name: Publish to crates.io

# Publishes the four workspace crates to crates.io in dependency order.
#
# Triggers:
#   - push of any v* tag (future releases auto-publish alongside release.yml)
#   - workflow_dispatch with an explicit tag input (catch-up runs for past tags)
#
# Idempotent: each crate's current crates.io version is checked before publish,
# so a partial failure can be re-run without "crate version already exists" errors.
#
# Prerequisite: repo secret CARGO_REGISTRY_TOKEN. The job exits cleanly if absent.

on:
  push:
    tags:
      - "v*"
  workflow_dispatch:
    inputs:
      tag:
        description: "Tag to publish (e.g. v0.4.1). Required for manual dispatches."
        required: true
        type: string

jobs:
  publish_crates:
    name: Publish crates
    runs-on: ubuntu-latest
    env:
      CARGO_REGISTRY_TOKEN: ${{ secrets.CARGO_REGISTRY_TOKEN }}
      CARGO_TERM_COLOR: always
    steps:
      - name: Skip if CARGO_REGISTRY_TOKEN is not configured
        if: env.CARGO_REGISTRY_TOKEN == ''
        run: |
          echo "CARGO_REGISTRY_TOKEN is not set; skipping crates.io publish."
          echo "CARGO_PUBLISH_SKIP=1" >> "$GITHUB_ENV"

      - name: Resolve ref
        if: env.CARGO_PUBLISH_SKIP != '1'
        id: ref
        run: |
          ref="${{ inputs.tag || github.ref_name }}"
          echo "ref=${ref}" >> "$GITHUB_OUTPUT"
          echo "Publishing from ref: ${ref}"

      - name: Checkout source at tag
        if: env.CARGO_PUBLISH_SKIP != '1'
        uses: actions/checkout@v5.0.1
        with:
          ref: ${{ steps.ref.outputs.ref }}

      - name: Install Linux dependencies
        if: env.CARGO_PUBLISH_SKIP != '1'
        run: |
          sudo apt-get update
          sudo apt-get install -y protobuf-compiler libprotobuf-dev

      - name: Install Rust stable
        if: env.CARGO_PUBLISH_SKIP != '1'
        uses: dtolnay/rust-toolchain@stable
        with:
          toolchain: stable

      - name: Cache Rust build data
        if: env.CARGO_PUBLISH_SKIP != '1'
        uses: Swatinem/rust-cache@v2
        with:
          workspaces: |
            . -> target

      - name: Publish crates in dependency order
        if: env.CARGO_PUBLISH_SKIP != '1'
        run: |
          set -euo pipefail

          publish_if_new() {
            local crate="$1"
            local version
            version=$(cargo metadata --format-version=1 --no-deps \
              | jq -r --arg c "$crate" '.packages[] | select(.name==$c) | .version')

            # crates.io API requires a User-Agent header — without it the
            # API responds 403 and the skip check below would silently
            # fall through to a real publish attempt that errors with
            # "already exists on crates.io index" when re-running after a
            # partial publish. Send a UA naming the workflow.
            local current
            current=$(curl -fsSL \
              -A 'ModernRelay-omnigraph-ci (https://github.com/ModernRelay/omnigraph)' \
              "https://crates.io/api/v1/crates/${crate}" \
              | jq -r '.crate.max_version' || echo "")

            if [[ "$current" == "$version" ]]; then
              echo "==> ${crate} ${version} already on crates.io, skipping"
              return 0
            fi

            echo "==> publishing ${crate} ${version} (current crates.io: ${current:-none})"
            # Defense in depth: if the skip check missed an existing
            # version (e.g. crates.io API hiccup), cargo publish errors
            # with "already exists on crates.io index". Treat that as
            # success so the workflow can be re-run idempotently.
            local output
            if ! output=$(cargo publish -p "$crate" --locked 2>&1); then
              echo "$output"
              if echo "$output" | grep -q "already exists on crates.io"; then
                echo "==> ${crate} ${version} was already published; treating as success"
                return 0
              fi
              return 1
            fi
            echo "$output"
          }

          # Order matters: each crate must precede anything that depends on it.
          # omnigraph-compiler and omnigraph-policy have no internal deps;
          # omnigraph-engine depends on both; server depends on engine + the
          # two leaf crates; cli depends on everything.
          publish_if_new omnigraph-compiler
          publish_if_new omnigraph-policy
          publish_if_new omnigraph-engine
          publish_if_new omnigraph-server
          publish_if_new omnigraph-cli