#!/usr/bin/env bash
set -euo pipefail

ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
WORK_DIR="${WORK_DIR:-$ROOT_DIR/External/NativeStatic/.work}"
TARGET_CPU="${TARGET_CPU:-arm64}"
RID="${RID:-osx-$TARGET_CPU}"
OUTPUT_DIR="${OUTPUT_DIR:-$ROOT_DIR/External/NativeStatic/$RID}"
SKIASHARP_VERSION="${SKIASHARP_VERSION:-2.88.9}"
ANGLE_BRANCH="${ANGLE_BRANCH:-7151}"
BUILD_JOBS="${BUILD_JOBS:-$(sysctl -n hw.ncpu)}"
ANGLE_PATCH_DIR="${ANGLE_PATCH_DIR:-$ROOT_DIR/External/NativeStatic/patches}"
SKIA_DEPS_RETRIES="${SKIA_DEPS_RETRIES:-3}"

require_cmd() {
  if ! command -v "$1" >/dev/null 2>&1; then
    echo "Missing required command: $1" >&2
    exit 1
  fi
}

ensure_tools() {
  require_cmd git
  require_cmd python3
  require_cmd clang
  require_cmd clang++
  require_cmd ar
  require_cmd ninja
}

ensure_depot_tools() {
  local depot_dir="$WORK_DIR/depot_tools"
  if [[ ! -d "$depot_dir/.git" ]]; then
    git clone --depth 1 https://chromium.googlesource.com/chromium/tools/depot_tools.git "$depot_dir"
  else
    git -C "$depot_dir" pull --ff-only
  fi
  export PATH="$depot_dir:$PATH"
}

copy_first_existing() {
  local dest="$1"
  shift
  for src in "$@"; do
    if [[ -f "$src" ]]; then
      cp "$src" "$dest"
      echo "Wrote $dest"
      return 0
    fi
  done
  echo "None of the expected files exist for $dest:" >&2
  printf '  %s\n' "$@" >&2
  return 1
}

resolve_skia_gn() {
  local skia_dir="$1"
  if [[ -x "$skia_dir/bin/gn" ]] && "$skia_dir/bin/gn" --version >/dev/null 2>&1; then
    echo "$skia_dir/bin/gn"
    return 0
  fi
  if command -v gn >/dev/null 2>&1; then
    command -v gn
    return 0
  fi
  echo "Missing runnable gn. Install Homebrew gn or provide a runnable $skia_dir/bin/gn." >&2
  return 1
}

patch_skia_2889_compat() {
  local skia_dir="$1"
  local parse_color="$skia_dir/src/utils/SkParseColor.cpp"
  if [[ -f "$parse_color" ]] && ! grep -q '#include <iterator>' "$parse_color"; then
    python3 - "$parse_color" <<'PY'
from pathlib import Path
import sys

path = Path(sys.argv[1])
text = path.read_text()
if '#include <iterator>' not in text:
    marker = '#include <algorithm>\n'
    if marker in text:
        text = text.replace(marker, marker + '#include <iterator>\n', 1)
    else:
        text = '#include <iterator>\n' + text
    path.write_text(text)
PY
  fi

  local zutil="$skia_dir/third_party/externals/zlib/zutil.h"
  if [[ -f "$zutil" ]] && grep -q 'define fdopen(fd,mode) NULL' "$zutil"; then
    python3 - "$zutil" <<'PY'
from pathlib import Path
import sys

path = Path(sys.argv[1])
text = path.read_text()
text = text.replace('#        define fdopen(fd,mode) NULL /* No fdopen() */\n', '')
path.write_text(text)
PY
  fi

  local pngpriv="$skia_dir/third_party/externals/libpng/pngpriv.h"
  if [[ -f "$pngpriv" ]] && grep -q '#      include <fp.h>' "$pngpriv"; then
    python3 - "$pngpriv" <<'PY'
from pathlib import Path
import sys

path = Path(sys.argv[1])
text = path.read_text()
text = text.replace('#      include <fp.h>\n', '')
path.write_text(text)
PY
  fi
  if [[ -f "$pngpriv" ]] && ! grep -q '#include <math.h>' "$pngpriv"; then
    python3 - "$pngpriv" <<'PY'
from pathlib import Path
import sys

path = Path(sys.argv[1])
text = path.read_text()
marker = '#include "png.h"\n'
if '#include <math.h>' not in text:
    if marker in text:
        text = text.replace(marker, marker + '#include <math.h>\n', 1)
    else:
        text = '#include <math.h>\n' + text
    path.write_text(text)
PY
  fi

  local pngc="$skia_dir/third_party/externals/libpng/png.c"
  if [[ -f "$pngc" ]] && ! grep -q '#include <math.h>' "$pngc"; then
    python3 - "$pngc" <<'PY'
from pathlib import Path
import sys

path = Path(sys.argv[1])
text = path.read_text()
marker = '#include "pngpriv.h"\n'
if '#include <math.h>' not in text:
    if marker in text:
        text = text.replace(marker, marker + '#include <math.h>\n', 1)
    else:
        text = '#include <math.h>\n' + text
    path.write_text(text)
PY
  fi
}

sync_skiasharp() {
  local src="$WORK_DIR/SkiaSharp-$SKIASHARP_VERSION"
  if [[ ! -d "$src/.git" ]]; then
    git clone --depth 1 --branch "release/$SKIASHARP_VERSION" https://github.com/mono/SkiaSharp.git "$src"
  else
    git -C "$src" fetch --depth 1 origin "release/$SKIASHARP_VERSION"
    git -C "$src" checkout -q FETCH_HEAD
  fi
  git -C "$src" submodule update --init --depth 1 externals/skia >&2
  echo "$src"
}

prepare_skia_git_sync_deps() {
  local sync_deps="$1/tools/git-sync-deps"
  python3 - "$sync_deps" <<'PY'
import pathlib
import sys

path = pathlib.Path(sys.argv[1])
text = path.read_text()
old = "  multithread(git_checkout_to_directory, list_of_arg_lists)"
new = "  for args in list_of_arg_lists:\n    git_checkout_to_directory(*args)"
if old in text:
    path.write_text(text.replace(old, new))
PY
}

sync_skia_deps() {
  local skia_dir="$1"
  prepare_skia_git_sync_deps "$skia_dir"

  local attempt
  for attempt in $(seq 1 "$SKIA_DEPS_RETRIES"); do
    if python3 "$skia_dir/tools/git-sync-deps"; then
      return 0
    fi
    if [[ "$attempt" == "$SKIA_DEPS_RETRIES" ]]; then
      return 1
    fi
    echo "git-sync-deps failed; retrying ($attempt/$SKIA_DEPS_RETRIES)..." >&2
    sleep 10
  done
}

build_skia() {
  ensure_tools
  ensure_depot_tools
  local src
  src="$(sync_skiasharp)"
  local skia_dir="$src/externals/skia"
  if [[ ! -x "$skia_dir/bin/gn" ]]; then
    sync_skia_deps "$skia_dir"
  fi
  patch_skia_2889_compat "$skia_dir"

  local out_dir="$skia_dir/out/mac-static-$TARGET_CPU"
  local mac_arch
  case "$TARGET_CPU" in
    x64) mac_arch="x86_64" ;;
    arm64) mac_arch="arm64" ;;
    *) echo "Unsupported macOS TARGET_CPU: $TARGET_CPU" >&2; exit 1 ;;
  esac
  mkdir -p "$out_dir" "$OUTPUT_DIR"
  cat >"$out_dir/args.gn" <<EOF_ARGS
target_os = "mac"
target_cpu = "$TARGET_CPU"
is_official_build = true
is_static_skiasharp = true
skia_enable_tools = false
skia_enable_ganesh = true
skia_enable_pdf = false
skia_enable_skottie = false
skia_use_dng_sdk = false
skia_use_fontconfig = false
skia_use_freetype = false
skia_use_harfbuzz = false
skia_use_icu = false
skia_use_piex = false
skia_use_sfntly = false
skia_use_system_expat = false
skia_use_system_libjpeg_turbo = false
skia_use_system_libpng = false
skia_use_system_libwebp = false
skia_use_system_zlib = false
skia_use_vulkan = false
skia_use_xps = false
cc = "clang"
cxx = "clang++"
ar = "ar"
extra_cflags = [ "-DSKIA_C_DLL", "-arch", "$mac_arch" ]
extra_cflags_cc = [ "-frtti" ]
extra_ldflags = [ "-arch", "$mac_arch" ]
EOF_ARGS

  local gn_cmd
  gn_cmd="$(resolve_skia_gn "$skia_dir")"
  (cd "$skia_dir" && "$gn_cmd" gen "$out_dir")
  ninja -C "$out_dir" -j "$BUILD_JOBS" skia SkiaSharp HarfBuzzSharp
  copy_first_existing "$OUTPUT_DIR/libskia.a" "$out_dir/libskia.a" "$out_dir/obj/libskia.a"
  copy_first_existing "$OUTPUT_DIR/libSkiaSharp.a" "$out_dir/libSkiaSharp.a" "$out_dir/obj/libSkiaSharp.a"
  copy_first_existing "$OUTPUT_DIR/libHarfBuzzSharp.a" "$out_dir/libHarfBuzzSharp.a" "$out_dir/obj/libHarfBuzzSharp.a"
}

sync_angle() {
  local src="$WORK_DIR/ANGLE-$ANGLE_BRANCH"
  if [[ ! -d "$src/.git" ]]; then
    git clone --depth 1 --branch "chromium/$ANGLE_BRANCH" https://github.com/google/angle.git "$src"
  else
    git -C "$src" fetch --depth 1 origin "chromium/$ANGLE_BRANCH"
    git -C "$src" checkout -q FETCH_HEAD
  fi
  echo "$src"
}

apply_angle_patches() {
  local src="$1"
  local patch="$ANGLE_PATCH_DIR/angle-chromium-$ANGLE_BRANCH.patch"

  if ! git -C "$src" grep -q 'angle_static_library("libANGLE_static")' -- BUILD.gn; then
    python3 - "$src/BUILD.gn" <<'PY'
import pathlib
import re
import sys

path = pathlib.Path(sys.argv[1])
text = path.read_text()
targets = '''angle_static_library("libANGLE_static") {
  complete_static_lib = true
  public_deps = [ ":libANGLE" ]
}

angle_static_library("libANGLE_with_capture_static") {
  complete_static_lib = true
  public_deps = [ ":libANGLE_with_capture" ]
}

angle_static_library("libGLESv2_static") {
'''
text = re.sub(r'^angle_static_library\("libGLESv2_static"\) \{', targets, text, count=1, flags=re.M)
text = re.sub(r'^angle_static_library\("libGLESv2_static"\) \{\n  sources = libglesv2_sources', 'angle_static_library("libGLESv2_static") {\n  complete_static_lib = true\n  sources = libglesv2_sources', text, count=1, flags=re.M)
path.write_text(text)
PY
  fi

  if [[ -f "$patch" ]] && git -C "$src" grep -q "'third_party/catapult'" -- DEPS; then
    git -C "$src" apply "$patch"
  fi
}

build_angle() {
  ensure_tools
  ensure_depot_tools
  local src
  src="$(sync_angle)"
  mkdir -p "$OUTPUT_DIR"
  apply_angle_patches "$src"
  cd "$src"
  python3 scripts/bootstrap.py
  gclient sync -f -D -R

  local out_dir="$src/out/mac-static-$TARGET_CPU"
  mkdir -p "$out_dir"
  cat >"$out_dir/args.gn" <<EOF_ARGS
target_os = "mac"
target_cpu = "$TARGET_CPU"
is_debug = false
is_component_build = false
is_clang = true
use_lld = false
use_thin_lto = false
symbol_level = 0
angle_build_tests = false
build_angle_deqp_tests = false
angle_enable_swiftshader = false
angle_enable_vulkan = false
angle_enable_wgpu = false
EOF_ARGS

  gn gen "$out_dir"
  ninja -C "$out_dir" -j "$BUILD_JOBS" libANGLE_static libGLESv2_static
  copy_first_existing "$OUTPUT_DIR/libANGLE_static.a" "$out_dir/libANGLE_static.a" "$out_dir/obj/libANGLE_static.a" "$out_dir/obj/libANGLE_static/libANGLE_static.a"
  copy_first_existing "$OUTPUT_DIR/libGLESv2_static.a" "$out_dir/libGLESv2_static.a" "$out_dir/obj/libGLESv2_static.a" "$out_dir/obj/libGLESv2_static/libGLESv2_static.a"
}

main() {
  mkdir -p "$WORK_DIR" "$OUTPUT_DIR"
  case "${1:-all}" in
    skia) build_skia ;;
    angle) build_angle ;;
    all) build_skia; build_angle ;;
    *) echo "Usage: scripts/build-macos-static-graphics.sh [skia|angle|all]" >&2; exit 1 ;;
  esac
}

main "$@"