# Nix project build file
#============================================================================




# init
#============================================================================


# init project
#-------------------------------------------------
project(
    'nix',
    'cpp',
    
    default_options : [
        'cpp_std=c++17',
        'warning_level=3',
        'optimization=3',
        'debug=true'
    ],
    version : run_command('cat', './.version').stdout().strip(),
    license : 'MIT'
)

# init compiler 
#-------------------------------------------------
cpp = meson.get_compiler('cpp')

add_project_arguments(get_option('cxxflags'), language : 'cpp')
add_project_link_arguments(get_option('ldflags'), language: 'cpp')


cmake = import('cmake')
pkg = import('pkgconfig')




# init configuration
#-------------------------------------------------
config_h = configuration_data()

config_h.set(
    'HAVE_CXX17', 1,
    description : 'Define if the compiler supports basic C++17 syntax')

package_name = meson.project_name()
config_h.set_quoted(
    'PACKAGE_NAME', package_name,
    description : 'Define to the full name of this package.'
    )

package_tarname = meson.project_name()
config_h.set_quoted(
    'PACKAGE_TARNAME', package_tarname,
    description : 'Define to the one symbol short name of this package.')

package_version = meson.project_version()
config_h.set_quoted(
    'PACKAGE_VERSION', package_version,
    description : 'Define to the version of this package.')

package_string = '@0@ @1@'.format(package_name, package_version)
config_h.set_quoted(
    'PACKAGE_STRING', package_string,
    description : 'Define to the full name and version of this package.')

package_url = 'https://nixos.org/nix/'
config_h.set_quoted(
    'PACKAGE_URL', package_url,
    description : 'Define to the home page for this package.')

package_bug_url = 'https://github.com/nixos/nix/issues'
config_h.set_quoted(
    'PACKAGE_BUGREPORT', package_bug_url,
    description : 'Define to the address where bug reports for this package should be sent.')




# env
#============================================================================


# set install directories
#-------------------------------------------------
prefix = get_option('prefix')
libdir = join_paths(prefix, get_option('libdir'))
bindir = join_paths(prefix, get_option('bindir'))
datadir = join_paths(prefix, get_option('datadir'))
sysconfdir = join_paths(prefix, get_option('sysconfdir'))
libexecdir = join_paths(prefix, get_option('libexecdir'))
mandir = join_paths(prefix, get_option('mandir'))
includedir = join_paths(prefix, get_option('includedir'))

# set nix directories
#-------------------------------------------------

# State should be stored in /nix/var, unless the user overrides it explicitly.
if get_option('normal_var')
    localstatedir = '/nix/var'
else
    localstatedir =  join_paths(prefix, get_option('localstatedir'))
endif

nixstoredir = get_option('nixstoredir')

profiledir =  join_paths(sysconfdir, 'profile.d')

# Construct a Nix system name (like "i686-linux").
#-------------------------------------------------
machine_name = host_machine.cpu()
sys_name = host_machine.system().to_lower()

cpu_archs = ['x86_64', 'armv6', 'armv7', '']

foreach cpu : cpu_archs 
    if (host_machine.cpu().contains(cpu))
        if cpu.contains('armv')
            machine_name = cpu + '1'
        else
            machine_name = cpu
        endif
        break
    endif
endforeach

system= '"' + machine_name + '-' + sys_name + '"'
message('system name: ' + system)
config_h.set(
    'SYSTEM', system,
    description : 'platform identifier (`cpu-os`)')




# checking headers
#============================================================================

if (cpp.has_header('sys/stat.h'))
    config_h.set(
        'HAVE_SYS_STAT_H', 1,
        description : 'Define to 1 if you have the <sys/stat.h> header file.')
endif

if (cpp.has_header('sys/types.h'))
    config_h.set(
        'HAVE_SYS_TYPES_H', 1,
        description : 'Define to 1 if you have the <sys/types.h> header file.')
endif

if (cpp.has_header('sys/dir.h'))
    config_h.set(
        'HAVE_DIR_H', 1,
        description : 'Define to 1 if you have the <sys/dir.h> header file, and it defines `DIR`')
endif

if (cpp.has_header('sys/ndir.h'))
    config_h.set(
        'HAVE_NDIR_H', 1,
        description : 'Define to 1 if you have the <sys/ndir.h> header file, and it defines `DIR`')
endif

has_dirent_h = cpp.has_header('dirent.h')
if (has_dirent_h)
    config_h.set(
        'HAVE_DIRENT_H', 1,
        description : 'Define to 1 if you have the <dirent.h> header file, and it defines `DIR`')
endif

if (cpp.has_header('locale.h'))
    config_h.set(
        'HAVE_LOCALE', 1,
        description : 'Define to 1 if you have the <locale.h> header file.')
endif

if (cpp.has_header('unistd.h'))
    config_h.set(
        'HAVE_UNISTD_H', 1,
        description: 'Define to 1 if you have the <unistd.h> header file.')
endif

if (cpp.has_header('stdint.h'))
    config_h.set(
        'HAVE_STDINT_H', 1,
        description: 'Define to 1 if you have the <stdint.h> header file.')
endif

if (cpp.has_header('stdlib.h'))
    config_h.set(
        'HAVE_STDLIB_H', 1,
        description: 'Define to 1 if you have the <stdlib.h> header file.')
endif

if (cpp.has_header('strings.h'))
    config_h.set(
        'HAVE_STRINGS_H', 1,
        description: 'Define to 1 if you have the <strings.h> header file.')
endif

if (cpp.has_header('string.h'))
    config_h.set(
        'HAVE_STRING_H', 1,
        description: 'Define to 1 if you have the <strings.h> header file.')
endif

if (cpp.has_header('bzlib.h'))
    config_h.set(
        'HAVE_BZLIB_H', 1,
        description : 'Define to 1 if you have the <bzlib.h> header file.')
endif

if (cpp.has_header('inttypes.h'))
    config_h.set(
        'HAVE_INTTYPES_H', 1,
        description : 'Define to 1 if you have the <inttypes.h> header file.')
endif

if (cpp.has_header('memory.h'))
    config_h.set(
        'HAVE_MEMORY_H', 1,
        description : 'Define to 1 if you have the <memory.h> header file.')
endif

if (cpp.has_header('editline.h'))
    config_h.set(
        'HAVE_EDITLINE_H', 1,
        description : 'Define to 1 if you have the <editline.h> header file.')
else
    error('Nix requires editline.h; however the header was not found.')
endif




# checking functions
#============================================================================


if (cpp.has_function('lutimes'))
    config_h.set(
        'HAVE_LUTIMES', 1,
        description : 'Define to 1 if you have the `lutimes` function.')
endif

if (cpp.has_function('lchown'))
    config_h.set(
        'HAVE_LCHOWN', 1,
        description : 'Define to 1 if you have the `lchown` function.')
endif

if (cpp.has_function('pipe2'))
    config_h.set(
        'HAVE_PIPE2', 1,
        description : 'Define to 1 if you have the `pipe2` function.')
endif

if (cpp.has_function('posix_fallocate'))
    config_h.set(
        'HAVE_POSIX_FALLOCATE', 1,
        description : 'Define to 1 if you have the `posix_fallocate` function.')
endif

if (cpp.has_function('setresuid'))
    config_h.set(
        'HAVE_SETRESUID', 1,
        description : 'Define to 1 if you have the `setresuid` function.')
endif

if (cpp.has_function('setreuid'))
    config_h.set(
        'HAVE_SETREUID', 1,
        description : 'Define to 1 if you have the `setreuid` function.')
endif

if (cpp.has_function('statvfs'))
    config_h.set(
        'HAVE_STATVFS', 1,
        description : 'Define to 1 if you have the `statvfs` function.')
endif

if (cpp.has_function('strsignal'))
    config_h.set(
        'HAVE_STRSIGNAL', 1,
        description : 'Define to 1 if you have the `strsignal` function.')
endif

if (cpp.has_function('sysconf'))
    config_h.set(
        'HAVE_SYSCONF', 1,
        description : 'Define to 1 if you have the `sysconf` function.')
endif

pubsetbuff_c = '''
    #include <iostream>
    using namespace std;
    static char buf[1024];
    void func() {
    cerr.rdbuf()->pubsetbuf(buf, sizeof(buf));
    }'''

if meson.get_compiler('cpp').compiles(
    pubsetbuff_c,
    name : 'pubsetbuf'
  )
    config_h.set(
        'HAVE_PUBSETBUF', 1,
        description : 'Define to 1 if you have the `pubsetbuf` function.')
endif



# checking data types
#============================================================================


dirent_h_prefix = '''
  #include <sys/types.h>
  #include <dirent.h>
'''

if has_dirent_h and meson.get_compiler('cpp').has_member('struct dirent', 'd_type', prefix: dirent_h_prefix)
  config_h.set('HAVE_STRUCT_DIRENT_D_TYPE', 1)
endif

# required dependancies
#============================================================================


# look for required programs
#--------------------------------------------------
cat = find_program('cat', required : true)
ln = find_program('ln', required : true)
cp = find_program('cp', required : true)
rm = find_program('rm', required : true)
bash = find_program('bash', required : true)
echo = find_program('echo', required : true)
patch = find_program('patch', required : true)
xmllint = find_program('xmllint', required : true)
flex = find_program('flex', required : true)
bison = find_program('bison', required : true)
sed = find_program('sed', required : true)
tar = find_program('tar', required : true)
bzip2 = find_program('bzip2', required : true)
gzip = find_program('gzip', required : true)
xz = find_program('xz', required : true)
dot = find_program('dot', required : false)
lsof = find_program('lsof', required : false)
tr = find_program('tr', required : true)
coreutils = run_command('dirname', cat.path()).stdout().strip()


# Check whether the store optimiser can optimise symlinks.
#-------------------------------------------------
gen_header = '''
ln -s bla tmp_link
if ln tmp_link tmp_link2 2> /dev/null; then
    echo 1
else
    echo 0
fi
'''

run_command('sh', '-c', 'rm tmp_link*') 
can_link_symlink = run_command('sh', '-c', gen_header).stdout().strip()
if can_link_symlink.to_int() == 1
    run_command('sh', '-c', 'rm tmp_link*')
endif 

config_h.set('CAN_LINK_SYMLINK', can_link_symlink,
description : 'Whether link() works on symlinks')


# Look for boost, a required dependency.
#--------------------------------------------------
boost_dep = declare_dependency(
    dependencies : [
        cpp.find_library('boost_system'),
        cpp.find_library('boost_context'),
        cpp.find_library('boost_thread')],
    link_args :  get_option('boost_link_args'))

if (boost_dep.found())
    config_h.set('HAVE_BOOST', 1, description : 'Define if the Boost library is available.')
endif


# Look for liblzma, a required dependency.
#--------------------------------------------------
liblzma_dep = declare_dependency(
    dependencies: dependency('liblzma'),
    link_args :  get_option('lzma_link_args'))


# Look for libbrotli{enc,dec}.
#--------------------------------------------------
libbrotli_dep = declare_dependency(
    dependencies: [
        dependency('libbrotlienc'),
        dependency('libbrotlidec')],
    link_args :  get_option('brotli_link_args'))


# Look for OpenSSL, a required dependency.
#--------------------------------------------------
openssl_dep = declare_dependency(
    dependencies: cpp.find_library('ssl'),
    link_args :  get_option('openssl_link_args'))


# Look for SQLite, a required dependency.
#--------------------------------------------------
sqlite3_dep = declare_dependency(
    dependencies : dependency('sqlite3', version : '>= 3.6.19'),
    link_args : get_option('sqlite3_link_args'))


# Look for libcurl, a required dependency.
#--------------------------------------------------
libcurl_dep = declare_dependency(
    dependencies : dependency('libcurl'),
    link_args :  get_option('curl_link_args'))


# Look for pthread, a required dependency.
#--------------------------------------------------
pthread_dep = declare_dependency(
    dependencies : dependency('threads'),
    link_args :  get_option('pthread_link_args'))


# Look for libdl, a required dependency.
#--------------------------------------------------
libdl_dep = declare_dependency(
    dependencies : cpp.find_library('dl'),
    link_args :  get_option('dl_link_args'))


# Look for libbz2, a required dependency.
#--------------------------------------------------
libbz2_dep = declare_dependency(
    dependencies : cpp.find_library('bz2'),
    link_args :  get_option('bz2_link_args'))


# Look for editline, a required dependency.
#--------------------------------------------------
# NOTE: The the libeditline.pc file was added only in libeditline >= 1.15.2, see 
# https://github.com/troglobit/editline/commit/0a8f2ef4203c3a4a4726b9dd1336869cd0da8607,
# but e.g. Ubuntu 16.04 has an older version, so we fall back to searching for
# editline.h when the pkg-config approach fails.

editline_dep = declare_dependency(
    dependencies : cpp.find_library('editline'),
    link_args :  get_option('editline_link_args'))

if not (
    cpp.has_function(
        'read_history',
        prefix : '#include <stdio.h>\n#include "editline.h"',
        args : '-lreadline'))
    warning('Nix requires libeditline; However, required functions do not work. Maybe ' +\
    'it is too old? >= 1.14 is required.')
endif




# Optional dependancies
#============================================================================


# Look for libsodium, an optional dependency.
#--------------------------------------------------
libsodium_lib = cpp.find_library('sodium', required: get_option('with_libsodium'))
if (libsodium_lib.found())
    libsodium_dep = declare_dependency(
        dependencies : libsodium_lib,
        link_args :  get_option('sodium_link_args'))
    config_h.set('HAVE_SODIUM', 1, description : 'Whether to use libsodium for cryptography.')
else
    libsodium_dep = dependency('', required: false)
endif


# Look for Boehm garbage collector, an optional dependency.
#--------------------------------------------------
if (get_option('with_gc'))
    gc_dep = declare_dependency(
        dependencies : dependency('bdw-gc'),
        link_args :  get_option('gc_link_args'))
    config_h.set(
        'HAVE_BOEHMGC', 1,
        description : 'Whether to use the Boehm garbage collector.')
else
    gc_dep = dependency('', required: false)
endif


# Look for aws-cpp-sdk-s3.
#--------------------------------------------------
if (get_option('with_s3'))
  enable_s3 = meson.get_compiler('cpp').check_header('aws/s3/S3Client.h')
  
  aws_version = meson.get_compiler('cpp').get_define(
    'AWS_SDK_VERSION_STRING',
    prefix : '#include <aws/core/VersionConfig.h>'
  ).strip('"').split('.')
  
  conf_data.set('ENABLE_S3', 1, description : 'Whether to enable S3 support via aws-sdk-cpp.')
  conf_data.set('AWS_VERSION_MAJOR', aws_version[0], description : 'Major version of aws-sdk-cpp.')
  conf_data.set('AWS_VERSION_MINOR', aws_version[1], description : 'Minor version of aws-sdk-cpp.')
endif




# OS Specific checks 
#============================================================================
# Look for libsecppomp, required for Linux sandboxing.
if sys_name.contains('linux')
    libseccomp_dep = dependency(
        'libseccomp',
        version : '>= 2.3.1',
        not_found_message : 'Nix requires libseccomp on a linux host system')
    config_h.set(
        'HAVE_SECCOMP', 1,
        description : 'Whether seccomp is available and should be used for sandboxing.')
else
    libseccomp_dep = dependency('', required: false)
endif

if (sys_name.contains('freebsd'))
    add_project_arguments('-D_GNU_SOURCE', language : 'cpp')
    config_h.set('_GNU_SOURCE', 1)  
endif

if (sys_name.contains('sunos'))
    # Solaris requires -lsocket -lnsl for network functions 
endif




# build
#============================================================================

conf = configure_file(
    output : 'config.h',
    configuration : config_h)

install_headers(
    conf,
    install_dir : join_paths(includedir, 'nix'))

add_project_arguments('-include', 'config.h', language : 'cpp')
src_inc = [include_directories('.', 'src')]

project_dirs = [
    'src',
    'scripts',
    'corepkgs',
    'misc',
    'doc',
    'tests'
]


foreach dir : project_dirs
    subdir(dir)
endforeach