#!/usr/bin/env python
#
# Copyright 2016 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.

"""Make a mapping of dependencies for fidl files.

The map contains one line per mapping, each of which is from a fidl file location
to a sequence of GN build targets. If the mapping is public (ie directly from the
source or through a public_deps dependency) then it is prepended with "pub ".

The sequence of targets has length greater than 1 if the file can be referenced
from this module through a sequence of dependencies.

An example entry is:

pub //garnet/public/lib/ui/views/fidl/views.fidl: //garnet/public/lib/media/fidl:services //apps/mozart/services/views:views
"""

import ast
import optparse
import os
import sys
import zipfile

# for some reason, gn seems to tack on an extra element in the directory
def fix_label(label):
  split_tag = label.split(':')
  split_label = split_tag[0].split('/')
  split_label.pop()
  split_tag[0] = '/'.join(split_label)
  return ':'.join(split_tag)

def rel_label(label, relpath):
  split_label = label.split(':')[0].split('/')
  for el in relpath.split('/'):
    if el == '..':
      split_label.pop()
    else:
      split_label.append(el)
  return '/'.join(split_label)

def handle_map_deps(o, depsmap, covered, target, is_public):
  #o.write('#pass-through from %s (public %s)\n' % (depsmap, is_public))
  for dep in file(depsmap):
    parts = dep.split()
    if parts[0] != 'pub': continue
    fileref = parts[1].rstrip(':')
    if fileref in covered: continue
    pubstr = 'pub ' if is_public else ''
    o.write('%s%s: %s %s\n' % (pubstr, fileref, target, ' '.join(parts[2:])))


def make_map(output, sources, map_deps, map_public_deps, target):
  target = fix_label(target)
  o = file(output, 'w')
  covered = set()
  for i in sources:
    covered.add(i)
    new_path = rel_label(target, i)
    o.write('pub %s: %s\n' % (new_path, target))
  for m in map_deps:
    handle_map_deps(o, m, covered, target, False)
  for m in map_public_deps:
    handle_map_deps(o, m, covered, target, True)

def main():
  parser = optparse.OptionParser()

  parser.add_option('--sources', help='List of source files.')
  parser.add_option('--target', help='Name of current target.')
  parser.add_option('--map-deps', help='List of map files of deps to aggregate.')
  parser.add_option('--map-public-deps', help='List of map files of public deps to aggregate.')
  parser.add_option('--output', help='Path to output archive.')

  options, _ = parser.parse_args()

  sources = []
  if (options.sources):
    sources = ast.literal_eval(options.sources)
  map_deps = []
  if options.map_deps:
    map_deps = ast.literal_eval(options.map_deps)
  map_public_deps = []
  if options.map_public_deps:
    map_public_deps = ast.literal_eval(options.map_public_deps)
  output = options.output
  target = options.target

  make_map(output, sources, map_deps, map_public_deps, target)

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