update-brew

#!/usr/bin/env nix-shell
#! nix-shell -p coreutils curl jq -i sh
set -eu

TMPDIR=$(mktemp -d)
trap "rm -rf '$TMPDIR'" EXIT

fetch() {
  local url="$1" dest="$2"
  curl -sfL "$url" -o "$dest"
}

BREW_API="https://formulae.brew.sh/api/formula"

# ---------- Phase 1: Fetch all zig formula JSONs ----------

echo "Fetching zig formula..." >&2
fetch "$BREW_API/zig.json" "$TMPDIR/zig.json"

VERSIONED=$(jq -r '.versioned_formulae[]' "$TMPDIR/zig.json")
ZIG_FORMULAS="zig"

for vf in $VERSIONED; do
  echo "Fetching $vf formula..." >&2
  fetch "$BREW_API/$vf.json" "$TMPDIR/$vf.json"
  ZIG_FORMULAS="$ZIG_FORMULAS $vf"
done

# ---------- Phase 2: Recursively fetch dependency formulas ----------

FETCHED="$ZIG_FORMULAS"

resolve_deps() {
  local queue="$1"
  while [ -n "$queue" ]; do
    local next_queue=""
    for formula in $queue; do
      local deps
      deps=$(jq -r '.dependencies[]' "$TMPDIR/$formula.json" 2>/dev/null || true)
      for dep in $deps; do
        # Check if already fetched
        case " $FETCHED " in
          *" $dep "*) continue ;;
        esac
        echo "Fetching dependency $dep..." >&2
        fetch "$BREW_API/$dep.json" "$TMPDIR/$dep.json"
        FETCHED="$FETCHED $dep"
        next_queue="$next_queue $dep"
      done
    done
    queue="$(echo "$next_queue" | xargs)"
  done
}

resolve_deps "$ZIG_FORMULAS"

echo "All formulas fetched: $FETCHED" >&2

# ---------- Phase 3: Assemble brew-sources.json ----------

# Build a single JSON database from all fetched formula files
DB="$TMPDIR/db.json"
jq -s 'map({(.name): .}) | add' "$TMPDIR"/*.json > "$DB"

# Pass zig formula names as a JSON array
ZIG_NAMES_JSON=$(printf '%s\n' $ZIG_FORMULAS | jq -R . | jq -s .)

echo "Assembling brew-sources.json..." >&2

jq -n \
  --argjson db "$(cat "$DB")" \
  --argjson zig_formulas "$ZIG_NAMES_JSON" \
'
def best_tag(tags; prefs):
  (prefs | map(select(. as $p | tags | has($p))) | first) // null;

def bottle_entry(formula_name; tag):
  $db[formula_name] as $f |
  $f.bottle.stable.files[tag] as $b |
  $f.versions.stable as $ver |
  ($f.revision // 0) as $rev |
  (if $rev > 0 then "\($ver)_\($rev)" else $ver end) as $pkg_ver |
  {
    url: $b.url,
    sha256: $b.sha256,
    root: "\(formula_name)/\($pkg_ver)"
  };

def platform_entry(zig_name; nix_plat; prefs):
  $db[zig_name] as $zf |
  $zf.bottle.stable.files as $files |
  best_tag($files; prefs) as $zig_tag |
  if $zig_tag == null then null
  else
    ($zf.dependencies // []) as $deps |
    ([$deps[] | . as $dep |
      $db[$dep].bottle.stable.files as $df |
      best_tag($df; prefs) as $dep_tag |
      if $dep_tag == null then empty
      else {($dep): bottle_entry($dep; $dep_tag)}
      end
    ] | add // {}) as $dep_bottles |
    {
      version: $zf.versions.stable,
      formula: zig_name,
      bottles: ({(zig_name): bottle_entry(zig_name; $zig_tag)} + $dep_bottles)
    }
  end;

[
  $zig_formulas[] | . as $zf |
  $db[$zf].versions.stable as $ver |
  {
    ($ver): (
      {}
      + (platform_entry($zf; "aarch64-darwin";
           ["arm64_ventura","arm64_sonoma","arm64_sequoia","arm64_tahoe"])
         | if . then {"aarch64-darwin": .} else {} end)
      + (platform_entry($zf; "x86_64-darwin";
           ["ventura","sonoma","sequoia","tahoe"])
         | if . then {"x86_64-darwin": .} else {} end)
    )
  }
] | add
' > brew-sources.json

echo "Wrote brew-sources.json" >&2