name: nix-hashes

permissions:
  contents: write

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

jobs:
  # Native runners required: bun install cross-compilation flags (--os/--cpu)
  # do not produce byte-identical node_modules as native installs.
  compute-hash:
    strategy:
      fail-fast: false
      matrix:
        include:
          - system: x86_64-linux
            runner: blacksmith-4vcpu-ubuntu-2404
          - system: aarch64-linux
            runner: blacksmith-4vcpu-ubuntu-2404-arm
          - system: x86_64-darwin
            runner: macos-15-intel
          - system: aarch64-darwin
            runner: macos-latest
    runs-on: ${{ matrix.runner }}

    steps:
      - name: Checkout repository
        uses: actions/checkout@v6

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

      - name: Compute node_modules hash
        id: hash
        env:
          SYSTEM: ${{ matrix.system }}
        run: |
          set -euo pipefail

          BUILD_LOG=$(mktemp)
          trap 'rm -f "$BUILD_LOG"' EXIT

          # Build with fakeHash to trigger hash mismatch and reveal correct hash
          nix build ".#packages.${SYSTEM}.node_modules_updater" --no-link 2>&1 | tee "$BUILD_LOG" || true

          HASH="$(grep -E 'got:\s+sha256-' "$BUILD_LOG" | sed -E 's/.*got:\s+(sha256-[A-Za-z0-9+/=]+).*/\1/' | head -n1 || true)"
          if [ -z "$HASH" ]; then
            HASH="$(grep -A2 'hash mismatch' "$BUILD_LOG" | grep 'got:' | sed -E 's/.*got:\s+(sha256-[A-Za-z0-9+/=]+).*/\1/' | head -n1 || true)"
          fi

          if [ -z "$HASH" ]; then
            echo "::error::Failed to compute hash for ${SYSTEM}"
            cat "$BUILD_LOG"
            exit 1
          fi

          echo "$HASH" > hash.txt
          echo "Computed hash for ${SYSTEM}: $HASH"

      - name: Upload hash
        uses: actions/upload-artifact@v4
        with:
          name: hash-${{ matrix.system }}
          path: hash.txt
          retention-days: 1

  update-hashes:
    needs: compute-hash
    if: github.event_name != 'pull_request'
    runs-on: blacksmith-4vcpu-ubuntu-2404

    steps:
      - name: Checkout repository
        uses: actions/checkout@v6
        with:
          token: ${{ secrets.GITHUB_TOKEN }}
          fetch-depth: 0
          ref: ${{ github.ref_name }}

      - name: Setup git committer
        uses: ./.github/actions/setup-git-committer
        with:
          opencode-app-id: ${{ vars.OPENCODE_APP_ID }}
          opencode-app-secret: ${{ secrets.OPENCODE_APP_SECRET }}

      - name: Pull latest changes
        run: |
          git pull --rebase --autostash origin "$GITHUB_REF_NAME"

      - name: Download hash artifacts
        uses: actions/download-artifact@v4
        with:
          path: hashes
          pattern: hash-*

      - name: Update hashes.json
        run: |
          set -euo pipefail

          HASH_FILE="nix/hashes.json"

          [ -f "$HASH_FILE" ] || echo '{"nodeModules":{}}' > "$HASH_FILE"

          for SYSTEM in x86_64-linux aarch64-linux x86_64-darwin aarch64-darwin; do
            FILE="hashes/hash-${SYSTEM}/hash.txt"
            if [ -f "$FILE" ]; then
              HASH="$(tr -d '[:space:]' < "$FILE")"
              echo "${SYSTEM}: ${HASH}"
              jq --arg sys "$SYSTEM" --arg h "$HASH" '.nodeModules[$sys] = $h' "$HASH_FILE" > tmp.json
              mv tmp.json "$HASH_FILE"
            else
              echo "::warning::Missing hash for ${SYSTEM}"
            fi
          done

          cat "$HASH_FILE"

      - name: Commit changes
        run: |
          set -euo pipefail

          HASH_FILE="nix/hashes.json"

          if [ -z "$(git status --short -- "$HASH_FILE")" ]; then
            echo "No changes to commit"
            echo "### Nix hashes" >> "$GITHUB_STEP_SUMMARY"
            echo "Status: no changes" >> "$GITHUB_STEP_SUMMARY"
            exit 0
          fi

          git add "$HASH_FILE"
          git commit -m "chore: update nix node_modules hashes"

          git pull --rebase --autostash origin "$GITHUB_REF_NAME"
          git push origin HEAD:"$GITHUB_REF_NAME"

          echo "### Nix hashes" >> "$GITHUB_STEP_SUMMARY"
          echo "Status: committed $(git rev-parse --short HEAD)" >> "$GITHUB_STEP_SUMMARY"