name: Update Nix Hashes

permissions:
  contents: write

on:
  workflow_dispatch:
  push:
    paths:
      - "bun.lock"
      - "package.json"
      - "packages/*/package.json"
      - "flake.lock"
      - ".github/workflows/update-nix-hashes.yml"
  pull_request:
    paths:
      - "bun.lock"
      - "package.json"
      - "packages/*/package.json"
      - "flake.lock"
      - ".github/workflows/update-nix-hashes.yml"

jobs:
  update-node-modules-hashes:
    if: github.event_name != 'pull_request' || github.event.pull_request.head.repo.full_name == github.repository
    runs-on: blacksmith-4vcpu-ubuntu-2404
    env:
      TITLE: node_modules hashes

    steps:
      - name: Checkout repository
        uses: actions/checkout@v6
        with:
          token: ${{ secrets.GITHUB_TOKEN }}
          fetch-depth: 0
          ref: ${{ github.head_ref || github.ref_name }}
          repository: ${{ github.event.pull_request.head.repo.full_name || github.repository }}

      - name: Setup Nix
        uses: nixbuild/nix-quick-install-action@v34

      - name: Configure git
        run: |
          git config --global user.email "action@github.com"
          git config --global user.name "Github Action"

      - name: Pull latest changes
        env:
          TARGET_BRANCH: ${{ github.head_ref || github.ref_name }}
        run: |
          BRANCH="${TARGET_BRANCH:-${GITHUB_REF_NAME}}"
          git pull --rebase --autostash origin "$BRANCH"

      - name: Compute all node_modules hashes
        run: |
          set -euo pipefail

          HASH_FILE="nix/hashes.json"
          SYSTEMS="x86_64-linux aarch64-linux x86_64-darwin aarch64-darwin"

          if [ ! -f "$HASH_FILE" ]; then
            mkdir -p "$(dirname "$HASH_FILE")"
            echo '{"nodeModules":{}}' > "$HASH_FILE"
          fi

          for SYSTEM in $SYSTEMS; do
            echo "Computing hash for ${SYSTEM}..."
            BUILD_LOG=$(mktemp)
            trap 'rm -f "$BUILD_LOG"' EXIT

            # The updater derivations use fakeHash, so they will fail and reveal the correct hash
            UPDATER_ATTR=".#packages.x86_64-linux.${SYSTEM}_node_modules"

            nix build "$UPDATER_ATTR" --no-link 2>&1 | tee "$BUILD_LOG" || true

            CORRECT_HASH="$(grep -E 'got:\s+sha256-[A-Za-z0-9+/=]+' "$BUILD_LOG" | awk '{print $2}' | head -n1 || true)"

            if [ -z "$CORRECT_HASH" ]; then
              CORRECT_HASH="$(grep -A2 'hash mismatch' "$BUILD_LOG" | grep 'got:' | awk '{print $2}' | sed 's/sha256:/sha256-/' || true)"
            fi

            if [ -z "$CORRECT_HASH" ]; then
              echo "Failed to determine correct node_modules hash for ${SYSTEM}."
              cat "$BUILD_LOG"
              exit 1
            fi

            echo "  ${SYSTEM}: ${CORRECT_HASH}"
            jq --arg sys "$SYSTEM" --arg h "$CORRECT_HASH" \
              '.nodeModules[$sys] = $h' "$HASH_FILE" > "${HASH_FILE}.tmp"
            mv "${HASH_FILE}.tmp" "$HASH_FILE"
          done

          echo "All hashes computed:"
          cat "$HASH_FILE"

      - name: Commit ${{ env.TITLE }} changes
        env:
          TARGET_BRANCH: ${{ github.head_ref || github.ref_name }}
        run: |
          set -euo pipefail

          HASH_FILE="nix/hashes.json"
          echo "Checking for changes..."

          summarize() {
            local status="$1"
            {
              echo "### Nix $TITLE"
              echo ""
              echo "- ref: ${GITHUB_REF_NAME}"
              echo "- status: ${status}"
            } >> "$GITHUB_STEP_SUMMARY"
            if [ -n "${GITHUB_SERVER_URL:-}" ] && [ -n "${GITHUB_REPOSITORY:-}" ] && [ -n "${GITHUB_RUN_ID:-}" ]; then
              echo "- run: ${GITHUB_SERVER_URL}/${GITHUB_REPOSITORY}/actions/runs/${GITHUB_RUN_ID}" >> "$GITHUB_STEP_SUMMARY"
            fi
            echo "" >> "$GITHUB_STEP_SUMMARY"
          }

          FILES=("$HASH_FILE")
          STATUS="$(git status --short -- "${FILES[@]}" || true)"
          if [ -z "$STATUS" ]; then
            echo "No changes detected."
            summarize "no changes"
            exit 0
          fi

          echo "Changes detected:"
          echo "$STATUS"
          git add "${FILES[@]}"
          git commit -m "Update $TITLE"

          BRANCH="${TARGET_BRANCH:-${GITHUB_REF_NAME}}"
          git pull --rebase --autostash origin "$BRANCH"
          git push origin HEAD:"$BRANCH"
          echo "Changes pushed successfully"

          summarize "committed $(git rev-parse --short HEAD)"