import argparse
import os
import shutil
import subprocess
import sys


def do_dependency(args):
    ret = False

    # hack for incremental build
    if args.pr_number is not None and not args.clean_build:
        if args.branch is None or args.base_branch is None:
            "branch ({}) and base branch ({}) is required for pull request #{}".format(
                args.branch, args.base_branch, args.pr_number
            )
            return ret
        # fetching the recent state of base branch
        fetch_cmd = ["git", "fetch", "origin", args.base_branch]
        print(fetch_cmd)
        subprocess.check_call(fetch_cmd, cwd=args.src_dir)
        # fetching and checkout PR changes
        fetch_pr_cmd = ["git", "fetch", "-t", "origin", args.branch]
        print(fetch_pr_cmd)
        subprocess.check_call(fetch_pr_cmd, cwd=args.src_dir)
        checkout_cmd = ["git", "checkout", "-B", args.branch]
        print(checkout_cmd)
        subprocess.check_call(checkout_cmd, cwd=args.src_dir)
        # get baseline commit
        merge_base_cmd = [
            "git",
            "merge-base",
            "origin/{}".format(args.base_branch),
            args.branch,
        ]
        print(merge_base_cmd)
        base_commit = subprocess.check_output(merge_base_cmd, cwd=args.src_dir)
        base_commit = base_commit.rstrip()
        diff_cmd = [
            "git",
            "--no-pager",
            "diff",
            base_commit,
            args.branch,
            "--name-only",
            "buildbot",
        ]
        print(diff_cmd)
        changed_build_scripts = subprocess.check_output(diff_cmd, cwd=args.src_dir)
        changed_build_scripts = (
            changed_build_scripts.rstrip()
            if changed_build_scripts is not None
            else None
        )
        # clean build directory if build scripts have changed
        if len(changed_build_scripts) > 0:
            if os.path.isdir(args.obj_dir):
                shutil.rmtree(args.obj_dir)
                if os.path.isdir(args.obj_dir):
                    print("failed to remove build directory: {}".format(args.obj_dir))
                    return ret
                # let's recover it
                os.makedirs(args.obj_dir)
                if not os.path.isdir(args.obj_dir):
                    print("failed to recover build directory: {}".format(args.obj_dir))
                    return ret

    # fetch OpenCL headers
    ocl_header_dir = os.path.join(args.obj_dir, "OpenCL-Headers")
    if not os.path.isdir(ocl_header_dir):
        clone_cmd = [
            "git",
            "clone",
            "https://github.com/KhronosGroup/OpenCL-Headers",
            "OpenCL-Headers",
            "-b",
            "main",
        ]
        subprocess.check_call(clone_cmd, cwd=args.obj_dir)
    else:
        fetch_cmd = ["git", "pull", "--ff", "--ff-only", "origin"]
        subprocess.check_call(fetch_cmd, cwd=ocl_header_dir)

    # Checkout fixed version to avoid unexpected issues coming from upstream
    # Specific version can be uplifted as soon as such need arise
    checkout_cmd = ["git", "checkout", "9ddb236e6eb3cf844f9e2f81677e1045f9bf838e"]
    subprocess.check_call(checkout_cmd, cwd=ocl_header_dir)

    # fetch and build OpenCL ICD loader
    icd_loader_dir = os.path.join(args.obj_dir, "OpenCL-ICD-Loader")
    if not os.path.isdir(icd_loader_dir):
        clone_cmd = [
            "git",
            "clone",
            "https://github.com/KhronosGroup/OpenCL-ICD-Loader",
            "OpenCL-ICD-Loader",
            "-b",
            "main",
        ]

        subprocess.check_call(clone_cmd, cwd=args.obj_dir)
    else:
        fetch_cmd = ["git", "pull", "--ff", "--ff-only", "origin"]
        subprocess.check_call(fetch_cmd, cwd=icd_loader_dir)

    # Checkout fixed version to avoid unexpected issues coming from upstream
    # Specific version can be uplifted as soon as such need arise
    checkout_cmd = ["git", "checkout", "9a3e962f16f5097d2054233ad8b6dad51b6f41b7"]
    subprocess.check_call(checkout_cmd, cwd=icd_loader_dir)

    icd_build_dir = os.path.join(icd_loader_dir, "build")
    if os.path.isdir(icd_build_dir):
        shutil.rmtree(icd_build_dir)
    os.makedirs(icd_build_dir)
    install_dir = os.path.join(args.obj_dir, "install")
    cmake_cmd = [
        "cmake",
        "-G",
        "Ninja",
        "-DCMAKE_INSTALL_PREFIX={}".format(install_dir),
        "-DOPENCL_ICD_LOADER_HEADERS_DIR={}".format(ocl_header_dir),
        "..",
    ]

    print("[Cmake Command]: {}".format(" ".join(cmake_cmd)))

    subprocess.check_call(cmake_cmd, cwd=icd_build_dir)

    env_tmp = os.environ
    env_tmp["C_INCLUDE_PATH"] = "{}".format(ocl_header_dir)
    subprocess.check_call(["ninja", "install"], env=env_tmp, cwd=icd_build_dir)

    ret = True
    return ret


def main():
    parser = argparse.ArgumentParser(
        prog="dependency.py",
        description="script to get and build dependency",
        formatter_class=argparse.RawTextHelpFormatter,
    )
    parser.add_argument(
        "-n", "--build-number", metavar="BUILD_NUM", help="build number"
    )
    parser.add_argument("-b", "--branch", metavar="BRANCH", help="pull request branch")
    parser.add_argument(
        "-d", "--base-branch", metavar="BASE_BRANCH", help="pull request base branch"
    )
    parser.add_argument(
        "-r", "--pr-number", metavar="PR_NUM", help="pull request number"
    )
    parser.add_argument(
        "-w",
        "--builder-dir",
        metavar="BUILDER_DIR",
        help="builder directory, which is the directory containing source and build directories",
    )
    parser.add_argument("-s", "--src-dir", metavar="SRC_DIR", help="source directory")
    parser.add_argument(
        "-o", "--obj-dir", metavar="OBJ_DIR", required=True, help="build directory"
    )
    parser.add_argument(
        "-c",
        "--clean-build",
        action="store_true",
        default=False,
        help="true if the build is clean build which has clobber step",
    )

    args = parser.parse_args()

    print("args:{}".format(args))

    return do_dependency(args)


if __name__ == "__main__":
    ret = main()
    exit_code = 0 if ret else 1
    sys.exit(exit_code)