#!/usr/bin/env bash
# Pecas comuns dos builds de jogos de 32blit do fredygames.com (ver a secao "32blit" da skill bundler).
# Nao e executado direto: Builds/build-<slug>.sh faz `. "$here/32blit-web/common.sh"` e chama blit_build.
#
# O SDK do 32blit (MIT, github.com/32blit/32blit-sdk) ja traz o backend SDL com suporte ao Emscripten
# (32blit-sdl/). Aqui ele e compilado de um commit fixo (sha256 do tarball), junto do jogo, com o Emscripten
# 6.0.10 de artifacts/tools/emsdk e as ferramentas de assets do 32blit (python, versoes fixas em
# requirements.txt) num venv em artifacts/tools/venv-32blit. Sem threads. A saida de cada jogo e
# artifacts/build/32blit-<slug>/{index.html,<jogo>.js,<jogo>.wasm}; host.js e o resto vem de web.local.
#
# Variaveis que o build-<slug>.sh define antes de chamar blit_build:
#   SLUG          pasta do jogo em Content/games e da saida
#   GAME_REPO     "dono/repo" no GitHub
#   GAME_COMMIT   commit (40 hex) do jogo
#   GAME_SHA256   sha256 do tarball https://github.com/<repo>/archive/<commit>.tar.gz
#   PATCH         (opcional) patch -p1 aplicado no fonte do jogo, caminho absoluto
#   GAME_SUBDIR   (opcional) pasta do CMakeLists do jogo dentro do tarball
# O nome do alvo (arquivo .js/.wasm), o titulo e o autor vem do `project()` e do metadata.yml do jogo.

SDK_COMMIT=4adc0482010f80f82665e792e33c921bb708e0f1
SDK_SHA256=931f86ece0fa0e82c707ab156f26754394b971839fcdbd17d9806db0393e7854
EMSCRIPTEN=6.0.10

blit_here="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
blit_root="$(git -C "$blit_here" rev-parse --show-toplevel 2>/dev/null || pwd)"
blit_cache="$blit_root/artifacts/cache/32blit"
blit_venv="$blit_root/artifacts/tools/venv-32blit"

blit_fetch() { # repo commit sha256 destino
  local repo="$1" commit="$2" sha="$3" dest="$4"
  if [ ! -f "$dest" ]; then
    mkdir -p "$(dirname "$dest")"
    curl -fsSL -o "$dest.part" "https://github.com/$repo/archive/$commit.tar.gz"
    mv "$dest.part" "$dest"
  fi
  echo "$sha  $dest" | shasum -a 256 -c - >&2
}

blit_init() {
  if ! emcc --version 2>/dev/null | head -1 | grep -q " $EMSCRIPTEN "; then
    echo "Precisa do Emscripten $EMSCRIPTEN no PATH (source artifacts/tools/emsdk/emsdk_env.sh)." >&2
    return 1
  fi
  if [ ! -x "$blit_venv/bin/32blit" ]; then
    python3 -m venv "$blit_venv"
    "$blit_venv/bin/pip" install -q --disable-pip-version-check -r "$blit_here/requirements.txt" >&2
  fi
  blit_fetch 32blit/32blit-sdk "$SDK_COMMIT" "$SDK_SHA256" "$blit_cache/sdk-${SDK_COMMIT:0:7}.tar.gz"
}

blit_build() {
  blit_init
  local out="$blit_root/artifacts/build/32blit-$SLUG"
  local work="$out/work" # caminho fixo: entra nos binarios, por isso o -ffile-prefix-map abaixo
  local tarball="$blit_cache/$SLUG-${GAME_COMMIT:0:7}.tar.gz"
  blit_fetch "$GAME_REPO" "$GAME_COMMIT" "$GAME_SHA256" "$tarball"

  rm -rf "$out"
  mkdir -p "$work/sdk" "$work/game"
  tar xzf "$blit_cache/sdk-${SDK_COMMIT:0:7}.tar.gz" -C "$work/sdk" --strip-components=1
  tar xzf "$tarball" -C "$work/game" --strip-components=1
  if [ -n "${PATCH:-}" ]; then
    patch -d "$work/game" -p1 --no-backup-if-mismatch < "$PATCH" >&2
  fi
  local src="$work/game${GAME_SUBDIR:+/$GAME_SUBDIR}"

  local target title author
  target="$(sed -n 's/^project(\([^ )]*\).*/\1/Ip' "$src/CMakeLists.txt" | head -1)"
  title="$("$blit_venv/bin/python3" -I -c 'import sys,yaml;print(yaml.safe_load(open(sys.argv[1]))["title"])' "$src/metadata.yml")"
  author="$("$blit_venv/bin/python3" -I -c 'import sys,yaml;print(yaml.safe_load(open(sys.argv[1])).get("author","Unknown"))' "$src/metadata.yml")"

  local flags="-ffile-prefix-map=$work=. -Wno-deprecated"
  (
    cd "$work"
    PATH="$blit_venv/bin:$PATH" emcmake cmake -Wno-dev -S "$src" -B "$work/build" \
      -D32BLIT_DIR="$work/sdk" -DPYTHON_EXECUTABLE="$blit_venv/bin/python3" \
      -DCMAKE_BUILD_TYPE=Release -DCMAKE_C_FLAGS="$flags" -DCMAKE_CXX_FLAGS="$flags" >&2
    PATH="$blit_venv/bin:$PATH" cmake --build "$work/build" -j"$(sysctl -n hw.ncpu 2>/dev/null || nproc)" >&2
  )
  cp "$work/build/$target.js" "$work/build/$target.wasm" "$out/"
  sed -e "s|@TITLE@|$title|g" -e "s|@GAME@|$target|g" -e "s|@SAVEDIR@|/libsdl/$author/$title|g" \
    "$blit_here/index.html.in" > "$out/index.html"
  rm -rf "$work"
  shasum -a 256 "$out/index.html" "$out/$target.js" "$out/$target.wasm"
}