yielded only $valid_count valid commits; falling back to git log."
            recent_good_commit=$(git log master --first-parent --format=%H --before='14 days ago' -n 1)
          fi
          if [ -z "$recent_good_commit" ]; then
            echo "Could not find a valid recent good commit on master"
            exit 1
          fi
          echo "recent_good_commit=$recent_good_commit"
          # Build oldv at recent_good_commit.
          ./v run cmd/tools/oldv.v -v "$recent_good_commit"
          cd "$HOME/.cache/oldv/v_at_$recent_good_commit"
          # Test updating
          ./v version && ./v -v up && ./v version
          ./v -o v2 cmd/v && ./v2 -o v3 cmd/v