#!/usr/bin/env python
"""
The script builds OpenCV.framework for iOS.
The built framework is universal, it can be used to build app and run it on either iOS simulator or real device.

Usage:
    ./build_framework.py <outputdir>

By cmake conventions (and especially if you work with OpenCV repository),
the output dir should not be a subdirectory of OpenCV source tree.

Script will create <outputdir>, if it's missing, and a few its subdirectories:

    <outputdir>
        build/
            iPhoneOS-*/
               [cmake-generated build tree for an iOS device target]
            iPhoneSimulator-*/
               [cmake-generated build tree for iOS simulator]
        {framework_name}.framework/
            [the framework content]

The script should handle minor OpenCV updates efficiently
- it does not recompile the library from scratch each time.
However, {framework_name}.framework directory is erased and recreated on each run.

Adding --dynamic parameter will build {framework_name}.framework as App Store dynamic framework. Only iOS 8+ versions are supported.
"""

from __future__ import print_function
import glob, re, os, os.path, shutil, string, sys, argparse, traceback, multiprocessing
from subprocess import check_call, check_output, CalledProcessError
from distutils.dir_util import copy_tree

IPHONEOS_DEPLOYMENT_TARGET='8.0'  # default, can be changed via command line options or environment variable

def execute(cmd, cwd = None):
    print("Executing: %s in %s" % (cmd, cwd), file=sys.stderr)
    print('Executing: ' + ' '.join(cmd))
    retcode = check_call(cmd, cwd = cwd)
    if retcode != 0:
        raise Exception("Child returned:", retcode)

def getXCodeMajor():
    ret = check_output(["xcodebuild", "-version"])
    m = re.match(r'Xcode\s+(\d+)\..*', ret, flags=re.IGNORECASE)
    if m:
        return int(m.group(1))
    else:
        raise Exception("Failed to parse Xcode version")

def getXCodeSetting(var, projectdir):
    ret = check_output(["xcodebuild", "-showBuildSettings"], cwd = projectdir)
    m = re.search("\s" + var + " = (.*)", ret)
    if m:
        return m.group(1)
    else:
        raise Exception("Failed to parse Xcode settings")

class Builder:
    def __init__(self, opencv, contrib, dynamic, bitcodedisabled, exclude, disable, enablenonfree, targets, debug, debug_info, framework_name):
        self.opencv = os.path.abspath(opencv)
        self.contrib = None
        if contrib:
            modpath = os.path.join(contrib, "modules")
            if os.path.isdir(modpath):
                self.contrib = os.path.abspath(modpath)
            else:
                print("Note: contrib repository is bad - modules subfolder not found", file=sys.stderr)
        self.dynamic = dynamic
        self.bitcodedisabled = bitcodedisabled
        self.exclude = exclude
        self.build_objc_wrapper = not "objc" in self.exclude
        self.disable = disable
        self.enablenonfree = enablenonfree
        self.targets = targets
        self.debug = debug
        self.debug_info = debug_info
        self.framework_name = framework_name

    def getBD(self, parent, t):

        if len(t[0]) == 1:
            res = os.path.join(parent, 'build-%s-%s' % (t[0][0].lower(), t[1].lower()))
        else:
            res = os.path.join(parent, 'build-%s' % t[1].lower())

        if not os.path.isdir(res):
            os.makedirs(res)
        return os.path.abspath(res)

    def _build(self, outdir):
        outdir = os.path.abspath(outdir)
        if not os.path.isdir(outdir):
            os.makedirs(outdir)
        mainWD = os.path.join(outdir, "build")
        dirs = []

        xcode_ver = getXCodeMajor()

        if self.dynamic and not self.build_objc_wrapper:
            alltargets = self.targets
        else:
            # if we are building a static library, we must build each architecture separately
            alltargets = []

            for t in self.targets:
                for at in t[0]:
                    current = ( [at], t[1] )

                    alltargets.append(current)

        for t in alltargets:
            mainBD = self.getBD(mainWD, t)
            dirs.append(mainBD)

            cmake_flags = []
            if self.contrib:
                cmake_flags.append("-DOPENCV_EXTRA_MODULES_PATH=%s" % self.contrib)
            if xcode_ver >= 7 and t[1] == 'iPhoneOS' and self.bitcodedisabled == False:
                cmake_flags.append("-DCMAKE_C_FLAGS=-fembed-bitcode")
                cmake_flags.append("-DCMAKE_CXX_FLAGS=-fembed-bitcode")
            self.buildOne(t[0], t[1], mainBD, cmake_flags)

            if not self.dynamic:
                self.mergeLibs(mainBD)
            elif self.dynamic and self.build_objc_wrapper:
                self.makeDynamicLib(mainBD)
        self.makeFramework(outdir, dirs)
        if self.build_objc_wrapper:
            print("To run tests call:")
            print(sys.argv[0].replace("build_framework", "run_tests") + " --framework_dir=" + outdir + " --framework_name=" + self.framework_name + " " + dirs[0] +  "/modules/objc/test")
            self.copy_samples(outdir)

    def build(self, outdir):
        try:
            self._build(outdir)
        except Exception as e:
            print("="*60, file=sys.stderr)
            print("ERROR: %s" % e, file=sys.stderr)
            print("="*60, file=sys.stderr)
            traceback.print_exc(file=sys.stderr)
            sys.exit(1)

    def getToolchain(self, arch, target):
        return None

    def getConfiguration(self):
        return "Debug" if self.debug else "Release"

    def getCMakeArgs(self, arch, target):

        args = [
            "cmake",
            "-GXcode",
            "-DAPPLE_FRAMEWORK=ON",
            "-DCMAKE_INSTALL_PREFIX=install",
            "-DCMAKE_BUILD_TYPE=%s" % self.getConfiguration(),
            "-DOPENCV_INCLUDE_INSTALL_PATH=include",
            "-DOPENCV_3P_LIB_INSTALL_PATH=lib/3rdparty",
            "-DFRAMEWORK_NAME=%s" % self.framework_name,
        ] + ([
            "-DBUILD_SHARED_LIBS=ON",
            "-DCMAKE_MACOSX_BUNDLE=ON",
            "-DCMAKE_XCODE_ATTRIBUTE_CODE_SIGNING_REQUIRED=NO",
        ] if self.dynamic and not self.build_objc_wrapper else []) + ([
            "-DDYNAMIC_PLIST=ON"
        ] if self.dynamic else []) + ([
            "-DOPENCV_ENABLE_NONFREE=ON"
        ] if self.enablenonfree else []) + ([
            "-DBUILD_WITH_DEBUG_INFO=ON"
        ] if self.debug_info else [])

        if len(self.exclude) > 0:
            args += ["-DBUILD_opencv_world=OFF"] if not (self.dynamic and not self.build_objc_wrapper) else []
            args += ["-DBUILD_opencv_%s=OFF" % m for m in self.exclude]

        if len(self.disable) > 0:
            args += ["-DWITH_%s=OFF" % f for f in self.disable]

        return args

    def getBuildCommand(self, archs, target):

        buildcmd = [
            "xcodebuild",
        ]

        if (self.dynamic or self.build_objc_wrapper) and not self.bitcodedisabled and target == "iPhoneOS":
            buildcmd.append("BITCODE_GENERATION_MODE=bitcode")

        if self.dynamic and not self.build_objc_wrapper:
            buildcmd += [
                "IPHONEOS_DEPLOYMENT_TARGET=" + os.environ['IPHONEOS_DEPLOYMENT_TARGET'],
                "ONLY_ACTIVE_ARCH=NO",
            ]

            for arch in archs:
                buildcmd.append("-arch")
                buildcmd.append(arch.lower())
        else:
            arch = ";".join(archs)
            buildcmd += [
                "IPHONEOS_DEPLOYMENT_TARGET=" + os.environ['IPHONEOS_DEPLOYMENT_TARGET'],
                "ARCHS=%s" % arch,
            ]

        buildcmd += [
                "-sdk", target.lower(),
                "-configuration", self.getConfiguration(),
                "-parallelizeTargets",
                "-jobs", str(multiprocessing.cpu_count()),
            ] + (["-target","ALL_BUILD"] if self.dynamic and not self.build_objc_wrapper else [])

        return buildcmd

    def getInfoPlist(self, builddirs):
        return os.path.join(builddirs[0], "ios", "Info.plist")

    def makeCMakeCmd(self, arch, target, dir, cmakeargs = []):
        toolchain = self.getToolchain(arch, target)
        cmakecmd = self.getCMakeArgs(arch, target) + \
            (["-DCMAKE_TOOLCHAIN_FILE=%s" % toolchain] if toolchain is not None else [])
        if target.lower().startswith("iphoneos"):
            cmakecmd.append("-DCPU_BASELINE=DETECT")
        cmakecmd.append(dir)
        cmakecmd.extend(cmakeargs)
        return cmakecmd

    def buildOne(self, arch, target, builddir, cmakeargs = []):
        # Run cmake
        #toolchain = self.getToolchain(arch, target)
        #cmakecmd = self.getCMakeArgs(arch, target) + \
        #    (["-DCMAKE_TOOLCHAIN_FILE=%s" % toolchain] if toolchain is not None else [])
        #if target.lower().startswith("iphoneos"):
        #    cmakecmd.append("-DCPU_BASELINE=DETECT")
        #cmakecmd.append(self.opencv)
        #cmakecmd.extend(cmakeargs)
        cmakecmd = self.makeCMakeCmd(arch, target, self.opencv, cmakeargs)
        execute(cmakecmd, cwd = builddir)

        # Clean and build
        clean_dir = os.path.join(builddir, "install")
        if os.path.isdir(clean_dir):
            shutil.rmtree(clean_dir)
        buildcmd = self.getBuildCommand(arch, target)
        execute(buildcmd + ["-target", "ALL_BUILD", "build"], cwd = builddir)
        execute(["cmake", "-DBUILD_TYPE=%s" % self.getConfiguration(), "-P", "cmake_install.cmake"], cwd = builddir)
        if self.build_objc_wrapper:
            cmakecmd = self.makeCMakeCmd(arch, target, builddir + "/modules/objc/gen", cmakeargs)
            cmakecmd.append("-DBUILD_ROOT=%s" % builddir)
            cmakecmd.append("-DCMAKE_INSTALL_NAME_TOOL=install_name_tool")
            cmakecmd.append("--no-warn-unused-cli")
            execute(cmakecmd, cwd = builddir + "/modules/objc/framework_build")

            execute(buildcmd + ["-target", "ALL_BUILD", "build"], cwd = builddir + "/modules/objc/framework_build")
            execute(["cmake", "-DBUILD_TYPE=%s" % self.getConfiguration(), "-DCMAKE_INSTALL_PREFIX=%s" % (builddir + "/install"), "-P", "cmake_install.cmake"], cwd = builddir + "/modules/objc/framework_build")

    def mergeLibs(self, builddir):
        res = os.path.join(builddir, "lib", self.getConfiguration(), "libopencv_merged.a")
        libs = glob.glob(os.path.join(builddir, "install", "lib", "*.a"))
        module = [os.path.join(builddir, "install", "lib", self.framework_name + ".framework", self.framework_name)] if self.build_objc_wrapper else []

        libs3 = glob.glob(os.path.join(builddir, "install", "lib", "3rdparty", "*.a"))
        print("Merging libraries:\n\t%s" % "\n\t".join(libs + libs3 + module), file=sys.stderr)
        execute(["libtool", "-static", "-o", res] + libs + libs3 + module)

    def makeDynamicLib(self, builddir):
        target = builddir[(builddir.rfind("build-") + 6):]
        target_platform = target[(target.rfind("-") + 1):]
        is_device = target_platform == "iphoneos"
        res = os.path.join(builddir, "install", "lib", self.framework_name + ".framework", self.framework_name)
        libs = glob.glob(os.path.join(builddir, "install", "lib", "*.a"))
        module = [os.path.join(builddir, "lib", self.getConfiguration(), self.framework_name + ".framework", self.framework_name)]

        libs3 = glob.glob(os.path.join(builddir, "install", "lib", "3rdparty", "*.a"))

        link_target = target[:target.find("-")] + "-apple-ios" + os.environ['IPHONEOS_DEPLOYMENT_TARGET'] + ("-simulator" if target.endswith("simulator") else "")
        bitcode_flags = ["-fembed-bitcode", "-Xlinker", "-bitcode_verify"] if is_device and not self.bitcodedisabled else []
        toolchain_dir = getXCodeSetting("TOOLCHAIN_DIR", builddir)
        swift_link_dirs = ["-L" + toolchain_dir + "/usr/lib/swift/" + target_platform, "-L/usr/lib/swift"]
        sdk_dir = getXCodeSetting("SDK_DIR", builddir)
        execute([
            "clang++",
            "-Xlinker", "-rpath",
            "-Xlinker", "/usr/lib/swift",
            "-target", link_target,
            "-isysroot", sdk_dir,
            "-install_name", ("@executable_path/Frameworks/" + self.framework_name + ".framework/" + self.framework_name) if is_device else res,
            "-dynamiclib", "-dead_strip", "-fobjc-link-runtime", "-all_load",
            "-o", res
        ] + swift_link_dirs + bitcode_flags + module + libs + libs3)

    def makeFramework(self, outdir, builddirs):
        name = self.framework_name

        # set the current dir to the dst root
        framework_dir = os.path.join(outdir, "%s.framework" % name)
        if os.path.isdir(framework_dir):
            shutil.rmtree(framework_dir)
        os.makedirs(framework_dir)

        if self.dynamic:
            dstdir = framework_dir
        else:
            dstdir = os.path.join(framework_dir, "Versions", "A")

        # copy headers from one of build folders
        shutil.copytree(os.path.join(builddirs[0], "install", "include", "opencv2"), os.path.join(dstdir, "Headers"))
        if name != "opencv2":
            for dirname, dirs, files in os.walk(os.path.join(dstdir, "Headers")):
                for filename in files:
                    filepath = os.path.join(dirname, filename)
                    with open(filepath) as file:
                        body = file.read()
                    body = body.replace("include \"opencv2/", "include \"" + name + "/")
                    body = body.replace("include <opencv2/", "include <" + name + "/")
                    with open(filepath, "w") as file:
                        file.write(body)
        if self.build_objc_wrapper:
            copy_tree(os.path.join(builddirs[0], "install", "lib", name + ".framework", "Headers"), os.path.join(dstdir, "Headers"))
            platform_name_map = {
                    "arm": "armv7-apple-ios",
                    "arm64": "arm64-apple-ios",
                    "i386": "i386-apple-ios-simulator",
                    "x86_64": "x86_64-apple-ios-simulator",
                } if builddirs[0].find("iphone") != -1 else {
                    "x86_64": "x86_64-apple-macos",
                }
            for d in builddirs:
                copy_tree(os.path.join(d, "install", "lib", name + ".framework", "Modules"), os.path.join(dstdir, "Modules"))
            for dirname, dirs, files in os.walk(os.path.join(dstdir, "Modules")):
                for filename in files:
                    filestem = os.path.splitext(filename)[0]
                    fileext = os.path.splitext(filename)[1]
                    if filestem in platform_name_map:
                        os.rename(os.path.join(dirname, filename), os.path.join(dirname, platform_name_map[filestem] + fileext))

        # make universal static lib
        if self.dynamic:
            libs = [os.path.join(d, "install", "lib", name + ".framework", name) for d in builddirs]
        else:
            libs = [os.path.join(d, "lib", self.getConfiguration(), "libopencv_merged.a") for d in builddirs]
        lipocmd = ["lipo", "-create"]
        lipocmd.extend(libs)
        lipocmd.extend(["-o", os.path.join(dstdir, name)])
        print("Creating universal library from:\n\t%s" % "\n\t".join(libs), file=sys.stderr)
        execute(lipocmd)

        # dynamic framework has different structure, just copy the Plist directly
        if self.dynamic:
            resdir = dstdir
            shutil.copyfile(self.getInfoPlist(builddirs), os.path.join(resdir, "Info.plist"))
        else:
            # copy Info.plist
            resdir = os.path.join(dstdir, "Resources")
            os.makedirs(resdir)
            shutil.copyfile(self.getInfoPlist(builddirs), os.path.join(resdir, "Info.plist"))

            # make symbolic links
            links = [
                (["A"], ["Versions", "Current"]),
                (["Versions", "Current", "Headers"], ["Headers"]),
                (["Versions", "Current", "Resources"], ["Resources"]),
                (["Versions", "Current", "Modules"], ["Modules"]),
                (["Versions", "Current", name], [name])
            ]
            for l in links:
                s = os.path.join(*l[0])
                d = os.path.join(framework_dir, *l[1])
                os.symlink(s, d)

        doc_path = os.path.join(builddirs[0], "modules", "objc", "doc_build", "docs")
        if os.path.exists(doc_path):
            shutil.copytree(doc_path, os.path.join(outdir, "docs"))
            shutil.copyfile(os.path.join(self.opencv, "doc", "opencv.ico"), os.path.join(outdir, "docs", "favicon.ico"))

    def copy_samples(self, outdir):
        return

class iOSBuilder(Builder):

    def getToolchain(self, arch, target):
        toolchain = os.path.join(self.opencv, "platforms", "ios", "cmake", "Toolchains", "Toolchain-%s_Xcode.cmake" % target)
        return toolchain

    def getCMakeArgs(self, arch, target):
        arch = ";".join(arch)

        args = Builder.getCMakeArgs(self, arch, target)
        args = args + [
            '-DIOS_ARCH=%s' % arch
        ]
        return args

    def copy_samples(self, outdir):
        print('Copying samples to: ' + outdir)
        samples_dir = os.path.join(outdir, "samples")
        shutil.copytree(os.path.join(self.opencv, "samples", "swift", "ios"), samples_dir)
        if self.framework_name != "OpenCV":
            for dirname, dirs, files in os.walk(samples_dir):
                for filename in files:
                    if not filename.endswith((".h", ".swift", ".pbxproj")):
                        continue
                    filepath = os.path.join(dirname, filename)
                    with open(filepath) as file:
                        body = file.read()
                    body = body.replace("import OpenCV", "import " + self.framework_name)
                    body = body.replace("#import <OpenCV/OpenCV.h>", "#import <" + self.framework_name + "/" + self.framework_name + ".h>")
                    body = body.replace("OpenCV.framework", self.framework_name + ".framework")
                    body = body.replace("../../OpenCV/**", "../../" + self.framework_name + "/**")
                    with open(filepath, "w") as file:
                        file.write(body)


if __name__ == "__main__":
    folder = os.path.abspath(os.path.join(os.path.dirname(sys.argv[0]), "../.."))
    parser = argparse.ArgumentParser(description='The script builds OpenCV.framework for iOS.')
    parser.add_argument('out', metavar='OUTDIR', help='folder to put built framework')
    parser.add_argument('--opencv', metavar='DIR', default=folder, help='folder with opencv repository (default is "../.." relative to script location)')
    parser.add_argument('--contrib', metavar='DIR', default=None, help='folder with opencv_contrib repository (default is "None" - build only main framework)')
    parser.add_argument('--without', metavar='MODULE', default=[], action='append', help='OpenCV modules to exclude from the framework')
    parser.add_argument('--disable', metavar='FEATURE', default=[], action='append', help='OpenCV features to disable (add WITH_*=OFF)')
    parser.add_argument('--dynamic', default=False, action='store_true', help='build dynamic framework (default is "False" - builds static framework)')
    parser.add_argument('--disable-bitcode', default=False, dest='bitcodedisabled', action='store_true', help='disable bitcode (enabled by default)')
    parser.add_argument('--iphoneos_deployment_target', default=os.environ.get('IPHONEOS_DEPLOYMENT_TARGET', IPHONEOS_DEPLOYMENT_TARGET), help='specify IPHONEOS_DEPLOYMENT_TARGET')
    parser.add_argument('--iphoneos_archs', default='armv7,armv7s,arm64', help='select iPhoneOS target ARCHS')
    parser.add_argument('--iphonesimulator_archs', default='i386,x86_64', help='select iPhoneSimulator target ARCHS')
    parser.add_argument('--enable_nonfree', default=False, dest='enablenonfree', action='store_true', help='enable non-free modules (disabled by default)')
    parser.add_argument('--debug', default=False, dest='debug', action='store_true', help='Build "Debug" binaries (disabled by default)')
    parser.add_argument('--debug_info', default=False, dest='debug_info', action='store_true', help='Build with debug information (useful for Release mode: BUILD_WITH_DEBUG_INFO=ON)')
    parser.add_argument('--framework_name', default='opencv2', dest='framework_name', help='Name of OpenCV framework (default: opencv2, will change to OpenCV in future version)')
    parser.add_argument('--legacy_build', default=False, dest='legacy_build', action='store_true', help='Build legacy opencv2 framework (default: False, equivalent to "--framework_name=opencv2 --without=objc")')
    args = parser.parse_args()

    os.environ['IPHONEOS_DEPLOYMENT_TARGET'] = args.iphoneos_deployment_target
    print('Using IPHONEOS_DEPLOYMENT_TARGET=' + os.environ['IPHONEOS_DEPLOYMENT_TARGET'])
    iphoneos_archs = args.iphoneos_archs.split(',')
    print('Using iPhoneOS ARCHS=' + str(iphoneos_archs))
    iphonesimulator_archs = args.iphonesimulator_archs.split(',')
    print('Using iPhoneSimulator ARCHS=' + str(iphonesimulator_archs))
    if args.legacy_build:
        args.framework_name = "opencv2"
        if not "objc" in args.without:
            args.without.append("objc")

    b = iOSBuilder(args.opencv, args.contrib, args.dynamic, args.bitcodedisabled, args.without, args.disable, args.enablenonfree,
        [
            (iphoneos_archs, "iPhoneOS"),
        ] if os.environ.get('BUILD_PRECOMMIT', None) else
        [
            (iphoneos_archs, "iPhoneOS"),
            (iphonesimulator_archs, "iPhoneSimulator"),
        ], args.debug, args.debug_info, args.framework_name)

    b.build(args.out)