#zyp - Zig YAMS PDF Extractor
#High - performance PDF text extraction using zpdf(https: // github.com/Lulzx/zpdf)

if not get_option ('plugin-zyp')
subdir_done()
endif

if host_machine.system() == 'darwin' and get_option('b_coverage')
  warning('Skipping zyp plugin in macOS coverage builds: Clang gcov runtime cannot link with the zyp bundle/benchmark.')
  subdir_done()
endif

#Find Zig compiler(requires 0.15.x; zpdf is not Zig 0.16 - compatible yet)
zig = find_program('zig', required: false)
if not zig.found()
  warning('Zig compiler not found, skipping zyp plugin. Install Zig 0.15.x to enable.')
  subdir_done()
endif

zig_version_result = run_command(zig, 'version', check: false)
if zig_version_result.returncode() != 0
  warning('Unable to determine Zig version, skipping zyp plugin.')
  subdir_done()
endif

zig_version = zig_version_result.stdout().strip()
if not zig_version.version_compare('>=0.15.0')
  warning('Zig @0@ is unsupported by zyp; zpdf requires Zig 0.15+. Skipping zyp plugin.'.format(zig_version))
  subdir_done()
endif

#Platform - specific library name and rpath
if host_machine.system() == 'darwin'
  zpdf_lib_name = 'libzpdf.dylib'
#@loader_path is used for shared libraries / modules to find libs in same directory
  zyp_install_rpath = '@loader_path'
  zyp_link_args = ['-fno-sanitize=thread']
elif host_machine.system() == 'windows'
  zpdf_lib_name = 'zpdf.dll'
  zpdf_import_lib_name = 'zpdf.lib'
  zyp_install_rpath = ''  # Windows doesn't use rpath
#Link against dynamic CRT libraries; avoid static CRT conflict
  zyp_link_args = [
    '/NODEFAULTLIB:libcmt',
    '/NODEFAULTLIB:libcmtd',
    'msvcrt.lib',
    'vcruntime.lib',
    'ucrt.lib',
  ]
else
  zpdf_lib_name = 'libzpdf.so'
#$ORIGIN refers to directory containing the loading module
  zyp_install_rpath = '$ORIGIN'
  zyp_link_args = ['-fno-sanitize=thread']
endif

#Build zpdf shared library via Zig and copy to build directory
#Zig outputs DLLs to zpdf / zig - out / bin / on Windows, shared libs to zig - out / lib / on Unix
zpdf_src_dir = meson.current_source_dir() / 'zpdf'
if host_machine.system() == 'windows'
#Windows : DLL goes to bin /, import lib goes to lib /
  zpdf_lib_src = zpdf_src_dir / 'zig-out' / 'bin' / zpdf_lib_name
  zpdf_import_lib_src = zpdf_src_dir / 'zig-out' / 'lib' / zpdf_import_lib_name
else
  zpdf_lib_src = zpdf_src_dir / 'zig-out' / 'lib' / zpdf_lib_name
endif
zpdf_build_dir = meson.current_build_dir()
fs = import('fs')
if not fs.exists(zpdf_src_dir / 'build.zig')
  warning('zpdf source not found (missing build.zig), skipping zyp plugin build.')
  subdir_done()
endif

#Platform - specific build command
if host_machine.system() == 'windows'
#Windows : Use PowerShell for build
#Build zpdf and copy both DLL and import lib to build directory
  zpdf_lib = custom_target('zpdf_shared',
    command: [
      'powershell', '-NoProfile', '-Command',
      'Push-Location "@0@"; & "@1@" build -Doptimize=ReleaseFast; Copy-Item "@2@" "@3@\\@4@"; Copy-Item "@5@" "@3@\\@6@"; Pop-Location'.format(
        zpdf_src_dir,
        zig.full_path(),
        zpdf_lib_src,
        zpdf_build_dir,
        zpdf_lib_name,
        zpdf_import_lib_src,
        zpdf_import_lib_name
      )
    ],
    output: [zpdf_lib_name, zpdf_import_lib_name],
    build_by_default: true,
    console: true,
  )
#Extract just the import library for linking
  zpdf_import_lib = zpdf_lib[1]
elif host_machine.system() == 'darwin'
  zpdf_build_command = (
    'cd "@0@" && "@1@" build -Doptimize=ReleaseFast -Dtarget=@2@-macos.${MACOSX_DEPLOYMENT_TARGET:-26.0} && cp "@3@" "@4@/@5@"'
  ).format(
    zpdf_src_dir,
    zig.full_path(),
    host_machine.cpu_family(),
    zpdf_lib_src,
    zpdf_build_dir,
    zpdf_lib_name
  )
  zpdf_lib = custom_target('zpdf_shared',
    command: [
      'sh', '-c', zpdf_build_command
    ],
    output: [zpdf_lib_name],
    build_by_default: true,
    console: true,
  )
else
#Unix(Linux / macOS) : Use shell
  zpdf_lib = custom_target('zpdf_shared',
    command: [
      'sh', '-c',
      'cd "@0@" && "@1@" build -Doptimize=ReleaseFast && cp "@2@" "@3@/@4@"'.format(
        zpdf_src_dir,
        zig.full_path(),
        zpdf_lib_src,
        zpdf_build_dir,
        zpdf_lib_name
      )
    ],
    output: [zpdf_lib_name],
    build_by_default: true,
    console: true,
  )
endif

#Create a dependency object that includes the exact custom-target output. Meson recognizes
#the shared/import-library suffix and passes this artifact to the linker while preserving its
#generated-file edge. Avoid a separate -L/-l lookup: Meson resolves that to an absolute input
#without a generating rule, which breaks a clean rebuild after the artifact is removed.
if host_machine.system() == 'windows'
#On Windows, link against the import library only (not the DLL).
  zpdf_dep = declare_dependency(sources: [zpdf_import_lib])
else
  zpdf_dep = declare_dependency(sources: [zpdf_lib])
endif

#Compiler - specific flags for this plugin.
zyp_cpp_args = []
if meson.get_compiler('cpp').get_id() != 'msvc'
  zyp_cpp_args = ['-std=c++20', '-fno-sanitize=thread']
endif

#Plugin sources
zyp_sources = files(
  'zyp_plugin.cpp',
  'zpdf_wrapper.cpp',
  'pdf_metadata.cpp',
)

#Build the plugin(minimal dependencies - no spdlog to avoid TSan conflicts)
zyp_plugin = shared_module('yams_zyp',
  zyp_sources,
  include_directories: [
    include_directories('../../include'),
    include_directories('.'),
  ],
  dependencies: [zpdf_dep],
  cpp_args: zyp_cpp_args,
  link_args: zyp_link_args + plugin_export_link_args,
  link_depends: plugin_export_link_depends,
  gnu_symbol_visibility: 'hidden',
#build_rpath ensures the plugin can find libzpdf during build / test
  build_rpath: zpdf_build_dir,
#install_rpath ensures the plugin can find libzpdf after installation
  install_rpath: zyp_install_rpath,
  build_by_default: true,
  install: true,
  install_dir: plugins_dir,
  name_prefix: '',
)

#Install zpdf library alongside the plugin
#Use platform - specific install script
if host_machine.system() == 'windows'
  meson.add_install_script('powershell', '-NoProfile', '-Command',
    '$dest = if ($env:DESTDIR) { Join-Path $env:DESTDIR "@1@" } else { "@1@" }; New-Item -ItemType Directory -Force -Path $dest | Out-Null; Copy-Item -Path "@0@" -Destination $dest'.format(
      zpdf_build_dir / zpdf_lib_name,
      get_option('prefix') / plugins_dir
    ),
    install_tag: 'runtime',
  )
else
  meson.add_install_script('sh', '-c',
    'mkdir -p "$DESTDIR@1@" && cp "@0@" "$DESTDIR@1@/"'.format(
      zpdf_build_dir / zpdf_lib_name,
      get_option('prefix') / plugins_dir
    ),
    install_tag: 'runtime',
  )
endif

#-- -- zyp extraction benchmark -- --
#Measures sequential vs parallel PDF extraction throughput.
#Usage : zyp_extraction_bench < pdf_path>[repeat_count]
zyp_extraction_bench_sources = files(
  '../../tests/benchmarks/zyp_extraction_bench.cpp',
  'zpdf_wrapper.cpp',
)

zyp_extraction_bench = executable('zyp_extraction_bench',
  zyp_extraction_bench_sources,
  include_directories: [
    include_directories('../../include'),
    include_directories('../..'),
    include_directories('.'),
  ],
  dependencies: [zpdf_dep],
  cpp_args: zyp_cpp_args,
  build_rpath: zpdf_build_dir,
  build_by_default: false,
  install: false,
  override_options: ['b_sanitize=none'],
)