import os
import sys
import amalgamation
import pickle
import subprocess

# where to cache which files have already been compiled
cache_file = 'amalgamation.cache'
ignored_files = ['utf8proc_data.cpp']

RESUME_AUTO = 0
RESUME_ALWAYS = 1
RESUME_NEVER = 2

# resume behavior
# by default, we resume if the previous test_compile was run on the same commit hash as this one
resume = RESUME_AUTO
for arg in sys.argv:
    if arg == '--resume':
        resume = RESUME_ALWAYS
    elif arg == '--restart':
        cache = RESUME_NEVER

if resume == RESUME_NEVER:
    try:
        os.remove(cache_file)
    except:
        pass


def get_git_hash():
    proc = subprocess.Popen(['git', 'rev-parse', 'HEAD'], stdout=subprocess.PIPE)
    return proc.stdout.read().strip()


current_hash = get_git_hash()

# load the cache, and check the commit hash
try:
    with open(cache_file, 'rb') as cf:
        cache = pickle.load(cf)
    if resume == RESUME_AUTO:
        # auto resume, check
        if cache['commit_hash'] != current_hash:
            cache = {}
except:
    cache = {}

cache['commit_hash'] = current_hash


def try_compilation(fpath, cache):
    if fpath in cache:
        return
    print(fpath)

    cmd = (
        'clang++ -std=c++11 -Wno-deprecated -Wno-writable-strings -S -MMD -MF dependencies.d -o deps.s '
        + fpath
        + ' '
        + ' '.join(["-I" + x for x in amalgamation.include_paths])
    )
    ret = os.system(cmd)
    if ret != 0:
        raise Exception('Failed compilation of file "' + fpath + '"!\n Command: ' + cmd)
    cache[fpath] = True
    with open(cache_file, 'wb') as cf:
        pickle.dump(cache, cf)


def compile_dir(dir, cache):
    files = os.listdir(dir)
    files.sort()
    for fname in files:
        if fname in amalgamation.excluded_compilation_files or fname in ignored_files:
            continue
        fpath = os.path.join(dir, fname)
        if os.path.isdir(fpath):
            compile_dir(fpath, cache)
        elif fname.endswith('.cpp') or fname.endswith('.hpp') or fname.endswith('.c') or fname.endswith('.cc'):
            try_compilation(fpath, cache)


# compile all files in the src directory (including headers!) individually
for cdir in amalgamation.compile_directories:
    compile_dir(cdir, cache)