#!/usr/bin/env python3

"""Merges all the header files."""
from glob import glob
from os import path as pt
import re
from collections import defaultdict
import sys

if len(sys.argv) != 3:
    print("Usage: {} <CROW_HEADERS_DIRECTORY_PATH> <CROW_OUTPUT_HEADER_PATH>".format(sys.argv[0]))
    sys.exit(1)

header_path = sys.argv[1]
output_path = sys.argv[2]

re_depends = re.compile('^#include "(.*)"', re.MULTILINE)
headers = [x.rsplit('/', 1)[-1] for x in glob(pt.join(header_path, '*.h*'))]
headers += ['crow/' + x.rsplit('/', 1)[-1] for x in glob(pt.join(header_path, 'crow/*.h*'))]
print(headers)
edges = defaultdict(list)
for header in headers:
    d = open(pt.join(header_path, header)).read()
    match = re_depends.findall(d)
    for m in match:
        # m should included before header
        edges[m].append(header)

visited = defaultdict(bool)
order = []


def dfs(x):
    """Ensure all header files are visited."""
    visited[x] = True
    for y in edges[x]:
        if not visited[y]:
            dfs(y)
    order.append(x)

for header in headers:
    if not visited[header]:
        dfs(header)

order = order[::-1]
for x in edges:
    print(x, edges[x])
for x in edges:
    for y in edges[x]:
        assert order.index(x) < order.index(y), 'cyclic include detected'

print(order)
build = []
for header in order:
    d = open(pt.join(header_path, header)).read()
    build.append(re_depends.sub(lambda x: '\n', d))
    build.append('\n')

open(output_path, 'w').write('\n'.join(build))