# Auto-update workflow for the fai/homebrew-tap repo.
#
# Lives here as the canonical source of truth. The bootstrap
# script (scripts/bootstrap-distribution-repos.sh in
# fai/platform) seeds this file into the tap repo at
# .forgejo/workflows/update.yml. Edit it here, run the
# bootstrap script, the tap repo picks up the new version.
#
# What it does:
#   * Every 4 hours, fetches the latest release manifest for
#     fai/platform.
#   * If the version differs from the one currently in
#     Formula/fai.rb, rewrites the formula's version + sha256
#     entries (macos-aarch64 + macos-x86_64) and commits.
#   * Workflow_dispatch trigger lets you force an update from
#     the Forgejo UI without waiting for the cron tick.
#
# Manifest contract: fai/platform's release.yml writes
# .binaries.{macos-aarch64,macos-x86_64}.sha256 — see
# crates/fai_hub/src/update.rs::ReleaseManifest for the
# authoritative schema.

name: Update Homebrew formula
on:
  schedule:
    - cron: '0 */4 * * *'
  workflow_dispatch: {}

jobs:
  update:
    name: Sync formula to latest platform release
    runs-on: ubuntu-latest
    steps:
      - name: Checkout via external URL
        run: |
          set -eu
          mkdir -p "$GITHUB_WORKSPACE"
          cd "$GITHUB_WORKSPACE"
          git init -q
          git remote add origin \
            "https://x-access-token:${GITHUB_TOKEN}@git.flemming.ai/${GITHUB_REPOSITORY}.git"
          git fetch --depth=1 origin "$GITHUB_REF_NAME"
          git checkout -q FETCH_HEAD

      - name: Install jq + curl
        run: |
          apt-get update -qq
          apt-get install -y --no-install-recommends jq curl ca-certificates

      - name: Fetch latest manifest
        id: manifest
        run: |
          set -eu
          # Forgejo's releases API returns newest-first.
          REL=$(curl -fsSL \
            "https://git.flemming.ai/api/v1/repos/fai/platform/releases?limit=1" \
            | jq -r '.[0]')
          TAG=$(echo "$REL" | jq -r '.tag_name')
          VERSION="${TAG#v}"
          MANIFEST=$(curl -fsSL \
            "https://git.flemming.ai/fai/platform/releases/download/${TAG}/manifest.json")
          MAC_ARM=$(echo "$MANIFEST" | jq -r '.binaries["macos-aarch64"].sha256 // empty')
          MAC_X64=$(echo "$MANIFEST" | jq -r '.binaries["macos-x86_64"].sha256 // empty')
          if [ -z "$MAC_ARM" ] || [ -z "$MAC_X64" ]; then
            echo "manifest for $TAG has no macOS entries yet — likely the local"
            echo "publish step hasn't run. Skipping update."
            echo "skip=true" >> "$GITHUB_OUTPUT"
            exit 0
          fi
          echo "version=$VERSION" >> "$GITHUB_OUTPUT"
          echo "sha_aarch64=$MAC_ARM" >> "$GITHUB_OUTPUT"
          echo "sha_x86_64=$MAC_X64" >> "$GITHUB_OUTPUT"

      - name: Detect formula version
        id: current
        if: steps.manifest.outputs.skip != 'true'
        run: |
          CUR=$(grep -E '^\s*version\s+"' Formula/fai.rb \
            | head -1 | sed -E 's/.*"([^"]+)".*/\1/')
          echo "version=$CUR" >> "$GITHUB_OUTPUT"

      - name: Rewrite Formula/fai.rb
        id: rewrite
        if: |
          steps.manifest.outputs.skip != 'true'
            && steps.manifest.outputs.version != steps.current.outputs.version
        env:
          NEW_VERSION: ${{ steps.manifest.outputs.version }}
          NEW_SHA_AARCH64: ${{ steps.manifest.outputs.sha_aarch64 }}
          NEW_SHA_X86_64: ${{ steps.manifest.outputs.sha_x86_64 }}
        run: |
          set -eu
          python3 - <<'PY'
          import os, re, pathlib
          p = pathlib.Path("Formula/fai.rb")
          src = p.read_text()
          new_version = os.environ["NEW_VERSION"]
          arm_sha = os.environ["NEW_SHA_AARCH64"]
          x64_sha = os.environ["NEW_SHA_X86_64"]
          # version line
          src = re.sub(r'(\bversion\s+)"[^"]+"',
                       f'\\1"{new_version}"', src, count=1)
          # find the two sha256 lines, one in the arm branch, one in
          # the else branch. The formula's structure is fixed —
          # aarch64 block comes first.
          lines = src.splitlines()
          replaced = 0
          for i, line in enumerate(lines):
            m = re.match(r'(\s*sha256\s+)"[^"]+"', line)
            if not m:
              continue
            sha = arm_sha if replaced == 0 else x64_sha
            lines[i] = f'{m.group(1)}"{sha}"'
            replaced += 1
            if replaced == 2:
              break
          if replaced != 2:
            raise SystemExit(f"expected 2 sha256 lines, rewrote {replaced}")
          p.write_text("\n".join(lines) + "\n")
          PY
          echo "rewritten=true" >> "$GITHUB_OUTPUT"

      - name: Commit + push
        if: steps.rewrite.outputs.rewritten == 'true'
        env:
          NEW_VERSION: ${{ steps.manifest.outputs.version }}
        run: |
          set -eu
          git config user.email "platform@flemming.ai"
          git config user.name "fai-tap-bot"
          git add Formula/fai.rb
          git commit -s -m "chore: formula -> v${NEW_VERSION}"
          git push origin "HEAD:${GITHUB_REF_NAME}"