#!/usr/bin/env python
import os
import re
import sys
import optparse
import subprocess

from os          import path
from collections import defaultdict

parser = optparse.OptionParser()
parser.add_option('--full',
    action='store_true',
    help='Check some things we typically ignore')
parser.add_option('--modified', '-m',
    action='store_true',
    help='Only check modified files')
(options, args) = parser.parse_args()

os.chdir(path.join(path.dirname(__file__), '..'))


# Exclude some directories and files from lint checking

exclude_trees = """
static/third
confirmation
zerver/tests/frontend/casperjs
zerver/migrations
node_modules
""".split()

exclude_files = """
zproject/test_settings.py
zproject/settings.py
tools/jslint/jslint.js
api/setup.py
api/integrations/perforce/git_p4.py
""".split()

if options.modified:
    # If the user specifies, use `git ls-files -m` to only check modified, non-staged
    # files in the current checkout.  This makes things fun faster.
    files = map(str.strip, subprocess.check_output(['git', 'ls-files', '-m']).split('\n'))
else:
    files = []

files += args

if not files and not options.modified:
    # If no files are specified on the command line, use the entire git checkout
    files = map(str.strip, subprocess.check_output(['git', 'ls-files']).split('\n'))

files = filter(bool, files) # remove empty file caused by trailing \n

if not files:
    raise Exception('There are no files to check!')

# Categorize by language all files we want to check
by_lang   = defaultdict(list)

for filepath in files:
    if (not filepath or not path.isfile(filepath)
        or (filepath in exclude_files)
        or any(filepath.startswith(d+'/') for d in exclude_trees)):
        continue

    _, exn = path.splitext(filepath)
    if not exn:
        # No extension; look at the first line
        with file(filepath) as f:
            if re.match(r'^#!.*\bpython', f.readline()):
                exn = '.py'

    by_lang[exn].append(filepath)

def check_trailing_whitespace(fn):
    failed = False
    for i, line in enumerate(open(fn)):
        if re.search('\s+$', line.strip('\n')):
            sys.stdout.write('Fix whitespace at %s line %s\n' % (fn, i+1))
            failed = True
    return failed

def perform_extra_js_checks(fn):
    failed = False
    for i, line in enumerate(open(fn)):
        line = line.strip('\n')
        if re.search('[^_]function\(', line):
            sys.stdout.write('The keyword "function" should be followed by a space in %s line %s\n' % (fn, i+1))
            print line
            failed = True
    return failed


def check_python_gotchas(fn):
    '''
    Check for certain Python gotchas that pyflakes doesn't catch.
    '''
    failed = False
    for i, line in enumerate(open(fn)):
        line = line.strip('\n')

        # Hacks to skip lines that confuse our dirt simple code:
        if re.match('\s*[*#]', line):
            continue
        if 'help=' in line:
            continue

        gotcha_regexes = [
                "'[^']*'\s+\([^']*$", # 'foo'(2) makes no sense
                '"[^"]*"\s+\([^"]*$', # ditto
                '% [a-z_]*$', # "%s" % s [we prefer "%s" % (s,)]
        ]
        for gotcha_regex in gotcha_regexes:
            if re.search(gotcha_regex, line):
                sys.stdout.write('Suspicious code at %s line %s (regex=%r)\n' % (fn, i+1, gotcha_regex))
                print line
                failed = True
                break
    return failed

# Invoke the appropriate lint checker for each language,
# and also check files for extra whitespace.

import logging
logging.basicConfig(format="%(asctime)s %(message)s")
logger = logging.getLogger()
# Change this to logging.INFO to see performance data
logger.setLevel(logging.WARNING)

def check_pyflakes():
    if not by_lang['.py']:
        return False
    failed = False
    pyflakes = subprocess.Popen(['pyflakes'] + by_lang['.py'],
        stdout = subprocess.PIPE,
        stderr = subprocess.PIPE)

    # pyflakes writes some output (like syntax errors) to stderr. :/
    for pipe in (pyflakes.stdout, pyflakes.stderr):
        for ln in pipe:
            if options.full or not \
                    ('imported but unused' in ln or
                     'redefinition of unused' in ln or
                     ("zerver/models.py" in ln and
                      " undefined name 'bugdown'" in ln) or
                     ("zerver/lib/tornado_ioloop_logging.py" in ln and
                      "redefinition of function 'instrument_tornado_ioloop'" in ln) or
                     ("zephyr_mirror_backend.py:" in ln and
                      "redefinition of unused 'simplejson' from line" in ln)):
                sys.stdout.write(ln)
                failed = True
    return failed

def check_custom_checks():
    failed = False

    for fn in by_lang['.js'] + by_lang['.py']:
        if check_trailing_whitespace(fn):
            failed = True

    for fn in by_lang['.py']:
        if check_python_gotchas(fn):
            failed = True

    for fn in by_lang['.js']:
        if perform_extra_js_checks(fn):
            failed = True

    return failed

lint_functions = {}

def run_parallel():
    pids = []
    for name, func in lint_functions.items():
        pid = os.fork()
        if pid == 0:
            logging.info("start " + name)
            result = func()
            logging.info("finish " + name)
            os._exit(result)
        pids.append(pid)
    failed = False

    for pid in pids:
        (_, status) = os.waitpid(pid, 0)
        if status != 0:
            failed = True
    return failed

def lint(func):
    lint_functions[func.__name__] = func
    return func

try:
    # Make the lint output bright red
    sys.stdout.write('\x1B[1;31m')
    sys.stdout.flush()

    @lint
    def templates():
        result = subprocess.call(['tools/check-templates'])
        return result

    @lint
    def jslint():
        result = subprocess.call(['tools/node', 'tools/jslint/check-all.js']
                                 + by_lang['.js'])
        return result

    @lint
    def puppet():
        if not by_lang['.pp']:
            return 0
        result = subprocess.call(['puppet', 'parser', 'validate'] + by_lang['.pp'])
        return result

    @lint
    def custom():
        failed = check_custom_checks()
        return 1 if failed else 0

    @lint
    def pyflakes():
        failed = check_pyflakes()
        return 1 if failed else 0

    failed = run_parallel()

    sys.exit(1 if failed else 0)

finally:
    # Restore normal terminal colors
    sys.stdout.write('\x1B[0m')