#!/usr/bin/env python3
"""Build Blender's pinned OpenEXR with the existing WASM Imath installation."""
import hashlib
import re
import shutil
import subprocess
import tarfile
import urllib.request
from pathlib import Path

ROOT = Path(__file__).resolve().parents[2]
BASE = ROOT / 'build_web_openexr'
IMATH = ROOT / 'build_web_ocio/install'

def main():
    versions = (ROOT / 'blender-5.2.0/build_files/build_environment/cmake/versions.cmake').read_text()
    value = lambda name: re.search(r'set\(OPENEXR_' + name + r' ([^)]+)\)', versions)[1]
    version, expected, algorithm = value('VERSION'), value('HASH'), value('HASH_TYPE').lower()
    if not (IMATH / 'lib/cmake/Imath/ImathConfig.cmake').is_file():
        raise SystemExit('Reuse/build the Web OCIO Imath installation first')
    BASE.mkdir(exist_ok=True)
    archive = BASE / ('openexr-' + version + '.tar.gz')
    if not archive.is_file():
        with urllib.request.urlopen('https://codeload.github.com/AcademySoftwareFoundation/openexr/tar.gz/refs/tags/v' + version, timeout=60) as response:
            data = response.read()
        if hashlib.new(algorithm, data).hexdigest() != expected:
            raise SystemExit('OpenEXR download differs from Blender pinned source hash')
        archive.write_bytes(data)
    if hashlib.new(algorithm, archive.read_bytes()).hexdigest() != expected:
        raise SystemExit('OpenEXR archive differs from Blender pinned source hash')
    source = BASE / ('openexr-' + version)
    if not (source / 'CMakeLists.txt').is_file():
        with tarfile.open(archive) as package: package.extractall(BASE, filter='data')
    toolchain = ROOT / '.emsdk/upstream/emscripten/cmake/Modules/Platform/Emscripten.cmake'
    subprocess.run(['cmake', '-S', str(source), '-B', str(BASE / 'build'), '-G', 'Ninja',
        '-DCMAKE_TOOLCHAIN_FILE=' + str(toolchain), '-DCMAKE_BUILD_TYPE=Release',
        '-DCMAKE_INSTALL_PREFIX=' + str(BASE / 'install'), '-DCMAKE_INSTALL_LIBDIR=lib',
        '-DCMAKE_PREFIX_PATH=' + str(IMATH), '-DCMAKE_FIND_ROOT_PATH=' + str(IMATH),
        '-DImath_DIR=' + str(IMATH / 'lib/cmake/Imath'), '-DCMAKE_CXX_FLAGS=-fexceptions',
        '-DCMAKE_C_FLAGS=', '-DBUILD_SHARED_LIBS=OFF', '-DBUILD_TESTING=OFF',
        '-DOPENEXR_ENABLE_THREADING=OFF', '-DBUILD_WEBSITE=OFF', '-DOPENEXR_INSTALL_DOCS=OFF',
        '-DOPENEXR_BUILD_TOOLS=OFF', '-DOPENEXR_BUILD_EXAMPLES=OFF', '-DOPENEXR_FORCE_INTERNAL_DEFLATE=ON'], cwd=ROOT, check=True)
    subprocess.run(['cmake', '--build', str(BASE / 'build'), '--target', 'install', '--parallel', '8'], cwd=ROOT, check=True)
    shutil.copy2(BASE / 'build/external/OpenJPH/src/core/libopenjph.a', BASE / 'install/lib/libopenjph.a')

if __name__ == '__main__':
    main()