#!/usr/bin/env python
# Copyright 2017 The Fuchsia Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

# Build script for a Go app.

import argparse
import os
import subprocess
import sys


def main():
    parser = argparse.ArgumentParser()
    parser.add_argument('--fuchsia-root', help='Path to root of Fuchsia project',
                        required=True)
    parser.add_argument('--root-out-dir', help='Path to root of build output',
                        required=True)
    parser.add_argument('--depfile', help='The path to the depfile',
                        required=True)
    parser.add_argument('--current-cpu', help='Target architecture.',
                        choices=['x64', 'arm64'], required=True)
    parser.add_argument('--current-os', help='Target operating system.',
                        choices=['fuchsia', 'linux', 'mac', 'win'], required=True)
    parser.add_argument('--go-tool', help='The go tool to use for builds')
    parser.add_argument('--is-test', help='True if the target is a go test',
                        default=False)
    parser.add_argument('--binname', help='Output file')
    parser.add_argument('package', help='The package name')
    args = parser.parse_args()

    goarch = {
        'x64': 'amd64',
        'arm64': 'arm64',
    }[args.current_cpu]
    goos = {
        'fuchsia': 'fuchsia',
        'linux': 'linux',
        'mac': 'darwin',
        'win': 'windows',
    }[args.current_os]
    gopath = args.root_out_dir

    if args.current_os == 'fuchsia':
        os.environ['CGO_ENABLED'] = '1'
    os.environ['GOARCH'] = goarch
    os.environ['GOOS'] = goos
    os.environ['GOPATH'] = gopath + ":" + os.path.join(args.root_out_dir, "gen/go")
    if 'GOBIN' in os.environ:
        del os.environ['GOBIN']
    if 'GOROOT' in os.environ:
        del os.environ['GOROOT']
    godepfile = os.path.join(args.fuchsia_root, 'buildtools/godepfile')

    if args.is_test:
        retcode = subprocess.call([args.go_tool, 'test', '-c', '-o', args.binname,
                                  args.package], env=os.environ)
    else:
        retcode = subprocess.call([args.go_tool, 'install', args.package],
                                  env=os.environ)

    if retcode == 0:
        if args.is_test:
            binname = args.binname
        else:
            # For regular Go binaries, they are placed in a "bin/fuchsia_ARCH"
            # output directory; this relocates them to the root of the
            # gopath. Tests are not impacted.
            binname = os.path.basename(args.package)
            src = os.path.join(gopath, "bin", "fuchsia_"+goarch, binname)
            if args.binname:
                dst = os.path.join(gopath, args.binname)
            else:
                dst = os.path.join(gopath, binname)
            os.rename(src, dst)

        if args.depfile is not None:
            with open(args.depfile, "wb") as out:
                os.environ['GOROOT'] = os.path.join(args.fuchsia_root, "third_party/go")
                if args.binname:
                    binname = os.path.basename(args.binname)
                subprocess.Popen([godepfile, '-o', binname, args.package], stdout=out, env=os.environ)
    return retcode


if __name__ == '__main__':
    sys.exit(main())